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Sample records for predatory behavior

  1. Predatory Strategies and Behavioral Diversity.

    ERIC Educational Resources Information Center

    Bekoff, Marc

    1983-01-01

    Briefly discusses the view that behavior may be thought of as a phenotypic adaptation that can be quantitatively studied, and then considered in more detail ways in which predatory animals, especially mammals, satisfy their need for food. Topics covered include predatory behavior, hunting modes, prey selection, hunting success, and others. (JN)

  2. Predatory luring behavior of odonates.

    PubMed

    Edgehouse, Michael; Brown, Christopher P

    2014-10-15

    Organisms in the order Odonata are highly predatory insects that have a wide distribution globally. To date, there has been zero evidence that odonates employ luring as a means of prey acquisition. However, in this study, we show that Aeshna palmata larvae use abdominal movements to lure larval Argia vivida, subsequently consuming the lured organism. We also present findings of a similar behavior from larval Ar. vivida in an attempt to lure larval A. palmata within striking distance.

  3. The predatory behavior of Pheidole megacephala.

    PubMed

    Dejean, Alain; Moreau, Corrie S; Uzac, Pierre; Le Breton, Julien; Kenne, Martin

    2007-09-01

    We studied the foraging and predatory behaviors of the invasive African myrmicine ant, Pheidole megacephala (F.) in its native range. Workers can singly capture a wide range of insects, including relatively large prey items. For still larger prey, they recruit at short range those nestmates situated within reach of an alarm pheromone and together spread-eagle the insect. These behaviors are complimented by a long-range recruitment (of nestmates remaining in the nest) based on prey size. P. megacephala scouts also use long-range recruitment when they detect the landmarks of termites and competing ant species, thus permitting them to avoid confronting these termites and ants solitarily.

  4. Lateralization of Eye Use in Cuttlefish: Opposite Direction for Anti-Predatory and Predatory Behaviors.

    PubMed

    Schnell, Alexandra K; Hanlon, Roger T; Benkada, Aïcha; Jozet-Alves, Christelle

    2016-01-01

    Vertebrates with laterally placed eyes typically exhibit preferential eye use for ecological activities such as scanning for predators or prey. Processing visual information predominately through the left or right visual field has been associated with specialized function of the left and right brain. Lateralized vertebrates often share a general pattern of lateralized brain function at the population level, whereby the left hemisphere controls routine behaviors and the right hemisphere controls emergency responses. Recent studies have shown evidence of preferential eye use in some invertebrates, but whether the visual fields are predominately associated with specific ecological activities remains untested. We used the European common cuttlefish, Sepia officinalis, to investigate whether the visual field they use is the same, or different, during anti-predatory, and predatory behavior. To test for lateralization of anti-predatory behavior, individual cuttlefish were placed in a new environment with opaque walls, thereby obliging them to choose which eye to orient away from the opaque wall to scan for potential predators (i.e., vigilant scanning). To test for lateralization of predatory behavior, individual cuttlefish were placed in the apex of an isosceles triangular arena and presented with two shrimp in opposite vertexes, thus requiring the cuttlefish to choose between attacking a prey item to the left or to the right of them. Cuttlefish were significantly more likely to favor the left visual field to scan for potential predators and the right visual field for prey attack. Moreover, individual cuttlefish that were leftward directed for vigilant scanning were predominately rightward directed for prey attack. Lateralized individuals also showed faster decision-making when presented with prey simultaneously. Cuttlefish appear to have opposite directions of lateralization for anti-predatory and predatory behavior, suggesting that there is functional specialization of

  5. Lateralization of Eye Use in Cuttlefish: Opposite Direction for Anti-Predatory and Predatory Behaviors

    PubMed Central

    Schnell, Alexandra K.; Hanlon, Roger T.; Benkada, Aïcha; Jozet-Alves, Christelle

    2016-01-01

    Vertebrates with laterally placed eyes typically exhibit preferential eye use for ecological activities such as scanning for predators or prey. Processing visual information predominately through the left or right visual field has been associated with specialized function of the left and right brain. Lateralized vertebrates often share a general pattern of lateralized brain function at the population level, whereby the left hemisphere controls routine behaviors and the right hemisphere controls emergency responses. Recent studies have shown evidence of preferential eye use in some invertebrates, but whether the visual fields are predominately associated with specific ecological activities remains untested. We used the European common cuttlefish, Sepia officinalis, to investigate whether the visual field they use is the same, or different, during anti-predatory, and predatory behavior. To test for lateralization of anti-predatory behavior, individual cuttlefish were placed in a new environment with opaque walls, thereby obliging them to choose which eye to orient away from the opaque wall to scan for potential predators (i.e., vigilant scanning). To test for lateralization of predatory behavior, individual cuttlefish were placed in the apex of an isosceles triangular arena and presented with two shrimp in opposite vertexes, thus requiring the cuttlefish to choose between attacking a prey item to the left or to the right of them. Cuttlefish were significantly more likely to favor the left visual field to scan for potential predators and the right visual field for prey attack. Moreover, individual cuttlefish that were leftward directed for vigilant scanning were predominately rightward directed for prey attack. Lateralized individuals also showed faster decision-making when presented with prey simultaneously. Cuttlefish appear to have opposite directions of lateralization for anti-predatory and predatory behavior, suggesting that there is functional specialization of

  6. Assaying Predatory Feeding Behaviors in Pristionchus and Other Nematodes

    PubMed Central

    Okumura, Misako; Sommer, Ralf J.

    2016-01-01

    This protocol provides multiple methods for the analysis and quantification of predatory feeding behaviors in nematodes. Many nematode species including Pristionchus pacificus display complex behaviors, the most striking of which is the predation of other nematode larvae. However, as these behaviors are absent in the model organism Caenorhabditis elegans, they have thus far only recently been described in detail along with the development of reliable behavioral assays 1. These predatory behaviors are dependent upon phenotypically plastic but fixed mouth morphs making the correct identification and categorization of these animals essential. In P. pacificus there are two mouth types, the stenostomatous and eurystomatous morphs 2, with only the wide mouthed eurystomatous containing an extra tooth and being capable of killing other nematode larvae. Through the isolation of an abundance of size matched prey larvae and subsequent exposure to predatory nematodes, assays including both "corpse assays" and "bite assays" on correctly identified mouth morph nematodes are possible. These assays provide a means to rapidly quantify predation success rates and provide a detailed behavioral analysis of individual nematodes engaged in predatory feeding activities. In addition, with the use of a high-speed camera, visualization of changes in pharyngeal activity including tooth and pumping dynamics are also possible. PMID:27684744

  7. Behavioral diversity of predatory arboreal ants in coffee agroecosystems.

    PubMed

    Philpott, Stacy M; Perfecto, Ivette; Vandermeer, John

    2008-02-01

    Aspects of predator assemblages that alter predator effects on prey have received extensive recent attention. Among other mechanisms, differences in behavior or resource use within predator trophic levels may enhance predator effects on prey, especially if effects of each predator species differ with environmental conditions. We address whether three common ant species (Azteca instabilis F. Smith, Camponotus textor Forel, and Crematogaster spp.) are functionally unique in coffee agroecosystems, asking if each species differs in (1) cooperative foraging behavior, (2) responses to experimentally introduced herbivores, and (3) responses to pest outbreaks. Furthermore, we examined the behaviors and effects of each ant species under different conditions by varying herbivore species, herbivore size, and herbivore density and carrying out observations in different seasons. Ant species significantly differed in foraging behaviors, in effects on individual herbivores, and in responses to pest outbreaks in terms of both type and time of response to herbivores. The behaviors and effects of each ant species differed in the dry and wet seasons and for different herbivore species and sizes. Although A. instabilis generally removed more larvae and more quickly removed larvae, this was not the case under all conditions. The data presented thus support that common ant species in coffee agroecosystems are behaviorally diverse in their responses to herbivores under different conditions. We discuss the implications of these differences in ant behaviors for enhancement of predatory function in light of both multipredator effects and in terms of the potential importance of predator diversity.

  8. Physical evidence of predatory behavior in Tyrannosaurus rex

    PubMed Central

    DePalma, Robert A.; Burnham, David A.; Martin, Larry D.; Rothschild, Bruce M.; Larson, Peter L.

    2013-01-01

    Feeding strategies of the large theropod, Tyrannosaurus rex, either as a predator or a scavenger, have been a topic of debate previously compromised by lack of definitive physical evidence. Tooth drag and bone puncture marks have been documented on suggested prey items, but are often difficult to attribute to a specific theropod. Further, postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present. Here we report definitive evidence of predation by T. rex: a tooth crown embedded in a hadrosaurid caudal centrum, surrounded by healed bone growth. This indicates that the prey escaped and lived for some time after the injury, providing direct evidence of predatory behavior by T. rex. The two traumatically fused hadrosaur vertebrae partially enclosing a T. rex tooth were discovered in the Hell Creek Formation of South Dakota. PMID:23858435

  9. Physical evidence of predatory behavior in Tyrannosaurus rex

    NASA Astrophysics Data System (ADS)

    DePalma, Robert A., II; Burnham, David A.; Martin, Larry D.; Rothschild, Bruce M.; Larson, Peter L.

    2013-07-01

    Feeding strategies of the large theropod, Tyrannosaurus rex, either as a predator or a scavenger, have been a topic of debate previously compromised by lack of definitive physical evidence. Tooth drag and bone puncture marks have been documented on suggested prey items, but are often difficult to attribute to a specific theropod. Further, postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present. Here we report definitive evidence of predation by T. rex: a tooth crown embedded in a hadrosaurid caudal centrum, surrounded by healed bone growth. This indicates that the prey escaped and lived for some time after the injury, providing direct evidence of predatory behavior by T. rex. The two traumatically fused hadrosaur vertebrae partially enclosing a T. rex tooth were discovered in the Hell Creek Formation of South Dakota.

  10. Physical evidence of predatory behavior in Tyrannosaurus rex.

    PubMed

    DePalma, Robert A; Burnham, David A; Martin, Larry D; Rothschild, Bruce M; Larson, Peter L

    2013-07-30

    Feeding strategies of the large theropod, Tyrannosaurus rex, either as a predator or a scavenger, have been a topic of debate previously compromised by lack of definitive physical evidence. Tooth drag and bone puncture marks have been documented on suggested prey items, but are often difficult to attribute to a specific theropod. Further, postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present. Here we report definitive evidence of predation by T. rex: a tooth crown embedded in a hadrosaurid caudal centrum, surrounded by healed bone growth. This indicates that the prey escaped and lived for some time after the injury, providing direct evidence of predatory behavior by T. rex. The two traumatically fused hadrosaur vertebrae partially enclosing a T. rex tooth were discovered in the Hell Creek Formation of South Dakota.

  11. Genomic Response to Selection for Predatory Behavior in a Mammalian Model of Adaptive Radiation.

    PubMed

    Konczal, Mateusz; Koteja, Paweł; Orlowska-Feuer, Patrycja; Radwan, Jacek; Sadowska, Edyta T; Babik, Wiesław

    2016-09-01

    If genetic architectures of various quantitative traits are similar, as studies on model organisms suggest, comparable selection pressures should produce similar molecular patterns for various traits. To test this prediction, we used a laboratory model of vertebrate adaptive radiation to investigate the genetic basis of the response to selection for predatory behavior and compare it with evolution of aerobic capacity reported in an earlier work. After 13 generations of selection, the proportion of bank voles (Myodes [=Clethrionomys] glareolus) showing predatory behavior was five times higher in selected lines than in controls. We analyzed the hippocampus and liver transcriptomes and found repeatable changes in allele frequencies and gene expression. Genes with the largest differences between predatory and control lines are associated with hunger, aggression, biological rhythms, and functioning of the nervous system. Evolution of predatory behavior could be meaningfully compared with evolution of high aerobic capacity, because the experiments and analyses were performed in the same methodological framework. The number of genes that changed expression was much smaller in predatory lines, and allele frequencies changed repeatably in predatory but not in aerobic lines. This suggests that more variants of smaller effects underlie variation in aerobic performance, whereas fewer variants of larger effects underlie variation in predatory behavior. Our results thus contradict the view that comparable selection pressures for different quantitative traits produce similar molecular patterns. Therefore, to gain knowledge about molecular-level response to selection for complex traits, we need to investigate not only multiple replicate populations but also multiple quantitative traits.

  12. Optimal diet theory: behavior of a starved predatory snail.

    PubMed

    Perry, D M

    1987-06-01

    The tenets of optimal foraging theory are used to contrast the behavior of the predatory snail Acantina spirata when feeding on the barnacles Balanus glandula and Chthamalus fissus under conditions of satiation and starvation. As predicted in optimal diet models, A. spirata is less selective (ratio of attack frequency on a prey species to number of individuals available) when the higher ranking prey has low abundance. When given a choice, starved snails attack both barnacle species equally, whereas satiated individuals preferentially attack B. glandula, the more profitable prey (ash-free dry weight of barnacles ingested per unit handling time). Under starvation conditions, equal attack frequency does not result in equal prey species consumption because Acanthina spirata is more successful at attacking C. fissus than B. glandula.The assumption of constant prey encounter rates in optimal diet models is not met when A. spirata goes from a state of satiation to starvation. The encounter rate on B. glandula is lowered due to a decrease in attack success. A loss of feeding skills in starved A. spirata is responsible for the greater difficulty snails have in gaining access through the opercular plates of B. glandula.Behavioral changes in A. spirata as snails pass from satiation to hunger translate into an energetic disadvantage during feeding for hungry snails for two reasons. First, higher prey handling times result in a decreased rate of biomass intake. Second, alteration in the relative attack frequency between barnacle species, combined with a decrease in attack success on the more profitable prey leads to more frequent ingestion of the less profitable prey.

  13. The role of the vomeronasal organ in rattlesnake (Crotalus viridis oreganus) predatory behavior.

    PubMed

    Alving, W R; Kardong, K V

    1996-01-01

    During predatory behavior, rattlesnakes depend primarily upon thermal and visual cues to initially aim a strike. However, it has been hypothesized that prey-related odors sensed by the vomeronasal system act as releasing stimuli of the strike and that such vomodors are primary stimuli during poststrike trailing and swallowing of the envenomated rodent. To test this, northern Pacific rattlesnakes were rendered avomic by bilateral lesions of the vomeronasal nerves, and their vomic and avomic predatory behaviors were compared. Avomic rattlesnakes exhibited fewer strikes and complete elimination of trailing and swallowing behavior. These results support the hypothesis that vomodors sensed via the vomeronasal organ are capable of acting as releasing stimuli of selected rattlesnake predatory behaviors. Sensory input via the vomeronasal organ is important during prestrike/strike behavior, and it is a major route of sensory input during poststrike trailing and ingestion of envenomated prey.

  14. Fin-tail coordination during escape and predatory behavior in larval zebrafish.

    PubMed

    McClenahan, Phil; Troup, Michael; Scott, Ethan K

    2012-01-01

    Larval zebrafish innately perform a suite of behaviors that are tightly linked to their evolutionary past, notably escape from threatening stimuli and pursuit and capture of prey. These behaviors have been carefully examined in the past, but mostly with regard to the movements of the trunk and tail of the larvae. Here, we employ kinematics analyses to describe the movements of the pectoral fins during escape and predatory behavior. In accord with previous studies, we find roles for the pectoral fins in slow swimming and immediately after striking prey. We find novel roles for the pectoral fins in long-latency, but not in short-latency C-bends. We also observe fin movements that occur during orienting J-turns and S-starts that drive high-velocity predatory strikes. Finally, we find that the use of pectoral fins following a predatory strike is scaled to the velocity of the strike, supporting a role for the fins in braking. The implications of these results for central control of coordinated movements are discussed, and we hope that these results will provide baselines for future analyses of cross-body coordination using mutants, morphants, and transgenic approaches.

  15. A proposed ethogram of large-carnivore predatory behavior, exemplified by the wolf

    USGS Publications Warehouse

    MacNulty, D.R.; Mech, L.D.; Smith, D.W.

    2007-01-01

    Although predatory behavior is traditionally described by a basic ethogram composed of 3 phases (search, pursue, and capture), behavioral studies of large terrestrial carnivores generally use the concept of a "hunt" to classify and measure foraging. This approach is problematic because there is no consensus on what behaviors constitute a hunt. We therefore examined how the basic ethogram could be used as a common framework for classifying large-carnivore behavior. We used >2,150 h of observed wolf (Canis lupus) behavior in Yellowstone National Park, including 517 and 134 encounters with elk (Cervus elaphus) and American bison (Bison bison), respectively, to demonstrate the functional importance of several frequently described, but rarely quantified, patterns of large-carnivore behavior not explicitly described by the basic ethogram (approaching, watching, and attacking groups). To account for these additionally important behaviors we propose a modified form of the basic ethogram (search, approach, watch, attack-group, attack-individual, and capture). We tested the applicability of this ethogram by comparing it to 31 previous classifications and descriptions involving 7 other species and 5 other wolf populations. Close correspondence among studies suggests that this ethogram may provide a generally useful scheme for classifying large-carnivore predatory behavior that is behaviorally less ambiguous than the concept of a hunt. ?? 2007 American Society of Mammalogists.

  16. Functional mapping of the prosencephalic systems involved in organizing predatory behavior in rats.

    PubMed

    Comoli, E; Ribeiro-Barbosa, E R; Negrão, N; Goto, M; Canteras, N S

    2005-01-01

    The study of the neural basis of predatory behavior has been largely neglected over the recent years. Using an ethologically based approach, we presently delineate the prosencephalic systems mobilized during predation by examining Fos immunoreactivity in rats performing insect hunting. These results were further compared with those obtained from animals killed after the early nocturnal surge of food ingestion. First, predatory behavior was associated with a distinct Fos up-regulation in the ventrolateral caudoputamen at intermediate rostro-caudal levels, suggesting a possible candidate to organize the stereotyped sequence of actions seen during insect hunting. Insect predation also presented conspicuous mobilization of a neural network formed by a distinct amygdalar circuit (i.e. the postpiriform-transition area, the anterior part of cortical nucleus, anterior part of basomedial nucleus, posterior part of basolateral nucleus, and medial part of central nucleus) and affiliated sites in the bed nuclei of the stria terminalis (i.e. the rhomboid nucleus) and in the hypothalamus (i.e. the parasubthalamic nucleus). Accordingly, this network is likely to encode prey-related motivational values, such as prey's odor and taste, and to influence autonomic and motor control accompanying predatory eating. Notably, regular food intake was also associated with a relatively weak Fos up-regulation in this network. However, during regular surge of food intake, we observed a much larger mobilization in hypothalamic sites related to the homeostatic control of eating, namely, the arcuate nucleus and autonomic parts of the paraventricular nucleus. Overall, the present findings suggest potential neural systems involved in integrating prey-related motivational values and in organizing the stereotyped sequences of action seen during predation. Moreover, the comparison with regular food intake contrasts putative neural mechanisms controlling predatory related eating vs. regular food intake.

  17. Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen

    PubMed Central

    Wu, Shengyong; Zhang, Ye; Xu, Xuenong; Lei, Zhongren

    2016-01-01

    Interactions between fungal entomopathogens and pest predators are particularly relevant in control of agricultural insect pests. In a laboratory study, we confirmed that the predatory mite, Neoseiulus barkeri, exhibited feeding behavior on the entomopathogenic fungus Beauveria bassiana conidia through DNA extracts. Using transmission electron microscopy, we determined that the majority of conidia found in the mite gut tended to dissolve within 24 h post ingestion, suggesting that the conidia had probably lost their viability. To our knowledge this is the first report of feeding behavior of phytoseiid mites on entomopathogenic fungus. The findings expand our knowledge of fungus–predator interactions. PMID:27041703

  18. Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen.

    PubMed

    Wu, Shengyong; Zhang, Ye; Xu, Xuenong; Lei, Zhongren

    2016-04-04

    Interactions between fungal entomopathogens and pest predators are particularly relevant in control of agricultural insect pests. In a laboratory study, we confirmed that the predatory mite, Neoseiulus barkeri, exhibited feeding behavior on the entomopathogenic fungus Beauveria bassiana conidia through DNA extracts. Using transmission electron microscopy, we determined that the majority of conidia found in the mite gut tended to dissolve within 24 h post ingestion, suggesting that the conidia had probably lost their viability. To our knowledge this is the first report of feeding behavior of phytoseiid mites on entomopathogenic fungus. The findings expand our knowledge of fungus-predator interactions.

  19. Tributyltin exposure influences predatory behavior, neurotransmitter content and receptor expression in Sebastiscus marmoratus.

    PubMed

    Yu, Ang; Wang, Xinli; Zuo, Zhenghong; Cai, Jiali; Wang, Chonggang

    2013-03-15

    Tributyltin (TBT) is a ubiquitous marine contaminant due to its extensive use as a biocide, fungicide and antifouling agent. However, the neurotoxic effect of TBT has not been extensively studied, especially in marine fish. This study was conducted to investigate the effects of TBT (10, 100 and 1000 ng/L) on the predatory behavior of Sebastiscus marmoratus and to look into the mechanism involved. The results showed that TBT exposure depressed predatory activity after 50 days exposure. Dopamine levels in the fish brains increased in a dose-dependent manner, while 5-hydroxytryptamine and norepinephrine levels decreased significantly in the TBT exposure group compared to the control. The mRNA levels of dopamine receptors, which have functions such as cognition, motor activity, motivation and reward, mood, attention and learning, were significantly down-regulated by TBT exposure. Although the levels of amino acid neurotransmitters, including glutamate, did not show marked alteration, the expression of the glutamatergic signaling pathway such as N-methyl-D-aspartate receptors, a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor, calmodulin, Ca(2+)/calmodulin-dependent protein kinases-II and cyclic adenosine monophosphate responsive element binding protein, was significantly reduced by TBT exposure, which indicated that central nerve activities were in a state of depression, thus affecting the predatory activities of the fish.

  20. Periaqueductal gray μ and κ opioid receptors determine behavioral selection from maternal to predatory behavior in lactating rats.

    PubMed

    Klein, Marianne Orlandini; Cruz, Aline de Mello; Machado, Franciele Corrêa; Picolo, Gisele; Canteras, Newton Sabino; Felicio, Luciano Freitas

    2014-11-01

    Every mother must optimize her time between caring for her young and her subsistence. The rostro lateral portion of the periaqueductal grey (rlPAG) is a critical site that modulates the switch between maternal and predatory behavior. Opioids play multiple roles in both maternal behavior and this switching process. The present study used a pharmacological approach to evaluate the functional role of rlPAG μ and κ opioid receptors in behavioral selection. Rat dams were implanted with a guide cannula in the rlPAG and divided into three experiments in which we tested the role of opioid agonists (Experiment 1), the influence of μ and κ opioid receptor blockade in the presence of morphine (Experiment 2), and the influence of μ and κ opioid receptor blockade (Experiment 3). After behavioral test, in Experiment 4, we evaluated rlPAG μ and κ receptor activation in all Experiments 1-3. The results showed that massive opioidergic activation induced by morphine in the rlPAG inhibited maternal behavior without interfering with predatory hunting. No behavioral changes and no receptor activation were promoted by the specific agonist alone. However, κ receptor blockade increased hunting behavior and increased the level of μ receptor activation in the rlPAG. Thus, endogenous opioidergic tone might be modulated by a functional interaction between opioid receptor subtypes. Such a compensatory receptor interaction appears to be relevant for behavioral selection among motivated behaviors. These findings indicate a role for multiple opioid receptor interactions in the modulation of behavioral selection between maternal and predatory behaviors in the PAG.

  1. Predatory behavior of grizzly bears feeding on elk calves in Yellowstone National Park

    USGS Publications Warehouse

    French, Steven P.; French, Marilynn G.

    1990-01-01

    Grizzly bears (Ursus arctos horribilis) were observed preying on elk calves (Cervus elaphus) on 60 occasions in Yellowstone National Park, with 29 confirmed kills. Some bears were deliberate predators and effectively preyed on elk calves for short periods each spring, killing up to 1 calf daily. Primary hunting techniques were searching and chasing although some bears used a variety of techniques during a single hunt. They hunted both day and night and preyed on calves in the open and in the woods. Excess killing occurred when circumstances permitted. One bear caught 5 calves in a 15-minute interval. Elk used a variety of antipredator defenses and occasionally attacked predacious bears. The current level of this feeding behavior appears to be greater than previously reported. This is probably related to the increased availability of calves providing a greater opportunity for learning, and the adaptation of a more predatory behavior by some grizzly bears in Yellowstone.

  2. Two weeks of predatory stress induces anxiety-like behavior with co-morbid depressive-like behavior in adult male mice.

    PubMed

    Burgado, Jillybeth; Harrell, Constance S; Eacret, Darrell; Reddy, Renuka; Barnum, Christopher J; Tansey, Malú G; Miller, Andrew H; Wang, Huichen; Neigh, Gretchen N

    2014-12-15

    Psychological stress can have devastating and lasting effects on a variety of behaviors, especially those associated with mental illnesses such as anxiety and depression. Animal models of chronic stress are frequently used to elucidate the mechanisms underlying the relationship between stress and mental health disorders and to develop improved treatment options. The current study expands upon a novel chronic stress paradigm for mice: predatory stress. The predatory stress model incorporates the natural predator-prey relationship that exists among rats and mice and allows for greater interaction between the animals, in turn increasing the extent of the stressful experience. In this study, we evaluated the behavioral effects of exposure to 15 days of predatory stress on an array of behavioral indices. Up to 2 weeks after the end of stress, adult male mice showed an increase of anxiety-like behaviors as measured by the open field and social interaction tests. Animals also expressed an increase in depressive-like behavior in the sucrose preference test. Notably, performance on the novel object recognition task, a memory test, improved after predatory stress. Taken as a whole, our results indicate that 15 exposures to this innovative predatory stress paradigm are sufficient to elicit robust anxiety-like behaviors with evidence of co-morbid depressive-like behavior, as well as changes in cognitive behavior in male mice.

  3. Supermodeled sabercat, predatory behavior in Smilodon fatalis revealed by high-resolution 3D computer simulation.

    PubMed

    McHenry, Colin R; Wroe, Stephen; Clausen, Philip D; Moreno, Karen; Cunningham, Eleanor

    2007-10-09

    The American sabercat Smilodon fatalis is among the most charismatic of fossil carnivores. Despite broad agreement that its extraordinary anatomy reflects unique hunting techniques, after >150 years of study, many questions remain concerning its predatory behavior. Were the "sabers" used to take down large prey? Were prey killed with an eviscerating bite to the abdomen? Was its bite powerful or weak compared with that of modern big cats? Here we quantitatively assess the sabercat's biomechanical performance using the most detailed computer reconstructions yet developed for the vertebrate skull. Our results demonstrate that bite force driven by jaw muscles was relatively weak in S. fatalis, one-third that of a lion (Panthera leo) of comparable size, and its skull was poorly optimized to resist the extrinsic loadings generated by struggling prey. Its skull is better optimized for bites on restrained prey where the bite is augmented by force from the cervical musculature. We conclude that prey were brought to ground and restrained before a killing bite, driven in large part by powerful cervical musculature. Because large prey is easier to restrain if its head is secured, the killing bite was most likely directed to the neck. We suggest that the more powerful jaw muscles of P. leo may be required for extended, asphyxiating bites and that the relatively low bite forces in S. fatalis might reflect its ability to kill large prey more quickly, avoiding the need for prolonged bites.

  4. Nesting habits shape feeding preferences and predatory behavior in an ant genus

    NASA Astrophysics Data System (ADS)

    Dejean, Alain; Labrière, Nicolas; Touchard, Axel; Petitclerc, Frédéric; Roux, Olivier

    2014-04-01

    We tested if nesting habits influence ant feeding preferences and predatory behavior in the monophyletic genus Pseudomyrmex (Pseudomyrmecinae) which comprises terrestrial and arboreal species, and, among the latter, plant-ants which are obligate inhabitants of myrmecophytes (i.e., plants sheltering so-called plant-ants in hollow structures). A cafeteria experiment revealed that the diet of ground-nesting Pseudomyrmex consists mostly of prey and that of arboreal species consists mostly of sugary substances, whereas the plant-ants discarded all the food we provided. Workers forage solitarily, detecting prey from a distance thanks to their hypertrophied eyes. Approach is followed by antennal contact, seizure, and the manipulation of the prey to sting it under its thorax (next to the ventral nerve cord). Arboreal species were not more efficient at capturing prey than were ground-nesting species. A large worker size favors prey capture. Workers from ground- and arboreal-nesting species show several uncommon behavioral traits, each known in different ant genera from different subfamilies: leaping abilities, the use of surface tension strengths to transport liquids, short-range recruitment followed by conflicts between nestmates, the consumption of the prey's hemolymph, and the retrieval of entire prey or pieces of prey after having cut it up. Yet, we never noted group ambushing. We also confirmed that Pseudomyrmex plant-ants live in a kind of food autarky as they feed only on rewards produced by their host myrmecophyte, or on honeydew produced by the hemipterans they attend and possibly on the fungi they cultivate.

  5. Nesting habits shape feeding preferences and predatory behavior in an ant genus.

    PubMed

    Dejean, Alain; Labrière, Nicolas; Touchard, Axel; Petitclerc, Frédéric; Roux, Olivier

    2014-04-01

    We tested if nesting habits influence ant feeding preferences and predatory behavior in the monophyletic genus Pseudomyrmex (Pseudomyrmecinae) which comprises terrestrial and arboreal species, and, among the latter, plant-ants which are obligate inhabitants of myrmecophytes (i.e., plants sheltering so-called plant-ants in hollow structures). A cafeteria experiment revealed that the diet of ground-nesting Pseudomyrmex consists mostly of prey and that of arboreal species consists mostly of sugary substances, whereas the plant-ants discarded all the food we provided. Workers forage solitarily, detecting prey from a distance thanks to their hypertrophied eyes. Approach is followed by antennal contact, seizure, and the manipulation of the prey to sting it under its thorax (next to the ventral nerve cord). Arboreal species were not more efficient at capturing prey than were ground-nesting species. A large worker size favors prey capture. Workers from ground- and arboreal-nesting species show several uncommon behavioral traits, each known in different ant genera from different subfamilies: leaping abilities, the use of surface tension strengths to transport liquids, short-range recruitment followed by conflicts between nestmates, the consumption of the prey's hemolymph, and the retrieval of entire prey or pieces of prey after having cut it up. Yet, we never noted group ambushing. We also confirmed that Pseudomyrmex plant-ants live in a kind of food autarky as they feed only on rewards produced by their host myrmecophyte, or on honeydew produced by the hemipterans they attend and possibly on the fungi they cultivate.

  6. Diet and predatory behavior of the Asian ant-eating spider, Asceua (formerly Doosia) japonica (Araneae: Zodariidae).

    PubMed

    Komatsu, Takashi

    2016-01-01

    Several spider taxa are specialized to prey on ants. Some species of Zodariidae are known to use specialized tactics to capture ants. In this study, I assessed the diet difference and predatory behavior of the Japanese zodariid Asceua japonica. In a series of surveys, all observed individuals in the field preyed on tiny arboreal ants representing several subfamilies. In addition, the species used tactics similar to those of its European relatives for preying on ants. This is the first observation of myrmecophagy of Zodariidae in East Asia.

  7. Forelimb anatomy and the discrimination of the predatory behavior of carnivorous mammals: the thylacine as a case study.

    PubMed

    Janis, Christine M; Figueirido, Borja

    2014-12-01

    Carnivorous mammals use their forelimbs in different ways to capture their prey. Most terrestrial carnivores have some cursorial (running) adaptations, but ambush predators retain considerable flexibility in their forelimb movement, important for grappling with their prey. In contrast, predators that rely on pursuit to run down their prey have sacrificed some of this flexibility for locomotor efficiency, in the greater restriction of the forelimb motion to the parasagittal plane. In this article, we measured aspects of the forelimb anatomy (44 linear measurements) in 36 species of carnivorous mammals of known predatory behavior, and used multivariate analyses to investigate how well the forelimb anatomy reflects the predatory mode (ambush, pursuit, or pounce-pursuit). A prime intention of this study was to establish morphological correlates of behavior that could then be applied to fossil mammals: for this purpose, five individuals of the recently extinct thylacine (Thylacinus cynocephalus) were also included as unknowns. We show that the three different types of predators can be distinguished by their morphology, both in analyses where all the forelimb bones are included together, and in the separate analyses of each bone individually. Of particular interest is the ability to distinguish between the two types of more cursorial predators, pursuit and pounce-pursuit, which have previously been considered as primarily size-based categories. Despite a prior consideration of the thylacine as a "pounce-pursuit" or an "ambush" type of predator, the thylacines did not consistently cluster with any type of predatory carnivores in our analyses. Rather, the thylacines appeared to be more generalized in their morphology than any of the extant carnivores. The absence of a large diversity of large carnivorous mammals in Australia, past and present, may explain the thylacine's generalized morphology.

  8. Rattlesnake hunting behavior: correlations between plasticity of predatory performance and neuroanatomy.

    PubMed

    Kardong, K V; Berkhoudt, H

    1999-01-01

    Rattlesnakes may shift between visual (eyes) and infrared (facial pits) stimuli without significant loss of predatory performance during an envenomating strike. The relative equivalency of these proximate stimuli is correlated with the organization of the associated neural pathways in the central nervous system. Visual and infrared information, although gathered by different sensory organs, converges within the optic tectum in an orderly spatiotopical representation where bimodal neurons respond to both stimuli. In turn, the tectum sends efferent pathways directly to premotor areas (brainstem) and indirectly to motor areas (spinal cord) where axial muscles involved in the strike might be activated. On the other hand, rattlesnakes do not maintain a high level of equivalent predatory performance when switching between chemosensory stimuli i.e., olfactory, and vomeronasal information. Deprived of vomeronasal input, strikes drop by about half, and poststrike trailing is lost entirely. Surprisingly, compensation by switching to information delivered via an intact olfactory input does not occur, despite the convergence of chemosensory information within the central nervous system. Finally, the launch of a targeted, envenomating strike involves both these modalities: radiation reception (visual, infrared) and chemoreception (olfactory, vomeronasal). However, in the absence of chemosensory information, the radiation modalities do not completely compensate, nor does the animal maintain a high level of predatory performance. Similarly, in the absence of radiation information, the chemosensory modalities do not completely compensate, nor does the animal maintain a high level of predatory performance. The absence of compensation in this multimodal system is also correlated with an absence of convergence of radiation and chemical information, at least at the level of first and second-order neurons, in the central nervous system.

  9. Effect of acute low body temperature on predatory behavior and prey-capture efficiency in a plethodontid salamander.

    PubMed

    Marvin, Glenn A; Davis, Kayla; Dawson, Jacob

    2016-05-01

    The low-temperature limit for feeding in some salamander species (Desmognathus, Plethodontidae) has been inferred from field studies of seasonal variation in salamander activity and gut contents, which could not determine whether feeding is more dependent on environmental conditions influencing salamander foraging behavior or prey availability and movement. We performed two controlled laboratory experiments to examine the effect of short-term (acute) low body temperature on predatory behavior and prey-capture efficiency in a semiaquatic plethodontid salamander (Desmognathus conanti). In the first experiment, we quantified variation in the feeding responses of cold salamanders (at 1, 3, 5 and 7°C) to a video recording of a walking, warm (15°C) cricket to determine the lower thermal limit for predatory behavior, independent of any temperature effect on movement of prey. Experimental-group salamanders exhibited vigorous feeding responses at 5 and 7°C, large variation in feeding responses both among and within individuals (over time) at 3°C, and little to no feeding response at 1°C. Feeding responses at both 1 and 3°C were significantly less than at each higher temperature, whereas responses of control-group individuals at 15°C did not vary over time. In the second experiment, we quantified feeding by cold salamanders (at 3, 5, 7 and 11°C) on live, warm crickets to examine thermal effects on prey-capture ability. The mean feeding response to live crickets was significantly less at 3°C than at higher temperatures; however, 50% of salamanders captured and ingested prey with high efficiency at this temperature. We conclude that many individuals stalk and capture prey at very low temperatures (down to 3°C). Our results support a growing body of data that indicate many plethodontid salamanders feed at temperatures only a few degrees above freezing.

  10. Cost-benefit analysis potential in feeding behavior of a predatory snail by integration of hunger, taste, and pain

    NASA Astrophysics Data System (ADS)

    Gillette, Rhanor; Huang, Rong-Chi; Hatcher, Nathan; Moroz, Leonid L.

    2000-03-01

    Hunger/satiation state interacts with appetitive and noxious stimuli to determine feeding and avoidance responses. In the predatory marine snail Pleurobranchaea californica, food chemostimuli induced proboscis extension and biting at concentration thresholds that varied directly with satiation state. However, food stimuli also tended to elicit avoidance behavior (withdrawal and avoidance turns) at concentration thresholds that were relatively low and fixed. When the feeding threshold for active feeding (proboscis extension with biting) was exceeded, ongoing avoidance and locomotion were interrupted and suppressed. Noxious chemostimuli usually stimulated avoidance, but, in animals with lower feeding thresholds for food stimuli, they often elicited feeding behavior. Thus, sensory pathways mediating appetitive and noxious stimuli may have dual access to neural networks of feeding and avoidance behavior, but their final effects are regulated by satiation state. These observations suggest that a simple cost-benefit computation regulates behavioral switching in the animal's foraging behavior, where food stimuli above or below the incentive level for feeding tend to induce feeding or avoidance, respectively. This decision mechanism can weigh the animal's need for nutrients against the potential risk from other predators and the cost of relative energy outlay in an attack on prey. Stimulation of orienting and attack by low-level noxious stimuli in the hungriest animals may reflect risk-taking that can enhance prey capture success. A simple, hedonically structured neural network model captures this computation.

  11. The use of artificial crabs for testing predatory behavior and health in the octopus.

    PubMed

    Amodio, Piero; Andrews, Paul; Salemme, Marinella; Ponte, Giovanna; Fiorito, Graziano

    2014-01-01

    The willingness of the cephalopod mollusc Octopus vulgaris to attack a live crab is traditionally used as a method to assess the overall health and welfare of octopuses in the laboratory. This method requires placing a crab in the home tank of an animal, measuring the time (latency) taken for the octopus to initiate an attack and withdrawing the crab immediately prior to capture. The same crab is commonly used to assess multiple octopuses as part of daily welfare assessment. Growing concern for the welfare of crustaceans and a review of all laboratory practices for the care and welfare of cephalopods following the inclusion of this taxon in 2010/63/EU prompted a study of the utility of an artificial crab to replace a live crab in the assessment of octopus health. On consecutive days O. vulgaris (N=21) were presented with a live, a dead or an artificial crab, and the latency to attack measured. Despite differences in the predatory performance towards the three different crab alternatives, octopuses readily attacked the artificial (and the dead) crab, showing that they can generalize and respond appropriately towards artificial prey. Researchers should consider using an artificial crab to replace the use of a live crab as part of the routine health assessment of O. vulgaris.

  12. The role of synchronized swimming as affiliative and anti-predatory behavior in long-finned pilot whales.

    PubMed

    Senigaglia, Valeria; de Stephanis, Renaud; Verborgh, Phillippe; Lusseau, David

    2012-09-01

    Synchronized swimming in cetaceans has been hypothesized to play a role in affiliative processes as well as anti-predatory responses. We compared observed variation in synchronized swimming at two research sites in relation to disturbance exposure to test these two hypotheses. This study describes and quantifies pair synchronization in long-finned pilot whales at the Strait of Gibraltar, Spain and Cape Breton, Canada. Synchronization differed depending on the behavioral state and the response is different in the two sites leading to the conclusion that environment can shape the occurrence and magnitude of certain behaviors. We also analyzed intra-population variations in synchronization among 4 social units of Pilot whales in the Strait of Gibraltar and the results of this study confirmed the affiliative role of synchronization and highlighted an influence of disturbance on synchronization. We can conclude that synchronization is a common behavior in long-finned pilot whales that allow for close proximity and rapid coordinated response of individuals, with the multiple functions of showing affiliation and reacting to disturbance.

  13. On predatory wasps and zombie cockroaches: Investigations of "free will" and spontaneous behavior in insects.

    PubMed

    Gal, Ram; Libersat, Frederic

    2010-09-01

    Accumulating evidence suggest that nonhuman organisms, including invertebrates, possess the ability to make non-random choices based purely on ongoing and endogenously-created neuronal processes. We study this precursor of spontaneity in cockroaches stung by A. compressa, a parasitoid wasp that employs cockroaches as a live food supply for its offspring. This wasp uses a neurotoxic venom cocktail to 'hijack' the nervous system of its cockroach prey and manipulate specific features of its decision making process, thereby turning the cockroach into a submissive 'zombie' unable to self-initiate locomotion. We discuss different behavioral and physiological aspects of this venom-induced 'zombified state' and highlight at least one neuronal substrate involved in the regulation of spontaneous behavior in insects.

  14. The predatory behavior of wintering Accipiter hawks: temporal patterns in activity of predators and prey.

    PubMed

    Roth, Timothy C; Lima, Steven L

    2007-05-01

    Studies focused on how prey trade-off predation and starvation risk are prevalent in behavioral ecology. However, our current understanding of these trade-offs is limited in one key respect: we know little about the behavior of predators. In this study, we provide some of the first detailed information on temporal patterns in the daily hunting behavior of bird-eating Accipiter hawks and relate that to their prey. During the winters of 1999-2004, twenty-one sharp-shinned hawks (A. striatus) and ten Cooper's hawks (A. cooperii) were intensively radio tracked in rural and urban habitats in western Indiana, USA. Cooper's hawks left roost before sunrise and usually returned to roost around sunset, while sharp-shinned hawks left roost at sunrise or later and returned to roost well before sunset. An overall measure of Cooper's-hawk-induced risk (a composite variable of attack rate and activity patterns) generally reflected the timing of prey activity, with peaks occurring around sunrise and sunset. In contrast, risk induced by the smaller sharp-shinned hawk did not strongly reflect the activity of their prey. Specifically, an early morning peak in prey activity did not correspond to a period with intense hawk activity. The lack of early morning hunting by sharp-shinned hawks may reflect the high risk of owl-induced predation experienced by these hawks. The net effect of this intraguild predation may be to "free" small birds from much hawk-induced predation risk prior to sunrise. This realization presents an alternative to energetics as an explanation for the early morning peak in small bird activity during the winter.

  15. Predatory behavior in a necrophagous bee Trigona hypogea (Hymenoptera; Apidae, Meliponini)

    NASA Astrophysics Data System (ADS)

    Mateus, Sidnei; Noll, Fernando B.

    Although most bees feed on nectar and pollen, several exceptions have been reported. The strangest of all is the habit found in some neotropical stingless bees, which have completely replaced pollen-eating by eating animal protein from corpses. For more than 20 years, it was believed that carrion was the only protein source for these bees. We report that these bees feed not only off dead animals, but on the living brood of social wasps and possibly other similar sources. Using well developed prey location and foraging behaviors, necrophagous bees discover recently abandoned wasps' nests and, within a few hours, prey upon all immatures found there.

  16. Digital holographic microscopy reveals prey-induced changes in swimming behavior of predatory dinoflagellates.

    PubMed

    Sheng, Jian; Malkiel, Edwin; Katz, Joseph; Adolf, Jason; Belas, Robert; Place, Allen R

    2007-10-30

    The shallow depth of field of conventional microscopy hampers analyses of 3D swimming behavior of fast dinoflagellates, whose motility influences macroassemblages of these cells into often-observed dense "blooms." The present analysis of cinematic digital holographic microscopy data enables simultaneous tracking and characterization of swimming of thousands of cells within dense suspensions. We focus on Karlodinium veneficum and Pfiesteria piscicida, mixotrophic and heterotrophic dinoflagellates, respectively, and their preys. Nearest-neighbor distance analysis shows that predator and prey cells are randomly distributed relative to themselves, but, in mixed culture, each predator clusters around its respective prey. Both dinoflagellate species exhibit complex highly variable swimming behavior as characterized by radius and pitch of helical swimming trajectories and by translational and angular velocity. K. veneficum moves in both left- and right-hand helices, whereas P. piscicida swims only in right-hand helices. When presented with its prey (Storeatula major), the slower K. veneficum reduces its velocity, radius, and pitch but increases its angular velocity, changes that reduce its hydrodynamic signature while still scanning its environment as "a spinning antenna." Conversely, the faster P. piscicida increases its speed, radius, and angular velocity but slightly reduces its pitch when exposed to prey (Rhodomonas sp.), suggesting the preferred predation tactics of an "active hunter."

  17. Predatory behavior of Polistes dominulus wasps in response to cardenolides and glucosinolates in Pieris napi caterpillars.

    PubMed

    Rayor, Linda S; Mooney, Larissa J; Renwick, J Alan

    2007-06-01

    To examine how plant allelochemicals in prey affect foraging choices made by generalist predator paper wasps, Polistes dominulus (Vespidae), we compared predation on Pieris napi (Pieridae) caterpillars reared on host plants with different allelochemicals. In naturalistic behavioral choice experiments, free-flying wasps chose between living pierids reared on cabbage (Brassica oleracea), which lacks deterrent allelochemicals, or alternate host plants with potentially deterrent allelochemicals. The alternative host plants were: wormwood mustard, (Erysimum cheiranthoides: Brassicaceae), which contains cardenolides; nasturtium (Tropaeolum majus: Tropaeolaceae) with high concentrations of chlorogenic acid; and black mustard (Brassica nigra: Brassicaceae) with high concentrations of the aliphatic glucosinolate, sinigrin. Although wasps captured equal numbers of caterpillars reared on cabbage and each alternate host plant, they spent significantly longer handling prey from the alternate host plants as they selectively removed the caterpillar's gut, which contained the plant material. This was true even if the caterpillar did not sequester toxins in its tissues, as revealed by high performance liquid chromatography (HPLC) analysis of Erysimum-reared pierids. Because handling time is longer, predators that capture pierids containing non-sequestered allelochemicals experience an overall reduction in foraging rate that may translate into a fitness cost.

  18. The effects of bupropion on hybrid striped bass brain chemistry and predatory behavior.

    PubMed

    Sweet, Lauren E; Bisesi, Joseph H; Lei, E N Y; Lam, Michael H W; Klaine, Stephen J

    2016-08-01

    Increased use of antidepressants has led to an increase in their detection in final treated wastewater effluents and receiving streams. Antidepressants are intended to modify human behavior by altering brain chemistry, and because of the high functional conservation of antidepressant target receptors in vertebrates, aquatic organisms may be at risk. The antidepressant bupropion is designed to alter brain norepinephrine and dopamine concentrations in humans. The objective of the present study was to understand if alteration of dopaminergic neurotransmitter concentrations in the hybrid striped bass (Morone saxatilis × Morone chrysops) brain by bupropion would alter this predator's ability to capture prey. The authors exposed hybrid striped bass to bupropion in a static system for 6 d, followed by a 6-d recovery period. During the present study's 12-d experiment, each hybrid striped bass was fed 4 unexposed fathead minnows every 3 d, and the time it took the hybrid striped bass to consume each of those 4 fathead minnows was quantified. After each feeding event, hybrid striped bass brains were harvested and analyzed for changes in several brain neurotransmitter concentrations, including serotonin, norepinephrine, dopamine, and many of their metabolites. Although bupropion altered the concentration of dopamine and many of the dopaminergic neurotransmitter metabolite concentrations in the brains on day 3 of the exposure, it did not alter the time to capture prey. This suggests that alteration of dopaminergic neurotransmitter concentrations in the hybrid striped bass brain does not alter a predator's ability to capture prey. Environ Toxicol Chem 2016;35:2058-2065. © 2016 SETAC.

  19. Effects of covering behavior and exposure to a predatory crab Charybdis japonica on survival and HSP70 expression of juvenile sea urchins Strongylocentrotus intermedius.

    PubMed

    Zhao, Chong; Ji, Nanjing; Zhang, Binglong; Sun, Ping; Feng, Wenping; Wei, Jing; Chang, Yaqing

    2014-01-01

    Predation is a complex process among predator, prey and environment. Juvenile sea urchins are more susceptible to predators than adults, which affects community structure. Behavior is involved in anti-predator responses by changes in the expression of anti-predator responsive genes. Here, we investigated the effects of exposure to a predatory crab Charybdis japonica and covering behavior on survival and HSP70 expression of juvenile sea urchins Strongylocentrotus intermedius. C. japonica consumed large numbers of juvenile S. intermedius in 12 hours with a mortality of 34.17±11.43%. Covering behavior did not significantly reduce predation. Exposure to C. japonica did not significantly upregulate HSP70 expression of juvenile S. intermedius in 12 hours. Covering behavior showed no significant regulative effect on the gene expression of HSP70 of juvenile S. intermedius exposed to C. japonica for 12 hours. The results indicate that the anti-predator function of covering behavior is limited and that HSP70 expression does not appear to play an important role in the anti-predator process of S. intermedius.

  20. Neural control of predatory aggression in wild and domesticated animals.

    PubMed

    Nikulina, E M

    1991-01-01

    The neural mechanisms of predatory aggression in laboratory animals were investigated in a variety of rodents and members of the order Carnivora. Experimental enhancement of brain serotonin (5-HT) blocked killing behavior in rats, mice, mink and silver foxes, indicating that there is a 5-HT inhibiting mechanism of predatory aggression in animals of different species. Suppressed killing behavior, at least in some strains of mice, does not depend for expression on the inhibitory effect of the brain 5-HT system, but is caused by the low tonus of the system activating predatory behavior. Long-term satiation of mink increased the level of 5-hydroxyindole acetic acid in the lateral hypothalamus and amygdala and enhanced the latency of predatory aggression. It is suggested that 5-HT represents a dietary responsive endogenous factor regulating predatory behavior in carnivores. Selection of Norway rats over many generations for tamed behavior towards man (domestication) leads to an increase in level and turnover of 5-HT in the midbrain and hypothalamus, but does not change predatory aggression. Substantially reduced defensive behavior of domesticated rats is thus unconnected with the neural mechanism of predatory aggression.

  1. Antibiotics from predatory bacteria

    PubMed Central

    Korp, Juliane; Vela Gurovic, María S

    2016-01-01

    Summary Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism. PMID:27340451

  2. Predatory Online Behavior: Modus Operandi of Convicted Sex Offenders in Identifying Potential Victims and Contacting Minors over the Internet

    ERIC Educational Resources Information Center

    Malesky, L. Alvin, Jr.

    2007-01-01

    Sex offenders have used the Internet to identify and contact minors for sexual exploitation (Armagh, 1998; Hernandez, 2000; Lamb, 1998; Lanning, 1998). Yet little is known about how these individuals select their online victims. In order to gain a better understanding of this behavior, the online activity of 31 men who perpetrated or attempted to…

  3. Academic nightmares: Predatory publishing.

    PubMed

    Van Nuland, Sonya E; Rogers, Kem A

    2016-12-02

    Academic researchers who seek to publish their work are confronted daily with a barrage of e-mails from aggressive marketing campaigns that solicit them to publish their research with a specialized, often newly launched, journal. Known as predatory journals, they often promise high editorial and publishing standards, yet their exploitive business models, poor quality control, and minimal overall transparency victimize those researchers with limited academic experience and pave the way for low-quality articles that threaten the foundation of evidence-based research. Understanding how to identify these predatory journals requires thorough due diligence on the part of the submitting authors, and a commitment by reputable publishers, institutions, and researchers to publicly identify these predators and eliminate them as a threat to the careers of young scientists seeking to disseminate their work in scholarly journals. Anat Sci Educ. © 2016 American Association of Anatomists.

  4. Predatory online behavior: modus operandi of convicted sex offenders in identifying potential victims and contacting minors over the internet.

    PubMed

    Malesky, L Alvin

    2007-01-01

    Sex offenders have used the Internet to identify and contact minors for sexual exploitation (Armagh, 1998; Hernandez, 2000; Lamb, 1998; Lanning, 1998). Yet little is known about how these individuals select their online victims. In order to gain a better understanding of this behavior, the online activity of 31 men who perpetrated or attempted to perpetrate contact sex offenses against minors they communicated with via the Internet, was examined. Three-fourths of the participants monitored chat room dialogue and almost one-half reviewed online profiles of minors in an attempt to identify potential victims. Recommendations to increase the online safety of children and adolescents are discussed.

  5. Effects of predatory fish on survival and behavior of larval gopher frogs (Rana capito) and Southern Leopard Frogs (Rana sphenocephala)

    USGS Publications Warehouse

    Gregoire, D.R.; Gunzburger, M.S.

    2008-01-01

    Southern Leopard Frogs, Rana sphenocephala, are habitat generalists occurring in virtually all freshwater habitats within their geographic range, whereas Gopher Frogs, Rana capito, typically breed in ponds that do not normally contain fish. To evaluate the potential for predation by fish to influence the distribution of these species, we conducted a randomized factorial experiment. We examined the survival rate and behavior of tadpoles when exposed to Warmouth Sunfish, Lepomis gulosus, Banded Sunfish, Enneacanthus obesus, and Eastern Mosquitofish, Gambusia holbrooki. We also conducted a choice experiment to examine the survival rate of the two species of tadpoles when a predator is given a choice of both species simultaneously. Lepomis gulosus consumed the most tadpoles and ate significantly more tadpoles of R. capito than R. sphenocephala. Gambusia holbrooki injured the most tadpoles, especially R. capito. Enneacanthus obesus did not have an effect on behavior or survival of either anuran species. Tadpoles of both anurans increased hiding when in the presence of L. gulosus and G. holbrooki, but a greater proportion of R. capito hid than did R. sphenocephala. Our results suggest that R. capito are more vulnerable to predation by fish than are R. sphenocephala. The introduction of fish may play a role in population declines of certain anurans breeding in normally fish-free wetlands, and even small fish, such as mosquitofish, may have significant negative effects on the tadpoles of R. capito. Copyright 2008 Society for the Study or Amphibians and Reptiles.

  6. Disruption of web structure and predatory behavior of a spider by plant-derived chemical defenses of an aposematic aphid.

    PubMed

    Malcolm, S B

    1989-06-01

    Two toxic and bitter-tasting cardenolides (cardiac-active steroids) were sequestered by the brightly colored oleander aphid,Aphis nerii B. de F., from the neotropical milkweed host plantAsclepias curassavica L. After feeding on milkweed-reared aphids, the orb-web spiderZygiella x-notata (Clerck) built severely disrupted webs and attacked fewer nontoxic, control aphids, whereas the webs of spiders fed only nontoxic aphids remained intact. The regularity and size of the prey-trapping area of webs were reduced significantly in proportion to the amount of toxic aphids eaten. The effects of toxic aphids on spider web structure were mimicked by feeding spiders the bitter-tasting cardenolide digitoxin, a cardenolide with similar steroidal structure and pharmacological activity to the two aphid cardenolides. These results show that the well-known effects of psychoactive drugs on spider web structure are more than interesting behavioral assays of drag activity. Similar effects, produced by plant-derived chemicals in the spider's aphid prey, are relevant to the ecology and evolution of interactions between prey defense and predator foraging.

  7. Human predatory behavior and the social implications of communal hunting based on evidence from the TD10.2 bison bone bed at Gran Dolina (Atapuerca, Spain).

    PubMed

    Rodríguez-Hidalgo, Antonio; Saladié, Palmira; Ollé, Andreu; Arsuaga, Juan Luis; Bermúdez de Castro, José María; Carbonell, Eudald

    2017-04-01

    Zooarcheological research is an important tool in reconstructing subsistence, as well as for inferring relevant aspects regarding social behavior in the past. The organization of hunting parties, forms of predation (number and rate of animals slaughtered), and the technology used (tactics and tools) must be taken into account in the identification and classification of hunting methods in prehistory. The archeological recognition of communal hunting reflects an interest in evolutionary terms and their inherent implications for anticipatory capacities, social complexity, and the development of cognitive tools, such as articulated language. Late and Middle Paleolithic faunal assemblages in Europe have produced convincing evidence of communal hunting of large ungulates allowing for the formation of hypotheses concerning the skills of Neanderthals anatomically modern humans as social predators. However, the emergence of this cooperative behavior is not currently understood. Here, faunal analysis, based on traditional/long-established zooarcheological methods, of nearly 25,000 faunal remains from the "bison bone bed" layer of the TD10.2 sub-unit at Gran Dolina, Atapuerca (Spain) is presented. In addition, other datasets related to the archeo-stratigraphy, paleo-landscape, paleo-environmental proxies, lithic assemblage, and ethno-archeological information of communal hunting have been considered in order to adopt a holistic approach to an investigation of the subsistence strategies developed during deposition of the archeological remains. The results indicate a monospecific assemblage heavily dominated by axial bison elements. The abundance of anthropogenic modifications and the anatomical profile are in concordance with early primary access to carcasses and the development of systematic butchering focused on the exploitation of meat and fat for transportation of high-yield elements to somewhere out of the cave. Together with a catastrophic and seasonal mortality pattern

  8. Predatory Open Access in Rehabilitation.

    PubMed

    Manca, Andrea; Martinez, Gianluca; Cugusi, Lucia; Dragone, Daniele; Mercuro, Giuseppe; Deriu, Franca

    2017-01-20

    Increasingly scholars and researchers are being solicited by predatory open access journals seeking manuscript submissions and abusing the author-pays model by charging authors with publishing fees without any or proper peer review. Such questionable editorial practices are threatening the reputation and credibility of scholarly publishing. To date, no investigation has been conducted on this phenomenon in the field of rehabilitation. This study attempts to identify specific predatory journals operating in this field to quantify the phenomenon and its geographic distribution. Beall's List has been used to this end which, although not perfect, is a comprehensive and up-to-date report of predatory publishers. Of the 1113 publishers on the list, 59 journals were identified, for a total of 5610 published articles. The median number of articles published by each journal was 21, and the median amount of article processing charges was $499. Only 1 out of 59 journals was included in the Directory of Open Access Journals, whereas 7 (12%) were indexed by PubMed. Most of the publishers were based in India (36%) followed by the United States (25%) and Pakistan (5%), and 25% were without a verifiable address. The data indicate that the threat of predatory publishing in rehabilitation is real. Physiatrists, physiotherapists, researchers, and academics operating in this field are advised to use the tools available to recognize predatory practices before considering publishing in open access journals.

  9. Impact of predatory threat on fear extinction in Lewis rats.

    PubMed

    Goswami, Sonal; Cascardi, Michele; Rodríguez-Sierra, Olga E; Duvarci, Sevil; Paré, Denis

    2010-10-01

    Humans with post-traumatic stress disorder (PTSD) are deficient at extinguishing conditioned fear responses. A study of identical twins concluded that this extinction deficit does not predate trauma but develops as a result of trauma. The present study tested whether the Lewis rat model of PTSD reproduces these features of the human syndrome. Lewis rats were subjected to classical auditory fear conditioning before or after exposure to a predatory threat that mimics a type of traumatic stress that leads to PTSD in humans. Exploratory behavior on the elevated plus maze 1 wk after predatory threat exposure was used to distinguish resilient vs. PTSD-like rats. Properties of extinction varied depending on whether fear conditioning and extinction occurred before or after predatory threat. When fear conditioning was carried out after predatory threat, PTSD-like rats showed a marked extinction deficit compared with resilient rats. In contrast, no differences were seen between resilient and PTSD-like rats when fear conditioning and extinction occurred prior to predatory threat. These findings in Lewis rats closely match the results seen in humans with PTSD, thereby suggesting that studies comparing neuronal interactions in resilient vs. at-risk Lewis rats might shed light on the causes and pathophysiology of human PTSD.

  10. Predatory senescence in ageing wolves

    USGS Publications Warehouse

    MacNulty, D.R.; Smith, D.W.; Vucetich, J.A.; Mech, L.D.; Stahler, D.R.; Packer, C.

    2009-01-01

    It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics. ?? 2009 Blackwell Publishing Ltd/CNRS.

  11. Predatory senescence in aging wolves

    USGS Publications Warehouse

    MacNulty, Daniel R.; Smith, Douglas W.; Vucetich, John A.; Mech, L. David; Stahler, Daniel R.; Packer, Craig

    2009-01-01

    It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics.

  12. Predatory senescence in ageing wolves.

    PubMed

    MacNulty, Daniel R; Smith, Douglas W; Vucetich, John A; Mech, L David; Stahler, Daniel R; Packer, Craig

    2009-12-01

    It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics.

  13. Feltiella acarisuga (predatory gall midge)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The predatory gall midge, Feltiella acarisuga is one of the most effective and widespread natural enemies of spider mites. Because of their flying and prey detecting capabilities, and high feeding potential, it is considered an important natural enemy of the two-spotted spider mite in a number of cr...

  14. Dangerous Predatory Publishers Threaten Medical Research.

    PubMed

    Beall, Jeffrey

    2016-10-01

    This article introduces predatory publishers in the context of biomedical sciences research. It describes the characteristics of predatory publishers, including spamming and using fake metrics, and it describes the problems they cause for science and universities. Predatory journals often fail to properly manage peer review, allowing pseudo-science to be published dressed up as authentic science. Academic evaluation is also affected, as some researchers take advantage of the quick, easy, and cheap publishing predatory journals provide. By understanding how predatory publishers operate, researchers can avoid becoming victimized by them.

  15. Dangerous Predatory Publishers Threaten Medical Research

    PubMed Central

    2016-01-01

    This article introduces predatory publishers in the context of biomedical sciences research. It describes the characteristics of predatory publishers, including spamming and using fake metrics, and it describes the problems they cause for science and universities. Predatory journals often fail to properly manage peer review, allowing pseudo-science to be published dressed up as authentic science. Academic evaluation is also affected, as some researchers take advantage of the quick, easy, and cheap publishing predatory journals provide. By understanding how predatory publishers operate, researchers can avoid becoming victimized by them. PMID:27550476

  16. Integrated Control of Predatory Hunting by the Central Nucleus of the Amygdala.

    PubMed

    Han, Wenfei; Tellez, Luis A; Rangel, Miguel J; Motta, Simone C; Zhang, Xiaobing; Perez, Isaac O; Canteras, Newton S; Shammah-Lagnado, Sara J; van den Pol, Anthony N; de Araujo, Ivan E

    2017-01-12

    Superior predatory skills led to the evolutionary triumph of jawed vertebrates. However, the mechanisms by which the vertebrate brain controls predation remain largely unknown. Here, we reveal a critical role for the central nucleus of the amygdala in predatory hunting. Both optogenetic and chemogenetic stimulation of central amygdala of mice elicited predatory-like attacks upon both insect and artificial prey. Coordinated control of cervical and mandibular musculatures, which is necessary for accurately positioning lethal bites on prey, was mediated by a central amygdala projection to the reticular formation in the brainstem. In contrast, prey pursuit was mediated by projections to the midbrain periaqueductal gray matter. Targeted lesions to these two pathways separately disrupted biting attacks upon prey versus the initiation of prey pursuit. Our findings delineate a neural network that integrates distinct behavioral modules and suggest that central amygdala neurons instruct predatory hunting across jawed vertebrates.

  17. Ranking Predatory Journals: Solve the Problem Instead of Removing It!

    PubMed Central

    Dadkhah, Mehdi; Bianciardi, Giorgio

    2016-01-01

    Predatory journals are a well-known issue for scholarly publishing and they are repositories for bogus research. In recent years, the number of predatory journals has risen and it is necessary to present a solution for this challenge. In this paper, we will discuss about a possible ranking of predatory journals. Our ranking approach is based on Beall’s criteria for detection of predatory journals and it can help editors to improve their journals or convert their questionable journals to non-predatory ones. Moreover, our approach could help young editors to protect their journals against predatory practice. Finally, we present a case study to clarify our approach. PMID:27123411

  18. Ranking Predatory Journals: Solve the Problem Instead of Removing It!

    PubMed

    Dadkhah, Mehdi; Bianciardi, Giorgio

    2016-03-01

    Predatory journals are a well-known issue for scholarly publishing and they are repositories for bogus research. In recent years, the number of predatory journals has risen and it is necessary to present a solution for this challenge. In this paper, we will discuss about a possible ranking of predatory journals. Our ranking approach is based on Beall's criteria for detection of predatory journals and it can help editors to improve their journals or convert their questionable journals to non-predatory ones. Moreover, our approach could help young editors to protect their journals against predatory practice. Finally, we present a case study to clarify our approach.

  19. Multiple Contaminant and Predatory Stressors in Experimental Pond Communities

    NASA Astrophysics Data System (ADS)

    Keeley, K.; Crumrine, P. W.; Barlow, P. F.

    2005-05-01

    Anthropogenic contaminants, such as agricultural pesticides found in aquatic systems, have the potential to negatively impact organisms via direct and indirect pathways. The magnitude of these indirect effects depends on the strength of the interactions through which they are propagated. We sought to determine how environmentally realistic levels of the insecticides endosulfan and malathion and the herbicide atrazine impact pond communities. We investigated the effects of these pesticides in mesocosm communities containing larval dragonflies (Anax junius), adult water bugs (Belostoma flumineum), and snails (Planorbella trivolvis). Dragonflies presented a moderate predatory threat to snails, as they affected snail behavior but not survival. Direct effects of pesticides on snails were limited, and pesticides only induced modest changes in snail behavior. All pesticides negatively influenced dragonfly survival and this was most pronounced in treatments with endosulfan. However, the reduction in dragonfly survival did not transmit benefits to snails that were detectable as changes in behavior or survival, as would be expected if dragonflies represented a stronger predatory threat. These results show that individuals in communities can be differentially impacted by contaminants, and indicate that strong indirect effects depend on the strength of underlying trophic interactions.

  20. Evaluating the predatory potential of carnivorous nematodes against Rotylenchulus reniformis and Meloidogyne incognita

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predatory behavior of a nematode is usually determined through gut content observation or prey delimitation counts. In this experiment, Mononchus and Neoactinolaimus predation of Rotylenchulus reniformis or Meloidogyne incognita was determined using a PCR-based nematode gut content analysis. Soil sa...

  1. Predatory Journals, Peer Review, and Education Research

    ERIC Educational Resources Information Center

    Beall, Jeffrey

    2017-01-01

    This commentary examines the problem of predatory journals, low-quality open-access journals that seek to earn revenue from scholarly authors without following scholarly publishing best practices. Seeking to accept as many papers as possible, they typically do not perform a standard peer review, leading to the publication of improperly vetted…

  2. Predatory Microorganisms Would Help Reclaim Water

    NASA Technical Reports Server (NTRS)

    Benjaminson, Morris A.; Lehrer, Stanley

    1995-01-01

    Wastewater-reclamation systems of proposed type use predatory, nonpathogenic microorganisms to consume pathogenic microorganisms. Unlike some other wastewater-reclamation systems, these systems do not require use of toxic chemicals, intense heat, or ionizing radiation (conductivity rays or ultraviolet) to destroy microorganisms.

  3. Predatory cannibalism in Drosophila melanogaster larvae.

    PubMed

    Vijendravarma, Roshan K; Narasimha, Sunitha; Kawecki, Tadeusz J

    2013-01-01

    Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found that under crowded laboratory conditions younger larvae regularly attack and consume 'wandering-stage' conspecifics, forming aggregations mediated by chemical cues from the attacked victim. Nutrition gained this way can be significant: an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults. Cannibalistic diet also induced plasticity of larval mouth parts. Finally, during 118 generations of experimental evolution, replicated populations maintained under larval malnutrition evolved enhanced propensity towards cannibalism. These results suggest that, at least under laboratory conditions, predation on conspecifics in Drosophila is a functional, adaptive behaviour, which can rapidly evolve in response to nutritional conditions.

  4. Effects of experience and cage enrichment on predatory skills of black-footed ferrets (Mustela nigripes)

    USGS Publications Warehouse

    Vargas, A.; Anderson, S.H.

    1999-01-01

    We studied ontogeny of predatory skills of growing black-footed ferrets (Mustela nigripes) raised under different captive conditions. To test effects of maturation, experience, and cage enrichment on predatory behavior, we exposed 70 juvenile black-footed ferrets to different numbers of live hamsters (Mesocricetus auratus) throughout development. Both maturation and experience increased the likelihood of a black-footed ferret making a successful kill. Black-footed ferrets exposed to greater environmental complexity (enriched cage, including encouragement of food-searching behaviors) also were more likely to kill than ferrets raised in a deprived environment. Behavioral studies of captive-raised black-footed ferrets can help refine current breeding techniques and ultimately enhance efforts to recover this endangered carnivore.

  5. White Sharks Exploit the Sun during Predatory Approaches.

    PubMed

    Huveneers, Charlie; Holman, Dirk; Robbins, Rachel; Fox, Andrew; Endler, John A; Taylor, Alex H

    2015-04-01

    There is no conclusive evidence of any nonhuman animal using the sun as part of its predation strategy. Here, we show that the world's largest predatory fish-the white shark (Carcharodon carcharias)-exploits the sun when approaching baits by positioning the sun directly behind them. On sunny days, sharks reversed their direction of approach along an east-west axis from morning to afternoon but had uniformly distributed approach directions during overcast conditions. These results show that white sharks have sufficient behavioral flexibility to exploit fluctuating environmental features when predating. This sun-tracking predation strategy has a number of potential functional roles, including improvement of prey detection, avoidance of retinal overstimulation, and predator concealment.

  6. Slime-trail tracking in the predatory snail, Euglandina rosea.

    PubMed

    Clifford, Kavan T; Gross, Liaini; Johnson, Kwame; Martin, Khalil J; Shaheen, Nagma; Harrington, Melissa A

    2003-10-01

    Euglandina rosea, a predatory land snail, tracks prey and mates by following slime trails. Euglandina follow slime trails more than 80% of the time, following trails of their own species, but not those of prey snails, in the direction that they were laid. The attractive elements of prey slime are small, water-soluble compounds detected by specialized lip extensions. Although olfaction plays no role in trail following, strong odors disrupt tracking. Inhibition of nitric oxide synthase also disrupts slime trail following, suggesting a role for nitric oxide in neural processing of slime trail stimuli. Euglandina can be conditioned to follow novel trails of glutamate or arginine paired with feeding on prey snails. These experiments demonstrate that slime-trail tracking in Euglandina is a robust, easily measured behavior that makes a good model system for studying sensory processing and learning in a novel modality.

  7. Medical publishing triage - chronicling predatory open access publishers.

    PubMed

    Beall, Jeffrey

    2013-01-01

    This editorial examines the problem of predatory publishers and how they have negatively affected scholarly communication. Society relies on high-quality, peer-reviewed articles for public policy, legal cases, and improving the public health. Researchers need to be aware of how predatory publishers operate and need to avoid falling into their traps. The editorial examines the recent history of predatory publishers and how they have become prominent in the world of scholarly journals.

  8. Predatory Invitations from Journals: More Than Just a Nuisance?

    PubMed

    Clemons, Mark; de Costa E Silva, Miguel; Joy, Anil Abraham; Cobey, Kelly D; Mazzarello, Sasha; Stober, Carol; Hutton, Brian

    2017-02-01

    Physicians and academic researchers are frequently targeted with spam invitations to submit manuscripts to predatory journals. This study was conducted to understand the nature and characteristics of these invitations. All spam e-mails received by an academic medical oncologist over a 3-month period were collected and categorized. Presumed predatory journal invitations were analyzed and cross-checked against Beall's list of "potential, probable, or possible predatory" journals and publishers. Invitations to submit to predatory journals were the most common single type of spam received. The Oncologist 2017;22:236-240.

  9. Pepper banker plant systems and predatory mitespepper banker plant systems and predatory mites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While developing the ornamental pepper banker plant system for greenhouse grown vegetables and ornamental crops we discovered that the predatory mites we were using could survive and reproduce on ornamental pepper without their prey especially if they were provided supplemental pollen or if the bank...

  10. Visual Detection of Speckles in the Fish Xenotoca variata by the Predatory Snake Thamnophis melanogaster in Water of Different Turbidity.

    PubMed

    Manjarrez, Javier; Rivas-González, Eric; Venegas-Barrera, Crystian S; Moyaho, Alejandro

    2015-01-01

    Semi-aquatic snakes integrate visual and chemical stimuli, and prey detection and capture success are therefore linked to the display of visual predatory behavior. The snake Thamnophis melanogaster responds preferentially to individuals of the fish Xenotoca variata with a greater number of bright, colorful spots (lateral speckles) compared with those with a smaller number; however, water turbidity can reduce underwater visibility and effect the vulnerability of fish. In this study, we tested whether the presence of iridescent speckles on the flanks of male X. variata interacted with water turbidity to modify the predatory behavior displayed by the snake T. melanogaster. We predicted that in an experimental laboratory test, the snakes would increase the frequency of their predatory behavior to the extent that the water turbidity decreases. The snakes were tested at six different levels of water turbidity, in combination with three categories of male fish (with few, a median number of, or many speckles). The results showed that in a pool with high or zero turbidity, the number of speckles is not a determining factor in the deployment of the predatory behavior of the snake T. melanogaster toward X. variata. Our findings suggest that snakes can view the fish at intermediate percentages of turbidity, but the number of speckles in male X. variata is irrelevant as an interspecific visual signal in environments with insufficient luminosity. The successful capture of aquatic prey is influenced by integration between chemical and visual signals, according to environmental factors that may influence the recognition of individual traits.

  11. Visual Detection of Speckles in the Fish Xenotoca variata by the Predatory Snake Thamnophis melanogaster in Water of Different Turbidity

    PubMed Central

    Manjarrez, Javier; Rivas-González, Eric; Venegas-Barrera, Crystian S.; Moyaho, Alejandro

    2015-01-01

    Semi-aquatic snakes integrate visual and chemical stimuli, and prey detection and capture success are therefore linked to the display of visual predatory behavior. The snake Thamnophis melanogaster responds preferentially to individuals of the fish Xenotoca variata with a greater number of bright, colorful spots (lateral speckles) compared with those with a smaller number; however, water turbidity can reduce underwater visibility and effect the vulnerability of fish. In this study, we tested whether the presence of iridescent speckles on the flanks of male X. variata interacted with water turbidity to modify the predatory behavior displayed by the snake T. melanogaster. We predicted that in an experimental laboratory test, the snakes would increase the frequency of their predatory behavior to the extent that the water turbidity decreases. The snakes were tested at six different levels of water turbidity, in combination with three categories of male fish (with few, a median number of, or many speckles). The results showed that in a pool with high or zero turbidity, the number of speckles is not a determining factor in the deployment of the predatory behavior of the snake T. melanogaster toward X. variata. Our findings suggest that snakes can view the fish at intermediate percentages of turbidity, but the number of speckles in male X. variata is irrelevant as an interspecific visual signal in environments with insufficient luminosity. The successful capture of aquatic prey is influenced by integration between chemical and visual signals, according to environmental factors that may influence the recognition of individual traits. PMID:26061294

  12. Predatory Bacteria Attenuate Klebsiella pneumoniae Burden in Rat Lungs

    PubMed Central

    Singleton, Eric; Tang, Chi; Zuena, Michael; Shukla, Sean; Gupta, Shilpi; Dharani, Sonal; Onyile, Onoyom; Rinaggio, Joseph; Connell, Nancy D.

    2016-01-01

    ABSTRACT Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are predatory bacteria that naturally—and obligately—prey on other Gram-negative bacteria, and their use has been proposed as a potential new approach to control microbial infection. The ability of predatory bacteria to prey on Gram-negative human pathogens in vitro is well documented; however, the in vivo safety and efficacy of predatory bacteria have yet to be fully assessed. In this study, we examined whether predatory bacteria can reduce bacterial burden in the lungs in an in vivo mammalian system. Initial safety studies were performed by intranasal inoculation of rats with predatory bacteria. No adverse effects or lung pathology were observed in rats exposed to high concentrations of predatory bacteria at up to 10 days postinoculation. Enzyme-linked immunosorbent assay (ELISA) of the immune response revealed a slight increase in inflammatory cytokine levels at 1 h postinoculation that was not sustained by 48 h. Additionally, dissemination experiments showed that predators were efficiently cleared from the host by 10 days postinoculation. To measure the ability of predatory bacteria to reduce microbial burden in vivo, we introduced sublethal concentrations of Klebsiella pneumoniae into the lungs of rats via intranasal inoculation and followed with multiple doses of predatory bacteria over 24 h. Predatory bacteria were able to reduce K. pneumoniae bacterial burden, on average, by more than 3.0 log10 in the lungs of most rats as measured by CFU plating. The work presented here provides further support for the idea of developing predatory bacteria as a novel biocontrol agent. PMID:27834203

  13. Hagfish predatory behaviour and slime defence mechanism

    PubMed Central

    Zintzen, Vincent; Roberts, Clive D.; Anderson, Marti J.; Stewart, Andrew L.; Struthers, Carl D.; Harvey, Euan S.

    2011-01-01

    Hagfishes (Myxinidae), a family of jawless marine pre-vertebrates, hold a unique evolutionary position, sharing a joint ancestor with the entire vertebrate lineage. They are thought to fulfil primarily the ecological niche of scavengers in the deep ocean. However, we present new footage from baited video cameras that captured images of hagfishes actively preying on other fish. Video images also revealed that hagfishes are able to choke their would-be predators with gill-clogging slime. This is the first time that predatory behaviour has been witnessed in this family, and also demonstrates the instantaneous effectiveness of hagfish slime to deter fish predators. These observations suggest that the functional adaptations and ecological role of hagfishes, past and present, might be far more diverse than previously assumed. We propose that the enduring success of this oldest extant family of fishes over 300 million years could largely be due to their unique combination of functional traits. PMID:22355648

  14. Functional Diversification within a Predatory Species Flock

    PubMed Central

    Burress, Edward D.; Duarte, Alejandro; Serra, Wilson S.; Loueiro, Marcelo; Gangloff, Michael M.; Siefferman, Lynn

    2013-01-01

    Ecological speciation is well-known from adaptive radiations in cichlid fishes inhabiting lentic ecosystems throughout the African rift valley and Central America. Here, we investigate the ecological and morphological diversification of a recently discovered lotic predatory Neotropical cichlid species flock in subtropical South America. We document morphological and functional diversification using geometric morphometrics, stable C and N isotopes, stomach contents and character evolution. This species flock displays species-specific diets and skull and pharyngeal jaw morphology. Moreover, this lineage appears to have independently evolved away from piscivory multiple times and derived forms are highly specialized morphologically and functionally relative to ancestral states. Ecological speciation played a fundamental role in this radiation and our data reveal novel conditions of ecological speciation including a species flock that evolved: 1) in a piscivorous lineage, 2) under lotic conditions and 3) with pronounced morphological novelties, including hypertrophied lips that appear to have evolved rapidly. PMID:24278349

  15. Behind the Spam: A ``Spectral Analysis'' of Predatory Publishers

    NASA Astrophysics Data System (ADS)

    Beall, Jeffrey

    2016-10-01

    Most researchers today are bombarded with spam email solicitations from questionable scholarly publishers. These emails solicit article manuscripts, editorial board service, and even ad hoc peer reviews. These ``predatory'' publishers exploit the scholarly publishing process, patterning themselves after legitimate scholarly publishers yet performing little or no peer review and quickly accepting submitted manuscripts and collecting fees from submitting authors. These counterfeit publishers and journals have published much junk science? especially in the field of cosmology? threatening the integrity of the academic record. This paper examines the current state of predatory publishing and advises researchers how to navigate scholarly publishing to best avoid predatory publishers and other scholarly publishing-related perils.

  16. Predatory aquatic beetles, suitable trace elements bioindicators.

    PubMed

    Burghelea, Carmen I; Zaharescu, Dragos G; Hooda, Peter S; Palanca-Soler, Antonio

    2011-05-01

    Predatory aquatic beetles are common colonizers of natural and managed aquatic environments. While as important components of the aquatic food webs they are prone to accumulate trace elements, they have been largely neglected from metal uptake studies. We aim to test the suitability of three dytiscid species, i.e.Hydroglyphus pusillus, Laccophilus minutus and Rhantus suturalis, as trace elements (Al, As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se and Zn) bioindicators. The work was carried out in a case area representing rice paddies and control sites (reservoirs) from an arid region known for its land degradation (Monegros, NE Spain). Categorical principal component analysis (CATPCA) was tested as a nonlinear approach to identify significant relationships between metals, species and habitat conditions so as to examine the ability of these species to reflect differences in metal uptake. Except Se and As, the average concentrations of all other elements in the beetles were higher in the rice fields than in the control habitats. The CATPCA determined that H. pusillus had high capacity to accumulate Fe, Ni and Mn regardless of the habitat type, and hence may not be capable of distinguishing habitat conditions with regards to these metals. On the other hand, L. minutus was found less sensitive for Se in non-managed habitats (i.e. reservoirs), while R. suturalis was good in accumulating Al, Mo and Pb in rice fields. The latter seems to be a promising bioindicator of metal enrichment in rice fields. We conclude that predatory aquatic beetles are good candidates for trace elements bioindication in impacted and non-impacted environments and can be used in environmental monitoring studies. CATPCA proved to be a reliable approach to unveil trends in metal accumulation in aquatic invertebrates according to their habitat status.

  17. Serial murder and the case of Aileen Wuornos: attachment theory, psychopathy, and predatory aggression.

    PubMed

    Arrigo, Bruce A; Griffin, Ayanna

    2004-01-01

    The extant research on female homicide has yet to offer any systematic assessment of why women murder serially. Part of the explanation is attributed to existing literature focusing on justifiable and excusable homicide, or women who kill their abusive partners because they have been battered, fear that their lives are in danger, or are otherwise victimized. Thus, predatory homicide perpetrated by women has not received extensive attention in the relevant literature. This article aims to address this deficiency by providing a detailed case study analysis of Aileen Wuornos, a convicted serial murderer executed at Broward Correctional Institution in Pembroke Pines, FL, on October 9, 2002. By linking the literature on attachment theory with the research on psychopathy and predatory aggression, this article argues that Aileen Wuornos was a cold blooded and calculated killer: a serial offender responsible for her delinquent and criminal behavior. Generalizing from the case of Aileen Wuornos, several tentative recommendations are proposed as linked to clinical and forensic prevention, diagnosis, and treatment, as well as future research on women, psychopathy, and predatory serial homicide.

  18. The predatory ecology of Deinonychus and the origin of flapping in birds.

    PubMed

    Fowler, Denver W; Freedman, Elizabeth A; Scannella, John B; Kambic, Robert E

    2011-01-01

    Most non-avian theropod dinosaurs are characterized by fearsome serrated teeth and sharp recurved claws. Interpretation of theropod predatory ecology is typically based on functional morphological analysis of these and other physical features. The notorious hypertrophied 'killing claw' on pedal digit (D) II of the maniraptoran theropod Deinonychus (Paraves: Dromaeosauridae) is hypothesized to have been a predatory adaptation for slashing or climbing, leading to the suggestion that Deinonychus and other dromaeosaurids were cursorial predators specialized for actively attacking and killing prey several times larger than themselves. However, this hypothesis is problematic as extant animals that possess similarly hypertrophied claws do not use them to slash or climb up prey. Here we offer an alternative interpretation: that the hypertrophied D-II claw of dromaeosaurids was functionally analogous to the enlarged talon also found on D-II of extant Accipitridae (hawks and eagles; one family of the birds commonly known as "raptors"). Here, the talon is used to maintain grip on prey of subequal body size to the predator, while the victim is pinned down by the body weight of the raptor and dismembered by the beak. The foot of Deinonychus exhibits morphology consistent with a grasping function, supportive of the prey immobilisation behavior model. Opposite morphological trends within Deinonychosauria (Dromaeosauridae + Troodontidae) are indicative of ecological separation. Placed in context of avian evolution, the grasping foot of Deinonychus and other terrestrial predatory paravians is hypothesized to have been an exaptation for the grasping foot of arboreal perching birds. Here we also describe "stability flapping", a novel behaviour executed for positioning and stability during the initial stages of prey immobilisation, which may have been pivotal to the evolution of the flapping stroke. These findings overhaul our perception of predatory dinosaurs and highlight the role

  19. The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds

    PubMed Central

    Fowler, Denver W.; Freedman, Elizabeth A.; Scannella, John B.; Kambic, Robert E.

    2011-01-01

    Most non-avian theropod dinosaurs are characterized by fearsome serrated teeth and sharp recurved claws. Interpretation of theropod predatory ecology is typically based on functional morphological analysis of these and other physical features. The notorious hypertrophied ‘killing claw’ on pedal digit (D) II of the maniraptoran theropod Deinonychus (Paraves: Dromaeosauridae) is hypothesized to have been a predatory adaptation for slashing or climbing, leading to the suggestion that Deinonychus and other dromaeosaurids were cursorial predators specialized for actively attacking and killing prey several times larger than themselves. However, this hypothesis is problematic as extant animals that possess similarly hypertrophied claws do not use them to slash or climb up prey. Here we offer an alternative interpretation: that the hypertrophied D-II claw of dromaeosaurids was functionally analogous to the enlarged talon also found on D-II of extant Accipitridae (hawks and eagles; one family of the birds commonly known as “raptors”). Here, the talon is used to maintain grip on prey of subequal body size to the predator, while the victim is pinned down by the body weight of the raptor and dismembered by the beak. The foot of Deinonychus exhibits morphology consistent with a grasping function, supportive of the prey immobilisation behavior model. Opposite morphological trends within Deinonychosauria (Dromaeosauridae + Troodontidae) are indicative of ecological separation. Placed in context of avian evolution, the grasping foot of Deinonychus and other terrestrial predatory paravians is hypothesized to have been an exaptation for the grasping foot of arboreal perching birds. Here we also describe “stability flapping”, a novel behaviour executed for positioning and stability during the initial stages of prey immobilisation, which may have been pivotal to the evolution of the flapping stroke. These findings overhaul our perception of predatory dinosaurs and

  20. Physiological benefits of nectar-feeding by a predatory beetle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrafloral nectar is an important food source for many animals, including predatory lady beetles (Coleoptera: Coccinellidae), although the physiological benefits of nectar consumption are poorly understood for most consumers. Under laboratory conditions, we confined new females of Coleomegilla macu...

  1. Predatory bacteria are nontoxic to the rabbit ocular surface

    PubMed Central

    Romanowski, Eric G.; Stella, Nicholas A.; Brothers, Kimberly M.; Yates, Kathleen A.; Funderburgh, Martha L.; Funderburgh, James L.; Gupta, Shilpi; Dharani, Sonal; Kadouri, Daniel E.; Shanks, Robert M. Q.

    2016-01-01

    Given the increasing emergence of antimicrobial resistant microbes and the near absent development of new antibiotic classes, innovative new therapeutic approaches to address this global problem are necessary. The use of predatory bacteria, bacteria that prey upon other bacteria, is gaining interest as an “out of the box” therapeutic treatment for multidrug resistant pathogenic bacterial infections. Before a new antimicrobial agent is used to treat infections, it must be tested for safety. The goal of this study was to test the tolerability of bacteria on the ocular surface using in vitro and in vivo models. Predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus were found to be non-toxic to human corneal stromal keratocytes in vitro; however, they did induce production of the proinflammatory chemokine IL-8 but not IL-1β. Predatory bacteria did not induce inflammation on the ocular surface of rabbit eyes, with and without corneal epithelial abrasions. Unlike a standard of care antibiotic vancomycin, predatory bacteria did not inhibit corneal epithelial wound healing or increase clinical inflammatory signs in vivo. Together these data support the safety of predatory bacteria on the ocular surface, but future studies are warranted regarding the use predatory bacteria in deeper tissues of the eye. PMID:27527833

  2. Predatory bird populations in the east Mojave Desert, California

    USGS Publications Warehouse

    Knight, R.L.; Camp, R.J.; Boarman, W.I.; Knight, H.A.L.

    1999-01-01

    We surveyed 7 species of predatory birds weekly during a 12-month period (December 1992 through November 1993) in the east Mojave Desert, California. The Common Raven (Corvus corax) was the most frequently observed species with an average of 6.9 sightings per 100 km. Turkey Vultures (Cathartes aura), Red-tailed Hawks (Buteo jamaicensis), Loggerhead Shrikes (Lanius ludovicianus), American Kestrels (Falco sparverius), Golden Eagles (Aquila chrysaetos), and Prairie Falcons (Falco mexicanus) were seen in decreasing order of frequency of observation through the study period. Ravens, Red-tailed Hawks, Loggerhead Shrikes, American Kestrels, and Prairie Falcons were seen throughout the year. Turkey Vultures were not present during winter months, while Golden Eagles were seen only during November and December. Turkey Vultures, Red-tailed Hawks, and ravens were most numerous on agricultural lands, while Loggerhead Shrikes were most Common at urban areas. Raven numbers increased with increasing number of linear rights-of-way parallel to the survey route. Perching was the most common behavior type, although Turkey Vultures and ravens were often observed soaring, flying, or standing on the ground near highways. Transmission powerline towers and telephone poles were used as perch sites disproportionately to availability.

  3. Investigating the presence of predatory bacteria on algal bloom samples using a T6SS gene marker.

    NASA Astrophysics Data System (ADS)

    Hendricks, J.; Sison-Mangus, M.; Mehic, S.; McMahon, E.

    2015-12-01

    Predation is considered to be a major driving force in evolution and ecology, which has been observed affecting individual organisms, communities, and entire ecosystems. The type VI secretion system (T6SS) is an intermembranal protein complex identified in certain bacteria, which appears to have evolved strictly as a mechanism of predation. The effects of bacteria on phytoplankton physiology are still understudied, however, studies have shown that the interactions between bacteria that inhabit the phycosphere of phytoplankton can possibly result in coevolution of native host and microbiota. It is unclear if bacteria can prey upon other bacteria to gain advantages during periods of high phytoplankton density. Here, we investigate the predatory interactions between bacteria and analyze environmental samples for the presence of predatory bacterial genes in an effort to understand bacteria-bacteria and phytoplankton interactions during algal blooms. DNA were extracted from bacterial samples collected weekly from size-fractionated samples using 3.0 um and 0.2 um membrane filters at the Santa Cruz wharf. PCR amplification and gel visualization for the presence of T6SS gene was carried out on bloom and non-bloom samples. Moreover, we carried out a lab- based experiment to observe bacteria-bacteria interaction that may hint for the presence of predatory behavior between bacterial taxa. We observed what appeared to be a predatory biofilm formation between certain bacterial species. These bacteria, however, did not contain the T6SS genes. On the contrary the T6SS gene was discovered in some of the bloom samples gathered from the Santa Cruz wharf. It is still unclear if the predatory mechanisms facilitate the abundance of certain groups of bacteria that contain the T6SS genes during algal blooms, but our evidence suggest that bacterial predation through T6SS mechanism is present during bloom events.

  4. Body size and predatory performance in wolves: Is bigger better?

    USGS Publications Warehouse

    MacNulty, D.R.; Smith, D.W.; Mech, L.D.; Eberly, L.E.

    2009-01-01

    Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. 2. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. 3. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance of different predatory tasks; larger size improved performance of a strength-related task (grappling and subduing elk) but failed to improve performance of a locomotor-related task (selecting an elk from a group) for wolves > 39 kg. 4. Sexual dimorphism in wolf size also explained why males outperformed females in each of the three tasks considered (attacking, selecting, and killing). 5. These findings support the generalization that bigger predators are overall better hunters, but they also indicate that increasing size ultimately limits elements of predatory behaviour that require superior locomotor performance. We argue that this could potentially narrow the dietary niche of larger carnivores as well as limit the evolution of larger size if prey are substantially more difficult to pursue than to handle. ?? 2009 British Ecological Society.

  5. Body size and predatory performance in wolves: is bigger better?

    PubMed

    MacNulty, Daniel R; Smith, Douglas W; Mech, L David; Eberly, Lynn E

    2009-05-01

    1. Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. 2. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. 3. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance of different predatory tasks; larger size improved performance of a strength-related task (grappling and subduing elk) but failed to improve performance of a locomotor-related task (selecting an elk from a group) for wolves > 39 kg. 4. Sexual dimorphism in wolf size also explained why males outperformed females in each of the three tasks considered (attacking, selecting, and killing). 5. These findings support the generalization that bigger predators are overall better hunters, but they also indicate that increasing size ultimately limits elements of predatory behaviour that require superior locomotor performance. We argue that this could potentially narrow the dietary niche of larger carnivores as well as limit the evolution of larger size if prey are substantially more difficult to pursue than to handle.

  6. Investigating the Responses of Human Epithelial Cells to Predatory Bacteria

    PubMed Central

    Monnappa, Ajay K.; Bari, Wasimul; Choi, Seong Yeol; Mitchell, Robert J.

    2016-01-01

    One beguiling alternative to antibiotics for treating multi-drug resistant infections are Bdellovibrio-and-like-organisms (BALOs), predatory bacteria known to attack human pathogens. Consequently, in this study, the responses from four cell lines (three human and one mouse) were characterized during an exposure to different predatory bacteria, Bdellovibrio bacteriovorus HD100, Bacteriovorus BY1 and Bacteriovorax stolpii EB1. TNF-α levels were induced in Raw 264.7 mouse macrophage cultures with each predator, but paled in comparison to those obtained with E. coli. This was true even though the latter strain was added at an 11.1-fold lower concentration (p < 0.01). Likewise, E. coli led to a significant (54%) loss in the Raw 264.7 murine macrophage viability while the predatory strains had no impact. Tests with various epithelial cells, including NuLi-1 airway, Caco2, HT29 and T84 colorectal cells, gave similar results, with E. coli inducing IL-8 production. The viabilities of the NuLi-1 and Caco-2 cells were slightly reduced (8%) when exposed to the predators, while T84 viability remained steady. In no cases did the predatory bacteria induce actin rearrangement. These results clearly demonstrate the gentle natures of predatory bacteria and their impacts on human cells. PMID:27629536

  7. Behind the Spam: A "Spectral Analysis" of Predatory Publishers

    NASA Astrophysics Data System (ADS)

    Beall, Jeffrey

    2015-08-01

    Most researchers today are bombarded with spam email solicitations from questionable scholarly publishers. These emails solicit article manuscripts, editorial board service, and even ad hoc peer reviews. These "predatory" publishers exploit the scholarly publishing process, patterning themselves after legitimate scholarly publishers yet performing little or no peer review and quickly accepting submitted manuscripts and collecting fees from submitting authors. These counterfeit publishers and journals have published much junk science — especially in the field of cosmology — threatening the integrity of the academic record. This presentation examines the current state of predatory publishing and related scams such as fake impact factors and advises researchers how to navigate scholarly publishing to best avoid predatory publishers and other scholarly publishing-related perils.

  8. Sexual Violence, Predatory Masculinity, and Medical Testimony in New Spain.

    PubMed

    Tortorici, Zeb

    2015-01-01

    This essay examines the medical and legal construction of predatory masculinity in New Spain by contrasting criminal cases of rape [estupro] with those of violent or coercive sodomy [sodomía]. In the context of male-female rape, the rulings of most criminal and ecclesiastical courts imply that predatory masculinity was a "natural" manifestation of male sexual desire, whereas in cases of sodomy and nonconsensual sexual acts between men, courts viewed such desire as "against nature." The processes by which the colonial state prosecuted certain sexual crimes simultaneously criminalized and validated predatory masculinity. By analyzing the roles of the medics, surgeons, and midwives who examined the bodies of the male and female victims in these cases, this essay argues for a commonality in the authoritative judgments based on medical evidence, whether conclusive or inconclusive.

  9. Predatory Publishing: An Emerging Threat to the Medical Literature.

    PubMed

    Harvey, H Benjamin; Weinstein, Debra F

    2017-02-01

    The quality of medical literature is increasingly threatened by irresponsible publishing, leading to rising retraction rates, irreproducible results, and a flood of inconsequential publications that distract readers from more meaningful scholarship. "Predatory publishers" offer rapid publication with loose peer review, exploiting a system in which faculty seek longer bibliographies to achieve academic promotion. In this Commentary, the authors highlight some of the evidence that this problem exists and suggest actions to address it. Recommendations for protecting the medical literature include preventing predatory journals from being indexed by the National Library of Medicine; encouraging academic promotions committees to ensure that they prioritize value over volume of publications and that faculty understand that priority; excluding publications from predatory journals on curricula vitae and requiring that retractions are included; developing sanctions for repeated retractions or duplicate publications; and convening an expert panel to better elucidate this problem and determine strategies to combat it.

  10. Community structure affects trophic ontogeny in a predatory fish.

    PubMed

    Sánchez-Hernández, Javier; Eloranta, Antti P; Finstad, Anders G; Amundsen, Per-Arne

    2017-01-01

    While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. Northern Scandinavian freshwater fish communities were used as a study system, including nine subarctic lakes with contrasting fish community configurations: (i) trout-only systems, (ii) two-species systems (brown trout and Arctic charr [Salvelinus alpinus] coexisting), and (iii) three-species systems (brown trout, Arctic charr, and three-spined sticklebacks [Gasterosteus aculeatus] coexisting). We expected that the presence of profitable small prey (stickleback) and mixed competitor-prey fish species (charr) supports early piscivory and high individual dietary specialization among trout in multispecies communities, whereas minor ontogenetic shifts were expected in trout-only systems. From logistic regression models, the presence of a suitable prey fish species (stickleback) emerged as the principal variable determining the size at ontogenetic niche shifts. Generalized additive mixed models indicated that fish community structure shaped ontogenetic niche shifts in trout, with the strongest positive relationships between body length, trophic position, and individual dietary specialization being observed in three-species communities. Our findings revealed that the presence of a small-sized prey fish species (stickleback) rather than a mixed competitor-prey fish species (charr) was

  11. Ultimate Drivers and Proximate Correlates of Polyandry in Predatory Mites

    PubMed Central

    Schausberger, Peter; Patiño-Ruiz, J. David; Osakabe, Masahiro; Murata, Yasumasa; Sugimoto, Naoya; Uesugi, Ryuji; Walzer, Andreas

    2016-01-01

    Polyandry is more widespread than anticipated from Bateman’s principle but its ultimate (evolutionary) causes and proximate (mechanistic) correlates are more difficult to pinpoint than those of polygyny. Here, we combined mating experiments, quantification of reproductive traits and microsatellite genotyping to determine the fitness implications of polyandry in two predatory mite species, where males are highly polygynous (up to 45 fertilized females during life), whereas females range from monandry to various polyandry levels. The medium-level polyandrous (up to eight male mates possible) Neoseiulus californicus received clear direct and indirect benefits: multiply mated females produced more offspring with higher survival chances over longer times than singly mated females. In contrast, singly and multiply mated females of the low-level polyandrous (commonly two male mates at maximum) Phytoseiulus persimilis produced similar numbers of offspring having similar survival chances. In both species, multiple mating resulted in mixed offspring paternities, opening the chance for indirect fitness benefits such as enhanced genetic compatibility, complementarity and/or variability. However, the female re-mating likelihood and the paternity chance of non-first male mates were lower in P. persimilis than in N. californicus. Regarding proximate factors, in both species first mating duration and female re-mating likelihood were negatively correlated. Based on occasional fertilization failure of first male mates in P. persimilis, and mixed offspring paternities in both species, we argue that fertilization assurance and the chance to gain indirect fitness benefits are the ultimate drivers of polyandry in P. persimilis, whereas those of N. californicus are higher offspring numbers coupled with enhanced offspring viability and possibly other indirect fitness benefits. Overall, the adaptive significance and proximate events well reflected the polyandry levels. Our study provides

  12. Purification and host specificity of predatory halobacteriovorax isolated from seawater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Halobacteriovorax (formerly Bacteriovorax) are small predatory bacteria found in the marine environment and may serve as biocontrol agents against pathogens in fish and shellfish. Four strains of Halobacteriovorax originally isolated in Vibrio parahaemolyticus O3:K6 host cells were separated from t...

  13. Are plant trichomes harmful to predatory insects and mites?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants may use epidermal hairs (trichomes) to defend themselves from attack by herbivores. Predatory arthropods may serve as biocontrol agents against herbivores. Whether or not plant trichomes work in concert with predators is undocumented in many cases. We reviewed the peer-reviewed literature ...

  14. Plant trichomes have mixed impacts on predatory insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In response to our review article on the role of plant trichomes on insect predators (Riddick & Simmons 2014), Krimmel (2014) acknowledged the challenges that are faced in bringing together the varied publications on the subject of impact of plant trichomes on predatory insects. He also suggested t...

  15. Educational Research and Predatory Tabloid Journalism: Authors Beware

    ERIC Educational Resources Information Center

    Marchant, Gregory J.

    2015-01-01

    This paper outlines the nature of predatory open-access journals. These are journals that do not exist as vehicles to promote research or the efforts of scholarly organizations, but exist simply as a means for profit. As with many efforts in education and the social sciences, when financial incentive is the main driving force, quality and…

  16. IN VITRO CULTURING OF THE PREDATORY SOIL NEMATODE CLARKUS PAPILLATUS

    EPA Science Inventory

    Clarkus papillatus is a widely distributed predatory soil nematode and is of interest in the study of soil ecology, yet very little information exists on its in vitro culturing. In this investigation, an artificial environment was created to maintain C. papillatus for multi-gener...

  17. Benefit-cost Trade-offs of Early Learning in Foraging Predatory Mites Amblyseius Swirskii

    PubMed Central

    Christiansen, Inga C.; Szin, Sandra; Schausberger, Peter

    2016-01-01

    Learning is changed behavior following experience, and ubiquitous in animals including plant-inhabiting predatory mites (Phytoseiidae). Learning has many benefits but also incurs costs, which are only poorly understood. Here, we addressed learning, especially its costs, in the generalist predatory mite Amblyseius swirskii, a biocontrol agent of several herbivores, which can also survive on pollen. The goals of our research were (1) to scrutinize if A. swirskii is able to learn during early life in foraging contexts and, if so, (2) to determine the costs of early learning. In the experiments, we used one difficult-to-grasp prey, i.e., thrips, and one easy-to-grasp prey, i.e., spider mites. Our experiments show that A. swirskii is able to learn during early life. Adult predators attacked prey experienced early in life (i.e., matching prey) more quickly than they attacked unknown (i.e., non-matching) prey. Furthermore, we observed both fitness benefits and operating (physiological) costs of early learning. Predators receiving the matching prey produced the most eggs, whereas predators receiving the non-matching prey produced the least. Thrips-experienced predators needed the longest for juvenile development. Our findings may be used to enhance A. swirskii’s efficacy in biological control, by priming young predators on a specific prey early in life. PMID:27006149

  18. Olfactory response of predatory mites to vegetative and reproductive parts of coconut palm infested by Aceria guerreronis.

    PubMed

    Melo, José Wagner S; Lima, Debora B; Pallini, Angelo; Oliveira, José Eudes M; Gondim, Manoel G C

    2011-10-01

    The phytophagous mite Aceria guerreronis Keifer is an important pest of coconut worldwide. A promising method of control for this pest is the use of predatory mites. Neoseiulus baraki (Athias-Henriot) and Proctolaelaps bickleyi Bram are predatory mites found in association with A. guerreronis in the field. To understand how these predators respond to olfactory cues from A. guerreronis and its host plant, the foraging behavior of the predatory mites was investigated in a Y-tube olfactometer and on T-shaped arenas. The predators were subjected to choose in an olfactometer: (1) isolated parts (leaflet, spikelet or fruit) of infested coconut plant or clean air stream; (2) isolated parts of non-infested or infested coconut plant; and (3) two different plant parts previously shown to be attractive. Using T-shaped arenas the predators were offered all possible binary combinations of discs of coconut fruit epidermis infested with A. guerreronis, non-infested discs or coconut pollen. The results showed that both predators were preferred (the volatile cues from) the infested plant parts over clean air. When subjected to odours from different infested or non-infested plant parts, predators preferred the infested parts. Among the infested plant parts, the spikelets induced the greatest attraction to predators. On the arenas, both predators preferred discs of coconut fruits infested with A. guerreronis over every other alternative. The results show that both predators are able to locate A. guerreronis by olfactory stimuli. Foraging strategies and implications for biological control are discussed.

  19. Predatory violence aiming at relief in a case of mass murder: Meloy's criteria for applied forensic practice.

    PubMed

    Declercq, Frédéric; Audenaert, Kurt

    2011-01-01

    Mass murder is the result of the complex interaction of several factors. What seems ubiquitous within mass murder are extreme feelings of anger and revenge. Yet despite these intense affective states, mass murders are, as a rule, not behaviorally impulsive, but rather prepared. The presence of extreme hate and anger evokes an impulsive outburst of rage, whereas planning and premeditation point in the direction of a cognitive, rather unemotional deed. This inconsistency is also reflected in reports of offenders' emotional states during the execution of their crimes: while some mass murderers have been described as calm, focused and emotionless during the events, others have shown signs of hostility, confusion, and distress. Considering mass murder from the perspective of its violence mode might shed some light on its nature and dynamics. With respect to the differentiation between affective and predatory violence, Meloy (1988) developed a model for applied forensic practice. The fully documented case of mass murder discussed in this study contains nine indices of predatory violence and one of affective violence. Furious affects of hate and anger were present but appeared to precede the cold-blooded killings. As a matter of fact, it is argued that the offender carried out the predatory murder in order to alleviate the psychological tension and symptoms generated by these severe ego-dystonic affects. The offender thus didn't seem to strive for narcissistic gratification of omnipotence, but rather seemed to aim to solve a problem.

  20. Male courtship vibrations delay predatory behaviour in female spiders.

    PubMed

    Wignall, Anne E; Herberstein, Marie E

    2013-12-19

    During courtship, individuals transfer information about identity, mating status and quality. However, male web-building spiders face a significant problem: how to begin courting female spiders without being mistaken for prey? Male Argiope spiders generate distinctive courtship vibrations (shudders) when entering a female's web. We tested whether courtship shudders delay female predatory behaviour, even when live prey is present in the web. We presented a live cricket to females during playbacks of shudder vibrations, or white noise, and compared female responses to a control in which we presented a live cricket with no playback vibrations. Females were much slower to respond to crickets during playback of shudder vibrations. Shudder vibrations also delayed female predatory behaviour in a related spider species, showing that these vibrations do not simply function for species identity. These results suggest that male web-building spiders employ a phylogenetically conserved vibratory signal to ameliorate the risk of pre-copulatory cannibalism.

  1. Divergent responses of exposed and naive Pacific tree frog tadpoles to invasive predatory crayfish.

    PubMed

    Pease, Katherine M; Wayne, Robert K

    2014-01-01

    Invasive predators can devastate native species and ecosystems. However, native species may be able to coexist with invasive predators through a variety of mechanisms, such as changes in morphology or behavior due to a plastic response or selection on fixed anti-predator traits. We examined whether exposed and naive populations of Pacific tree frog tadpoles (Pseudacris regilla) display divergent morphological and behavioral traits in response to the invasive predatory red swamp crayfish (Procambarus clarkii). Tadpoles were collected from three study streams with and three without crayfish, in the Santa Monica Mountains of Southern California. We analyzed tadpole morphology and tested anti-predator behavior and survival in the laboratory. Tadpoles from streams with crayfish had shallower, narrower tails than tadpoles from streams without crayfish. Tadpoles from streams with and without crayfish were less active after exposure to crayfish chemical cues. The divergent morphology of naive and exposed tadpoles is consistent with tadpoles exhibiting a plastic response to crayfish or undergoing selection from crayfish predation. In laboratory predation experiments, we found no difference in survival between tadpoles from streams with and without crayfish but tadpoles that survived predation had deeper tail muscles than those that were killed or injured. Our results suggest that deeper tails are advantageous in the presence of crayfish, yet tadpoles from crayfish streams had shallower tails than those from crayfish-free streams. Shallower tails may have an alternative unmeasured advantage or there may be a physiological constraint to developing deeper tails in the wild. These results highlight the ability of a native frog to respond to an invasive predatory crayfish, potentially allowing for coexistence.

  2. Purification and Host Specificity of Predatory Halobacteriovorax Isolates from Seawater.

    PubMed

    Richards, Gary P; Fay, Johnna P; Uknalis, Joseph; Olanya, O Modesto; Watson, Michael A

    2015-11-20

    Halobacteriovorax (formerly Bacteriovorax) is a small predatory bacterium found in the marine environment and modulates bacterial pathogens in shellfish. Four strains of Halobacteriovorax originally isolated in Vibrio parahaemolyticus O3:K6 host cells were separated from their prey by an enrichment-filtration-dilution technique for specificity testing in other bacteria. This technique was essential, since 0.45-μm filtration alone was unable to remove infectious Vibrio minicells, as determined by scanning electron microscopy and cultural methods. Purified Halobacteriovorax strains were screened for predation against other V. parahaemolyticus strains and against Vibrio vulnificus, Vibrio alginolyticus, Escherichia coli O157:H7, and Salmonella enterica serovar Typhimurium DT104, all potential threats to seafood safety. They showed high host specificity and were predatory only against strains of V. parahaemolyticus. In addition, strains of Halobacteriovorax that were predatory for E. coli O157:H7 and S. Typhimurium DT104 were isolated from a tidal river at 5 ppt salinity. In a modified plaque assay agar, they killed their respective prey over a broad range of salinities (5 to 30 ppt). Plaques became smaller as the salinity levels rose, suggesting that the lower salinities were optimal for the predators' replication. These species also showed broader host specificity, infectious against each other's original hosts as well as against V. parahaemolyticus strains. In summary, this study characterized strains of Halobacteriovorax which may be considered for use in the development of broad-based biocontrol technologies to enhance the safety of commercially marketed shellfish and other foods.

  3. Predatory prokaryotes: predation and primary consumption evolved in bacteria

    NASA Technical Reports Server (NTRS)

    Guerrero, R.; Pedros-Alio, C.; Esteve, I.; Mas, J.; Chase, D.; Margulis, L.

    1986-01-01

    Two kinds of predatory bacteria have been observed and characterized by light and electron microscopy in samples from freshwater sulfurous lakes in northeastern Spain. The first bacterium, named Vampirococcus, is Gram-negative and ovoidal (0.6 micrometer wide). An anaerobic epibiont, it adheres to the surface of phototrophic bacteria (Chromatium spp.) by specific attachment structures and, as it grows and divides by fission, destroys its prey. An important in situ predatory role can be inferred for Vampirococcus from direct counts in natural samples. The second bacterium, named Daptobacter, is a Gram-negative, facultatively anaerobic straight rod (0.5 x 1.5 micrometers) with a single polar flagellum, which collides, penetrates, and grows inside the cytoplasm of its prey (several genera of Chromatiaceae). Considering also the well-known case of Bdellovibrio, a Gram-negative, aerobic curved rod that penetrates and divides in the periplasmic space of many chemotrophic Gram-negative bacteria, there are three types of predatory prokaryotes presently known (epibiotic, cytoplasmic, and periplasmic). Thus, we conclude that antagonistic relationships such as primary consumption, predation, and scavenging had already evolved in microbial ecosystems prior to the appearance of eukaryotes. Furthermore, because they represent methods by which prokaryotes can penetrate other prokaryotes in the absence of phagocytosis, these associations can be considered preadaptation for the origin of intracellular organelles.

  4. Predatory fish depletion and recovery potential on Caribbean reefs.

    PubMed

    Valdivia, Abel; Cox, Courtney Ellen; Bruno, John Francis

    2017-03-01

    The natural, prehuman abundance of most large predators is unknown because of the lack of historical data and a limited understanding of the natural factors that control their populations. Determining the supportable predator biomass at a given location (that is, the predator carrying capacity) would help managers to optimize protection and would provide site-specific recovery goals. We assess the relationship between predatory reef fish biomass and several anthropogenic and environmental variables at 39 reefs across the Caribbean to (i) estimate their roles determining local predator biomass and (ii) determine site-specific recovery potential if fishing was eliminated. We show that predatory reef fish biomass tends to be higher in marine reserves but is strongly negatively related to human activities, especially coastal development. However, human activities and natural factors, including reef complexity and prey abundance, explain more than 50% of the spatial variation in predator biomass. Comparing site-specific predator carrying capacities to field observations, we infer that current predatory reef fish biomass is 60 to 90% lower than the potential supportable biomass in most sites, even within most marine reserves. We also found that the scope for recovery varies among reefs by at least an order of magnitude. This suggests that we could underestimate unfished biomass at sites that provide ideal conditions for predators or greatly overestimate that of seemingly predator-depleted sites that may have never supported large predator populations because of suboptimal environmental conditions.

  5. Predatory fish depletion and recovery potential on Caribbean reefs

    PubMed Central

    Valdivia, Abel; Cox, Courtney Ellen; Bruno, John Francis

    2017-01-01

    The natural, prehuman abundance of most large predators is unknown because of the lack of historical data and a limited understanding of the natural factors that control their populations. Determining the supportable predator biomass at a given location (that is, the predator carrying capacity) would help managers to optimize protection and would provide site-specific recovery goals. We assess the relationship between predatory reef fish biomass and several anthropogenic and environmental variables at 39 reefs across the Caribbean to (i) estimate their roles determining local predator biomass and (ii) determine site-specific recovery potential if fishing was eliminated. We show that predatory reef fish biomass tends to be higher in marine reserves but is strongly negatively related to human activities, especially coastal development. However, human activities and natural factors, including reef complexity and prey abundance, explain more than 50% of the spatial variation in predator biomass. Comparing site-specific predator carrying capacities to field observations, we infer that current predatory reef fish biomass is 60 to 90% lower than the potential supportable biomass in most sites, even within most marine reserves. We also found that the scope for recovery varies among reefs by at least an order of magnitude. This suggests that we could underestimate unfished biomass at sites that provide ideal conditions for predators or greatly overestimate that of seemingly predator-depleted sites that may have never supported large predator populations because of suboptimal environmental conditions. PMID:28275730

  6. Habitat changes and changing predatory habits in North American fossil canids.

    PubMed

    Figueirido, B; Martín-Serra, A; Tseng, Z J; Janis, C M

    2015-08-18

    The spread of open grassy habitats and the evolution of long-legged herbivorous mammals with high-crowned cheek teeth have been viewed as an example of coevolution. Previous studies indicate that specialized predatory techniques in carnivores do not correlate with the spread of open habitats in North America. Here we analyse new data on elbow-joint shape for North American canids over the past ∼37 million years and show that incipiently specialized species first appeared along with the initial spread of open habitats in the late Oligocene. Elbow-joint morphologies indicative of the behavior of modern pounce-pursuit predators emerged by the late Miocene coincident with a shift in plant communities from C3 to C4 grasses. Finally, pursuit canids first emerged during the Pleistocene. Our results indicate that climate change and its impact on vegetation and habitat structure can be critical for the emergence of ecological innovations and can alter the direction of lineage evolution.

  7. Purification and Host Specificity of Predatory Halobacteriovorax Isolates from Seawater

    PubMed Central

    Fay, Johnna P.; Uknalis, Joseph; Olanya, O. Modesto; Watson, Michael A.

    2015-01-01

    Halobacteriovorax (formerly Bacteriovorax) is a small predatory bacterium found in the marine environment and modulates bacterial pathogens in shellfish. Four strains of Halobacteriovorax originally isolated in Vibrio parahaemolyticus O3:K6 host cells were separated from their prey by an enrichment-filtration-dilution technique for specificity testing in other bacteria. This technique was essential, since 0.45-μm filtration alone was unable to remove infectious Vibrio minicells, as determined by scanning electron microscopy and cultural methods. Purified Halobacteriovorax strains were screened for predation against other V. parahaemolyticus strains and against Vibrio vulnificus, Vibrio alginolyticus, Escherichia coli O157:H7, and Salmonella enterica serovar Typhimurium DT104, all potential threats to seafood safety. They showed high host specificity and were predatory only against strains of V. parahaemolyticus. In addition, strains of Halobacteriovorax that were predatory for E. coli O157:H7 and S. Typhimurium DT104 were isolated from a tidal river at 5 ppt salinity. In a modified plaque assay agar, they killed their respective prey over a broad range of salinities (5 to 30 ppt). Plaques became smaller as the salinity levels rose, suggesting that the lower salinities were optimal for the predators' replication. These species also showed broader host specificity, infectious against each other's original hosts as well as against V. parahaemolyticus strains. In summary, this study characterized strains of Halobacteriovorax which may be considered for use in the development of broad-based biocontrol technologies to enhance the safety of commercially marketed shellfish and other foods. PMID:26590288

  8. Initiation of Chromosomal Replication in Predatory Bacterium Bdellovibrio bacteriovorus

    PubMed Central

    Makowski, Łukasz; Donczew, Rafał; Weigel, Christoph; Zawilak-Pawlik, Anna; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase) and replicating cells (the intracellular-growth phase). The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although, we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC) is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box [5′-NN(A/T)TCCACA-3′]. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus). We compared the architecture of the DnaA–oriC complexes (orisomes) in homologous (oriC and DnaA from B. bacteriovorus) and heterologous (BdoriC and DnaA from prey, Escherichia coli or Pseudomonas aeruginosa) systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium. PMID:27965633

  9. Predatory Odor Disrupts Social Novelty Preference in Long-Evans Rats

    ERIC Educational Resources Information Center

    Anderson, Matthew J.; Layton, William B.

    2012-01-01

    The present study examined the effects of predatory odor (cat urine) on social novelty preference in Long-Evans rats. Adult male subjects encountered a juvenile conspecific at training, were exposed to either clean cat litter (control) or litter soiled with cat urine (predatory odor), and were tested for social novelty preference. While the…

  10. Body condition predicts energy stores in apex predatory sharks

    PubMed Central

    Gallagher, Austin J.; Wagner, Dominique N.; Irschick, Duncan J.; Hammerschlag, Neil

    2014-01-01

    Animal condition typically reflects the accumulation of energy stores (e.g. fatty acids), which can influence an individual's decision to undertake challenging life-history events, such as migration and reproduction. Accordingly, researchers often use measures of animal body size and/or weight as an index of condition. However, values of condition, such as fatty acid levels, may not always reflect the physiological state of animals accurately. While the relationships between condition indices and energy stores have been explored in some species (e.g. birds), they have yet to be examined in top predatory fishes, which often undertake extensive and energetically expensive migrations. We used an apex predatory shark (Galeocerdo cuvier, the tiger shark) as a model species to evaluate the relationship between triglycerides (energy metabolite) and a metric of overall body condition. We captured, blood sampled, measured and released 28 sharks (size range 125–303 cm pre-caudal length). In the laboratory, we assayed each plasma sample for triglyceride values. We detected a positive and significant relationship between condition and triglyceride values (P < 0.02). This result may have conservation implications if the largest and highest-condition sharks are exploited in fisheries, because these individuals are likely to have the highest potential for successful reproduction. Our results suggest that researchers may use either plasma triglyceride values or an appropriate measure of body condition for assessing health in large sharks. PMID:27293643

  11. Loss of large predatory sharks from the Mediterranean Sea.

    PubMed

    Ferretti, Francesco; Myers, Ransom A; Serena, Fabrizio; Lotze, Heike K

    2008-08-01

    Evidence for severe declines in large predatory fishes is increasing around the world. Because of its long history of intense fishing, the Mediterranean Sea offers a unique perspective on fish population declines over historical timescales. We used a diverse set of records dating back to the early 19th and mid 20th century to reconstruct long-term population trends of large predatory sharks in the northwestern Mediterranean Sea. We compiled 9 time series of abundance indices from commercial and recreational fishery landings, scientific surveys, and sighting records. Generalized linear models were used to extract instantaneous rates of change from each data set, and a meta-analysis was conducted to compare population trends. Only 5 of the 20 species we considered had sufficient records for analysis. Hammerhead (Sphyrna spp.), blue (Prionace glauca), mackerel (Isurus oxyrinchus and Lamna nasus), and thresher sharks (Alopias vulpinus) declined between 96 and 99.99% relative to their former abundance. According to World Conservation Union (IUCN) criteria, these species would be considered critically endangered. So far, the lack of quantitative population assessments has impeded shark conservation in the Mediterranean Sea. Our study fills this critical information gap, suggesting that current levels of exploitation put large sharks at risk of extinction in the Mediterranean Sea. Possible ecosystem effects of these losses involve a disruption of top-down control and a release of midlevel consumers.

  12. Effect of predatory bacteria on the gut bacterial microbiota in rats

    PubMed Central

    Shatzkes, Kenneth; Tang, Chi; Singleton, Eric; Shukla, Sean; Zuena, Michael; Gupta, Shilpi; Dharani, Sonal; Rinaggio, Joseph; Connell, Nancy D.; Kadouri, Daniel E.

    2017-01-01

    Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are Gram-negative proteobacteria that are obligate predators of other Gram-negative bacteria and are considered potential alternatives to antibiotics. Most studies focusing on predatory bacteria have been performed in vitro, thus the effect of predatory bacteria on a live host, including the impact on the ecology of the native microbiota, has yet to be fully examined. In this study, intrarectal inoculations of Sprague-Dawley rats with predatory bacteria were performed. Additionally, feces were collected for seven days post-inoculation to determine the effect on gut bacterial diversity. Rat colonic tissue exhibited no abnormal histopathological effects due to predatory bacteria. A modest increase in pro-inflammatory cytokines was measured in the colons of rats inoculated with predatory bacteria by 24 and 48 hours, with all but IL-13 returning to baseline by seven days. V4 16S rRNA gene sequencing of fecal DNA demonstrated minimal shifts in taxonomic representation over the week due to predatory bacteria. Changes in bacterial populations due to exposure to B. bacteriovorus are predicted to contribute to health, however, an overgrowth of Prevotella was observed due to exposure to M. aeruginosavorus. This study further addresses safety concerns associated with the potential use of predatory bacteria to treat infections. PMID:28262674

  13. Effect of predatory bacteria on the gut bacterial microbiota in rats.

    PubMed

    Shatzkes, Kenneth; Tang, Chi; Singleton, Eric; Shukla, Sean; Zuena, Michael; Gupta, Shilpi; Dharani, Sonal; Rinaggio, Joseph; Connell, Nancy D; Kadouri, Daniel E

    2017-03-06

    Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are Gram-negative proteobacteria that are obligate predators of other Gram-negative bacteria and are considered potential alternatives to antibiotics. Most studies focusing on predatory bacteria have been performed in vitro, thus the effect of predatory bacteria on a live host, including the impact on the ecology of the native microbiota, has yet to be fully examined. In this study, intrarectal inoculations of Sprague-Dawley rats with predatory bacteria were performed. Additionally, feces were collected for seven days post-inoculation to determine the effect on gut bacterial diversity. Rat colonic tissue exhibited no abnormal histopathological effects due to predatory bacteria. A modest increase in pro-inflammatory cytokines was measured in the colons of rats inoculated with predatory bacteria by 24 and 48 hours, with all but IL-13 returning to baseline by seven days. V4 16S rRNA gene sequencing of fecal DNA demonstrated minimal shifts in taxonomic representation over the week due to predatory bacteria. Changes in bacterial populations due to exposure to B. bacteriovorus are predicted to contribute to health, however, an overgrowth of Prevotella was observed due to exposure to M. aeruginosavorus. This study further addresses safety concerns associated with the potential use of predatory bacteria to treat infections.

  14. Susceptibility of Select Agents to Predation by Predatory Bacteria

    PubMed Central

    Russo, Riccardo; Chae, Richard; Mukherjee, Somdatta; Singleton, Eric J.; Occi, James L.; Kadouri, Daniel E.; Connell, Nancy D.

    2015-01-01

    Select Agents are microorganisms and toxins considered to be exploitable as biological weapons. Although infections by many Select Agents can be treated by conventional antibiotics, the risk of an emerging or engineered drug resistant strain is of great concern. One group of microorganisms that is showing potential to control drug resistant Gram-negative bacteria are the predatory bacteria from the genera Bdellovibrio spp. and Micavibrio spp. In this study, we have examined the ability of Bdellovibrio bacteriovorus (B. bacteriovorus) strain 109J, HD100 and Micavibrio aeruginosavorus (M. aeruginosavorus) ARL-13 to prey on a variety of Select Agents. Our findings demonstrate that B. bacteriovorus and M. aeruginosavorus are able to prey efficiently on Yersinia pestis and Burkholderia mallei. Modest predation was also measured in co-cultures of B. bacteriovorus and Francisella tularensis. However, neither of the predators showed predation when Burkholderia pseudomallei and Brucella melitensis were used as prey. PMID:27682124

  15. Constitutive and Operational Variation of Learning in Foraging Predatory Mites

    PubMed Central

    Seiter, Michael

    2016-01-01

    Learning is widely documented across animal taxa but studies stringently scrutinizing the causes of constitutive or operational variation of learning among populations and individuals are scarce. The ability to learn is genetically determined and subject to constitutive variation while the performance in learning depends on the immediate circumstances and is subject to operational variation. We assessed variation in learning ability and performance of plant-inhabiting predatory mites, Amblyseius swirskii, caused by population origin, rearing diet, and type of experience. Using an early learning foraging paradigm, we determined that homogeneous single prey environments did not select for reduced learning ability, as compared to natural prey-diverse environments, whereas a multi-generational pollen diet resulted in loss of learning, as compared to a diet of live prey. Associative learning produced stronger effects than non-associative learning but both types of experience produced persistent memory. Our study represents a key example of environmentally caused variation in learning ability and performance. PMID:27814380

  16. Optimal foraging for specific nutrients in predatory beetles.

    PubMed

    Jensen, Kim; Mayntz, David; Toft, Søren; Clissold, Fiona J; Hunt, John; Raubenheimer, David; Simpson, Stephen J

    2012-06-07

    Evolutionary theory predicts that animals should forage to maximize their fitness, which in predators is traditionally assumed equivalent to maximizing energy intake rather than balancing the intake of specific nutrients. We restricted female predatory ground beetles (Anchomenus dorsalis) to one of a range of diets varying in lipid and protein content, and showed that total egg production peaked at a target intake of both nutrients. Other beetles given a choice to feed from two diets differing only in protein and lipid composition selectively ingested nutrient combinations at this target intake. When restricted to nutritionally imbalanced diets, beetles balanced the over- and under-ingestion of lipid and protein around a nutrient composition that maximized egg production under those constrained circumstances. Selective foraging for specific nutrients in this predator thus maximizes its reproductive performance. Our findings have implications for predator foraging behaviour and in the structuring of ecological communities.

  17. Evidence for predatory control of the invasive round goby

    USGS Publications Warehouse

    Madenjian, C.P.; Stapanian, M.A.; Witzel, L.D.; Einhouse, D.W.; Pothoven, S.A.; Whitford, H.L.

    2011-01-01

    We coupled bioenergetics modeling with bottom trawl survey results to evaluate the capacity of piscivorous fish in eastern Lake Erie to exert predatory control of the invading population of round goby Neogobius melanostomus. In the offshore (>20 m deep) waters of eastern Lake Erie, burbot Lota lota is a native top predator, feeding on a suite of prey fishes. The round goby invaded eastern Lake Erie during the late 1990s, and round goby population size increased dramatically during 1999–2004. According to annual bottom trawl survey results, round goby abundance in offshore waters peaked in 2004, but then declined during 2004–2008. Coincidentally, round goby became an important component of burbot diet beginning in 2003. Using bottom trawling and gill netting, we estimated adult burbot abundance and age structure in eastern Lake Erie during 2007. Diet composition and energy density of eastern Lake Erie burbot were also determined during 2007. This information, along with estimates of burbot growth, burbot mortality, burbot water temperature regime, and energy densities of prey fish from the literature, were incorporated into a bioenergetics model application to estimate annual consumption of round goby by the adult burbot population. Results indicated that the adult burbot population in eastern Lake Erie annually consumed 1,361 metric tons of round goby. Based on the results of bottom trawling, we estimated the biomass of yearling and older round goby in offshore waters eastern Lake Erie during 2007–2008 to be 2,232 metric tons. Thus, the adult burbot population was feeding on round goby at an annual rate equal to 61% of the estimated round goby standing stock. We concluded that the burbot population had high potential to exert predatory control on round goby in offshore waters of eastern Lake Erie.

  18. Topography and morphology of retinal ganglion cells in Falconiforms: a study on predatory and carrion-eating birds.

    PubMed

    Inzunza, O; Bravo, H; Smith, R L; Angel, M

    1991-02-01

    The topographic distribution of retinal ganglion cells and their cell body size have been studied in five Falconiform species, including predatory (chilean eagle Buteo fuscenses australis, and sparrow hawk Falco sparverius) and carrion-eating (chimango caracara Milvago chimango; condor Vultur gryphus, and black vulture Coragyps atratus) birds. All these species had a well defined nasal fovea and a horizontal streak. Instead of a temporal fovea as in eagles and hawks, an afoveate temporal area is present in chimango, condor, and vulture. The highest ganglion cell density was found in the nasal fovea of Falco and Buteo with 65,000 and 62,000 cells/mm2, respectively. A negative correlation between ganglion cell density and cell body size was found in all the species studied. The specializations of the temporal retina showed a rather homogenous population of medium sized neurons, while the nasal foveas showed a homogeneous population of smaller ganglion cells. Finally, the peripheral retina showed a heterogeneous population of large, medium, and small ganglion cells. Predatory behavior appears to be closely related to foveal specializations, and is best exemplified in the eagle and hawk and to a lesser extent in the chimango.

  19. Influence of diet conditions on predation response of a predatory mite to a polyphagous insect pest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), an invasive polyphagous species, is an economically important pest. A modified standard petri dish assay method was employed to examine the functional response and predation capacity of predatory mites (Amblyseius swirskii Anthias-...

  20. Detection of plant-parasitic nematode DNA in the gut of predatory and omnivorous nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A protocol for molecular gut analysis of nematodes was developed to determine if predatory and omnivorous nematodes from five different guilds prey on Rotylenchulus reniformis, Meloidogyne incognita, and Radopholus similis. Mononchoides, Mononchus, Neoactinolaimus, Mesodorylaimus, and Aporcelaimell...

  1. The Pressure to Publish More and the Scope of Predatory Publishing Activities.

    PubMed

    Gasparyan, Armen Yuri; Nurmashev, Bekaidar; Voronov, Alexander A; Gerasimov, Alexey N; Koroleva, Anna M; Kitas, George D

    2016-12-01

    This article overviews unethical publishing practices in connection with the pressure to publish more. Both open-access and subscription publishing models can be abused by 'predatory' authors, editors, and publishing outlets. Relevant examples of 'prolific' scholars are viewed through the prism of the violation of ethical authorship in established journals and indiscriminately boosting publication records elsewhere. The instances of ethical transgressions by brokering editorial agencies and agents, operating predominantly in non-Anglophone countries, are presented to raise awareness of predatory activities. The scheme of predatory publishing activities is presented, and several measures are proposed to tackle the issue of predatory publishing. The awareness campaigns by professional societies, consultations with information facilitators, implementation of the criteria of best target journals, and crediting of scholars with use of integrative citation metrics, such as the h-index, are believed to make a difference.

  2. [Predatory journals: how their publishers operate and how to avoid them].

    PubMed

    Kratochvíl, Jiří; Plch, Lukáš

    2017-01-01

    Authors who publish in scientific or scholarly journals today face the risk of publishing in so-called predatory journals. These journals exploit the noble idea of the Open Access movement, whose goal is to make the latest scientific findings available for free. Predatory journals, unlike the reputable ones working on an Open Access basis, neglect the review process and publish low-quality submissions. The basic attributes of predatory journals are a very quick review process or even none at all, failure to be transparent about author fees for publishing an article, misleading potential authors by imitating the names of well-established journals, and false information on indexing in renowned databases or assigned impact factor. Some preventive measures against publishing in predatory journals or drawing information from them are: a thorough credibility check of the journals webpages, verification of the journals indexing on Bealls List and in the following databases: Web of Science Core Collection, Scopus, ERIH PLUS and DOAJ. Asking other scientists or scholars about their experience with a given journal can also be helpful. Without these necessary steps authors face an increased risk of publishing in a journal of poor quality, which will prevent them from obtaining Research and Development Council points (awarded based on the Information Register of Research & Development results); even more importantly, it may damage their reputation as well as the good name of their home institution in the professional community.Key words: academic writing - medical journals - Open Access - predatory journals - predatory publishers - scientific publications.

  3. Selective prey avoidance learning in the predatory sea slug Pleurobranchaea californica.

    PubMed

    Noboa, Vanessa; Gillette, Rhanor

    2013-09-01

    Predator-prey interactions involving aposematic signaling, where predators learn the warning cues of well-defended prey, are clear examples of cost-benefit decisions in foraging animals. However, knowledge of the selectivity of predator learning and the natural conditions where it occurs is lacking for those foragers simpler in brain and body plan. We pursued the question in the sea slug Pleurobranchaea californica, a generalist forager of marked simplicity of body form, nervous system and behavior. This predator exploits many different types of prey, some of which are costly to attack. When offered Flabellina iodinea, an aeolid nudibranch with a stinging defense, biting attack was followed by rapid rejection and aversive turns. The predatory sea slug rapidly learned avoidance. Notable exceptions were animals with extremely high or low feeding thresholds that either ignored F. iodinea or completely consumed it, respectively. Experienced slugs showed strong avoidance of F. iodinea for days after exposure. Aposematic odor learning was selective: avoidance was not linked to change in feeding thresholds, and trained animals readily attacked and consumed a related aeolid, Hermissenda crassicornis. For P. californica, aposematic learning is a cognitive adaptation in which sensation, motivation and memory are integrated to direct cost-benefit choice, and thereby lend flexibility to the generalist's foraging strategy.

  4. Comparative morphology of the odoriferous system in three predatory stink bugs (Heteroptera: Asopinae).

    PubMed

    Martínez, Luis Carlos; Plata-Rueda, Angelica; Zanuncio, José Cola; Tavares, Wagner de Souza; Serrão, José Eduardo

    2017-02-25

    The metathoracic scent system in Heteroptera produces and releases defensive volatile compounds. The odor produced by predatory stink bugs differs from phytophagous bugs, suggesting a variation between the structure and function of the metathoracic scent system. The anatomy and ultrastructure of the external thoracic efferent system, scent gland, and reservoir in the stink bug predators Brontocoris tabidus, Podisus nigrispinus, and Supputius cincticeps (Heteroptera: Pentatomidae: Asopinae) were studied. External thoracic efferent systems of B. tabidus, P. nigrispinus, and S. cincticeps have anatomical differences in ostiole, peritreme, and evaporatorium. Scent glands have a secretory portion and a reservoir. The reservoir has irregular projections, and in B. tabidus, it is enlarged and heart shaped, whereas in P. nigrispinus and S. cincticeps it is flattened and semicircular. The secretory tissue of the scent gland has well-developed globular secretory cells that produce odorous compounds, and the reservoir has a single layer of cubical cells lined by a cuticular intima. Secretory cells are type III with an intracellular end apparatus, well-developed nucleus with decondensed chromatin, and cytoplasm rich in mitochondria, lysosomes, granules, and smooth endoplasmic reticulum. These findings suggest that there are differences in physiological function of the odoriferous system and the volatile compounds produced by the secretory cells, which may indicate variation in defensive behavior of these species.

  5. Mucus trail tracking in a predatory snail: olfactory processing retooled to serve a novel sensory modality

    PubMed Central

    Patel, Kinjal; Shaheen, Nagma; Witherspoon, Jessica; Robinson, Natallia; Harrington, Melissa A

    2014-01-01

    Introduction The rosy wolfsnail (Euglandina rosea), a predatory land snail, finds prey snails and potential mates by following their mucus trails. Euglandina have evolved unique, mobile lip extensions that detect mucus and aid in following trails. Currently, little is known of the neural substrates of the trail-following behavior. Methods To investigate the neural correlates of trail following we used tract-tracing experiments in which nerves were backfilled with either nickel-lysine or Lucifer yellow, extracellular recording of spiking neurons in snail procerebra using a multielectrode array, and behavioral assays of trail following and movement toward the source of a conditioned odor. Results The tract-tracing experiments demonstrate that in Euglandina, the nerves carrying mucus signals innervate the same region of the central ganglia as the olfactory nerves, while the electrophysiology studies show that mucus stimulation of the sensory epithelium on the lip extensions alters the frequency and pattern of neural activity in the procerebrum in a manner similar to odor stimulation of the olfactory epithelium on the optic tentacles of another land snail species, Cantareus aspersa (previously known as Helix aspersa). While Euglandina learn to follow trails of novel chemicals that they contact with their lip extensions in one to three trials, these snails proved remarkably resistant to associative learning in the olfactory modality. Even after seven to nine pairings of odorant molecules with food, they showed no orientation toward the conditioned odor. This is in marked contrast to Cantareus snails, which reliably oriented toward conditioned odors after two to three trials. Conclusions The apparent inability of Euglandina to learn to associate food with odors and use odor cues to drive behavior suggests that the capability for sophisticated neural processing of nonvolatile mucus cues detected by the lip extensions has evolved at the expense of processing of odorant

  6. The ubiquity of intraguild predation among predatory arthropods.

    PubMed

    Gagnon, Annie-Ève; Heimpel, George E; Brodeur, Jacques

    2011-01-01

    Intraguild predation (IGP) occurs when one predator species attacks another predator species with which it competes for a shared prey species. Despite the apparent omnipresence of intraguild interactions in natural and managed ecosystems, very few studies have quantified rates of IGP in various taxa under field conditions. We used molecular analyses of gut contents to assess the nature and incidence of IGP among four species of coccinellid predators in soybean fields. Over half of the 368 predator individuals collected in soybean contained the DNA of other coccinellid species indicating that IGP was very common at our field site. Furthermore, 13.2% of the sampled individuals contained two and even three other coccinellid species in their gut. The interaction was reciprocal, as each of the four coccinellid species has the capacity to feed on the others. To our knowledge, this study represents the most convincing field evidence of a high prevalence of IGP among predatory arthropods. The finding has important implications for conservation biology and biological control.

  7. Prey-Induced Swimming Dynamics Changes among Predatory Algae

    NASA Astrophysics Data System (ADS)

    Katz, J.; Sheng, J.; Malkiel, E.; Adolf, J.; Place, A.; Belas, R.

    2007-11-01

    High speed, cinematic digital holographic microscopy allows us to track thousands of microorganisms over a volume with substantial depth without loss of resolution. This technique enables us, for the first time, to examine, measure and characterize the swimming dynamics of microorganisms located within dense suspensions. The present experiments examine dense populations of predatory algae, K. veneficum and P. piscicida, prior to and after introducing prey. Swimming dynamics are characterized by radius and pitch of helical swimming trajectories, by translational and angular velocity, and their velocity spectra. K. veneficum moves in both left and right hand helices, while P. piscicida swims only in right hand helices. The radii increase with increasing velocity for both cases. Presented with its prey, K. veneficum reduces its velocity, radius and pitch, but increases its angular velocity. Conversely, P. piscicida increases its speed, radius and angular velocity. Power spectra of velocity reveal differences between scales of vertical velocity and those of horizontal components. Power spectra of velocity component aligned with the helix centerline reveals a shift in K. veneficum's swimming strategy from almost random-walk to a levy-walk as prey is introduced. P. piscicida always displays clear preference towards levy-walk, but spectral slope increases as prey is introduced.

  8. Conserving herbivorous and predatory insects in urban green spaces

    PubMed Central

    Mata, Luis; Threlfall, Caragh G.; Williams, Nicholas S. G.; Hahs, Amy K.; Malipatil, Mallik; Stork, Nigel E.; Livesley, Stephen J.

    2017-01-01

    Insects are key components of urban ecological networks and are greatly impacted by anthropogenic activities. Yet, few studies have examined how insect functional groups respond to changes to urban vegetation associated with different management actions. We investigated the response of herbivorous and predatory heteropteran bugs to differences in vegetation structure and diversity in golf courses, gardens and parks. We assessed how the species richness of these groups varied amongst green space types, and the effect of vegetation volume and plant diversity on trophic- and species-specific occupancy. We found that golf courses sustain higher species richness of herbivores and predators than parks and gardens. At the trophic- and species-specific levels, herbivores and predators show strong positive responses to vegetation volume. The effect of plant diversity, however, is distinctly species-specific, with species showing both positive and negative responses. Our findings further suggest that high occupancy of bugs is obtained in green spaces with specific combinations of vegetation structure and diversity. The challenge for managers is to boost green space conservation value through actions promoting synergistic combinations of vegetation structure and diversity. Tackling this conservation challenge could provide enormous benefits for other elements of urban ecological networks and people that live in cities. PMID:28102333

  9. Conserving herbivorous and predatory insects in urban green spaces.

    PubMed

    Mata, Luis; Threlfall, Caragh G; Williams, Nicholas S G; Hahs, Amy K; Malipatil, Mallik; Stork, Nigel E; Livesley, Stephen J

    2017-01-19

    Insects are key components of urban ecological networks and are greatly impacted by anthropogenic activities. Yet, few studies have examined how insect functional groups respond to changes to urban vegetation associated with different management actions. We investigated the response of herbivorous and predatory heteropteran bugs to differences in vegetation structure and diversity in golf courses, gardens and parks. We assessed how the species richness of these groups varied amongst green space types, and the effect of vegetation volume and plant diversity on trophic- and species-specific occupancy. We found that golf courses sustain higher species richness of herbivores and predators than parks and gardens. At the trophic- and species-specific levels, herbivores and predators show strong positive responses to vegetation volume. The effect of plant diversity, however, is distinctly species-specific, with species showing both positive and negative responses. Our findings further suggest that high occupancy of bugs is obtained in green spaces with specific combinations of vegetation structure and diversity. The challenge for managers is to boost green space conservation value through actions promoting synergistic combinations of vegetation structure and diversity. Tackling this conservation challenge could provide enormous benefits for other elements of urban ecological networks and people that live in cities.

  10. The impact of coffee and pasture agriculture on predatory and omnivorous leaf-litter ants.

    PubMed

    Dias, Nivia da Silva; Zanetti, Ronald; Santos, Mônica Silva; Peñaflor, Maria Fernanda Gomes Villalba; Broglio, Sônia Maria Forti; Delabie, Jacques Hubert Charles

    2013-01-01

    Ants are known to function as reliable biological indicators for habitat impact assessment. They play a wide range of ecological roles depending on their feeding and nesting habits. By clustering ants in guilds, it is possible both to assess how agriculture and forest fragmentation can disturb ant communities and to predict the ecological impacts due to losses of a specific guild. This study aimed at determining the impact of non-shaded coffee and pasture agriculture on predatory and omnivorous guilds of leaf-litter ants of Atlantic Forest fragments in Minas Gerais, Brazil. Both coffee and pasture agriculture influenced leaf-litter ant community, although coffee was more disruptive than pasture. Coffee agriculture not only disturbed the diversity of predatory ants, but also negatively affected the number of predatory and omnivorous ants when compared to forest fragments. In contrast, pasture agriculture only disrupted the abundance of predatory ants. Fragment edges skirting crops were negatively affected in terms of leaf-litter ant abundance, but not diversity. Cluster analysis showed that forest fragments were similar irrespective of the cultivation, but the borders were similar to the crop. The study assessed agriculture impact by surveying ant guilds, and revealed that the predatory guild is more susceptible than omnivorous ants.

  11. Neural mechanisms of predatory aggression in rats-implications for abnormal intraspecific aggression.

    PubMed

    Tulogdi, Aron; Biro, Laszlo; Barsvari, Beata; Stankovic, Mona; Haller, Jozsef; Toth, Mate

    2015-04-15

    Our recent studies showed that brain areas that are activated in a model of escalated aggression overlap with those that promote predatory aggression in cats. This finding raised the interesting possibility that the brain mechanisms that control certain types of abnormal aggression include those involved in predation. However, the mechanisms of predatory aggression are poorly known in rats, a species that is in many respects different from cats. To get more insights into such mechanisms, here we studied the brain activation patterns associated with spontaneous muricide in rats. Subjects not exposed to mice, and those which did not show muricide were used as controls. We found that muricide increased the activation of the central and basolateral amygdala, and lateral hypothalamus as compared to both controls; in addition, a ventral shift in periaqueductal gray activation was observed. Interestingly, these are the brain regions from where predatory aggression can be elicited, or enhanced by electrical stimulation in cats. The analysis of more than 10 other brain regions showed that brain areas that inhibited (or were neutral to) cat predatory aggression were not affected by muricide. Brain activation patterns partly overlapped with those seen earlier in the cockroach hunting model of rat predatory aggression, and were highly similar with those observed in the glucocorticoid dysfunction model of escalated aggression. These findings show that the brain mechanisms underlying predation are evolutionarily conservative, and indirectly support our earlier assumption regarding the involvement of predation-related brain mechanisms in certain forms of escalated social aggression in rats.

  12. Role of supplemental foods and habitat structural complexity in persistence and coexistence of generalist predatory mites.

    PubMed

    Pozzebon, Alberto; Loeb, Gregory M; Duso, Carlo

    2015-10-09

    Plant traits can influence the interactions between herbivore arthropods and their natural enemies. In these interactions generalist predators are often present, preying on herbivores and also on other arthropods in the same trophic guild. Variation in the strength of intraguild predation (IGP) may be related to habitat structural complexity and to additional resources outside the narrow predator-prey relationship. In this paper we study the food web interactions on grape, which involves two generalist predatory mites. We evaluated the effects of grape powdery mildew (GPM) as supplemental food, and habitat structural complexity provided by domatia. The inoculation of GPM resulted in higher predatory mite densities and reduced the negative impact of unfavorable leaf structure for one species. Access to domatia was the main factor in promoting population abundance and persistence of predatory mites. Access to domatia and GPM availability favored the coexistence of predatory mites at a low density of the intraguild prey. Our findings suggest that structural and nutritional diversity/complexity promote predatory mite abundance and can help to maintain the beneficial mites - plants association. The effect of these factors on coexistence between predators is influenced by the supplemental food quality and relative differences in body size of interacting species.

  13. Predatory feeding behaviour in Pristionchus nematodes is dependent on phenotypic plasticity and induced by serotonin.

    PubMed

    Wilecki, Martin; Lightfoot, James W; Susoy, Vladislav; Sommer, Ralf J

    2015-05-01

    Behavioural innovation and morphological adaptation are intrinsically linked but their relationship is often poorly understood. In nematodes, a huge diversity of feeding morphologies and behaviours can be observed to meet their distinctive dietary and environmental demands. Pristionchus and their relatives show varied feeding activities, both consuming bacteria and also predating other nematodes. In addition, Pristionchus nematodes display dimorphic mouth structures triggered by an irreversible developmental switch, which generates a narrower mouthed form with a single tooth and a wider mouthed form with an additional tooth. However, little is known about the specific predatory adaptations of these mouth forms or the associated mechanisms and behaviours. Through a mechanistic analysis of predation behaviours, in particular in the model organism Pristionchus pacificus, we reveal multifaceted feeding modes characterised by dynamic rhythmic switching and tooth stimulation. This complex feeding mode switch is regulated by the neurotransmitter serotonin in a previously uncharacterised role, a process that appears conserved across several predatory nematode species. Furthermore, we investigated the effects of starvation, prey size and prey preference on P. pacificus predatory feeding kinetics, revealing predation to be a fundamental component of the P. pacificus feeding repertoire, thus providing an additional rich source of nutrition in addition to bacteria. Finally, we found that mouth form morphology also has a striking impact on predation, suppressing predatory behaviour in the narrow mouthed form. Our results therefore hint at the regulatory networks involved in controlling predatory feeding and underscore P. pacificus as a model for understanding the evolution of complex behaviours.

  14. The Impact of Coffee and Pasture Agriculture on Predatory and Omnivorous Leaf-Litter Ants

    PubMed Central

    Dias, Nivia da Silva; Zanetti, Ronald; Santos, Mônica Silva; Peñaflor, Maria Fernanda Gomes Villalba; Broglio, Sônia Maria Forti; Delabie, Jacques Hubert Charles

    2013-01-01

    Ants are known to function as reliable biological indicators for habitat impact assessment. They play a wide range of ecological roles depending on their feeding and nesting habits. By clustering ants in guilds, it is possible both to assess how agriculture and forest fragmentation can disturb ant communities and to predict the ecological impacts due to losses of a specific guild. This study aimed at determining the impact of non-shaded coffee and pasture agriculture on predatory and omnivorous guilds of leaf-litter ants of Atlantic Forest fragments in Minas Gerais, Brazil. Both coffee and pasture agriculture influenced leaf-litter ant community, although coffee was more disruptive than pasture. Coffee agriculture not only disturbed the diversity of predatory ants, but also negatively affected the number of predatory and omnivorous ants when compared to forest fragments. In contrast, pasture agriculture only disrupted the abundance of predatory ants. Fragment edges skirting crops were negatively affected in terms of leaf-litter ant abundance, but not diversity. Cluster analysis showed that forest fragments were similar irrespective of the cultivation, but the borders were similar to the crop. The study assessed agriculture impact by surveying ant guilds, and revealed that the predatory guild is more susceptible than omnivorous ants. PMID:23902334

  15. Impacts of Synergy-505 on the Functional Response and Behavior of the Reduviid Bug, Rhynocoris marginatus

    PubMed Central

    Ambrose, D. P.; Rajan, S. J.; Raja, J. M.

    2010-01-01

    The impact of the insecticide, Synergy-505 (chlorpyrifos 50% and cypermethrin 5% E.C), on the functional response, predatory behavior, and mating behavior of a non-target reduviid, Rhynocoris marginatus (Fabricius) (Hemiptera: Reduviidae), a potential biological control agent, were studied. Though both normal and Synergy-505-exposed R. marginatus exhibited Holling's type II curvilinear functional response, Synergy-505 caused a less pronounced type II functional response with reduced numbers of prey killed, attack rate, searching time, and prolonged handling time in 4th and 5th nymphal instars and adult males and females reflecting reduced predatory potential. Synergy-505 also delayed the predatory and mating events. The impacts of Synergy-505 on functional response, predatory behavior, and mating behavior were more evident at higher concentrations of Synergy-505. PMID:21265616

  16. Maize Benefits the Predatory Beetle, Propylea japonica (Thunberg), to Provide Potential to Enhance Biological Control for Aphids in Cotton

    PubMed Central

    Ouyang, Fang; Men, Xingyuan; Yang, Bing; Su, Jianwei; Zhang, Yongsheng; Zhao, Zihua; Ge, Feng

    2012-01-01

    Background Biological control provided by natural enemies play an important role in integrated pest management. Generalist insect predators provide an important biological service in the regulation of agricultural insect pests. Our goal is to understand the explicit process of oviposition preference, habitat selection and feeding behavior of predators in farmland ecosystem consisting of multiple crops, which is central to devising and delivering an integrated pest management program. Methodology The hypotheses was that maize can serve as habitat for natural enemies and benefits predators to provide potential to enhance biological control for pest insects in cotton. This explicit process of a predatory beetle, Propylea japonica, in agricultural ecosystem composed of cotton and maize were examined by field investigation and stable carbon isotope analysis during 2008–2010. Principal Finding Field investigation showed that P. japonica adults will search host plants for high prey abundance before laying eggs, indicating indirectly that P. japonica adults prefer to inhabit maize plants and travel to cotton plants to actively prey on aphids. The δ13C values of adult P. japonica in a dietary shift experiment found that individual beetles were shifting from a C3- to a C4-based diet of aphids reared on maize or cotton, respectively, and began to reflect the isotope ratio of their new C4 resources within one week. Approximately 80–100% of the diet of P. japonica adults in maize originated from a C3-based resource in June, July and August, while approximately 80% of the diet originated from a C4-based resource in September. Conclusion/Significance Results suggest that maize can serve as a habitat or refuge source for the predatory beetle, P. japonica, and benefits predators to provide potential to enhance biological control for insect pests in cotton. PMID:22984499

  17. The Dark Side of Dissemination: Traditional and Open Access Versus Predatory Journals

    PubMed Central

    Masten, Yondell B.; Ashcraft, Alyce S.

    2016-01-01

    Abstract AIM The purpose of the article is to alert faculty about predatory online journals, review characteristics of three broad categories of journals, and provide suggestions for faculty evaluation of journals before submission of scholarship for publication. BACKGROUND The availability of online journals in recent years has rapidly increased the number of journals available for publication of faculty scholarship. However, not all online journals meet the same standards as traditional journals. METHOD The article is not a report for a research study. RESULTS Currently, there are three broad categories of journals for faculty scholarship publication: traditional, open access scholarly, and predatory open access journals. CONCLUSION Faculty authors need to carefully evaluate the journal characteristics and publisher business practices before submitting a manuscript for publication to prevent inadvertent submission to a predatory open access journal. PMID:27740559

  18. The Pressure to Publish More and the Scope of Predatory Publishing Activities

    PubMed Central

    Nurmashev, Bekaidar

    2016-01-01

    This article overviews unethical publishing practices in connection with the pressure to publish more. Both open-access and subscription publishing models can be abused by ‘predatory’ authors, editors, and publishing outlets. Relevant examples of ‘prolific’ scholars are viewed through the prism of the violation of ethical authorship in established journals and indiscriminately boosting publication records elsewhere. The instances of ethical transgressions by brokering editorial agencies and agents, operating predominantly in non-Anglophone countries, are presented to raise awareness of predatory activities. The scheme of predatory publishing activities is presented, and several measures are proposed to tackle the issue of predatory publishing. The awareness campaigns by professional societies, consultations with information facilitators, implementation of the criteria of best target journals, and crediting of scholars with use of integrative citation metrics, such as the h-index, are believed to make a difference. PMID:27822923

  19. 40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... insects; exemption from the requirement of a tolerance. 180.1101 Section 180.1101 Protection of... predatory insects; exemption from the requirement of a tolerance. Parasitic (parasitoid) and predatory insects are exempted from the requirement of a tolerance for residues when they are used in...

  20. 40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... insects; exemption from the requirement of a tolerance. 180.1101 Section 180.1101 Protection of... predatory insects; exemption from the requirement of a tolerance. Parasitic (parasitoid) and predatory insects are exempted from the requirement of a tolerance for residues when they are used in...

  1. 40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... insects; exemption from the requirement of a tolerance. 180.1101 Section 180.1101 Protection of... predatory insects; exemption from the requirement of a tolerance. Parasitic (parasitoid) and predatory insects are exempted from the requirement of a tolerance for residues when they are used in...

  2. 40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... insects; exemption from the requirement of a tolerance. 180.1101 Section 180.1101 Protection of... predatory insects; exemption from the requirement of a tolerance. Parasitic (parasitoid) and predatory insects are exempted from the requirement of a tolerance for residues when they are used in...

  3. Mass Death of Predatory Carp, Chanodichthys erythropterus, Induced by Plerocercoid Larvae of Ligula intestinalis (Cestoda: Diphyllobothriidae)

    PubMed Central

    Sohn, Woon-Mok; Na, Byoung-Kuk; Jung, Soo Gun; Kim, Koo Hwan

    2016-01-01

    We describe here the mass death of predatory carp, Chanodichthys erythropterus, in Korea induced by plerocercoid larvae of Ligula intestinalis as a result of host manipulation. The carcasses of fish with ligulid larvae were first found in the river-edge areas of Chilgok-bo in Nakdong-gang (River), Korea at early February 2016. This ecological phenomena also occurred in the adjacent areas of 3 dams of Nakdong-gang, i.e., Gangjeong-bo, Dalseong-bo, and Hapcheon-Changnyeong-bo. Total 1,173 fish carcasses were collected from the 4 regions. To examine the cause of death, we captured 10 wondering carp in the river-edge areas of Hapcheon-Changnyeong-bo with a landing net. They were 24.0-28.5 cm in length and 147-257 g in weight, and had 2-11 plerocercoid larvae in the abdominal cavity. Their digestive organs were slender and empty, and reproductive organs were not observed at all. The plerocercoid larvae occupied almost all spaces of the abdominal cavity under the air bladders. The proportion of larvae per fish was 14.6-32.1% of body weight. The larvae were ivory-white, 21.5-63.0 cm long, and 6.0-13.8 g in weight. We suggest that the preference for the river-edge in infected fish during winter is a modified behavioral response by host manipulation of the tapeworm larvae. The life cycle of this tapeworm seems to be successfully continued as the infected fish can be easily eaten by avian definitive hosts. PMID:27417095

  4. A Fundamental Step in IPM on Grapevine: Evaluating the Side Effects of Pesticides on Predatory Mites

    PubMed Central

    Pozzebon, Alberto; Tirello, Paola; Moret, Renzo; Pederiva, Marco; Duso, Carlo

    2015-01-01

    Knowledge on side effects of pesticides on non-target beneficial arthropods is a key point in Integrated Pest Management (IPM). Here we present the results of four experiments conducted in vineyards where the effects of chlorpyrifos, thiamethoxam, indoxacarb, flufenoxuron, and tebufenozide were evaluated on the generalist predatory mites Typhlodromus pyri Scheuten and Amblyseius andersoni (Chant), key biocontrol agents of herbivorous mites on grapevines. Results show that indoxacarb and tebufenozide had a low impact on the predatory mites considered here, while a significant impact was observed for chlorpyrifos, flufenoxuron, and thiamethoxam. The information obtained here should be considered in the design of IPM strategies on grapevine. PMID:26466903

  5. Predatory bacteria as natural modulators of Vibrio parahaemolyticus and Vibrio vulnificus in seawater and oysters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study shows that naturally occurring Vibrio predatory bacteria (VPB) exert a major role in controlling pathogenic vibrios in seawater and shellfish. The growth and persistence of Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) were assessed in natural seawater and in the Eastern oyster...

  6. Acaricides and predatory mites against the begonia mite, Polyphagotarsonemus latus (Acari: Tarsonemidae), on Hedera helix.

    PubMed

    Audenaert, Joachim; Vissers, Marc; Haleydt, Bart; Verhoeven, Ruth; Goossens, Frans; Gobin, Bruno

    2009-01-01

    In recent years, the begonia mite (Polyphagotarsonemus lotus) has become an important threat to different ornamental cultures in warm greenhouses. At present there are no professional plant protection products registered in Belgium for the control of mites of the Tarsonemidae family. In a screening trial, we evaluated the efficacy of a range of different acaricides: abamectin, milbemectin, pyridaben, spirodiclofen. Based on the results of the screening trial several products were selected for a full efficacy trial following EPPO guidelines. The best control results were obtained with two products from the avermectine group: abamectin and milbemectin. As growers currently have to rely solely on the use of natural enemies there is a strong need for practical evaluation of efficacies of the various predatory mite species (Amblyseius swirskii, A. cucumeris, A. andersoni) used in biological mite control. In a series of experiments, we screened the use of different species of predatory mites. The first efficacy trials on heavily infested plants at different rates of dosage and under different circumstances (temperature, dose rate, application technique) were started in May 2008. In these experiments Amblyseius swirskii showed good efficacy. But temperature was the limiting factor: the predatory mite needed a minimal temperature of 18 degrees C to obtain good results. Further research is necessary to search for predatory mites that can be used in winter conditions (lower temperatures, less light).

  7. A new genus of predatory katydids (Orthoptera: Tettigoniidae: Listroscelidinae) from the Amazonian Rainforest.

    PubMed

    Mendes, Diego Matheus De Mello; Chamorro-Rengifo, Juliana; Rafael, José Albertino

    2016-09-12

    Most of the predatory katydids Listroscelidini species known were described from the Brazilian Atlantic Forest. Here a new genus and species from the Amazonian Rainforest is described. Based on its morphological characteristics, this new genus represents an intermediate form between two closely related genera, Listroscelis Serville and Monocerophora Walker.

  8. The impact of insecticides applied in apple orchards on the predatory mite Kampimodromus aberrans (Acari: Phytoseiidae).

    PubMed

    Duso, Carlo; Ahmad, Shakeel; Tirello, Paola; Pozzebon, Alberto; Klaric, Virna; Baldessari, Mario; Malagnini, Valeria; Angeli, Gino

    2014-03-01

    Kampimodromus aberrans is an effective predatory mite in fruit orchards. The side-effects of insecticides on this species have been little studied. Field and laboratory experiments were conducted to evaluate the effects of insecticides on K. aberrans. Field experiments showed the detrimental effects of etofenprox, tau-fluvalinate and spinosad on predatory mites. Spider mite (Panonychus ulmi) populations reached higher densities on plots treated with etofenprox and tau-fluvalinate than in the other treatments. Single or multiple applications of neonicotinoids caused no detrimental effects on predatory mites. In the laboratory, spinosad and tau-fluvalinate caused 100 % mortality. Etofenprox caused a significant mortality and reduced fecundity. The remaining insecticides did not affect female survival except for imidacloprid. Thiamethoxam, clothianidin, thiacloprid, chlorpyrifos, lufenuron and methoxyfenozide were associated with a significant reduction in fecundity. No effect on fecundity was found for indoxacarb or acetamiprid. Escape rate of K. aberrans in laboratory was relatively high for etofenprox and spinosad, and to a lesser extent thiacloprid. The use of etofenprox, tau-fluvalinate and spinosad was detrimental for K. aberrans and the first two insecticides induced spider mite population increases. The remaining insecticides caused no negative effects on predatory mites in field trials. Some of them (reduced fecundity and repellence) should be considered with caution in integrated pest management programs.

  9. The effect of insecticides on the non-target predatory mite Kampimodromus aberrans: laboratory studies.

    PubMed

    Tirello, Paola; Pozzebon, Alberto; Duso, Carlo

    2013-10-01

    The side-effects of pesticides on predatory mites have been investigated at various levels and international teams (e.g., the IOBC/wprs Working Group "Pesticides and beneficial organisms") have selected a few species of predatory mites occurring in Central and Northern Europe as representative for such studies. Key biocontrol species occurring in Southern Europe have received much less attention. Kampimodromus aberrans is the most important predator of herbivorous mites in South-European vineyards treated with selective pesticides. The impact of pesticides on K. aberrans populations has been studied in field conditions whereas few toxicological tests have been conducted in the laboratory because of difficulties in rearing this species. A method for rearing K. aberrans in the laboratory has recently been set up allowing toxicological studies to be conducted. In this paper, a toxicological method to assess the effects of pesticides on K. aberrans is described and the effects of insecticides frequently used in European vineyards on two K. aberrans strains are reported. These strains were collected from vineyards treated with organophosphates. Insecticides characterized by different modes of action were selected for trials. Among these, etofenprox and spinosad were classified as harmful to predatory mites. Chlorpyrifos reduced predatory mite fecundity, and was classified as moderately harmful for both strains. The toxicity of thiamethoxam and flufenoxuron varied with the strain (low to moderate). Indoxacarb and methoxyfenozide appeared to be harmless or slightly harmful. Implications of this study for adopting IPM tactics with a reduced risk for K. aberrans are discussed.

  10. On local(ly) ESS of a pair of prey-predator system with predatory switching.

    PubMed

    Mukherjee, D; Roy, A B

    1998-08-01

    This paper concentrates on the study of ecological stability for guaranteeing evolutionary stable strategies (ESS) in a two pre-predator system taking into consideration of handling time, with predatory switching. Here predators are polyphagous in nature. The conditions for ESS of the model system are obtained at the equivalence point. We also derive the invasion conditions of a mutant predator.

  11. Do plant trichomes cause more harm than good to predatory insects?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants may use epidermal hairs (trichomes) as a morphological defense against attacks from some herbivores. Predatory arthropods can serve plants as biocontrol agents against herbivores. Whether or not plant trichomes work in concert with predators is equivocal. We reviewed the scientific literat...

  12. Awareness of "Predatory" Open-Access Journals among Prospective Veterinary and Medical Authors Attending Scientific Writing Workshops.

    PubMed

    Christopher, Mary M; Young, Karen M

    2015-01-01

    Authors face many choices when selecting a journal for publication. Prospective authors, especially trainees, may be unaware of "predatory" online journals or how to differentiate them from legitimate journals. In this study, we assessed awareness of open-access and predatory journals among prospective authors attending scientific writing workshops; our long-term goal was to inform educational goals for the workshops. We surveyed participants of writing workshops at veterinary and medical schools and an international conference over a 1-year period. The survey included 14 statements for respondents to indicate agreement level on a Likert-like scale and four questions on awareness of resources about predatory journals; respondents also defined "predatory journal." A total of 145 participants completed the survey: 106 (73.1%) from veterinary schools and 86 (59.3%) graduate students or residents. Fewer faculty (vs trainees) agreed that open access was an important factor in deciding where to publish; faculty and postdoctoral researchers were more likely to expect to pay more to publish in an open-access journal. Most respondents (120/145, 82.7%) agreed/strongly agreed that the decision to accept a manuscript should not be influenced by publication charges, but 50% (56/112) indicated that they "didn't know" how publishing costs were supported. Of the 142 respondents who answered, 33 (23.0%) indicated awareness of the term "predatory journal"; 34 (23.9%) were aware of the Directory of Open Access Journals; 24 (16.9%) were aware of the Science "sting" article about predatory journals; and 7 (4.8%) were aware of Beall's list. Most (93/144, 64.5%) definitions of predatory journals described poor but not predatory journal practices, and some respondents misunderstood the term completely. Mentors should help novice authors to be aware of predatory journals and to distinguish between legitimate and illegitimate open-access journals, thus selecting the best journal for their

  13. A co-invasive microsporidian parasite that reduces the predatory behaviour of its host Dikerogammarus villosus (Crustacea, Amphipoda).

    PubMed

    Bacela-Spychalska, K; Rigaud, T; Wattier, R A

    2014-02-01

    Parasites are known to affect the predatory behaviour or diet of their hosts. In relation to biological invasions, parasites may significantly influence the invasiveness of the host population and/or mediate the relationships between the invader and the invaded community. Dikerogammarus villosus, a recently introduced species, has had a major impact in European rivers. Notably, its high position in trophic web and high predatory behaviour, have both facilitated its invasive success, and affected other macroinvertebrate taxa in colonized habitats. The intracellular parasite Cucumispora dikerogammari, specific to D. villosus, has successfully dispersed together with this amphipod. Data presented here have shown that D. villosus infected by this parasite have a reduced predatory behaviour compared with healthy individuals, and are much more active suggesting that the co-invasive parasite may diminish the predatory pressure of D. villosus on newly colonized communities.

  14. Back from the dead; the curious tale of the predatory cyanobacterium Vampirovibrio chlorellavorus

    PubMed Central

    Soo, Rochelle M.; Woodcroft, Ben J.; Parks, Donovan H.; Tyson, Gene W.

    2015-01-01

    An uncultured non-photosynthetic basal lineage of the Cyanobacteria, the Melainabacteria, was recently characterised by metagenomic analyses of aphotic environmental samples. However, a predatory bacterium, Vampirovibrio chlorellavorus, originally described in 1972 appears to be the first cultured representative of the Melainabacteria based on a 16S rRNA sequence recovered from a lyophilised co-culture of the organism. Here, we sequenced the genome of V. chlorellavorus directly from 36 year-old lyophilised material that could not be resuscitated confirming its identity as a member of the Melainabacteria. We identified attributes in the genome that likely allow V. chlorellavorus to function as an obligate predator of the microalga Chlorella vulgaris, and predict that it is the first described predator to use an Agrobacterium tumefaciens-like conjugative type IV secretion system to invade its host. V. chlorellavorus is the first cyanobacterium recognised to have a predatory lifestyle and further supports the assertion that Melainabacteria are non-photosynthetic. PMID:26038723

  15. Stealth predation and the predatory success of the invasive ctenophore Mnemiopsis leidyi

    PubMed Central

    Colin, Sean P.; Costello, John H.; Hansson, Lars J.; Titelman, Josefin; Dabiri, John O.

    2010-01-01

    In contrast to higher metazoans such as copepods and fish, ctenophores are a basal metazoan lineage possessing a relatively narrow set of sensory-motor capabilities. Yet lobate ctenophores can capture prey at rates comparable to sophisticated predatory copepods and fish, and they are capable of altering the composition of coastal planktonic communities. Here, we demonstrate that the predatory success of the lobate ctenophore Mnemiopsis leidyi lies in its use of cilia to generate a feeding current that continuously entrains large volumes of fluid, yet is virtually undetectable to its prey. This form of stealth predation enables M. leidyi to feed as a generalist predator capturing prey, including microplankton (approximately 50 μm), copepods (approximately 1 mm), and fish larvae (>3 mm). The efficacy and versatility of this stealth feeding mechanism has enabled M. leidyi to be notoriously destructive as a predator and successful as an invasive species. PMID:20855619

  16. Stealth predation and the predatory success of the invasive ctenophore Mnemiopsis leidyi.

    PubMed

    Colin, Sean P; Costello, John H; Hansson, Lars J; Titelman, Josefin; Dabiri, John O

    2010-10-05

    In contrast to higher metazoans such as copepods and fish, ctenophores are a basal metazoan lineage possessing a relatively narrow set of sensory-motor capabilities. Yet lobate ctenophores can capture prey at rates comparable to sophisticated predatory copepods and fish, and they are capable of altering the composition of coastal planktonic communities. Here, we demonstrate that the predatory success of the lobate ctenophore Mnemiopsis leidyi lies in its use of cilia to generate a feeding current that continuously entrains large volumes of fluid, yet is virtually undetectable to its prey. This form of stealth predation enables M. leidyi to feed as a generalist predator capturing prey, including microplankton (approximately 50 μm), copepods (approximately 1 mm), and fish larvae (>3 mm). The efficacy and versatility of this stealth feeding mechanism has enabled M. leidyi to be notoriously destructive as a predator and successful as an invasive species.

  17. Can predatory bird feathers be used as a non-destructive biomonitoring tool of organic pollutants?

    PubMed Central

    Jaspers, Veerle L.B; Voorspoels, Stefan; Covaci, Adrian; Eens, Marcel

    2006-01-01

    The monitoring of different types of pollutants that are released into the environment and that present risks for both humans and wildlife has become increasingly important. In this study, we examined whether feathers of predatory birds can be used as a non-destructive biomonitor of organic pollutants. We demonstrate that polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and polybrominated diphenyl ethers (PBDEs) are measurable in one single tail feather of common buzzards (Buteo buteo) and that levels in this feather and internal tissues are significantly related to each other (0.35predatory birds could be useful in non-destructive biomonitoring of organic pollutants, although further validation may be necessary. PMID:17148383

  18. Relationships among predatory fish, sea urchins and barrens in Mediterranean rocky reefs across a latitudinal gradient.

    PubMed

    Guidetti, P; Dulcić, J

    2007-03-01

    Previous studies conducted on a local scale emphasised the potential of trophic cascades in Mediterranean rocky reefs (involving predatory fish, sea urchins and macroalgae) in affecting the transition between benthic communities dominated by erected macroalgae and barrens (i.e., bare rock with partial cover of encrusting algae). Distribution patterns of fish predators of sea urchins (Diplodus sargus sargus, Diplodus vulgaris, Coris julis and Thalassoma pavo), sea urchins (Paracentrotus lividus and Arbacia lixula) and barrens, and fish predation rates upon sea urchins, were assessed in shallow (3-6m depth) sublittoral rocky reefs in the northern, central and southern sectors of the eastern Adriatic Sea, i.e., on a large spatial scale of hundreds of kilometres. No dramatic differences were observed in predatory fish density across latitude, except for a lower density of small D. sargus sargus in the northern Adriatic and an increasing density of T. pavo from north to south. P. lividus did not show any significant difference across latitude, whereas A. lixula was more abundant in the southern than in the central Adriatic. Barrens were more extended in the southern than in the central and northern sectors, and were related with sea urchin density. Fish predation upon adult sea urchins did not change on a large scale, whereas it was slightly higher in the southern sector for juveniles when predation rates of both urchins were pooled. Results show that: (1) assemblages of predatory fish and sea urchins, and barren extent change across latitude in the eastern Adriatic Sea, (2) the weak relations between predatory fish density and predation rates on urchins reveal that factors other than top-down control can be important over large scale (with the caveat that the study was conducted in fished areas) and (3) patterns of interaction among strongly interacting taxa could change on large spatial scales and the number of species involved.

  19. Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities

    PubMed Central

    Stallings, Christopher D.

    2009-01-01

    Background Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. Methodology/Principal Findings Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. Conclusions/Significance Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable. PMID:19421312

  20. Who Eats Whom in a Pool? A Comparative Study of Prey Selectivity by Predatory Aquatic Insects

    PubMed Central

    Klecka, Jan; Boukal, David S.

    2012-01-01

    Predatory aquatic insects are a diverse group comprising top predators in small fishless water bodies. Knowledge of their diet composition is fragmentary, which hinders the understanding of mechanisms maintaining their high local diversity and of their impacts on local food web structure and dynamics. We conducted multiple-choice predation experiments using nine common species of predatory aquatic insects, including adult and larval Coleoptera, adult Heteroptera and larval Odonata, and complemented them with literature survey of similar experiments. All predators in our experiments fed selectively on the seven prey species offered, and vulnerability to predation varied strongly between the prey. The predators most often preferred dipteran larvae; previous studies further reported preferences for cladocerans. Diet overlaps between all predator pairs and predator overlaps between all prey pairs were non-zero. Modularity analysis separated all primarily nectonic predator and prey species from two groups of large and small benthic predators and their prey. These results, together with limited evidence from the literature, suggest a highly interconnected food web with several modules, in which similarly sized predators from the same microhabitat are likely to compete strongly for resources in the field (observed Pianka’s diet overlap indices >0.85). Our experiments further imply that ontogenetic diet shifts are common in predatory aquatic insects, although we observed higher diet overlaps than previously reported. Hence, individuals may or may not shift between food web modules during ontogeny. PMID:22679487

  1. Predatory activity of Butlerius nematodes and nematophagous fungi against Haemonchus contortus infective larvae.

    PubMed

    Silva, Manoel Eduardo da; Uriostegui, Miguel Angel Mercado; Millán-Orozco, Jair; Gives, Pedro Mendoza de; Hernández, Enrique Liébano; Braga, Fabio Ribeiro; Araújo, Jackson Victor de

    2017-01-26

    The purpose of this study was to evaluate the predatory activity of the nematode Butlerius spp. and fungal isolates of Duddingtonia flagrans, Clonostachys rosea, Arthrobotrys musiformis and Trichoderma esau against H. contortus infective larvae (L3) in grass pots. Forty-eight plastic gardening pots containing 140 g of sterile soil were used. Panicum spp. grass seeds (200 mg) were sown into each pot and individually watered with 10 mL of tap water. Twelve days after seeding, the pots were randomly divided into 6 groups (n=8). Two thousand H. contortus infective larvae (L3) were added to each group. Additionally, the following treatments were established: Group 1 - 2000 Butlerius spp. larvae; group 2 - A. musiformis (1x107 conidia); group 3 - T. esau (1x107 conidia); group 4 - C. rosea (1x107 conidia), group 5 - D. flagrans (1x107conidia) and Group 6 - no biological controller (control group). The larval population of H. contortus exposed to Butlerius spp. was reduced by 61.9%. Population reductions of 90.4, 66.7, 61.9 and 85.7% were recorded in the pots containing A. musiformis, T. esau, C. rosea and D. flagrans, respectively. The results of this study indicate that the predatory nematode Butlerius spp. and the assessed fungi display an important predatory activity can be considered suitable potential biological control agents.

  2. Predatory fish select for coordinated collective motion in virtual prey.

    PubMed

    Ioannou, C C; Guttal, V; Couzin, I D

    2012-09-07

    Movement in animal groups is highly varied and ranges from seemingly disordered motion in swarms to coordinated aligned motion in flocks and schools. These social interactions are often thought to reduce risk from predators, despite a lack of direct evidence. We investigated risk-related selection for collective motion by allowing real predators (bluegill sunfish) to hunt mobile virtual prey. By fusing simulated and real animal behavior, we isolated predator effects while controlling for confounding factors. Prey with a tendency to be attracted toward, and to align direction of travel with, near neighbors tended to form mobile coordinated groups and were rarely attacked. These results demonstrate that collective motion could evolve as a response to predation, without prey being able to detect and respond to predators.

  3. Interpreting the intentions of internet predators:an examination of online predatory behavior.

    PubMed

    Marcum, Catherine D

    2007-01-01

    Internet predators are finding new ways to prey on the vulnerabilities of youth in chat rooms and lure them into sexual activities. This study will examine three chat room transcripts between adult predators and adult volunteers of the group "Perverted Justice" posing as youth. These conversations will be analyzed to interpret the underlying meanings behind the words and actions of the predators and how they affect potential victims. The purpose of this article is to provide insight to the reader of the increased amount of child sexual abuse on the Internet, the often-blatant tactics used by online predators to pursue this abuse, and how they are continuing to successfully manipulate children with them.

  4. Interpreting the Intentions of Internet Predators: An Examination of Online Predatory Behavior

    ERIC Educational Resources Information Center

    Marcum, Catherine D.

    2007-01-01

    Internet predators are finding new ways to prey on the vulnerabilities of youth in chat rooms and lure them into sexual activities. This study will examine three chat room transcripts between adult predators and adult volunteers of the group "Perverted Justice" posing as youth. These conversations will be analyzed to interpret the underlying…

  5. Energetics of the yo-yo dives of predatory sharks.

    PubMed

    Iosilevskii, Gil; Papastamatiou, Yannis P; Meyer, Carl G; Holland, Kim N

    2012-02-07

    Sharks zigzag vertically through the water in a series of alternating ascending and descending segments, changing depth by a few tens of meters over a period of a few hundred seconds. This 'yo-yo' like behavior has several characteristic patterns, identifiable by the way the swimming and vertical velocities vary along the dive. We suggest that these patterns represent different optimal strategies minimizing the cost of locomotion under different constraints; moreover, these constraints can be inferred by matching the pattern of a dive with a (standard) optimal swimming strategy for which the constraints are known. We used three sets of constraints and two definitions of the 'cost of locomotion' to analytically generate four standard optimal strategies; we have used high resolution tracking data from four tiger sharks to identify two different yo-yo diving patterns. These patterns seem to match two of the standard strategies: one that maximizes range, given an alternating power supply (e.g., swimming actively on ascents and lazily on descents); and the other that maximizes range, given an alternating vertical velocity (implying an 'intentional' up-and-down motion).

  6. Behaviorism

    ERIC Educational Resources Information Center

    Moore, J.

    2011-01-01

    Early forms of psychology assumed that mental life was the appropriate subject matter for psychology, and introspection was an appropriate method to engage that subject matter. In 1913, John B. Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the…

  7. Discriminating Between Legitimate and Predatory Open Access Journals: Report from the International Federation for Emergency Medicine Research Committee

    PubMed Central

    Hansoti, Bhakti; Langdorf, Mark I.; Murphy, Linda S.

    2016-01-01

    Introduction Open access (OA) medical publishing is growing rapidly. While subscription-based publishing does not charge the author, OA does. This opens the door for “predatory” publishers who take authors’ money but provide no substantial peer review or indexing to truly disseminate research findings. Discriminating between predatory and legitimate OA publishers is difficult. Methods We searched a number of library indexing databases that were available to us through the University of California, Irvine Libraries for journals in the field of emergency medicine (EM). Using criteria from Jeffrey Beall, University of Colorado librarian and an expert on predatory publishing, and the Research Committee of the International Federation for EM, we categorized EM journals as legitimate or likely predatory. Results We identified 150 journal titles related to EM from all sources, 55 of which met our criteria for OA (37%, the rest subscription based). Of these 55, 25 (45%) were likely to be predatory. We present lists of clearly legitimate OA journals, and, conversely, likely predatory ones. We present criteria a researcher can use to discriminate between the two. We present the indexing profiles of legitimate EM OA journals, to inform the researcher about degree of dissemination of research findings by journal. Conclusion OA journals are proliferating rapidly. About half in EM are legitimate. The rest take substantial money from unsuspecting, usually junior, researchers and provide no value for true dissemination of findings. Researchers should be educated and aware of scam journals. PMID:27625710

  8. Seasonal climatic variations influence the efficacy of predatory mites used for control of western flower thrips in greenhouse ornamental crops.

    PubMed

    Hewitt, Laura C; Shipp, Les; Buitenhuis, Rose; Scott-Dupree, Cynthia

    2015-04-01

    The influence of seasonal greenhouse climate on the efficacy of predatory mites for thrips control was determined for potted chrysanthemum. Trials in controlled environment chambers, small-scale greenhouses and commercial greenhouses were conducted to determine which biological control agent-that is, Amblyseius swirskii Athias-Henriot or Neoseiulus cucumeris (Oudemans)-is more efficacious for control of western flower thrips, Frankliniella occidentalis (Pergande), in different seasons. Under simulated summer conditions, no differences were observed in the predation and oviposition rates of both predatory mites in the laboratory trials. However, small-scale greenhouse trials showed that A. swirskii performed better than N. cucumeris in summer (i.e., more efficacious thrips control, higher predator abundance and less overall damage to the crop). Under simulated winter conditions, laboratory trials demonstrated variable differences in predation rates of the two predatory mites. The small-scale greenhouse trials in winter showed no differences in thrips control and predatory mite abundance between the two predatory mites, but plants with A. swirskii had less damage overall. The results from the small-scale trials were validated and confirmed in commercial greenhouse trials. Overall, A. swirskii performed better in the summer and equally good or better (less damage overall) under winter conditions, whereas N. cucumeris is a more cost effective biological control agent for winter months.

  9. Do chimpanzee nests serve an anti-predatory function?

    PubMed

    Stewart, Fiona A; Pruetz, J D

    2013-06-01

    Sleep is a vulnerable state for animals as it compromises the ability to detect predators. The evolution of shelter construction in the great apes may have been a solution to the trade-off between restorative sleep and predation-risk, which allowed a large bodied ape to sleep recumbent in a safe, comfortable spot. In this article we review the evidence of predator pressure on great apes and specifically investigate the potential influence of predation-risk on chimpanzee nesting behavior by comparing nests between chimpanzees living in a habitat of several potential predators (Issa, Ugalla, Tanzania) and a habitat relatively devoid of predators (Fongoli, Senegal). Chimpanzees in Issa did not nest more frequently in forest vegetation than chimpanzees in Fongoli although forest vegetation is expected to provide greater opportunity for escape from terrestrial predators. Nor do chimpanzees in Issa nest in larger groups or aggregate together more than Fongoli chimpanzees, as would be expected if larger groups provide protection from or greater detection of predators. Nests in Issa also did not appear to provide greater opportunities for escape than nests in Fongoli. Chimpanzees in Issa nested more frequently within the same tree as other community members, which may indicate that these chimpanzees nest in greater proximity than chimpanzees in Fongoli. Finally, Issa chimpanzees built their nests proportionately higher and more peripherally within trees. The selection of high and peripheral nesting locations within trees may make Issa chimpanzees inaccessible to potential predators. Many factors influence nest site selection in chimpanzees, of which danger from terrestrial predators is likely to be one.

  10. High rate of prey consumption in a small predatory fish on coral reefs

    NASA Astrophysics Data System (ADS)

    Feeney, W. E.; Lönnstedt, O. M.; Bosiger, Y.; Martin, J.; Jones, G. P.; Rowe, R. J.; McCormick, M. I.

    2012-09-01

    Small piscivores are regarded as important regulators of the composition of coral reef fish communities, but few studies have investigated their predatory ecology or impact on assemblages of juvenile fishes. This study investigated the foraging ecology of a common coral reef predator, the dottyback Pseudochromis fuscus, using underwater focal animal observations. Observations were conducted at two times of year: the summer, when recruit fishes were an available food item and winter, when remaining juveniles had outgrown vulnerability to P. fuscus. During the summer, P. fuscus directed 76% of its strikes at invertebrates and 24% at recruiting juvenile fishes. When striking at fishes, P. fuscus exhibited two distinct feeding modes: an ambush (26% successful) and a pursuit mode (5% successful). Predator activity in the field peaked at midday, averaging 2.5 captures h-1 of juvenile fishes. Monitoring of activity and foraging in the laboratory over 24-h periods found that P. fuscus was a diurnal predator and was active for 13 h d-1 during the summer. The number of hours during which foraging was recorded differed greatly among individuals ( n = 10), ranging from 4 to 13 h. The number of predatory strikes did not increase with standard length, but the success rate and consumption rate of juvenile fishes did increase with size. Estimated hourly mortality on juvenile fish ranged from 0.49 fish h-1 in small P. fuscus individuals (30-39 mm standard length, SL; equating to 6.3 per 13 h day) to 2.4 fish h-1 in large P. fuscus individuals (55-65 mm SL; 30.6 per 13 h day). During the winter, P. fuscus struck at invertebrates with a similar rate to the summer period. These observations of the predatory ecology of P. fuscus support the hypothesis that in coral reef systems, small piscivores, because of their high metabolism and activity, are probably important regulators of coral reef fish community composition.

  11. Distribution of Po-210 in two species of predatory marine fish from the Brazilian coast.

    PubMed

    Mársico, E T; Ferreira, M S; São Clemente, S C; Gouvea, R C S; Jesus, E F O; Conti, C C; Conte, C A; Kelecom, A G A C

    2014-02-01

    Polonium-210 ((210)Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher (210)Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg(-1) for G. brasiliensis and it was 6 mBq kg(-1) for C. microlepidotus. The activity concentrations varied significantly between the species and among organs.

  12. Interactions of Bacillus thuringiensis Cry1Ac toxin in genetically engineered cotton with predatory heteropterans.

    PubMed

    Torres, Jorge B; Ruberson, John R

    2008-06-01

    A number of cotton varieties have been genetically transformed with genes from Bacillus thuringiensis (Bt) to continuously produce Bt endotoxins, offering whole plant and season-long protection against many lepidopteran larvae. Constant whole-plant toxin expression creates a significant opportunity for non-target herbivores to acquire and bio-accumulate the toxin for higher trophic levels. In the present study we investigated movement of Cry1Ac toxin from the transgenic cotton plant through specific predator-prey pairings, using omnivorous predators with common cotton pests as prey: (1) the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), with the predator Podisus maculiventris (Heteroptera: Pentatomidae); (2) the two-spotted spider mite, Tetranychus urticae (Acarina: Tetranychidae), with the predatory big-eyed bug Geocoris punctipes (Heteroptera: Geocoridae) and (3) with the predatory damsel bug Nabis roseipennis (Heteropera: Nabidae); and (4) the thrips Frankliniella occidentalis (Thysanoptera: Thripidae) with the predatory pirate bug Orius insidiosus (Heteroptera: Anthocoridae). We quantified Cry1Ac toxin in the cotton plants, and in the pests and predators, and the effects of continuous feeding on S. exigua larvae fed either Bt or non-Bt cotton on life history traits of P. maculiventris. All three herbivores were able to convey Cry1Ac toxin to their respective predators. Among the herbivores, T. urticae exhibited 16.8 times more toxin in their bodies than that expressed in Bt-cotton plant, followed by S. exigua (1.05 times), and F. occidentalis immatures and adults (0.63 and 0.73 times, respectively). Of the toxin in the respective herbivorous prey, 4, 40, 17 and 14% of that amount was measured in the predators G. punctipes, P. maculiventris, O. insidiosus, and N. roseipennis, respectively. The predator P. maculiventris exhibited similar life history characteristics (developmental time, survival, longevity, and fecundity) regardless of the prey's food

  13. Predatory Trading and Risk Minimisation: How to (B)Eat the Competition

    NASA Astrophysics Data System (ADS)

    Mehta, Anita

    We present a model of predatory traders interacting with each other in the presence of a central reserve (which dissipates their wealth through say, taxation), as well as inflation. This model is examined on a network for the purposes of correlating complexity of interactions with systemic risk. We suggest the use of selective networking to enhance the survival rates of arbitrarily chosen traders. Our conclusions show that networking with `doomed' traders is the most risk-free scenario, and that if a trader is to network with peers, it is far better to do so with those who have less intrinsic wealth than himself to ensure individual, and perhaps systemic stability.

  14. Effect of salinity on the predatory performance of Diplonychus rusticus (Fabricius).

    PubMed

    Chandramohan, G; Arivoli, S; Venkatesan, P

    2008-05-01

    Predatory efficiency of Diplonychus rusticus (Fabricius) was recorded at different prey density with different salinity ranges. When the salinity level (ppt) was increased, the predation rate of the bug decreased. Fifth nymphal stage showed higher predation in the 2, 4 and 6 ppt levels of salinityin both 1 hr and 24 hr period of exposure at prey densities 50, 100, 150 and 200. At prey density 150, adult bugs killed more prey in the 2 ppt level of salinity in both lhr and 24 hr treatments.

  15. The rhetorical construction of the predatorial virus: a Burkian analysis of nonfiction accounts of the Ebola virus.

    PubMed

    Weldon, R A

    2001-01-01

    Over the past 5 years, a new subgenre of horror films, referred to as plague films, has turned our focus to the threat of a hemorrhagic viral pandemic, comparable to the Spanish Flu epidemic of 1916. Based on the Ebola viral outbreaks of 1976, various writers have presented their accounts under the guise of increasing interest and prevention strategies. Disregarding inappropriate health care practices as the cause of these epidemics, accountability is refocused onto the rhetorically constructed, predatory nature of the virus. By employing Burke's theory of dramatism and pentadic analysis, the author examines this rhetorical construction of Ebola as a predatorial virus and its implications for public perceptions of public health endeavors.

  16. Invading predatory crustacean Dikerogammarus villosus eliminates both native and exotic species.

    PubMed Central

    Dick, J T; Platvoet, D

    2000-01-01

    As the tempo of biological invasions increases, explanations and predictions of their impacts become more crucial. Particularly with regard to biodiversity, we require elucidation of interspecific behavioural interactions among invaders and natives. In freshwaters in The Netherlands, we show that the invasive Ponto-Caspian crustacean amphipod Dikerogammarus villosus is rapidly eliminating Gammarus duebeni, a native European amphipod, and Gammarus tigrinus, until now a spectacularly successful invader from North America. In the laboratory, survival of single (unguarded) female G. duebeni was significantly lower when male D. villosus were free to roam as compared with isolated within microcosms. In addition, survival of paired (guarded) female G. duebeni was significantly lower when male D. villosus as compared with male G. duebeni were present. D. villosus killed and consumed both recently moulted and, unusually, intermoult victims. Survival of G. tigrinus was significantly lower when D. villosus were free to roam as compared with isolated within microcosms and, again, both moulted and intermoult victims were preyed upon. Male D. villosus were significantly more predatory than were females, while female G. tigrinus were significantly more often preyed upon than were males. Predation by D. villosus on both species occurred over a range of water conductivities, an environmental feature previously shown to promote amphipod coexistence. This predatory invader is predicted to reduce further the amphipod diversity in a range of freshwater habitats in Europe and North America. PMID:10874746

  17. Effects of lambda-cyhalothrin on mosquito larvae and predatory aquatic insects.

    PubMed

    Lawler, Sharon P; Dritz, Deborah A; Christiansen, Julie A; Cornel, Anthony J

    2007-03-01

    Agricultural insecticides can affect mosquito production in rice fields by controlling mosquitoes, disrupting biological control or contributing to selection of insecticide resistance. The duration of insecticidal activity of the pyrethroid lambda-cyhalothrin was quantified on predatory insects in rice fields and on three kinds of mosquito larva: a pyrethroid-susceptible strain of Culex tarsalis Coquillet, a pyrethroid-resistant strain of Cx pipiens L. (sensu lato) and non-resistant Cx pipiens s.l. Lambda-cyhalothrin killed most caged, susceptible mosquitoes for up to 21 days. It killed fewer resistant Cx pipiens s.l., but suppressed their survival for over a week. Lambda-cyhalothrin suppressed field populations of predatory insects through day 29. Agricultural use of lambda-cyhalothrin can provide incidental mosquito control. However, the pyrethroid persisted in sediment and gradually decreased in activity, which could contribute to selection of pyrethroid-resistant mosquitoes. Because caged mosquitoes showed good survival before predators recovered, disruption of biological control is possible. It is therefore advisable for growers and mosquito control agencies to communicate about pesticide use.

  18. Responses of herbivore and predatory mites to tomato plants exposed to jasmonic acid seed treatment.

    PubMed

    Smart, Lesley E; Martin, Janet L; Limpalaër, Marlène; Bruce, Toby J A; Pickett, John A

    2013-10-01

    Jasmonic acid (JA) signalling can influence plant defense and the production of plant volatiles that mediate interactions with insects. Here, we tested whether a JA seed treatment could alter direct and indirect defenses. First, oviposition levels of herbivorous mites, Tetranychus urticae, on JA seed-treated and control tomato plants were compared. They were not significantly different on tomato cv. 'Moneymaker', however, there was a significant reduction in oviposition on treated plants in additional experiments with cv. 'Carousel'. Second, responses of predatory mites, Phytoseiulus persimilis, were assessed in a Y-tube olfactometer. Volatiles from JA seed-treated tomato cv. 'Moneymaker' plants were significantly more attractive than volatiles from control plants. Volatiles collected from plants were analysed by GC/MS, and samples from JA seed-treated plants contained more methyl salicylate and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT) than samples from control plants. Our results indicate that JA seed treatment can make tomato plants more attractive to predatory mites, but that direct effects on herbivorous mites are variable and cultivar dependent.

  19. Anystis baccarum: An Important Generalist Predatory Mite to be Considered in Apple Orchard Pest Management Strategies.

    PubMed

    Cuthbertson, Andrew G S; Qiu, Bao-Li; Murchie, Archie K

    2014-07-24

    The increasing concern over the continued use of pesticides is pressurising apple growers to look for alternatives to chemical pest control. The re-discovery, and subsequent conservation, of the beneficial predatory mite, Anystis baccarum (Linnaeus) (Acari: Anystidae), in Bramley apple orchards in Northern Ireland offers a potential alternative control component for incorporation into integrated pest management strategies. Anystis baccarum readily feeds upon economically important invertebrate pest species including European fruit tree red spider mite, Panonychus ulmi (Koch) (Acari: Tetranychidae) and show a level of compatibility with chemical pesticides. Recent mis-identification by apple growers of this beneficial mite species had resulted in unnecessary pesticide applications being applied within Northern Irish apple orchards. However, dissemination of information to the apple growers and promotion of the benefits this mite offers in apple orchards has helped to conserve its populations. Apple growers, across the United Kingdom, must be encouraged to be aware of A. baccarum, and indeed all predatory fauna, within their orchards and seek to conserve populations. In doing so, it will ensure that the British apple market remains an environmentally sustainable production system.

  20. Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

    USGS Publications Warehouse

    Nemec, Kristine T.; Allen, Craig R.; Danielson, Stephen D.; Helzer, Christopher J.

    2014-01-01

    In recent decades, agricultural producers and non-governmental organizations have restored thousands of hectares of former cropland in the central United States with native grasses and forbs. However, the ability of these grassland restorations to attract predatory invertebrates has not been well documented, even though predators provide an important ecosystem service to agricultural producers by naturally regulating herbivores. This study assessed the effects of plant richness and seeding density on the richness and abundance of surface-dwelling (ants, ground beetles, and spiders) and aboveground (ladybird beetles) predatory invertebrates. In the spring of 2006, twenty-four 55 m × 55 m-plots were planted to six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Natural Resources Conservation Service Conservation Reserve Program mix, CP25), at low and high seeding densities. Ants, ground beetles, and spiders were sampled using pitfall traps and ladybird beetles were sampled using sweep netting in 2007–2009. The abundance of ants, ground beetles, and spiders showed no response to seed mix richness or seeding density but there was a significant positive effect of richness on ladybird beetle abundance. Seeding density had a significant positive effect on ground beetle and spider species richness and Shannon–Weaver diversity. These results may be related to differences in the plant species composition and relative amount of grass basal cover among the treatments rather than richness.

  1. Publishing Ethics and Predatory Practices: A Dilemma for All Stakeholders of Science Communication.

    PubMed

    Gasparyan, Armen Yuri; Yessirkepov, Marlen; Diyanova, Svetlana N; Kitas, George D

    2015-08-01

    Publishing scholarly articles in traditional and newly-launched journals is a responsible task, requiring diligence from authors, reviewers, editors, and publishers. The current generation of scientific authors has ample opportunities for publicizing their research. However, they have to selectively target journals and publish in compliance with the established norms of publishing ethics. Over the past few years, numerous illegitimate or predatory journals have emerged in most fields of science. By exploiting gold Open Access publishing, these journals paved the way for low-quality articles that threatened to change the landscape of evidence-based science. Authors, reviewers, editors, established publishers, and learned associations should be informed about predatory publishing practices and contribute to the trustworthiness of scholarly publications. In line with this, there have been several attempts to distinguish legitimate and illegitimate journals by blacklisting unethical journals (the Jeffrey Beall's list), issuing a statement on transparency and best publishing practices (the Open Access Scholarly Publishers Association's and other global organizations' draft document), and tightening the indexing criteria by the Directory of Open Access Journals. None of these measures alone turned to be sufficient. All stakeholders of science communication should be aware of multiple facets of unethical practices and publish well-checked and evidence-based articles.

  2. Publishing Ethics and Predatory Practices: A Dilemma for All Stakeholders of Science Communication

    PubMed Central

    Yessirkepov, Marlen; Diyanova, Svetlana N.; Kitas, George D.

    2015-01-01

    Publishing scholarly articles in traditional and newly-launched journals is a responsible task, requiring diligence from authors, reviewers, editors, and publishers. The current generation of scientific authors has ample opportunities for publicizing their research. However, they have to selectively target journals and publish in compliance with the established norms of publishing ethics. Over the past few years, numerous illegitimate or predatory journals have emerged in most fields of science. By exploiting gold Open Access publishing, these journals paved the way for low-quality articles that threatened to change the landscape of evidence-based science. Authors, reviewers, editors, established publishers, and learned associations should be informed about predatory publishing practices and contribute to the trustworthiness of scholarly publications. In line with this, there have been several attempts to distinguish legitimate and illegitimate journals by blacklisting unethical journals (the Jeffrey Beall's list), issuing a statement on transparency and best publishing practices (the Open Access Scholarly Publishers Association's and other global organizations' draft document), and tightening the indexing criteria by the Directory of Open Access Journals. None of these measures alone turned to be sufficient. All stakeholders of science communication should be aware of multiple facets of unethical practices and publish well-checked and evidence-based articles. PMID:26240476

  3. Rhizobial galactoglucan determines the predatory pattern of Myxococcus xanthus and protects Sinorhizobium meliloti from predation.

    PubMed

    Pérez, Juana; Jiménez-Zurdo, José I; Martínez-Abarca, Francisco; Millán, Vicenta; Shimkets, Lawrence J; Muñoz-Dorado, José

    2014-07-01

    Myxococcus xanthus is a social bacterium that preys on prokaryotic and eukaryotic microorganisms. Co-culture of M. xanthus with reference laboratory strains and field isolates of the legume symbiont Sinorhizobium meliloti revealed two different predatory patterns that resemble frontal and wolf-pack attacks. Use of mutants impaired in the two types of M. xanthus surface motility (A or adventurous and S or social motility) and a csgA mutant, which is unable to form macroscopic travelling waves known as ripples, has demonstrated that both motility systems but not rippling are required for efficient predation. To avoid frontal attack and reduce killing rates, rhizobial cells require a functional expR gene. ExpR regulates expression of genes involved in a variety of functions. The use of S. meliloti mutants impaired in several of these functions revealed that the exopolysaccharide galactoglucan (EPS II) is the major determinant of the M. xanthus predatory pattern. The data also suggest that this biopolymer confers an ecological advantage to rhizobial survival in soil, which may have broad environmental implications.

  4. Molecular Diversity and Gene Evolution of the Venom Arsenal of Terebridae Predatory Marine Snails.

    PubMed

    Gorson, Juliette; Ramrattan, Girish; Verdes, Aida; Wright, Elizabeth M; Kantor, Yuri; Rajaram Srinivasan, Ramakrishnan; Musunuri, Raj; Packer, Daniel; Albano, Gabriel; Qiu, Wei-Gang; Holford, Mandë

    2015-05-28

    Venom peptides from predatory organisms are a resource for investigating evolutionary processes such as adaptive radiation or diversification, and exemplify promising targets for biomedical drug development. Terebridae are an understudied lineage of conoidean snails, which also includes cone snails and turrids. Characterization of cone snail venom peptides, conotoxins, has revealed a cocktail of bioactive compounds used to investigate physiological cellular function, predator-prey interactions, and to develop novel therapeutics. However, venom diversity of other conoidean snails remains poorly understood. The present research applies a venomics approach to characterize novel terebrid venom peptides, teretoxins, from the venom gland transcriptomes of Triplostephanus anilis and Terebra subulata. Next-generation sequencing and de novo assembly identified 139 putative teretoxins that were analyzed for the presence of canonical peptide features as identified in conotoxins. To meet the challenges of de novo assembly, multiple approaches for cross validation of findings were performed to achieve reliable assemblies of venom duct transcriptomes and to obtain a robust portrait of Terebridae venom. Phylogenetic methodology was used to identify 14 teretoxin gene superfamilies for the first time, 13 of which are unique to the Terebridae. Additionally, basic local algorithm search tool homology-based searches to venom-related genes and posttranslational modification enzymes identified a convergence of certain venom proteins, such as actinoporin, commonly found in venoms. This research provides novel insights into venom evolution and recruitment in Conoidean predatory marine snails and identifies a plethora of terebrid venom peptides that can be used to investigate fundamental questions pertaining to gene evolution.

  5. MEGA ♪ --Empirical Support for Nomenclature on the Anomalies: Sexually Violent and Predatory Youth.

    PubMed

    Miccio-Fonseca, L C; Rasmussen, Lucinda A Lee

    2015-10-01

    Applied are empirical findings supporting the authors' previously presented nomenclature identifying two subsets of sexually abusive youth overlooked by most contemporary risk assessment tools: sexually violent and predatory sexually violent youth. The cross-validation findings on an ecologically framed risk assessment tool, MEGA (♪) (Multiplex Empirically Guided Inventory of Ecological Aggregates for Assessing Sexually Abusive Children and Adolescents [Ages 19 and Under]) (N = 1,056 male and female sexually abusive youth, ages 4-19, including youth with low intellectual functioning), from the United States, Canada, England, and Scotland, were utilized. Findings provided normative data, with cutoff scores according to age and gender. Most contemporary risk assessment tools have three levels (low, moderate, and high), which may in fact be limited in assessing the range of risk level. The MEGA (♪) cross-validation established a new range of risk level, with the fourth level (very high) definitively identifying the most dangerous youth, thus empirically supporting the nomenclature of sexually violent and predatory sexually violent youth.

  6. The influence of intraguild competitors on reproductive decisions by two predatory Heteroptera, Orius insidiosus (Anthocoridae) and Nabis americoferus (Nabidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship between the oviposition site preferences of predators in the face of intraguild competitors has received little attention, but it likely shapes the reproductive ecology of predatory species. In this study, oviposition intensity and the within-plant distribution of Orius insidiosus (...

  7. Karnyothrips flavipes, a previously unreported predatory thrips of the coffee berry borer: DNA-based gut content analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new predator of the coffee berry borer, Hypothenemus hampei, was found in the coffee growing area of Kisii in Western Kenya. Field observations, laboratory trials and gut content analysis using molecular tools have confirmed the role of the predatory thrips Karnyothrips flavipes Jones (Phlaeothrip...

  8. Convergent evolution of eye ultrastructure and divergent evolution of vision-mediated predatory behaviour in jumping spiders.

    PubMed

    Su, K F; Meier, R; Jackson, R R; Harland, D P; Li, D

    2007-07-01

    All jumping spiders have unique, complex eyes with exceptional spatial acuity and some of the most elaborate vision-guided predatory strategies ever documented for any animal of their size. However, it is only recently that phylogenetic techniques have been used to reconstruct the relationships and key evolutionary events within the Salticidae. Here, we used data for 35 species and six genes (4.8 kb) for reconstructing the phylogenetic relationships between Spartaeinae, Lyssomaninae and Salticoida. We document a remarkable case of morphological convergence of eye ultrastructure in two clades with divergent predatory behaviour. We, furthermore, find evidence for a stepwise, gradual evolution of a complex predatory strategy. Divergent predatory behaviour ranges from cursorial hunting to building prey-catching webs and araneophagy with web invasion and aggressive mimicry. Web invasion and aggressive mimicry evolved once from an ancestral spartaeine that was already araneophagic and had no difficulty entering webs due to glue immunity. Web invasion and aggressive mimicry was lost once, in Paracyrba, which has replaced one highly specialized predation strategy with another (hunting mosquitoes). In contrast to the evolution of divergent behaviour, eyes with similarly high spatial acuity and ultrastructural design evolved convergently in the Salticoida and in Portia.

  9. Best practices for scholarly authors in the age of predatory journals.

    PubMed

    Beall, J

    2016-02-01

    'Continuous effort, not strength or intelligence, is the key to understanding our potential.' Margaret J Wheatley. The focus of any academic or research author is to share his or her findings, and to gain respect and reward for publishing. The ideal journal is one that not only publishes an article quickly but also helps the author to improve the article before publication through peer review, selects only the best research so that the author's article lies alongside other high quality articles, and provides maximum (and long-term) visibility and access to the article. Unfortunately, in the real world, authors need to make tradeoffs between high quality journals, those that work quickly, those that are willing to accept the article and those that provide the best access. Into this mix has come the potential of open access as a means of increasing visibility: journals publish the article without a subscription barrier so anyone, anywhere, can read the article. However, the growth of open access (pushed by institutions, grant bodies and governments as a means of improving human health and knowledge) has come with some unforeseen consequences. In this article, Jeffrey Beall discusses one recent phenomenon that has arisen from the open access movement: that of 'predatory publishers'. These are individuals or companies that use the open access financial system (author pays, rather than library subscribes) to defraud authors and readers by promising reputable publishing platforms but delivering nothing of the sort. They frequently have imaginary editorial boards, do not operate any peer review or quality control, are unclear about payment requirements and opaque about ownership or location, include plagiarised content and publish whatever somebody will pay them to publish. Predatory publishers generally make false promises to authors and behave unethically. They also undermine the scholarly information and publishing environment with a deluge of poor quality, unchecked

  10. Laboratory and field efficacy of Pedalium murex and predatory copepod, Mesocyclops longisetus on rural malaria vector, Anopheles culicifacies

    PubMed Central

    Chitra, Thangadurai; Murugan, Kadarkarai; Kumar, Arjunan Naresh; Madhiyazhagan, Pari; Nataraj, Thiyagarajan; Indumathi, Duraisamy; Hwang, Jiang-Shiou

    2013-01-01

    Objective To test the potentiality of the leaf extract of Pedalium murex (P. murex) and predatory copepod Mesocyclops longisetus (M. longisetus) in individual and combination in controlling the rural malarial vector, Anopheles culicifacies (An. culicifacies) in laboratory and field studies. Methods P. murex leaves were collected from in and around Erode, Tamilnadu, India. The active compounds were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus. Laboratory studies on larvicidal and pupicidal effects of methanolic extract of P. murex tested against the rural malarial vector, An. culicifacies were significant. Results Evaluated lethal concentrations (LC50) of P. murex extract were 2.68, 3.60, 4.50, 6.44 and 7.60 mg/L for I, II, III, IV and pupae of An. culicifacies, respectively. Predatory copepod, M. longisetus was examined for their predatory efficacy against the malarial vector, An. culicifacies. M. longisetus showed effective predation on the early instar (47% and 36% on I and II instar) when compared with the later ones (3% and 1% on III and IV instar). Predatory efficacy of M. longisetus was increased (70% and 45% on I and II instar) when the application was along with the P. murex extract. Conclusions Predator survival test showed that the methanolic extract of P. murex is non-toxic to the predatory copepod, M. longisetus. Experiments were also conducted to evaluate the efficacy of methanolic extract of P. murex and M. longisetus in the direct breeding sites (paddy fields) of An. culicifacies. Reduction in larval density was very high and sustained for a long time in combined treatment of P. murex and M. longisetus.

  11. Rapid determination of scopolamine in evidence of recreational and predatory use.

    PubMed

    Sáiz, Jorge; Mai, Thanh Duc; López, María López; Bartolomé, Carmen; Hauser, Peter C; García-Ruiz, Carmen

    2013-12-01

    In recent years, scopolamine has become a drug of common use for recreational and predatory purposes and several ways of administration have been devised. A method for the rapid analysis of suspicious samples was developed, using a portable capillary electrophoresis with contactless conductivity detection. The method allows the separation of scopolamine from atropine which has a similar structure and is present along with scopolamine in some samples. The method was demonstrated to be useful for the fast analysis of several types of evidential items which have recently been reported to have been abused with fatal consequences or employed for criminal purposes. An infusion of Datura stramonium L., in which scopolamine and atropine naturally coexist, was analyzed for being frequently consumed for recreational purposes. A spiked moisturizing cream and six spiked alcoholic beverages were also analyzed. In spite of the complexity of the specimens, the sample pre-treatment methods developed were simple and fast.

  12. The skull of the giant predatory pliosaur Rhomaleosaurus cramptoni: implications for plesiosaur phylogenetics

    NASA Astrophysics Data System (ADS)

    Smith, Adam S.; Dyke, Gareth J.

    2008-10-01

    The predatory pliosaurs were among the largest creatures ever to inhabit the oceans, some reaching gigantic proportions greater than 15 m in length. Fossils of this subclade of plesiosaurs are known from sediments all over the world, ranging in age from the Hettangian (approximately 198 Myr) to the Turonian (approximately 92 Myr). However, due to a lack of detailed studies and because only incomplete specimens are usually reported, pliosaur evolution remains poorly understood. In this paper, we describe the three dimensionally preserved skull of the giant Jurassic pliosaur Rhomaleosaurus cramptoni. The first phylogenetic analysis dedicated to in-group relationships of pliosaurs allows us to hypothesise a number of well-supported lineages that correlate with marine biogeography and the palaeoecology of these reptiles. Rhomaleosaurids comprised a short-lived and early diverging lineage within pliosaurs, whose open-water top-predator niche was filled by other pliosaur taxa by the mid-late Jurassic.

  13. A Devonian predatory fish provides insights into the early evolution of modern sarcopterygians

    PubMed Central

    Lu, Jing; Zhu, Min; Ahlberg, Per Erik; Qiao, Tuo; Zhu, You’an; Zhao, Wenjin; Jia, Liantao

    2016-01-01

    Crown or modern sarcopterygians (coelacanths, lungfishes, and tetrapods) differ substantially from stem sarcopterygians, such as Guiyu and Psarolepis, and a lack of transitional fossil taxa limits our understanding of the origin of the crown group. The Onychodontiformes, an enigmatic Devonian predatory fish group, seems to have characteristics of both stem and crown sarcopterygians but is difficult to place because of insufficient anatomical information. We describe the new skull material of Qingmenodus, a Pragian (~409-million-year-old) onychodont from China, using high-resolution computed tomography to image internal structures of the braincase. In addition to its remarkable similarities with stem sarcopterygians in the ethmosphenoid portion, Qingmenodus exhibits coelacanth-like neurocranial features in the otic region. A phylogenetic analysis based on a revised data set unambiguously assigns onychodonts to crown sarcopterygians as stem coelacanths. Qingmenodus thus bridges the morphological gap between stem sarcopterygians and coelacanths and helps to illuminate the early evolution and diversification of crown sarcopterygians. PMID:27386576

  14. Tetrodotoxin levels in larval and metamorphosed newts (Taricha granulosa) and palatability to predatory dragonflies.

    PubMed

    Gall, Brian G; Stokes, Amber N; French, Susannah S; Schlepphorst, Elizabeth A; Brodie, Edmund D; Brodie, Edmund D

    2011-06-01

    Some populations of the newt Taricha granulosa possess extremely high concentrations of the neurotoxin tetrodotoxin (TTX). Tetrodotoxin is present in adult newts and their eggs, but has been assumed to be absent from the larval stage. We tested larval and metamorphosed juveniles for the presence of TTX and evaluated the palatability of these developmental stages to predatory dragonfly nymphs. All developmental stages retained substantial quantities of TTX and almost all individuals were unpalatable to dragonfly nymphs. Tetrodotoxin quantity varied greatly among individuals. When adjusted for mass, TTX concentrations declined steadily through metamorphosis. Several juveniles were palatable to dragonflies and these individuals had significantly lower TTX levels than unpalatable juveniles. These results suggest that despite previous assumptions, substantial quantities of TTX, originally deposited in the embryo, are retained by the developing larvae and metamorphosed juveniles and this quantity is enough to make them unpalatable to some potential predators.

  15. Large predatory coral trout species unlikely to meet increasing energetic demands in a warming ocean

    PubMed Central

    Johansen, J.L.; Pratchett, M.S.; Messmer, V.; Coker, D.J.; Tobin, A.J.; Hoey, A.S.

    2015-01-01

    Increased ocean temperature due to climate change is raising metabolic demands and energy requirements of marine ectotherms. If productivity of marine systems and fisheries are to persist, individual species must compensate for this demand through increasing energy acquisition or decreasing energy expenditure. Here we reveal that the most important coral reef fishery species in the Indo-west Pacific, the large predatory coral trout Plectropomus leopardus (Serranidae), can behaviourally adjust food intake to maintain body-condition under elevated temperatures, and acclimate over time to consume larger meals. However, these increased energetic demands are unlikely to be met by adequate production at lower trophic levels, as smaller prey species are often the first to decline in response to climate-induced loss of live coral and structural complexity. Consequently, ubiquitous increases in energy consumption due to climate change will increase top-down competition for a dwindling biomass of prey, potentially distorting entire food webs and associated fisheries. PMID:26345733

  16. The predatory behaviour of the thylacine: Tasmanian tiger or marsupial wolf?

    PubMed

    Figueirido, Borja; Janis, Christine M

    2011-12-23

    The extinct thylacine (Thylacinus cynocephalus) and the extant grey wolf (Canis lupus) are textbook examples of convergence between marsupials and placentals. Craniodental studies confirm the thylacine's carnivorous diet, but little attention has been paid to its postcranial skeleton, which would confirm or refute rare eyewitness reports of a more ambushing predatory mode than the pack-hunting pursuit mode of wolves and other large canids. Here we show that thylacines had the elbow morphology typical of an ambush predator, and propose that the 'Tasmanian tiger' vernacular name might be more apt than the 'marsupial wolf'. The 'niche overlap hypothesis' with dingoes (Canis lupus dingo) as a main cause of thylacine extinction in mainland Australia is discussed in the light of this new information.

  17. Organization of somatosensory cortex in the northern grasshopper mouse (Onychomys leucogaster), a predatory rodent

    PubMed Central

    Sarko, Diana K.; Leitch, Duncan B.; Girard, Isabelle; Sikes, Robert S.; Catania, Kenneth C.

    2010-01-01

    Northern grasshopper mice (Onychomys leucogaster) are among the most highly carnivorous rodents in North America. Because predatory mammals may have specialization of senses used to detect prey, we investigated the organization of sensory areas within grasshopper mouse neocortex and quantified the number of myelinated axons in grasshopper mouse trigeminal, cochlear, and optic nerves. Multiunit electrophysiological recordings combined with analysis of flattened sections of neocortex processed for cytochrome oxidase were used to determine the topography of primary somatosensory cortex (S1) and the location and size of both the visual and auditory cortex in adult animals. These findings were then related to the distinctive chemoarchitecture of layer IV visible in flattened cortical sections of juvenile grasshopper mice labeled with the serotonin transporter (SERT) antibody, revealing a striking correspondence between electrophysiological maps and cortical anatomy. PMID:21120928

  18. The skull of the giant predatory pliosaur Rhomaleosaurus cramptoni: implications for plesiosaur phylogenetics.

    PubMed

    Smith, Adam S; Dyke, Gareth J

    2008-10-01

    The predatory pliosaurs were among the largest creatures ever to inhabit the oceans, some reaching gigantic proportions greater than 15 m in length. Fossils of this subclade of plesiosaurs are known from sediments all over the world, ranging in age from the Hettangian (approximately 198 Myr) to the Turonian (approximately 92 Myr). However, due to a lack of detailed studies and because only incomplete specimens are usually reported, pliosaur evolution remains poorly understood. In this paper, we describe the three dimensionally preserved skull of the giant Jurassic pliosaur Rhomaleosaurus cramptoni. The first phylogenetic analysis dedicated to in-group relationships of pliosaurs allows us to hypothesise a number of well-supported lineages that correlate with marine biogeography and the palaeoecology of these reptiles. Rhomaleosaurids comprised a short-lived and early diverging lineage within pliosaurs, whose open-water top-predator niche was filled by other pliosaur taxa by the mid-late Jurassic.

  19. Large predatory coral trout species unlikely to meet increasing energetic demands in a warming ocean.

    PubMed

    Johansen, J L; Pratchett, M S; Messmer, V; Coker, D J; Tobin, A J; Hoey, A S

    2015-09-08

    Increased ocean temperature due to climate change is raising metabolic demands and energy requirements of marine ectotherms. If productivity of marine systems and fisheries are to persist, individual species must compensate for this demand through increasing energy acquisition or decreasing energy expenditure. Here we reveal that the most important coral reef fishery species in the Indo-west Pacific, the large predatory coral trout Plectropomus leopardus (Serranidae), can behaviourally adjust food intake to maintain body-condition under elevated temperatures, and acclimate over time to consume larger meals. However, these increased energetic demands are unlikely to be met by adequate production at lower trophic levels, as smaller prey species are often the first to decline in response to climate-induced loss of live coral and structural complexity. Consequently, ubiquitous increases in energy consumption due to climate change will increase top-down competition for a dwindling biomass of prey, potentially distorting entire food webs and associated fisheries.

  20. A behavioural framework for the evolution of feeding in predatory aquatic mammals.

    PubMed

    Hocking, David P; Marx, Felix G; Park, Travis; Fitzgerald, Erich M G; Evans, Alistair R

    2017-03-15

    Extant aquatic mammals are a key component of aquatic ecosystems. Their morphology, ecological role and behaviour are, to a large extent, shaped by their feeding ecology. Nevertheless, the nature of this crucial aspect of their biology is often oversimplified and, consequently, misinterpreted. Here, we introduce a new framework that categorizes the feeding cycle of predatory aquatic mammals into four distinct functional stages (prey capture, manipulation and processing, water removal and swallowing), and details the feeding behaviours that can be employed at each stage. Based on this comprehensive scheme, we propose that the feeding strategies of living aquatic mammals form an evolutionary sequence that recalls the land-to-water transition of their ancestors. Our new conception helps to explain and predict the origin of particular feeding styles, such as baleen-assisted filter feeding in whales and raptorial 'pierce' feeding in pinnipeds, and informs the structure of present and past ecosystems.

  1. The Dual Protection of a Micro Land Snail against a Micro Predatory Snail

    PubMed Central

    Wada, Shinichiro; Chiba, Satoshi

    2013-01-01

    Defense against a single predatory attack strategy may best be achieved not by a single trait but by a combination of different traits. We tested this hypothesis experimentally by examining the unique shell traits (the protruded aperture and the denticles within the aperture) of the micro land snail Bensonella plicidens. We artificially altered shell characteristics by removing the denticles and/or cutting the protruded aperture. These snails were offered to the carnivorous micro land snail Indoennea bicolor, which preys on the snails by gaining entry to their shell. B. plicidens exhibited the best defence when both of the traits studied were present; the defensive ability of B. plicidens decreased if either trait was removed and was further reduced if both traits were removed. These results suggest that a combination of different traits provides more effective defence against attack by the predator than either single trait by itself. PMID:23326582

  2. Predatory fish sounds can alter crab foraging behaviour and influence bivalve abundance

    PubMed Central

    Hughes, A. Randall; Mann, David A.; Kimbro, David L.

    2014-01-01

    The risk of predation can have large effects on ecological communities via changes in prey behaviour, morphology and reproduction. Although prey can use a variety of sensory signals to detect predation risk, relatively little is known regarding the effects of predator acoustic cues on prey foraging behaviour. Here we show that an ecologically important marine crab species can detect sound across a range of frequencies, probably in response to particle acceleration. Further, crabs suppress their resource consumption in the presence of experimental acoustic stimuli from multiple predatory fish species, and the sign and strength of this response is similar to that elicited by water-borne chemical cues. When acoustic and chemical cues were combined, consumption differed from expectations based on independent cue effects, suggesting redundancies among cue types. These results highlight that predator acoustic cues may influence prey behaviour across a range of vertebrate and invertebrate taxa, with the potential for cascading effects on resource abundance. PMID:24943367

  3. A behavioural framework for the evolution of feeding in predatory aquatic mammals

    PubMed Central

    Fitzgerald, Erich M. G.; Evans, Alistair R.

    2017-01-01

    Extant aquatic mammals are a key component of aquatic ecosystems. Their morphology, ecological role and behaviour are, to a large extent, shaped by their feeding ecology. Nevertheless, the nature of this crucial aspect of their biology is often oversimplified and, consequently, misinterpreted. Here, we introduce a new framework that categorizes the feeding cycle of predatory aquatic mammals into four distinct functional stages (prey capture, manipulation and processing, water removal and swallowing), and details the feeding behaviours that can be employed at each stage. Based on this comprehensive scheme, we propose that the feeding strategies of living aquatic mammals form an evolutionary sequence that recalls the land-to-water transition of their ancestors. Our new conception helps to explain and predict the origin of particular feeding styles, such as baleen-assisted filter feeding in whales and raptorial ‘pierce’ feeding in pinnipeds, and informs the structure of present and past ecosystems. PMID:28250183

  4. Ink from longfin inshore squid, Doryteuthis pealeii, as a chemical and visual defense against two predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis.

    PubMed

    Derby, Charles D; Tottempudi, Mihika; Love-Chezem, Tiffany; Wolfe, Lanna S

    2013-12-01

    Chemical and visual defenses are used by many organisms to avoid being approached or eaten by predators. An example is inking molluscs-including gastropods such as sea hares and cephalopods such as squid, cuttlefish, and octopus-which release a colored ink upon approach or attack. Previous work showed that ink can protect molluscs through a combination of chemical, visual, and other effects. In this study, we examined the effects of ink from longfin inshore squid, Doryteuthis pealeii, on the behavior of two species of predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis. Using a cloud assay, we found that ink from longfin inshore squid affected the approach phase of predation by summer flounder, primarily through its visual effects. Using a food assay, we found that the ink affected the consummatory and ingestive phase of predation of both sea catfish and summer flounder, through the ink's chemical properties. Fractionation of ink showed that most of its deterrent chemical activity is associated with melanin granules, suggesting that either compounds adhering to these granules or melanin itself are the most biologically active. This work provides the basis for a comparative approach to identify deterrent molecules from inking cephalopods and to examine neural mechanisms whereby these chemicals affect behavior of fish, using the sea catfish as a chemosensory model.

  5. Molecular Diversity and Gene Evolution of the Venom Arsenal of Terebridae Predatory Marine Snails

    PubMed Central

    Gorson, Juliette; Ramrattan, Girish; Verdes, Aida; Wright, Elizabeth M.; Kantor, Yuri; Rajaram Srinivasan, Ramakrishnan; Musunuri, Raj; Packer, Daniel; Albano, Gabriel; Qiu, Wei-Gang; Holford, Mandë

    2015-01-01

    Venom peptides from predatory organisms are a resource for investigating evolutionary processes such as adaptive radiation or diversification, and exemplify promising targets for biomedical drug development. Terebridae are an understudied lineage of conoidean snails, which also includes cone snails and turrids. Characterization of cone snail venom peptides, conotoxins, has revealed a cocktail of bioactive compounds used to investigate physiological cellular function, predator-prey interactions, and to develop novel therapeutics. However, venom diversity of other conoidean snails remains poorly understood. The present research applies a venomics approach to characterize novel terebrid venom peptides, teretoxins, from the venom gland transcriptomes of Triplostephanus anilis and Terebra subulata. Next-generation sequencing and de novo assembly identified 139 putative teretoxins that were analyzed for the presence of canonical peptide features as identified in conotoxins. To meet the challenges of de novo assembly, multiple approaches for cross validation of findings were performed to achieve reliable assemblies of venom duct transcriptomes and to obtain a robust portrait of Terebridae venom. Phylogenetic methodology was used to identify 14 teretoxin gene superfamilies for the first time, 13 of which are unique to the Terebridae. Additionally, basic local algorithm search tool homology-based searches to venom-related genes and posttranslational modification enzymes identified a convergence of certain venom proteins, such as actinoporin, commonly found in venoms. This research provides novel insights into venom evolution and recruitment in Conoidean predatory marine snails and identifies a plethora of terebrid venom peptides that can be used to investigate fundamental questions pertaining to gene evolution. PMID:26025559

  6. Marine reserves reestablish lost predatory interactions and cause community changes in rocky reefs.

    PubMed

    Guidetti, Paolo

    2006-06-01

    In the last decades, marine reserves have dramatically increased in number worldwide. Here I examined the potential of no-take marine reserves to reestablish lost predatory interactions and, in turn, cause community-wide changes in Mediterranean rocky reefs. Protected locations supported higher density and size of the most effective fish preying on sea urchins (the sea breams Diplodus sargus and D. vulgaris) than unprotected locations. Density of sea urchins (Paracentrotus lividus and Arbacia lixula) was lower at protected than at unprotected locations. Size structure of P. lividus was bimodal (a symptom of predation on medium-sized urchins) only at the protected locations. Coralline barrens were less extended at protected than at unprotected locations, whereas turf-forming and erect-branched algae showed an opposite pattern. Erect-unbranched and erect-calcified algae and conspicuous zoobenthic organisms did not show any pattern related to protection. Tethering experiments showed that predation impact on urchins was (1) higher at protected than at unprotected locations, (2) higher on P. lividus than on A. lixula, and (3) higher on medium-sized (2-3.5 cm test diameter) than large-sized (>3.5 cm) urchins. Sea urchins preyed on by fish in natural conditions were smaller at unprotected than at protected locations. The analysis of sea urchin remains found in Diplodus fish stomachs revealed that medium-sized P. lividus were the most frequently preyed upon urchins and that size range of consumed sea urchins expanded with increasing size of Diplodus fish. These results suggest that (1) depletion and size reduction of predatory fish caused by fishing alter patterns of predation on sea urchins, and that (2) fishing bans (e.g., within no-take marine reserves) may reestablish lost interactions among strongly interactive species in temperate rocky reefs with potential community-wide effects.

  7. Analysis of gene gain and loss in the evolution of predatory bacteria.

    PubMed

    Li, Nan; Wang, Kai; Williams, Henry N; Sun, Jun; Ding, Changling; Leng, Xiaoyun; Dong, Ke

    2017-01-20

    Predatory bacteria are ubiquitously distributed in nature in including in aquatic environments, sewage, intestinal tracts of animals and humans, rhizophere and, soils. However, our understanding of their evolutionary history is limited. Results of recent studies have shown that acquiring novel genes is a major force driving bacterial evolution. Therefore, to gain a better understanding of the impact of gene gain and loss in the evolution of bacterial predators, this study employed comparative genomic approaches to identify core-set gene families and species-specific gene families, and model gene gain and loss events among 11 genomes that represented diverse lineages. In total, 1977 gene families were classified. Of these 509 (pattern 11111111111) were present all of the 11 species. Among the non-core set gene families, 52 were present only in saltwater bacteria predators and had no ortholog in the other genomes. Similarly 109 and 44 were present only in the genomes of Micavibrio spp. and Bdellovibrio spp., respectively. In this study, the gain loss mapping engine GLOOME was selected to analyze and estimate the expectations and probabilities of both gain and loss events in the predatory bacteria. In total, 354 gene families were involved in significant gene gain events, and 407 gene families were classified into gene loss events with high supported value. Moreover, 18 families from the core set gene family were identified as putative genes under positive selection. The results of this study suggest that acquisition of particular genes that encode functional proteins in metabolism and cellular processes and signaling, especially ABC systems, may help bacterial predators adapt to surrounding environmental changes and present different predation strategies for survival in their habitats.

  8. Transcriptome Analysis in Venom Gland of the Predatory Giant Ant Dinoponera quadriceps: Insights into the Polypeptide Toxin Arsenal of Hymenopterans

    PubMed Central

    Chong, Cheong-Meng; Leung, Siu Wai; Prieto-da-Silva, Álvaro R. B.; Havt, Alexandre; Quinet, Yves P.; Martins, Alice M. C.; Lee, Simon M. Y.; Rádis-Baptista, Gandhi

    2014-01-01

    Background Dinoponera quadriceps is a predatory giant ant that inhabits the Neotropical region and subdues its prey (insects) with stings that deliver a toxic cocktail of molecules. Human accidents occasionally occur and cause local pain and systemic symptoms. A comprehensive study of the D. quadriceps venom gland transcriptome is required to advance our knowledge about the toxin repertoire of the giant ant venom and to understand the physiopathological basis of Hymenoptera envenomation. Results We conducted a transcriptome analysis of a cDNA library from the D. quadriceps venom gland with Sanger sequencing in combination with whole-transcriptome shotgun deep sequencing. From the cDNA library, a total of 420 independent clones were analyzed. Although the proportion of dinoponeratoxin isoform precursors was high, the first giant ant venom inhibitor cysteine-knot (ICK) toxin was found. The deep next generation sequencing yielded a total of 2,514,767 raw reads that were assembled into 18,546 contigs. A BLAST search of the assembled contigs against non-redundant and Swiss-Prot databases showed that 6,463 contigs corresponded to BLASTx hits and indicated an interesting diversity of transcripts related to venom gene expression. The majority of these venom-related sequences code for a major polypeptide core, which comprises venom allergens, lethal-like proteins and esterases, and a minor peptide framework composed of inter-specific structurally conserved cysteine-rich toxins. Both the cDNA library and deep sequencing yielded large proportions of contigs that showed no similarities with known sequences. Conclusions To our knowledge, this is the first report of the venom gland transcriptome of the New World giant ant D. quadriceps. The glandular venom system was dissected, and the toxin arsenal was revealed; this process brought to light novel sequences that included an ICK-folded toxins, allergen proteins, esterases (phospholipases and carboxylesterases), and lethal

  9. Mercury Bioaccumulation Response to Recent Hg Pollution Abatement in an Oceanic Predatory Fish, Blue Marlin, Versus the Response in a Coastal Predatory Species, Bluefish, in the Western North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Barber, R. T.; Cross, F. A.

    2015-12-01

    The consumption of marine fish, especially predatory species high in the food chain, is the major route through which people in developed countries are exposed to mercury. Recent work on a coastal species, bluefish (Pomatomus saltatrix), determined that the mercury concentration in fish from the U. S. Mid-Atlantic coast decreased 43% from 1972 to 2011. This mercury decline in a coastal marine fish parallels the mercury decline in many freshwater fish in the U.S. and Canada during the same time period. The result heightens interest in determining whether or not there has been any change in mercury concentration in oceanic predatory fish species, that is, fish that are permanent residents of the open ocean, during the past four decades. To answer this question we compared mercury analyses we made in the 1970s on tournament-caught blue marlin (Makaira nigricans) with those we made from 1998 to 2013. This comparison indicates that from the 1970s to 2013 mercury concentration in blue marlin caught in the western North Atlantic Ocean off the U.S. east coast has declined about 45%, a decline that is remarkably similar to the decline reported in coastal bluefish. These results suggest that a large area of the western North Atlantic Ocean is responding to reductions in emissions of mercury in the U.S. and Canada with reduced mercury bioaccumulation in predatory fish.

  10. Best practices for scholarly authors in the age of predatory journals

    PubMed Central

    Beall, J

    2016-01-01

    ‘Continuous effort, not strength or intelligence, is the key to understanding our potential.’ Margaret J Wheatley The focus of any academic or research author is to share his or her findings, and to gain respect and reward for publishing. The ideal journal is one that not only publishes an article quickly but also helps the author to improve the article before publication through peer review, selects only the best research so that the author’s article lies alongside other high quality articles, and provides maximum (and long-term) visibility and access to the article. Unfortunately, in the real world, authors need to make tradeoffs between high quality journals, those that work quickly, those that are willing to accept the article and those that provide the best access. Into this mix has come the potential of open access as a means of increasing visibility: journals publish the article without a subscription barrier so anyone, anywhere, can read the article. However, the growth of open access (pushed by institutions, grant bodies and governments as a means of improving human health and knowledge) has come with some unforeseen consequences. In this article, Jeffrey Beall discusses one recent phenomenon that has arisen from the open access movement: that of ‘predatory publishers’. These are individuals or companies that use the open access financial system (author pays, rather than library subscribes) to defraud authors and readers by promising reputable publishing platforms but delivering nothing of the sort. They frequently have imaginary editorial boards, do not operate any peer review or quality control, are unclear about payment requirements and opaque about ownership or location, include plagiarised content and publish whatever somebody will pay them to publish. Predatory publishers generally make false promises to authors and behave unethically. They also undermine the scholarly information and publishing environment with a deluge of poor quality

  11. An Extended Cyclic Di-GMP Network in the Predatory Bacterium Bdellovibrio bacteriovorus

    PubMed Central

    Rotem, Or; Nesper, Jutta; Borovok, Ilya; Gorovits, Rena; Kolot, Mikhail; Pasternak, Zohar; Shin, Irina; Glatter, Timo; Pietrokovski, Shmuel; Jenal, Urs

    2015-01-01

    ABSTRACT Over the course of the last 3 decades the role of the second messenger cyclic di-GMP (c-di-GMP) as a master regulator of bacterial physiology was determined. Although the control over c-di-GMP levels via synthesis and breakdown and the allosteric regulation of c-di-GMP over receptor proteins (effectors) and riboswitches have been extensively studied, relatively few effectors have been identified and most are of unknown functions. The obligate predatory bacterium Bdellovibrio bacteriovorus has a peculiar dimorphic life cycle, in which a phenotypic transition from a free-living attack phase (AP) to a sessile, intracellular predatory growth phase (GP) is tightly regulated by specific c-di-GMP diguanylate cyclases. B. bacteriovorus also bears one of the largest complement of defined effectors, almost none of known functions, suggesting that additional proteins may be involved in c-di-GMP signaling. In order to uncover novel c-di-GMP effectors, a c-di-GMP capture-compound mass-spectroscopy experiment was performed on wild-type AP and host-independent (HI) mutant cultures, the latter serving as a proxy for wild-type GP cells. Eighty-four proteins were identified as candidate c-di-GMP binders. Of these proteins, 65 did not include any recognized c-di-GMP binding site, and 3 carried known unorthodox binding sites. Putative functions could be assigned to 59 proteins. These proteins are included in metabolic pathways, regulatory circuits, cell transport, and motility, thereby creating a potentially large c-di-GMP network. False candidate effectors may include members of protein complexes, as well as proteins binding nucleotides or other cofactors that were, respectively, carried over or unspecifically interacted with the capture compound during the pulldown. Of the 84 candidates, 62 were found to specifically bind the c-di-GMP capture compound in AP or in HI cultures, suggesting c-di-GMP control over the whole-cell cycle of the bacterium. High affinity and

  12. Toxicity of the herbicide glufosinate-ammonium to predatory insects and mites of Tetranychus urticae (Acari: Tetranychidae) under laboratory conditions.

    PubMed

    Ahn, Y J; Kim, Y J; Yoo, J K

    2001-02-01

    The toxicities of the herbicide glufosinate-ammonium to three predatory insect and two predatory mite species of Tetranychus urticae Koch were determined in the laboratory by the direct contact application. At a concentration of 540 ppm (a field application rate for weed control in apple orchards), glufosinate-ammonium was almost nontoxic to eggs of Amblyseius womersleyi Schicha, Phytoseiulus persimilis Athias-Henriot, and T. urticae but highly toxic to nymphs and adults of these three mite species, indicating that a common mode of action between predatory and phytophagous mites might be involved. In tests with predatory insects using 540 ppm, glufosinate-ammonium revealed little or no harm to larvae and pupae of Chrysopa pallens Rambur but was slightly harmful to eggs (71.2% mortality), nymphs (65.0% mortality), and adults (57.7% mortality) of Orius strigicollis Poppius. The herbicide showed no direct effect on eggs and adults of Harmonia axyridis (Pallas) but was harmful, slightly harmful, and harmless to first instars (100% mortality), fourth instars (51.1% mortality), and pupae (24.5% mortality), respectively. The larvae and nymphs of predators died within 12 h after treatment, suggesting that the larvicidal and nymphicidal action may be attributable to a direct effect rather than an inhibitory action of chitin synthesis. On the basis of our data, glufosinate-ammonium caused smaller effects on test predators than on T. urticae with the exception of P. persimilis, although the mechanism or cause of selectivity remains unknown. Glufosinate-ammonium merits further study as a key component of integrated pest management.

  13. Field studies to determine mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation.

    PubMed

    Miles, M; Kemmitt, G

    2005-01-01

    Mancozeb is an ethylene bisdithiocarbamate (EBDC) fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a number of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites has been reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted in France, Germany, Italy, Portugal and Spain where either 2 or 4 applications of mancozeb containing products were made per season at different spray timings. These trials covered the representative range of uses, agronomic practices, mite species and geographical locations in Europe. In this paper findings from ten field studies in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

  14. The first exposure assessment of legacy and unrestricted brominated flame retardants in predatory birds of Pakistan.

    PubMed

    Abbasi, Naeem Akhtar; Eulaers, Igor; Jaspers, Veerle Leontina Bernard; Chaudhry, Muhammad Jamshed Iqbal; Frantz, Adrien; Ambus, Per Lennart; Covaci, Adrian; Malik, Riffat Naseem

    2017-01-01

    The exposure to legacy polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs) and unrestricted 1,2-bis (2,4,6-tribromophenoxy) ethane (BTBPE), bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5-tetrabromo-benzoate (EH-TBB) was examined in tail feathers of 76 birds belonging to ten predatory species inhabiting Pakistan. In addition, different feather types of six individuals of Black kite (Milvus migrans) were compared for their brominated flame retardant (BFR) levels. Black kite was found to be the most contaminated species with a median (minimum-maximum) tail feather concentration of 2.4 (0.70-7.5) ng g(-1) dw for ∑PBDEs, 1.5 (0.5-8.1) ng g(-1) dw for ∑HBCDDs and 0.10 ( 0.05 for both). Similarly, no significant concentration differences were observed among different feather types (all P > 0.05) suggesting their similar exposure. While variables such as species, trophic guild and δ(15)N values were evaluated as major predictors for BFR accumulation in the studied species, we predict that combined effects of just mentioned factors may govern the intra- and interspecific differences in BFR contamination profiles. We urge for further investigation of BFR exposure and potential toxicological effects in

  15. Stickleback increase in the Baltic Sea - A thorny issue for coastal predatory fish

    NASA Astrophysics Data System (ADS)

    Bergström, Ulf; Olsson, Jens; Casini, Michele; Eriksson, Britas Klemens; Fredriksson, Ronny; Wennhage, Håkan; Appelberg, Magnus

    2015-09-01

    In the Baltic Sea, the mesopredator three-spined stickleback (Gasterosteus aculeatus) spends a large part of its life cycle in the open sea, but reproduces in shallow coastal habitats. In coastal waters, it may occur in high abundances, is a potent predator on eggs and larvae of fish, and has been shown to induce trophic cascades with resulting eutrophication symptoms through regulation of invertebrate grazers. Despite its potential significance for the coastal food web, little is known about its life history and population ecology. This paper provides a description of life history traits, migration patterns and spatiotemporal development of the species in the Baltic Sea during the past decades, and tests the hypothesis that stickleback may have a negative impact on populations of coastal predatory fish. Offshore and coastal data during the last 30 years show that stickleback has increased fourfold in the Bothnian Sea, 45-fold in the Central Baltic Sea and sevenfold in the Southern Baltic Sea. The abundances are similar in the two northern basins, and two orders of magnitude lower in the Southern Baltic Sea. The coastward spawning migration of sticklebacks from offshore areas peaks in early May, with most spawners being two years of age at a mean length of 65 mm. The early juvenile stage is spent at the coast, whereafter sticklebacks perform a seaward feeding migration in early autumn at a size of around 35 mm. A negative spatial relation between the abundance of stickleback and early life stages of perch and pike at coastal spawning areas was observed in spatial survey data, indicating strong interactions between the species. A negative temporal relationship was observed also between adult perch and stickleback in coastal fish monitoring programmes supporting the hypothesis that stickleback may have negative population level effects on coastal fish predators. The recent increase in stickleback populations in different basins of the Baltic Sea in combination with

  16. Intraguild predation between Amblyseius swirskii and two native Chinese predatory mite species and their development on intraguild prey.

    PubMed

    Guo, Yingwei; Lv, Jiale; Jiang, Xiaohuan; Wang, Boming; Gao, Yulin; Wang, Endong; Xu, Xuenong

    2016-03-14

    Amblyseius swirskii, native to the east and southeast Mediterranean region, is a successful biological control agent of whiteflies. In this study, we investigated intraguild predations (IGP) between each stage of A. swirskii and each stage of two Phytoseiid species that occur in China, Amblyseius orientalis and Neoseiulus californicus. When there was no whitefly egg provided as the extraguild prey, IGP between A. swirskii and A. orientalis, and between A. swirskii and N. californicus, was observed in 10 and 20 out of 35 combinations, respectively. When IGP was observed, A. swirskii was the intraguild predator in 70% and 65% cases of A. orientalis and N. californicus predation, respectively. These results suggest that A. swirskii is a more aggressive intraguild predator compared to either A. orientalis or N. californicus. When whitefly eggs were provided as the extraguild prey, IGP between A. swirskii and N. californicus decreased greatly, but no significant decrease of IGP was observed between A. swirskii and A. orientalis. Amblyseius swirskii was able to complete development on both heterospecific predatory mites, and both heterospecific predatory mites completed their development on A. swirskii. Possible impacts that A. swirskii may have on local predatory mite populations in China are discussed.

  17. Genome Sequencing of the Phytoseiid Predatory Mite Metaseiulus occidentalis Reveals Completely Atomized Hox Genes and Superdynamic Intron Evolution.

    PubMed

    Hoy, Marjorie A; Waterhouse, Robert M; Wu, Ke; Estep, Alden S; Ioannidis, Panagiotis; Palmer, William J; Pomerantz, Aaron F; Simão, Felipe A; Thomas, Jainy; Jiggins, Francis M; Murphy, Terence D; Pritham, Ellen J; Robertson, Hugh M; Zdobnov, Evgeny M; Gibbs, Richard A; Richards, Stephen

    2016-06-27

    Metaseiulus occidentalis is an eyeless phytoseiid predatory mite employed for the biological control of agricultural pests including spider mites. Despite appearances, these predator and prey mites are separated by some 400 Myr of evolution and radically different lifestyles. We present a 152-Mb draft assembly of the M. occidentalis genome: Larger than that of its favored prey, Tetranychus urticae, but considerably smaller than those of many other chelicerates, enabling an extremely contiguous and complete assembly to be built-the best arachnid to date. Aided by transcriptome data, genome annotation cataloged 18,338 protein-coding genes and identified large numbers of Helitron transposable elements. Comparisons with other arthropods revealed a particularly dynamic and turbulent genomic evolutionary history. Its genes exhibit elevated molecular evolution, with strikingly high numbers of intron gains and losses, in stark contrast to the deer tick Ixodes scapularis Uniquely among examined arthropods, this predatory mite's Hox genes are completely atomized, dispersed across the genome, and it encodes five copies of the normally single-copy RNA processing Dicer-2 gene. Examining gene families linked to characteristic biological traits of this tiny predator provides initial insights into processes of sex determination, development, immune defense, and how it detects, disables, and digests its prey. As the first reference genome for the Phytoseiidae, and for any species with the rare sex determination system of parahaploidy, the genome of the western orchard predatory mite improves genomic sampling of chelicerates and provides invaluable new resources for functional genomic analyses of this family of agriculturally important mites.

  18. Comparison of bacterial microbiota of the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae) and its factitious prey Tyrophagus putrescentiae (Acari: Acaridae).

    PubMed

    Pekas, Apostolos; Palevsky, Eric; Sumner, Jason C; Perotti, M Alejandra; Nesvorna, Marta; Hubert, Jan

    2017-12-01

    Neoseiulus cucumeris is a predatory mite used for biological control of arthropod pests. Mass-reared predators are fed with factitious prey mites such as Tyrophagus putrescentiae. Although some information on certain endosymbionts of N. cucumeris and T. putrescentiae exists, it is unclear whether both species share bacterial communities. The bacterial communities in populations of predator and prey mites, as well as the occurence of potential acaropathogenic bacteria were analyzed. The comparisons were based on the following groups: (i) N. cucumeris mass-production; (ii) N. cucumeris laboratory population with disease symptoms; (iii) T. putrescentiae pure populations and; (iv) T. putrescentiae from rearing units of N. cucumeris. Only 15% of OTUs were present in all samples from predatory and prey mite populations (core OTUs): the intracellular symbionts Wolbachia, Cardinium, plus other Blattabacterium-like, Solitalea-like, and Bartonella-like symbionts. Environmental bacteria were more abundant in predatory mites, while symbiotic bacteria prevailed in prey mites. Relative numbers of certain bacterial taxa were significantly different between the microbiota of prey mites reared with and without N. cucumeris. No significant differences were found in the bacterial communities of healthy N. cucumeris compared to N. cucumeris showing disease symptoms. We did not identify any confirmed acaropathogenic bacteria among microbiota.

  19. Propensity towards cannibalism among Hypoaspis aculeifer and H. miles, two soil-dwelling predatory mite species.

    PubMed

    Berndt, Oliver; Meyhöfer, Rainer; Poehling, Hans-Michael

    2003-01-01

    In biological control programmes, the two predatory soil mites Hypoaspis aculeifer and H. miles are often applied against soil-borne pests like mushroom flies, springtails and mites. Although the mites show high consumption rates on varying prey types in Petri dish experiments and in greenhouses, their overall efficiency is sometimes limited. We hypothesized that intraspecific interactions, like cannibalism, could contribute to this decreased competence. Therefore, experiments were conducted to show the propensity of H. aculeifer and H. miles to cannibalise. Adult mites and nymphs were introduced as predators with conspecific eggs, larvae, nymphs, adult females or males as prey and the number of killed individuals was recorded. Additionally, the oviposition rate on conspecific prey was quantified and the correlation with the number of prey consumed was calculated to assess the influence of cannibalism on egg production. The results illustrate that cannibalism occurs infrequently in both Hypoaspis spp., the only exception being H. aculeifer nymphs, which cannibalised one conspecific egg per day. Moreover, cannibalism never occurred in the presence of alternative prey. Oviposition rate decreased during the experiment in both species but it was positively correlated with the cannibalism rate only for H. aculeifer. The benefit of cannibalism for populations of H. aculeifer and H. miles is discussed.

  20. A predatory bivalved euarthropod from the Cambrian (Stage 3) Xiaoshiba Lagerstätte, South China

    PubMed Central

    Yang, Jie; Ortega-Hernández, Javier; Lan, Tian; Hou, Jin-bo; Zhang, Xi-guang

    2016-01-01

    Bivalved euarthropods represent a conspicuous component of exceptionally-preserved fossil biotas throughout the Lower Palaeozoic. However, most of these taxa are known from isolated valves, and thus there is a limited understanding of their morphological organization and palaeoecology in the context of early animal-dominated communities. The bivalved euarthropod Clypecaris serrata sp. nov., recovered from the Cambrian (Stage 3) Hongjingshao Formation in Kunming, southern China, is characterized by having a robust first pair of raptorial appendages that bear well-developed ventral-facing spines, paired dorsal spines on the trunk, and posteriorly oriented serrations on the anteroventral margins of both valves. The raptorial limbs of C. serrata were adapted for grasping prey employing a descending stroke for transporting it close the mouth, whereas the backwards-facing marginal serrations of the bivalved carapace may have helped to secure the food items during feeding. The new taxon offers novel insights on the morphology of the enigmatic genus Clypecaris, and indicates that the possession of paired dorsal spines is a diagnostic trait of the Family Clypecarididae within upper stem-group Euarthropoda. C. serrata evinces functional adaptations for an active predatory lifestyle within the context of Cambrian bivalved euarthropods, and contributes towards the better understanding of feeding diversity in early ecosystems. PMID:27283406

  1. Locomotion speeds from trackways: Predatory dinosaurs moved faster than herbivorous dinosaurs

    NASA Astrophysics Data System (ADS)

    Lee, Scott A.

    2014-03-01

    Fossilized trackways from dinosaurs leaves evidence of their locomotion from the stride length S and foot length F which yields the leg length L. From studies of living animals, it is known that a walking animal has a relative stride length RSL (= S/L) less than 2 and a running animal has a RSL greater than 2. A statistical analysis was performed of trackways associated with three groups of herbivorous dinosaurs: sauropods (N = 23), the armored ankylosaurs and stegosaurs (N = 10), and the unarmored ornithopods (N = 23) as well as the predatory theropods (N = 35). The average RSL of the sauropods and the armored dinosaurs were both 0.9 +/- 0.3. The ornithopods had an average RSL of 1.2 +/- 0.2. None of the trackways associated with herbivorous dinosaurs have an RSL greater than 1.5, indicating that they were all walking. The theropods showed the fastest and most varied locomomtion: their highest average RSL was 1.8 +/- 0.7. Nine of the theropod trackways had an RSL greater than 2.0, indicating that the dinosaurs were running when they made those trackways. One of the theropod trackways had an RSL of 4.5, indicating that it was running very fast compared to its body length.

  2. Purification and Characterization of Midgut α-Amylase in a Predatory Bug, Andralus spinidens

    PubMed Central

    Sorkhabi-Abdolmaleki, Sahar; Zibaee, Arash; Hoda, Hassan; Fazeli-Dinan, Mahmoud

    2014-01-01

    α-Amylases are widespread enzymes that catalyze endohydrolysis of long α-1,4-glucan chains such as starch and glycogen. The highest amylolytic activity was found in 5th instar nymphs and midgut of the predatory bug, Andrallus spinidens F. (Hemiptera: Pentatomidae). The α-amylase was purified following a three-step procedure. The purified α-amylase had a specific activity of 13.46 U/mg protein, recovery of 4.21, purification fold of 13.87, and molecular weight of 21.3 kDa. The enzyme had optimal pH and temperature of 7 and 45°C, respectively. Na+, Mn+, Mg2+, and Zn2+ significantly decreased activity of the purified α-amylase, but some concentrations of K+, Ca2+, and Cu2+ had the opposite effect. EDTA, EGTA, and DTC significantly decreased enzymatic activity, showing the presence of metal ions in the catalytic site of the enzyme. Kinetic parameters of the purified α-amylase showed a Km of 3.71% in starch and 4.96% for glycogen, suggesting that the enzyme had a higher affinity for starch. PMID:25373212

  3. Combined effect of predatory zooplankton and allelopathic aquatic macrophytes on algal suppression.

    PubMed

    Zuo, Shengpeng; Wan, Kun; Ma, Sumin

    2015-01-01

    The present study evaluated the combined effects of four typical predatory zooplankton and allelopathic aquatic macrophytes on algal control in a microcosm system. It would determine the effects of diverse species and biological restoration on the growth of harmful water-bloom microalgae in great lakes polluted by excess nutrients. It was found that the mixtures of each zooplankton and the floating plant Nymphoides peltatum had stronger inhibitory effects on harmful water-bloom microalgae than the individual species in clean or eutrophic water bodies. In addition, a community of four zooplankton types had a synergistic effect on algal inhibition. Algal suppression by the zooplankton community was enhanced significantly when the macrophyte was co-cultured in the microcosm. Furthermore, Chlorella pyrenoidosa was more susceptible than Microcystis aeruginosa when exposed to grazing by zooplankton and the allelopathic potential of the macrophyte. Algal inhibition was also weaker in eutrophic conditions compared with the control. These findings indicate that diverse species may enhance algal inhibition. Therefore, it is necessary to restore biological diversity and rebuild an ecologically balanced food chain or web to facilitate the control of harmful algal blooms in eutrophic lakes.

  4. Response of predatory zooplankton populations to the experimental acidification of Little Rock Lake, Wisconsin

    SciTech Connect

    Sierszen, M.E.; Frost, T.M.

    1993-01-01

    To assess the effects of lake acidification on large predatory zooplankton, the authors monitored population levels of four limnetic taxa for 6 years in a lake with two basins, one of which was experimentally acidified (2 years at each of three levels: pH 5.6, 5.2 and 4.7). Concentrations of phantom midge (Chaoborus spp.), the most abundant large predator, remained similar in the treatment and reference basins until the fourth year (pH 5.2) when they increased in the treatment basin. In contrast, Epischura lacustris and Leptodora kindtii disappeared from limnetic samples, and water mites declined to near zero upon acidification. Treatment basin populations of E. lacustris declined sharply during the second year of acidification. The nature of the decline suggested sensitivity of an early life stage during the first year at pH 5.6. Leptodora kindtii showed no population response at pH 5.6, but declined to essentially zero at pH 5.2. Treatment basin populations of water mites fluctuated until declining in the fifth and sixth years (pH 4.7). These changes indicate a variety of direct and indirect responses to lake acidification.

  5. Transcriptome and Difference Analysis of Fenpropathrin Resistant Predatory Mite, Neoseiulus barkeri (Hughes).

    PubMed

    Cong, Lin; Chen, Fei; Yu, Shijiang; Ding, Lili; Yang, Juan; Luo, Ren; Tian, Huixia; Li, Hongjun; Liu, Haoqiang; Ran, Chun

    2016-05-27

    Several fenpropathrin-resistant predatory mites have been reported. However, the molecular mechanism of the resistance remains unknown. In the present study, the Neoseiulus barkeri (N. barkeri) transcriptome was generated using the Illumina sequencing platform, 34,211 unigenes were obtained, and 15,987 were manually annotated. After manual annotation, attentions were attracted to resistance-related genes, such as voltage-gated sodium channel (VGSC), cytochrome P450s (P450s), and glutathione S-transferases (GSTs). A polymorphism analysis detected two point mutations (E1233G and S1282G) in the linker region between VGSC domain II and III. In addition, 43 putative P450 genes and 10 putative GST genes were identified from the transcriptome. Among them, two P450 genes, NbCYP4EV2 and NbCYP4EZ1, and four GST genes, NbGSTd01, NbGSTd02, NbGSTd03 and NbGSTm03, were remarkably overexpressed 3.64-46.69-fold in the fenpropathrin resistant strain compared to that in the susceptible strain. These results suggest that fenpropathrin resistance in N. barkeri is a complex biological process involving many genetic changes and provide new insight into the N. barkeri resistance mechanism.

  6. Transcriptome and Difference Analysis of Fenpropathrin Resistant Predatory Mite, Neoseiulus barkeri (Hughes)

    PubMed Central

    Cong, Lin; Chen, Fei; Yu, Shijiang; Ding, Lili; Yang, Juan; Luo, Ren; Tian, Huixia; Li, Hongjun; Liu, Haoqiang; Ran, Chun

    2016-01-01

    Several fenpropathrin-resistant predatory mites have been reported. However, the molecular mechanism of the resistance remains unknown. In the present study, the Neoseiulus barkeri (N. barkeri) transcriptome was generated using the Illumina sequencing platform, 34,211 unigenes were obtained, and 15,987 were manually annotated. After manual annotation, attentions were attracted to resistance-related genes, such as voltage-gated sodium channel (VGSC), cytochrome P450s (P450s), and glutathione S-transferases (GSTs). A polymorphism analysis detected two point mutations (E1233G and S1282G) in the linker region between VGSC domain II and III. In addition, 43 putative P450 genes and 10 putative GST genes were identified from the transcriptome. Among them, two P450 genes, NbCYP4EV2 and NbCYP4EZ1, and four GST genes, NbGSTd01, NbGSTd02, NbGSTd03 and NbGSTm03, were remarkably overexpressed 3.64–46.69-fold in the fenpropathrin resistant strain compared to that in the susceptible strain. These results suggest that fenpropathrin resistance in N. barkeri is a complex biological process involving many genetic changes and provide new insight into the N. barkeri resistance mechanism. PMID:27240349

  7. Nutritional plasticity of the predatory ladybeetle Harmonia axyridis (Coleoptera: Coccinellidae): comparison between natural and substitution prey.

    PubMed

    Specty, Olivier; Febvay, Gérard; Grenier, Simon; Delobel, Bernard; Piotte, Christine; Pageaux, Jean-François; Ferran, André; Guillaud, Josette

    2003-02-01

    The predatory coccinellid Harmonia axyridis is a polyphagous species, efficient at controlling certain aphid species and already commercialized in Europe for that purpose. The complete development of this predator can be accomplished using the aphid Acyrthosiphon pisum or Ephestia kuehniella eggs as substitution prey. Biochemical analyses were conducted on the proteins, lipids, and carbohydrates of these two different prey species. E. kuehniella eggs were 2 times richer in amino acids than A. pisum adults (12% of the fresh weight vs. 6%). E. kuehniella eggs were 3 times richer in lipids than the aphids but, on the contrary, the aphids were 1.5 times richer in glycogen. The impact of these two kinds of food on the body composition of the coccinellid was evaluated to appreciate the degree of nutritional plasticity of the coccinellid. The composition of the coccinellids feeding either on E. kuehniella eggs or on aphids was compared for amino acid, fatty acid and glycogen contents, revealing a good capability of H. axyridis to develop on foods that are very different in their biochemical composition. Nevertheless, when fed on aphids, the crude protein content of the predator was reduced and the lipid content decreased by a factor of two, with a change in amino and fatty acid patterns. Some biological parameters, such as larval mortality, adult weight, and fecundity, were modified according to the food eaten.

  8. Snake (Colubridae: Thamnophis) predatory responses to chemical cues from native and introduced prey species

    USGS Publications Warehouse

    Mullin, S.J.; Imbert, H.; Fish, J.M.; Ervin, E.L.; Fisher, R.N.

    2004-01-01

    Several aquatic vertebrates have been introduced into freshwater systems in California over the past 100 years. Some populations of the two-striped garter snake (Thamnophis hammondii) have lived in sympatry with these species since their introduction; other populations have never encountered them. To assess the possible adaptation to a novel prey, we tested the predatory responses of T. hammondii from different populations to different chemosensory cues from native and introduced prey species. We presented chemical extracts from potential prey types and 2 control odors to individual snakes on cotton swabs and recorded the number of tongue flicks and attacks directed at each swab. Subject response was higher for prey odors than control substances. Odors from introduced centrarchid fish (Lepomis) elicited higher response levels than other prey types, including native anuran larvae (Pseudacris regilla). The pattern of response was similar for both populations of snakes (experienced and nai??ve, with respect to the introduced prey). We suggest that the generalist aquatic lifestyle of T. hammondii has allowed it to take advantage of increasing populations of introduced prey. Decisions on the management strategies for some of these introduced prey species should include consideration of how T. hammondii populations might respond in areas of sympatry.

  9. A new North American therizinosaurid and the role of herbivory in 'predatory' dinosaur evolution.

    PubMed

    Zanno, Lindsay E; Gillette, David D; Albright, L Barry; Titus, Alan L

    2009-10-07

    Historically, ecomorphological inferences regarding theropod (i.e. 'predatory') dinosaurs were guided by an assumption that they were singularly hypercarnivorous. A recent plethora of maniraptoran discoveries has produced evidence challenging this notion. Here, we report on a new species of maniraptoran theropod, Nothronychus graffami sp. nov. Relative completeness of this specimen permits a phylogenetic reassessment of Therizinosauria-the theropod clade exhibiting the most substantial anatomical evidence of herbivory. In the most comprehensive phylogenetic study of the clade conducted to date, we recover Therizinosauria as the basalmost maniraptoran lineage. Using concentrated changes tests, we present evidence for correlated character evolution among herbivorous and hypercarnivorous taxa and propose ecomorphological indicators for future interpretations of diet among maniraptoran clades. Maximum parsimony optimizations of character evolution within our study indicate an ancestral origin for dietary plasticity and facultative herbivory (omnivory) within the clade. These findings suggest that hypercarnivory in paravian dinosaurs is a secondarily derived dietary specialization and provide a potential mechanism for the invasion of novel morpho- and ecospace early in coelurosaurian evolution-the loss of obligate carnivory and origin of dietary opportunism.

  10. A predatory bivalved euarthropod from the Cambrian (Stage 3) Xiaoshiba Lagerstätte, South China

    NASA Astrophysics Data System (ADS)

    Yang, Jie; Ortega-Hernández, Javier; Lan, Tian; Hou, Jin-Bo; Zhang, Xi-Guang

    2016-06-01

    Bivalved euarthropods represent a conspicuous component of exceptionally-preserved fossil biotas throughout the Lower Palaeozoic. However, most of these taxa are known from isolated valves, and thus there is a limited understanding of their morphological organization and palaeoecology in the context of early animal-dominated communities. The bivalved euarthropod Clypecaris serrata sp. nov., recovered from the Cambrian (Stage 3) Hongjingshao Formation in Kunming, southern China, is characterized by having a robust first pair of raptorial appendages that bear well-developed ventral-facing spines, paired dorsal spines on the trunk, and posteriorly oriented serrations on the anteroventral margins of both valves. The raptorial limbs of C. serrata were adapted for grasping prey employing a descending stroke for transporting it close the mouth, whereas the backwards-facing marginal serrations of the bivalved carapace may have helped to secure the food items during feeding. The new taxon offers novel insights on the morphology of the enigmatic genus Clypecaris, and indicates that the possession of paired dorsal spines is a diagnostic trait of the Family Clypecarididae within upper stem-group Euarthropoda. C. serrata evinces functional adaptations for an active predatory lifestyle within the context of Cambrian bivalved euarthropods, and contributes towards the better understanding of feeding diversity in early ecosystems.

  11. Causes of mortality and unintentional poisoning in predatory and scavenging birds in California

    PubMed Central

    Kelly, Terra R.; Poppenga, Robert H.; Woods, Leslie A.; Hernandez, Yvette Z.; Boyce, Walter M.; Samaniego, Francisco J.; Torres, Steve G.; Johnson, Christine K.

    2014-01-01

    Objectives We documented causes of mortality in an opportunistic sample of golden eagles, turkey vultures and common ravens, and assessed exposure to several contaminants that have been found in carrion and common prey for these species. Methods Dead birds were submitted for testing through wildlife rehabilitation centres and a network of wildlife biologists in California from 2007 to 2009. Results The leading causes of mortality in this study were collision-related trauma (63 per cent), lead intoxication (17 per cent) and anticoagulant rodenticide poisoning (8 per cent). Elevated liver lead concentration (≥2 µg/g) and bone lead concentration (>6 µg/g) were detected in 25 and 49 per cent of birds tested, respectively. Approximately 84 per cent of birds tested had detectable rodenticide residues. The majority of rodenticide exposure occurred in peri-urban areas, suggesting that retail sale and use of commensal rodent baits, particularly in residential and semi-residential areas in California, may provide a pathway of exposure. Conclusions Monitoring anthropogenic causes of mortality in predatory and scavenging bird species provides important data needed to inform on mitigation and regulatory efforts aimed at reducing threats to these populations. PMID:26392875

  12. Physiological selectivity and activity reduction of insecticides by rainfall to predatory wasps of Tuta absoluta.

    PubMed

    Barros, Emerson C; Bacci, Leandro; Picanco, Marcelo C; Martins, Júlio C; Rosado, Jander F; Silva, Gerson A

    2015-01-01

    In this study, we carried out three bioassays with nine used insecticides in tomato crops to identify their efficiency against tomato leaf miner Tuta absoluta, the physiological selectivity and the activity reduction of insecticides by three rain regimes to predatory wasps Protonectarina sylveirae and Polybia scutellaris. We assessed the mortality caused by the recommended doses of abamectin, beta-cyfluthrin, cartap, chlorfenapyr, etofenprox, methamidophos, permethrin, phenthoate and spinosad to T. absoluta and wasps at the moment of application. In addition, we evaluated the wasp mortality due to the insecticides for 30 days on plants that did not receive rain and on plants that received 4 or 125 mm of rain. Spinosad, cartap, chlorfenapyr, phenthoate, abamectin and methamidophos caused mortality higher than 90% to T. absoluta, whereas the pyrethroids beta-cyfluthrin, etofenprox and permethrin caused mortality between 8.5% and 46.25%. At the moment of application, all the insecticides were highly toxic to the wasps, causing mortality higher than 80%. In the absence of rain, all the insecticides continued to cause high mortality to the wasps for 30 days after the application. The toxicity of spinosad and methamidophos on both wasp species; beta-cyfluthrin on P. sylveirae and chlorfenapyr and abamectin on P. scutellaris, decreased when the plants received 4 mm of rain. In contrast, the other insecticides only showed reduced toxicity on the wasps when the plants received 125 mm of rain.

  13. Survey of Predatory Coccinellids (Coleoptera: Coccinellidae) in the Chitral District, Pakistan

    PubMed Central

    Khan, Inamullah; Din, Sadrud; Khan Khalil, Said; Ather Rafi, Muhammad

    2007-01-01

    An extensive survey of predatory Coccinellid beetles (Coleoptera: Coccinellidae) was conducted in the Chitral District, Pakistan, over a period of 7 months (April through October, 2001). A total of 2600 specimens of Coccinellids were collected from 12 different localities having altitudes from 1219.40–2651.63 m. Twelve different species belonging to 9 genera of 3 tribes and 2 sub-families were recorded. Two sub-families, viz, Coccinellinae Latreille, 1807 and Chilocorinae Mulsant, 1846 were identified. The following 8 species belonged to family Coccinellinae Latreille 1807 and tribe Coccinellini Latreille 1807: Coccinella septempunctata Linnaeus, 1758, Hippodamia (Adonia) variegata Goeze, 1777, Calvia punctata (Mulsant, 1846), Adalia bipunctata (Linnaeus, 1758),Adalia tetraspilota (Hope, 1831), Aiolocaria hexaspilota Hope 1851, Macroilleis (Halyzia) hauseri Mader, 1930,Oenopia conglobata Linnaeus, 1758. Only one species namely Halyzia tschitscherini Semenov, 1965 represented tribe Psylloborini of the sub-family Coccinellinae Latreille, 1807. Three species occurred from sub-family Chilocorinae Mulsant 1846 and tribe Chilocorini Mulsant 1846: Chilocorus rubidus Hope, 1831, Chilocorus circumdatus (Gyllenhal, 1808), Priscibrumus uropygialis (Mulsant, 1853). From the aforementioned species 6 were recorded for the first time from Pakistan: Chilocorus circumdatus, Calvia punctata, Adalia bipunctata, Macroilleis (Halyzia) hauseri, Priscibrumus uropygialis, and Oenopia conglobata. PMID:20334592

  14. A case of cellulitis of the hands caused by a predatory bird attack

    PubMed Central

    Khan, M Adil Abbas; Farid, Mohammed; Sobani, Zain A; Ali, Syed Nadir; Malick, Huzaifa; Baqir, Maryam; Sharif, Hasanat; Beg, M Asim

    2011-01-01

    Many species have been drastically affected by rapid urbanization. Harris's hawks from their natural habitat of open spaces and a supply of rodents, lizards and other small prey have been forced to change their natural environment adapting to living in open spaces in sub- and peri-urban areas. Specific areas include playgrounds, parks and school courtyards. The migration of this predatory species into these areas poses a risk to individuals, and especially the children are often attacked by claws, talons and beaks intentionally or as collateral damage while attacking rodent prey. In addition, the diverse micro-organisms harbored in the beaks and talons can result in wound infections, presenting a challenge to clinical management. Here we would like to present a case of an 80-year-old man with cellulitis of both hands after sustaining minor injuries from the talons of a Harris's hawk and review the management options. We would also like to draw attention to the matter that, even though previously a rarity, more cases of injuries caused by birds of prey may be seen in hospital settings. PMID:23569751

  15. Canalization of body size matters for lifetime reproductive success of male predatory mites (Acari: Phytoseiidae)

    PubMed Central

    Walzer, Andreas; Schausberger, Peter

    2014-01-01

    The adaptive canalization hypothesis predicts that highly fitness-relevant traits are canalized via past selection, resulting in low phenotypic plasticity and high robustness to environmental stress. Accordingly, we hypothesized that the level of phenotypic plasticity of male body size of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity) reflects the effects of body size variation on fitness, especially male lifetime reproductive success (LRS). We first generated small and standard-sized males of P. persimilis and N. californicus by rearing them to adulthood under limited and ample prey supply, respectively. Then, adult small and standard-sized males were provided with surplus virgin females throughout life to assess their mating and reproductive traits. Small male body size did not affect male longevity or the number of fertilized females but reduced male LRS of P. persimilis but not N. californicus. Proximately, the lower LRS of small than standard-sized P. persimilis males correlated with shorter mating durations, probably decreasing the amount of transferred sperm. Ultimately, we suggest that male body size is more strongly canalized in P. persimilis than N. californicus because deviation from standard body size has larger detrimental fitness effects in P. persimilis than N. californicus. © 2014 The Authors. Biological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 889–899. PMID:25132689

  16. Role of Proteases in Extra-Oral Digestion of a Predatory Bug, Andrallus spinidens

    PubMed Central

    Zibaee, Arash; Hoda, Hassan; Mahmoud, Fazeli-Dinan

    2012-01-01

    Roles of salivary proteases in the extra-oral digestion of the predatory bug, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae) were studied by using 2% azocasein as a general substrate and specific protease substrates, as well as synthetic and endogenous inhibitors. It was found that salivary glands of A. spinidens have two anterior, two lateral, and two posterior lobes. Azocasein was used to measure the activity of general proteases in the salivary glands using different buffer solutions. The enzyme had the highest activity at pH 8. General protease activity was highest at 40 °C and was stable for 6–16 hours. The use of specific substrates showed that trypsin-like, chymotrypsin-like, aminopeptidase, and carboxypeptidase are the active proteases present in salivary glands, by the maximum activity of trypsin-like protease in addition to their optimal pH between 8–9. Ca2+ and Mg2+ increased proteolytic activity about 216%, while other ions decreased it. Specific inhibitors including SBTI, PMSF, TLCK, and TPCK significantly decreased enzyme activity, as well as the specific inhibitors of methalloproteases including phenanthroline, EGTA, and TTHA. Extracted endogenous trypsin inhibitors extracted from potential prey, Chilo suppressalis, Naranga aenescens, Pieris brassicae, Hyphantria cunea, and Ephestia kuhniella, had different effects on trypsin-like protease activity of A. spinidens salivary glands. With the exception of C. suppressalis, the endogenous inhibitors significantly decreased enzyme activity in A. spinidens. PMID:22954419

  17. From repulsion to attraction: species- and spatial context-dependent threat sensitive response of the spider mite Tetranychus urticae to predatory mite cues

    NASA Astrophysics Data System (ADS)

    Fernández Ferrari, M. Celeste; Schausberger, Peter

    2013-06-01

    Prey perceiving predation risk commonly change their behavior to avoid predation. However, antipredator strategies are costly. Therefore, according to the threat-sensitive predator avoidance hypothesis, prey should match the intensity of their antipredator behaviors to the degree of threat, which may depend on the predator species and the spatial context. We assessed threat sensitivity of the two-spotted spider mite, Tetranychus urticae, to the cues of three predatory mites, Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius andersoni, posing different degrees of risk in two spatial contexts. We first conducted a no-choice test measuring oviposition and activity of T. urticae exposed to chemical traces of predators or traces plus predator eggs. Then, we tested the site preference of T. urticae in choice tests, using artificial cages and leaves. In the no-choice test, T. urticae deposited their first egg later in the presence of cues of P. persimilis than of the other two predators and cue absence, indicating interspecific threat-sensitivity. T. urticae laid also fewer eggs in the presence of cues of P. persimilis and A. andersoni than of N. californicus and cue absence. In the artificial cage test, the spider mites preferred the site with predator traces, whereas in the leaf test, they preferentially resided on leaves without traces. We argue that in a nonplant environment, chemical predator traces do not indicate a risk for T. urticae, and instead, these traces function as indirect habitat cues. The spider mites were attracted to these cues because they associated them with the existence of a nearby host plant.

  18. The Pheromone of the Cave Cricket, Hadenoecus cumberlandicus, Causes Cricket Aggregation but Does Not Attract the Co-Distributed Predatory Spider, Meta ovalis

    PubMed Central

    Yoder, Jay A.; Christensen, Brady S.; Croxall, Travis J.; Tank, Justin L.; Hobbs, Horton H.

    2010-01-01

    Food input by the cave cricket, Hadenoecus cumberlandicus Hubble & Norton (Orthoptera: Rhaphidophoridae), is vital to the cave community, making this cricket a true keystone species. Bioassays conducted on cave walls and in the laboratory show that clustering in H. cumberlandicus is guided by a pheromone, presumably excreta. This aggregation pheromone was demonstrated by using filter paper discs that had previous adult H. cumberlandicus exposure, resulting in > 70% response by either nymphs or adults, prompting attraction (thus, active component is a volatile), followed by reduced mobility (arrestment) on treated surfaces. Adults were similarly responsive to pheromone from nymphs, agreeing with mixed stage composition of clusters in the cave. Effects of [0.001M – 0.1M] uric acid (insect excreta's principle component) on H. cumberlandicus behavior were inconsistent. This pheromone is not a host cue (kairomone) and is not used as a repellent (allomone) as noted through lack of responses to natural H. cumberlandicus pheromone and uric acid concentrations by a co-occurring predatory cave orb weaver spider, Meta ovalis Gertsch (Araneae: Tetragnathidae). This pheromone is not serving as a sex pheromone because nymphs were affected by it and because this population of H. cumberlandicus is parthenogenic. The conclusion of this study is that the biological value of the aggregation pheromone is to concentrate H. cumberlandicus in sheltered sites in the cave conducive for minimizing water stress. Rather than signaling H. cumberlandicus presence and quality, the reduced mobility expressed as a result of contacting this pheromone conceivably may act as a defense tactic (antipredator behavior) against M. ovalis, which shares this favored habitat site. PMID:20572786

  19. Prey-mediated effects of the protease inhibitor aprotinin on the predatory carabid beetle Nebria brevicollis.

    PubMed

    Burgess, E P.J.; Lövei, G L.; Malone, L A.; Nielsen, I W.; Gatehouse, H S.; Christeller, J T.

    2002-12-01

    To investigate the potential non-target impacts of transgenic pest-resistant plants, prey-mediated impacts of a protease inhibitor (PI) on the predatory carabid, Nebria brevicollis, were investigated. The PI used was aprotinin, a serine PI of mammalian origin with insecticidal properties when incorporated in artificial diet or expressed in transgenic plants. Field-collected N. brevicollis adults, kept at 23 degrees C, 16:8 L:D, were fed, over their pre-aestivation activity period of 24 days, with Helicoverpa armigera larvae reared on an artificial diet containing 0.5% (w:w, fresh mass) aprotinin. These larvae contained 22.62 &mgr;g aprotinin/g insect. Control prey was reared on diet without aprotinin. Beetle survival and body mass were unaffected by prey type. Beetles consuming PI-fed prey lost significantly more mass than the control beetles during two periods of mass loss, but gained significantly more mass during the final period of mass gain. This was not due to differences in amounts of prey supplied or consumed. The final mass gain coincided with increased consumption of PI-prey. Female beetles were significantly heavier than males, but we found no consistent gender-based differences in response to PI-prey. At the end of the experiment, body mass of all beetles was similar to field-collected ones (approximately 55 mg). All experimental beetles had significantly lower activities of digestive cysteine proteases and the serine proteases chymotrypsin and trypsin than field-collected ones. Beetles consuming PI-fed prey had significantly lower levels of trypsin and higher levels of chymotrypsin and elastase than the control beetles.

  20. Plant diversity and identity effects on predatory nematodes and their prey

    PubMed Central

    Kostenko, Olga; Duyts, Henk; Grootemaat, Saskia; De Deyn, Gerlinde B; Bezemer, T Martijn

    2015-01-01

    There is considerable evidence that both plant diversity and plant identity can influence the level of predation and predator abundance aboveground. However, how the level of predation in the soil and the abundance of predatory soil fauna are related to plant diversity and identity remains largely unknown. In a biodiversity field experiment, we examined the effects of plant diversity and identity on the infectivity of entomopathogenic nematodes (EPNs, Heterorhabditis and Steinernema spp.), which prey on soil arthropods, and abundance of carnivorous non-EPNs, which are predators of other nematode groups. To obtain a comprehensive view of the potential prey/food availability, we also quantified the abundance of soil insects and nonpredatory nematodes and the root biomass in the experimental plots. We used structural equation modeling (SEM) to investigate possible pathways by which plant diversity and identity may affect EPN infectivity and the abundance of carnivorous non-EPNs. Heterorhabditis spp. infectivity and the abundance of carnivorous non-EPNs were not directly related to plant diversity or the proportion of legumes, grasses and forbs in the plant community. However, Steinernema spp. infectivity was higher in monocultures of Festuca rubra and Trifolium pratense than in monocultures of the other six plant species. SEM revealed that legumes positively affected Steinernema infectivity, whereas plant diversity indirectly affected the infectivity of HeterorhabditisEPNs via effects on the abundance of soil insects. The abundance of prey (soil insects and root-feeding, bacterivorous, and fungivorous nematodes) increased with higher plant diversity. The abundance of prey nematodes was also positively affected by legumes. These plant community effects could not be explained by changes in root biomass. Our results show that plant diversity and identity effects on belowground biota (particularly soil nematode community) can differ between organisms that belong to the

  1. Specific detection of the floodwater mosquitoes Aedes sticticus and Aedes vexans DNA in predatory diving beetles.

    PubMed

    Vinnersten, Thomas Z Persson; Halvarsson, Peter; Lundström, Jan O

    2015-08-01

    Floodwater mosquitoes (Diptera: Culicidae) are associated with periodically flooded wet meadows, marshes, and swamps in floodplains of major rivers worldwide, and their larvae are abundant in the shallow parts of flooded areas. The nuisance caused by the blood-seeking adult female mosquitoes motivates mosquito control. Larviciding with Bacillus thuringiensis israelensis is considered the most environmentally safe method. However, some concern has been raised whether aquatic predatory insects could be indirectly affected by this reduction in a potential vital prey. Top predators in the temporary wetlands in the River Dalälven floodplains are diving beetles (Coleoptera: Dytiscidae), and Aedes sticticus and Ae. vexans are the target species for mosquito control. For detailed studies on this aquatic predator-prey system, we developed a polymerase chain reaction (PCR) assay for detection of mosquito DNA in the guts of medium-sized diving beetles. Primers were designed for amplifying short mitochondrial DNA fragments of the cytochrome C oxidase subunit I (COI) gene in Ae. sticticus and Ae. vexans, respectively. Primer specificity was confirmed and half-life detectability of Ae. sticticus DNA in diving beetle guts was derived from a feeding and digestion experiment. The Ae. sticticus DNA within diving beetle guts was detected up to 12 h postfeeding, and half-life detectability was estimated to 5.6 h. In addition, field caught diving beetles were screened for Ae. sticticus and Ae. vexans DNA and in 14% of the diving beetles one or both mosquito species were detected, showing that these mosquito species are utilized as food by the diving beetles.

  2. Subsurface observations of white shark Carcharodon carcharias predatory behaviour using an autonomous underwater vehicle.

    PubMed

    Skomal, G B; Hoyos-Padilla, E M; Kukulya, A; Stokey, R

    2015-12-01

    In this study, an autonomous underwater vehicle (AUV) was used to test this technology as a viable tool for directly observing the behaviour of marine animals and to investigate the behaviour, habitat use and feeding ecology of white sharks Carcharodon carcharias near Guadalupe Island off the coast of Mexico. During the period 31 October to 7 November 2013, six AUV missions were conducted to track one male and three female C. carcharias, ranging in estimated total length (LT ) from 3·9 to 5·7 m, off the north-east coast of Guadalupe Island. In doing so, the AUV generated over 13 h of behavioural data for C. carcharias at depths down to 90 m. The sharks remained in the area for the duration of each mission and moved through broad depth and temperature ranges from the surface to 163·8 m depth (mean ± S.D. = 112·5 ± 40·3 m) and 7·9-27·1° C (mean ± S.D. = 12·7 ± 2·9° C), respectively. Video footage and AUV sensor data revealed that two of the C. carcharias being tracked and eight other C. carcharias in the area approached (n = 17), bumped (n = 4) and bit (n = 9) the AUV during these tracks. This study demonstrated that an AUV can be used to effectively track and observe the behaviour of a large pelagic animal, C. carcharias. In doing so, the first observations of subsurface predatory behaviour were generated for this species. At its current state of development, this technology clearly offers a new and innovative tool for tracking the fine-scale behaviour of marine animals.

  3. Impact of Terminalia chebula Retz. against Aedes aegypti L. and non-target aquatic predatory insects.

    PubMed

    Thanigaivel, Annamalai; Vasantha-Srinivasan, Prabhakaran; Senthil-Nathan, Sengottayan; Edwin, Edward-Sam; Ponsankar, Athirstam; Chellappandian, Muthiah; Selin-Rani, Selvaraj; Lija-Escaline, Jalasteen; Kalaivani, Kandaswamy

    2017-03-01

    Aedes aegypti Linn is one of the most important mosquito species. The vectors are responsible for causing deadly diseases like dengue and dengue hemorrhagic fever. Several chemical pesticides used to control these dengue vectors caused severe toxic significances on human health and other non-target beneficial insects. Therefore the current investigation has been made to access the bio-efficacy of the crude seed extracts of T. chebula against the dengue vector Ae. aegypti. The GC-MS analysis of crude seed extracts of T. chebula identified nine chemical compounds with major peak area in the 1,2,3-Benzenetriol (61.96%), followed by Tridecanoic acid (09.55%). Ae. aegypti larvae showed dose dependent mortality rate was observed between the treatments. Prominent protection rate at greater concentrations of 100ppm and moderate protection at 75 and 50ppm was observed in the repellent assay. Lethal concentration (LC50 and LC90) of fourth instar larvae of Ae. aegypti was observed in 138 and 220ppm concentration respectively. Similarly, the seed extracts showed 100% adulticidal activity at the concentration of 400ppm at 30min of exposure time. Phytochemicals present in the seed extracts of T. chebula significantly affects the major portions of the midgut tissues of Ae. aegypti at the concentration of 100ppm. The toxicological evaluation of seed extracts also proved non-toxic towards the A. bouvieri and Tx. splendens aquatic predatory insects. Hence, the present result suggest that bio-rational plant derived T. chebula could be incorporated in the dengue vector control and have no adverse effects on non-target beneficial insects.

  4. Ocean Warming and CO₂-Induced Acidification Impact the Lipid Content of a Marine Predatory Gastropod.

    PubMed

    Valles-Regino, Roselyn; Tate, Rick; Kelaher, Brendan; Savins, Dale; Dowell, Ashley; Benkendorff, Kirsten

    2015-09-24

    Ocean warming and acidification are current global environmental challenges impacting aquatic organisms. A shift in conditions outside the optimal environmental range for marine species is likely to generate stress that could impact metabolic activity, with consequences for the biosynthesis of marine lipids. The aim of this study was to investigate differences in the lipid content of Dicathais orbita exposed to current and predicted future climate change scenarios. The whelks were exposed to a combination of temperature and CO₂-induced acidification treatments in controlled flowthrough seawater mesocosms for 35 days. Under current conditions, D. orbita foot tissue has an average of 6 mg lipid/g tissue, but at predicted future ocean temperatures, the total lipid content dropped significantly, to almost half. The fatty acid composition is dominated by polyunsaturated fatty acids (PUFA 52%) with an n-3:6 fatty acid ratio of almost 2, which remains unchanged under future ocean conditions. However, we detected an interactive effect of temperature and pCO₂ on the % PUFAs and n-3 and n-6 fatty acids were significantly reduced by elevated water temperature, while both the saturated and monounsaturated fatty acids were significantly reduced under increased pCO₂ acidifying conditions. The present study indicates the potential for relatively small predicted changes in ocean conditions to reduce lipid reserves and alter the fatty acid composition of a predatory marine mollusc. This has potential implications for the growth and survivorship of whelks under future conditions, but only minimal implications for human consumption of D. orbita as nutritional seafood are predicted.

  5. Social familiarity modulates group living and foraging behaviour of juvenile predatory mites

    NASA Astrophysics Data System (ADS)

    Strodl, Markus A.; Schausberger, Peter

    2012-04-01

    Environmental stressors during early life may have persistent consequences for phenotypic development and fitness. In group-living species, an important stressor during juvenile development is the presence and familiarity status of conspecific individuals. To alleviate intraspecific conflicts during juvenile development, many animals evolved the ability to discriminate familiar and unfamiliar individuals based on prior association and use this ability to preferentially associate with familiar individuals. Assuming that familiar neighbours require less attention than unfamiliar ones, as predicted by limited attention theory, assorting with familiar individuals should increase the efficiency in other tasks. We assessed the influence of social familiarity on within-group association behaviour, development and foraging of juvenile life stages of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. The observed groups consisted either of mixed-age familiar and unfamiliar juvenile mites or of age-synchronized familiar or unfamiliar juvenile mites or of pairs of familiar or unfamiliar larvae. Overall, familiar mites preferentially grouped together and foraged more efficiently, i.e. needed less prey at similar developmental speed and body size at maturity, than unfamiliar mites. Preferential association of familiar mites was also apparent in the inter-exuviae distances. Social familiarity was established by imprinting in the larval stage, was not cancelled or overridden by later conspecific contacts and persisted into adulthood. Life stage had an effect on grouping with larvae being closer together than nymphal stages. Ultimately, optimized foraging during the developmental phase may relax within-group competition, enhance current and future food supply needed for optimal development and optimize patch exploitation and leaving under limited food.

  6. Amblyseius swirskii: what made this predatory mite such a successful biocontrol agent?

    PubMed

    Calvo, F Javier; Knapp, Markus; van Houten, Yvonne M; Hoogerbrugge, Hans; Belda, José E

    2015-04-01

    The predatory mite Amblyseius swirskii quickly became one of the most successful biocontrol agents in protected cultivation after its introduction into the market in 2005 and is now released in more than 50 countries. There are several key factors contributing to this success: (1) it can control several major pests including the western flower thrips, Frankliniella occidentalis, the whiteflies Bemisia tabaci and Trialeurodes vaporariorum and the broad mite, Polyphagotarsonemus latus, simultaneously in vegetables and ornamental crops; (2) it can develop and reproduce feeding on non-prey food sources such as pollen, which allows populations of the predator to build up on plants before the pests are present and to persist in the crop during periods when prey is scarce or absent; and (3) it can be easily reared on factitious prey, which allows economic mass production. However, despite the fact that A. swirskii provides growers with a robust control method, external demands were initially a key factor in promoting the use of this predator, particularly in Spain. In 2006, when exports of fresh vegetables from Spain were stopped due to the presence of pesticide residues, growers were forced to look for alternatives to chemical control. This resulted in the massive adoption of biological control-based integrated pest management programmes based on the use of A. swirskii in sweet pepper. Biological control increased from 5 % in 2005, 1 year before A. swirskii was commercially released, to almost 100 % of a total 6,000 ha of protected sweet pepper in Spain within 3 years. Later, it was demonstrated that A. swirskii was equally effective in other crops and countries, resulting in extensive worldwide use of A. swirskii in greenhouses.

  7. Plant diversity and identity effects on predatory nematodes and their prey.

    PubMed

    Kostenko, Olga; Duyts, Henk; Grootemaat, Saskia; De Deyn, Gerlinde B; Bezemer, T Martijn

    2015-02-01

    There is considerable evidence that both plant diversity and plant identity can influence the level of predation and predator abundance aboveground. However, how the level of predation in the soil and the abundance of predatory soil fauna are related to plant diversity and identity remains largely unknown. In a biodiversity field experiment, we examined the effects of plant diversity and identity on the infectivity of entomopathogenic nematodes (EPNs, Heterorhabditis and Steinernema spp.), which prey on soil arthropods, and abundance of carnivorous non-EPNs, which are predators of other nematode groups. To obtain a comprehensive view of the potential prey/food availability, we also quantified the abundance of soil insects and nonpredatory nematodes and the root biomass in the experimental plots. We used structural equation modeling (SEM) to investigate possible pathways by which plant diversity and identity may affect EPN infectivity and the abundance of carnivorous non-EPNs. Heterorhabditis spp. infectivity and the abundance of carnivorous non-EPNs were not directly related to plant diversity or the proportion of legumes, grasses and forbs in the plant community. However, Steinernema spp. infectivity was higher in monocultures of Festuca rubra and Trifolium pratense than in monocultures of the other six plant species. SEM revealed that legumes positively affected Steinernema infectivity, whereas plant diversity indirectly affected the infectivity of HeterorhabditisEPNs via effects on the abundance of soil insects. The abundance of prey (soil insects and root-feeding, bacterivorous, and fungivorous nematodes) increased with higher plant diversity. The abundance of prey nematodes was also positively affected by legumes. These plant community effects could not be explained by changes in root biomass. Our results show that plant diversity and identity effects on belowground biota (particularly soil nematode community) can differ between organisms that belong to the

  8. High exposure rates of anticoagulant rodenticides in predatory bird species in intensively managed landscapes in Denmark.

    PubMed

    Christensen, Thomas Kjær; Lassen, Pia; Elmeros, Morten

    2012-10-01

    The extensive use of anticoagulant rodenticides (ARs) for rodent control has led to widespread secondary exposure in nontarget predatory wildlife species. We investigated exposure rates and concentrations of five ARs in liver samples from five raptors and six owls from Denmark. A total of 430 birds were analysed. ARs were detected in 84-100 % of individual birds within each species. Multiple AR exposure was detected in 73 % of all birds. Average number of substances detected in individual birds was 2.2 with no differences between owls and raptors. Difenacoum, bromadiolone, and brodifacoum were the most prevalent substances and occurred in the highest concentrations. Second-generation ARs made up 96 % of the summed AR burden. Among the six core species (sample size >30), summed AR concentrations were lower in rough-legged buzzard (Buteo lagopus) and long-eared owl (Asio otus) than in barn owl (Tyto alba), buzzard (B. buteo), kestrel (Falco tinnunculus), and tawny owl (Strix aluco). There was a strong tendency for seasonal variations in the summed AR concentration with levels being lowest during autumn, which is probably related to an influx of less-exposed migrating birds from northern Scandinavia during autumn. High hepatic AR residue concentrations (>100 ng/g wet weight), which have been associated with symptoms of rodenticide poisoning and increased mortality, were recorded high frequencies (12.9-37.4 %) in five of the six core species. The results suggest that the present use of ARs in Denmark, at least locally, may have adverse effects on reproduction and, ultimately, population status in some raptors and owls.

  9. Discovery of Bioactive Metabolites in Biofuel Microalgae That Offer Protection against Predatory Bacteria

    PubMed Central

    Bagwell, Christopher E.; Abernathy, Amanda; Barnwell, Remy; Milliken, Charles E.; Noble, Peter A.; Dale, Taraka; Beauchesne, Kevin R.; Moeller, Peter D. R.

    2016-01-01

    protection of biomass from predatory losses. PMID:27148205

  10. Interdependent effects of male and female body size plasticity on mating behaviour of predatory mites

    PubMed Central

    Walzer, Andreas; Schausberger, Peter

    2015-01-01

    The adaptive canalization hypothesis predicts that traits with low phenotypic plasticity are more fitness relevant, because they have been canalized via strong past selection, than traits with high phenotypic plasticity. Based on differing male body size plasticities of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity), we accordingly hypothesized that small male body size entails higher costs in female choice and male–male competition in P. persimilis than N. californicus. Males of both species are highly polygynous but females differ in the level of polyandry (low level in P. persimilis; medium level in N. californicus). We videotaped the mating interactions in triplets of either P. persimilis or N. californicus, consisting of a virgin female (small or standard-sized) and a small and a standard-sized male. Mating by both small and standard-sized P. persimilis females was biased towards standard-sized males, resulting from the interplay between female preference for standard-sized males and the inferiority of small males in male–male competition. In contrast, mating by N. californicus females was equally balanced between small and standard-sized males. Small N. californicus males were more aggressive (‘Napoleon complex’) in male–male competition, reducing the likelihood of encounter between the standard-sized male and the female, and thus counterbalancing female preference for standard-sized males. Our results support the hypothesis that male body size is more important to fitness in the low-level polyandrous P. persimilis than in the medium-level polyandrous N. californicus and provide a key example of the implications of sexually selected body size plasticity on mating behaviour. PMID:25673881

  11. Behavioural and developmental responses of predatory coral reef fish to variation in the abundance of prey

    NASA Astrophysics Data System (ADS)

    Beukers-Stewart, B. D.; Beukers-Stewart, J. S.; Jones, G. P.

    2011-09-01

    Ecological theory suggests that the behaviour, growth and abundance of predators will be strongly influenced by the abundance of prey. Predators may in turn play an important role in structuring prey populations and communities. Responses of predators to variation in prey abundance have most commonly been demonstrated in low-diversity communities where food webs are relatively simple. How predators respond in highly diverse assemblages such as in coral reef habitats is largely unknown. This study describes an experiment that examined how the movement, diet and growth of the coral reef piscivore, Cephalopholis boenak (Serranidae) responded to variation in the abundance of its prey. Predator densities were standardised on small patch reefs made from the lagoonal reef-building coral, Porites cylindrica. These patch reefs exhibited natural variation in the abundance and community structure of multiple species of prey. However, our experiment generated a relatively simple predator-prey relationship, with C. boenak primarily responding to the most abundant species of prey. Three responses of predators were observed: aggregative, functional and developmental. Thirty-one per cent of individuals moved between patch reefs during the experiment, all from areas of relatively low to high prey density. Feeding rates were higher on patch reefs of high prey density, while growth rates of fish that remained on low prey density reefs throughout the experiment were lower. Growth rates of C. boenak on the experimental reefs were also much higher than for those living on natural patch reefs over the same time period, corresponding with overall differences in prey abundance. These results suggest that local abundance, feeding rate and growth of C. boenak were closely linked to the abundance of their main prey. This combination of predatory responses is a potential mechanism behind recent observations of density-dependent mortality and population regulation of prey in coral reef fish

  12. Effects of predatory ants on lower trophic levels across a gradient of coffee management complexity.

    PubMed

    Philpott, S M; Perfecto, I; Vandermeer, J

    2008-05-01

    1. Ants are important predators in agricultural systems, and have complex and often strong effects on lower trophic levels. Agricultural intensification reduces habitat complexity, food web diversity and structure, and affects predator communities. Theory predicts that strong top-down cascades are less likely to occur as habitat and food web complexity decrease. 2. To examine relationships between habitat complexity and predator effects, we excluded ants from coffee plants in coffee agroecosystems varying in vegetation complexity. Specifically, we studied the effects of eliminating ants on arthropod assemblages, herbivory, damage by the coffee berry borer and coffee yields in four sites differing in management intensification. We also sampled ant assemblages in each management type to see whether changes in ant assemblages relate to any observed changes in top-down effects. 3. Removing ants did not change total arthropod densities, herbivory, coffee berry borer damage or coffee yields. Ants did affect densities of some arthropod orders, but did not affect densities of different feeding groups. The effects of ants on lower trophic levels did not change with coffee management intensity. 4. Diversity and activity of ants on experimental plants did not change with coffee intensification, but the ant species composition differed. 5. Although variation in habitat complexity may affect trophic cascades, manipulating predatory ants across a range of coffee agroecosystems varying in management intensity did not result in differing effects on arthropod assemblages, herbivory, coffee berry borer attack or coffee yields. Thus, there is no clear pattern that top-down effects of ants in coffee agroecosystems intensify or dampen with decreased habitat complexity.

  13. Discovery of Bioactive Metabolites in Biofuel Microalgae That Offer Protection against Predatory Bacteria.

    PubMed

    Bagwell, Christopher E; Abernathy, Amanda; Barnwell, Remy; Milliken, Charles E; Noble, Peter A; Dale, Taraka; Beauchesne, Kevin R; Moeller, Peter D R

    2016-01-01

    protection of biomass from predatory losses.

  14. Microbial community of predatory bugs of the genus Macrolophus (Hemiptera: Miridae)

    PubMed Central

    2012-01-01

    Background The predatory mirids of the genus Macrolophus are key natural enemies of various economically important agricultural pests. Both M. caliginosus and M. pygmaeus are commercially available for the augmentative biological control of arthropod pests in European greenhouses. The latter species is known to be infected with Wolbachia -inducing cytoplasmic incompatibility in its host- but the presence of other endosymbionts has not been demonstrated. In the present study, the microbial diversity was examined in various populations of M. caliginosus and M. pygmaeus by 16S rRNA sequencing and denaturing gradient gel electrophoresis. Results Besides Wolbachia, a co-infection of 2 Rickettsia species was detected in all M. pygmaeus populations. Based on a concatenated alignment of the 16S rRNA gene, the gltA gene and the coxA gene, the first is phylogenetically related to Rickettsia bellii, whereas the other is closely related to Rickettsia limoniae. All M. caliginosus populations were infected with the same Wolbachia and limoniae-like Rickettsia strain as M. pygmaeus, but did not harbour the bellii-like Rickettsia strain. Interestingly, individuals with a single infection were not found. A PCR assay on the ovaries of M. pygmaeus and M. caliginosus indicated that all endosymbionts are vertically transmitted. The presence of Wolbachia and Rickettsia in oocytes was confirmed by a fluorescence in situ hybridisation. A bio-assay comparing an infected and an uninfected M. pygmaeus population suggested that the endosymbionts had minor effects on nymphal development of their insect host and did not influence its fecundity. Conclusion Two species of the palaearctic mirid genus Macrolophus are infected with multiple endosymbionts, including Wolbachia and Rickettsia. Independent of the origin, all tested populations of both M. pygmaeus and M. caliginosus were infected with three and two endosymbionts, respectively. There was no indication that infection with endosymbiotic

  15. Maternal manipulation of hatching asynchrony limits sibling cannibalism in the predatory mite Phytoseiulus persimilis.

    PubMed

    Schausberger, P; Hoffmann, D

    2008-11-01

    1. Sibling cannibalism is a common phenomenon in the animal kingdom but entails a high risk of direct and inclusive fitness loss for the mother and her offspring. Therefore, mechanisms limiting sibling cannibalism are expected to be selected for. One way of maternal manipulation of sibling cannibalism is to influence hatching asynchrony between nearby laid eggs. This has rarely been tested experimentally. 2. We examined the ability of ovipositing females of the cannibalistic predatory mite Phytoseiulus persimilis to influence the occurrence of sibling cannibalism among offspring by manipulating hatching asynchrony of nearby laid eggs. 3. In the first experiment, we assessed the occurrence of sibling cannibalism in relation to the hatching interval (24 h and 48 h) between nearby laid eggs. In the second experiment, we tested whether ovipositing females discriminate sites containing young (24-h old) and old (48-h old) eggs, fresh and old traces (metabolic waste products and possibly pheromones) left by the same female (24 h and 48 h ago), or young eggs plus fresh female traces and old eggs plus old female traces. Both experiments were conducted with and without prey. 4. Without prey, siblings were more likely to cannibalize each other if the hatching interval between nearby laid eggs was short (24 h). Cannibalism occurred less often when senior siblings (protonymphs) experienced a delay in the opportunity to cannibalize junior siblings (larvae). 5. Independent of prey availability, females preferentially added new eggs to sites containing old eggs plus old female traces but did neither distinguish between young and old eggs presented without own traces nor between fresh and old traces presented without eggs. 6. We discuss cue perception and use by P. persimilis females and contrast the outcome of our experiments and theoretical predictions of sibling cannibalism. We conclude that P. persimilis mothers increase hatching asynchrony of nearby laid eggs to prevent

  16. Predatory Bacteria as Natural Modulators of Vibrio parahaemolyticus and Vibrio vulnificus in Seawater and Oysters

    PubMed Central

    Fay, Johnna P.; Dickens, Keyana A.; Parent, Michelle A.; Soroka, Douglas S.; Boyd, E. Fidelma

    2012-01-01

    This study shows that naturally occurring Vibrio predatory bacteria (VPB) exert a major role in controlling pathogenic vibrios in seawater and shellfish. The growth and persistence of Vibrio parahaemolyticus and Vibrio vulnificus were assessed in natural seawater and in the Eastern oyster, Crassostrea virginica. The pathogens examined were V. vulnificus strain VV1003, V. parahaemolyticus O1:KUT (KUT stands for K untypeable), and V. parahaemolyticus O3:K6 and corresponding O3:K6 mutants deficient in the toxRS virulence regulatory gene or the rpoS alternative stress response sigma factor gene. Vibrios were selected for streptomycin resistance, which facilitated their enumeration. In natural seawater, oysters bioconcentrated each Vibrio strain for 24 h at 22°C; however, counts rapidly declined to near negligible levels by 72 h. In natural seawater with or without oysters, vibrios decreased more than 3 log units to near negligible levels within 72 h. Neither toxRS nor rpoS had a significant effect on Vibrio levels. In autoclaved seawater, V. parahaemolyticus O3:K6 counts increased 1,000-fold over 72 h. Failure of the vibrios to persist in natural seawater and oysters led to screening of the water samples for VPB on lawns of V. parahaemolyticus O3:K6 host cells. Many VPB, including Bdellovibrio and like organisms (BALOs; Bdellovibrio bacteriovorus and Bacteriovorax stolpii) and Micavibrio aeruginosavorus-like predators, were detected by plaque assay and electron microscopic analysis of plaque-purified isolates from Atlantic, Gulf Coast, and Hawaiian seawater. When V. parahaemolyticus O3:K6 was added to natural seawater containing trace amounts of VPB, Vibrio counts diminished 3 log units to nondetectable levels, while VPB increased 3 log units within 48 h. We propose a new paradigm that VPB are important modulators of pathogenic vibrios in seawater and oysters. PMID:22904049

  17. Ocean Warming and CO2-Induced Acidification Impact the Lipid Content of a Marine Predatory Gastropod

    PubMed Central

    Valles-Regino, Roselyn; Tate, Rick; Kelaher, Brendan; Savins, Dale; Dowell, Ashley; Benkendorff, Kirsten

    2015-01-01

    Ocean warming and acidification are current global environmental challenges impacting aquatic organisms. A shift in conditions outside the optimal environmental range for marine species is likely to generate stress that could impact metabolic activity, with consequences for the biosynthesis of marine lipids. The aim of this study was to investigate differences in the lipid content of Dicathais orbita exposed to current and predicted future climate change scenarios. The whelks were exposed to a combination of temperature and CO2-induced acidification treatments in controlled flowthrough seawater mesocosms for 35 days. Under current conditions, D. orbita foot tissue has an average of 6 mg lipid/g tissue, but at predicted future ocean temperatures, the total lipid content dropped significantly, to almost half. The fatty acid composition is dominated by polyunsaturated fatty acids (PUFA 52%) with an n-3:6 fatty acid ratio of almost 2, which remains unchanged under future ocean conditions. However, we detected an interactive effect of temperature and pCO2 on the % PUFAs and n-3 and n-6 fatty acids were significantly reduced by elevated water temperature, while both the saturated and monounsaturated fatty acids were significantly reduced under increased pCO2 acidifying conditions. The present study indicates the potential for relatively small predicted changes in ocean conditions to reduce lipid reserves and alter the fatty acid composition of a predatory marine mollusc. This has potential implications for the growth and survivorship of whelks under future conditions, but only minimal implications for human consumption of D. orbita as nutritional seafood are predicted. PMID:26404318

  18. Integration of multiple intraguild predator cues for oviposition decisions by a predatory mite

    PubMed Central

    Walzer, Andreas; Schausberger, Peter

    2012-01-01

    In mutual intraguild predation (IGP), the role of individual guild members is strongly context dependent and, during ontogeny, can shift from an intraguild (IG) prey to a food competitor or to an IG predator. Consequently, recognition of an offspring's predator is more complex for IG than classic prey females. Thus, IG prey females should be able to modulate their oviposition decisions by integrating multiple IG predator cues and by experience. Using a guild of plant-inhabiting predatory mites sharing the spider mite Tetranychus urticae as prey and passing through ontogenetic role shifts in mutual IGP, we assessed the effects of single and combined direct cues of the IG predator Amblyseius andersoni (eggs and traces left by a female on the substrate) on prey patch selection and oviposition behaviour of naïve and IG predator-experienced IG prey females of Phytoseiulus persimilis. The IG prey females preferentially resided in patches without predator cues when the alternative patch contained traces of predator females or the cue combination. Preferential egg placement in patches without predator cues was only apparent in the choice situation with the cue combination. Experience increased the responsiveness of females exposed to the IG predator cue combination, indicated by immediate selection of the prey patch without predator cues and almost perfect oviposition avoidance in patches with the cue combination. We argue that the evolution of the ability of IG prey females to evaluate offspring's IGP risk accurately is driven by the irreversibility of oviposition and the functionally complex relationships between predator guild members. PMID:23264692

  19. Genome Sequencing of the Phytoseiid Predatory Mite Metaseiulus occidentalis Reveals Completely Atomized Hox Genes and Superdynamic Intron Evolution

    PubMed Central

    Hoy, Marjorie A.; Waterhouse, Robert M.; Wu, Ke; Estep, Alden S.; Ioannidis, Panagiotis; Palmer, William J.; Pomerantz, Aaron F.; Simão, Felipe A.; Thomas, Jainy; Jiggins, Francis M.; Murphy, Terence D.; Pritham, Ellen J.; Robertson, Hugh M.; Zdobnov, Evgeny M.; Gibbs, Richard A.; Richards, Stephen

    2016-01-01

    Metaseiulus occidentalis is an eyeless phytoseiid predatory mite employed for the biological control of agricultural pests including spider mites. Despite appearances, these predator and prey mites are separated by some 400 Myr of evolution and radically different lifestyles. We present a 152-Mb draft assembly of the M. occidentalis genome: Larger than that of its favored prey, Tetranychus urticae, but considerably smaller than those of many other chelicerates, enabling an extremely contiguous and complete assembly to be built—the best arachnid to date. Aided by transcriptome data, genome annotation cataloged 18,338 protein-coding genes and identified large numbers of Helitron transposable elements. Comparisons with other arthropods revealed a particularly dynamic and turbulent genomic evolutionary history. Its genes exhibit elevated molecular evolution, with strikingly high numbers of intron gains and losses, in stark contrast to the deer tick Ixodes scapularis. Uniquely among examined arthropods, this predatory mite’s Hox genes are completely atomized, dispersed across the genome, and it encodes five copies of the normally single-copy RNA processing Dicer-2 gene. Examining gene families linked to characteristic biological traits of this tiny predator provides initial insights into processes of sex determination, development, immune defense, and how it detects, disables, and digests its prey. As the first reference genome for the Phytoseiidae, and for any species with the rare sex determination system of parahaploidy, the genome of the western orchard predatory mite improves genomic sampling of chelicerates and provides invaluable new resources for functional genomic analyses of this family of agriculturally important mites. PMID:26951779

  20. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size.

    PubMed

    Keiser, Carl N; Wright, Colin M; Pruitt, Jonathan N

    2015-10-01

    Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside.

  1. Risk assessment of Cry toxins of Bacillus thuringiensis on the predatory mites Euseius concordis and Neoseiulus californicus (Acari: Phytoseiidae).

    PubMed

    de Castro, Thiago Rodrigues; Ausique, John Jairo Saldarriaga; Nunes, Daiane Heloisa; Ibanhes, Fernando Henrique; Delalibera Júnior, Italo

    2013-04-01

    Genetically modified plants carrying Cry toxins of Bacillus thuringiensis (Bt) are widely used for pest control. Possible adverse effects as a result of the use of this control technique to non-target organisms is still a concern; however, few studies have addressed the effects of Bt crops on phytoseiid predatory mites. Phytoseiids are important for the natural control of phytophagous mites, but they can also feed on pollen, plant exudates, etc. Thus, phytoseiids may ingest Bt toxins through several pathways. In this paper, we evaluate the direct effect of Bt-toxins by feeding the predators on Bt cell suspensions, on solution of a Bt toxin and the tri-trophic effect by Bt expressed in transgenic plants. We present a method of conducting toxicological tests with Phytoseiidae which can be useful in studies of risk analysis of toxins to be expressed by genetically engineered plants. This method was used to evaluate the potential effect of ingestion of suspensions of Bt (1.25 × 10(8) spores/ml) and of purified protein Cry1Ia12 (0.006 mg/ml and 0.018 mg/ml) on Euseius concordis, a predatory mite that develops and reproduces best on pollen. The effects of genetically modified Bollgard(®) cotton, which carries the Cry1Ac protein, on Neoseiulus californicus, a selective predator that feeds more on spider mites than on pollen or insects, was determined by feeding them with Tetranychus urticae reared in Bollgard(®) cotton and on the non-transgenic isoline. When E. concordis was fed with suspension of Bt isolate derived from product Dipel(®) PM, no significant effects were detected. Similarly, Cry1Ia12 Bt toxin, at a concentration of 0.006 mg/ml, did not affect E. concordis. At a concentration of 0.018 mg/ml, however, the intake of this protein reduced the reproduction of E. concordis. There were no effects of Bollgard(®) cotton on the biological traits and on the predatory capacity of N. californicus. Results indicate that the Cry toxins of B. thuringiensis

  2. Comparative analyses of contaminant levels in bottom feeding and predatory fish using the National Contaminant Biomonitoring Program data

    SciTech Connect

    Kidwell, J.M.; Phillips, L.J.; Birchard, G.F.

    1995-06-01

    Both bottom feeding and predatory fish accumulate chemical contaminants found in water. Bottom feeders are readily exposed to the greater quantities of chlorinated hydrocarbons and metals that accumulate in sediments. Predators, on the other hand, may bioaccumulate organochlorine pesticides, PCBs, and metals from the surrounding water or from feeding on other fish, including bottom feeders, which may result in the biomagnification of these compounds in their tissues. This study used National Contaminant Biomonitoring Program data produced by the Fish and Wildlife Service to test the hypothesis that differences exist between bottom feeders and predators in tissue levels of organochlorine pesticides, PCBs, and metals. 7 refs., 2 tabs.

  3. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small 'laying hen' cages.

    PubMed

    Lesna, Izabela; Sabelis, Maurice W; van Niekerk, Thea G C M; Komdeur, Jan

    2012-12-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in cages, each with 2-3 laying hens, initially 300 poultry red mites and later the release of 1,000 predators. These small-scale tests were designed to prevent mite escape from the cages and they were carried out in three replicates at each of three temperature regimes: 26, 30 (constant day and night) and 33-25 °C (day-night cycle). After 6 weeks total population sizes of poultry red mites and predatory mites were assessed. For the temperature regimes of 26 and 33/25 °C S. scimitus reduced the poultry red mite population relative to the control experiments by a factor 3 and 30, respectively, and A. casalis by a factor of 18 and 55, respectively. At 30 °C the predators had less effect on red mites, with a reduction of 1.3-fold for S. scimitus and 5.6-fold for A. casalis. This possibly reflected hen manure condition or an effect of other invertebrates in the hen feed. Poultry red mite control was not negatively affected by temperatures as high as 33 °C and was always better in trials with A. casalis than in those with S. scimitus. In none of the experiments predators managed to eradicate the population of poultry red mites. This may be due to a prey refuge effect since most predatory mites were found in and around the manure tray at the bottom of the cage, whereas most poultry red mites were found higher up in the cage (i.e. on the walls, the cover, the perch, the nest box and the food box). The efficacy of applying predatory mites in the poultry industry may be promoted by reducing this refuge effect, boosting predatory mite populations using alternative prey and prolonged predator release devices. Biocontrol success, however, will strongly depend on how the poultry is

  4. Using a bank of predatory fish samples for bioindication of radioactive contamination of aquatic food chains in the area affected by the Chernobyl accident.

    PubMed

    Kryshev, I I; Ryabov, I N; Sazykina, T G

    1993-11-01

    From the analysis of experimental data on radioactive contamination of various fish, it is suggested that predatory fish specimens can be used as bioindicators of radionuclide accumulation in reservoir food chains of the Chernobyl emergency area. The increased content of cesium radionuclides were detected in the muscle tissue of predatory fish collected in various regions of the Chernobyl emergency area. In most of the water bodies studied, maximum contamination levels of predatory fish by radionuclides of cesium occurred in 1987-1988, whereas in 'nonpredatory' fish the concentration of cesium was maximum, as a rule, in the first year following the accident. The exposure doses of fish of various ecological groups and ages are estimated. The exposure doses of various population groups, using fish from contaminated water bodies, are also estimated. When forming the environmental data bank for the Chernobyl accident zone it is suggested that perch, pike-perch and pike be used as bioindicators of radioactive contamination of food chains.

  5. Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions.

    PubMed

    Carlos de Sá, Luís; Luís, Luís G; Guilhermino, Lúcia

    2015-01-01

    Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the preyselection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey.All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (upto 50%), while M-est fish did not, suggesting that developmental conditions may influence the preyselection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.

  6. Potential impact of low-concentration silver nanoparticles on predator-prey interactions between predatory dragonfly nymphs and Daphnia magna as a prey.

    PubMed

    Pokhrel, Lok R; Dubey, Brajesh

    2012-07-17

    This study investigated the potential impacts of low-concentration citrate-coated silver nanoparticles (citrate-nAg; 2 μg L(-1) as total Ag) on the interactions of Daphnia magna Straus (as a prey) with the predatory dragonfly ( Anax junius : Odonata) nymph using the behavioral, survival, and reproductive end points. Four different toxicity bioassays were evaluated: (i) horizontal migration; (ii) vertical migration; (iii) 48 h survival; and (iv) 21 day reproduction; using four different treatment combinations: (i) Daphnia + citrate-nAg; (ii) Daphnia + predator; (iii) Daphnia + citrate-nAg + predator; and (iv) Daphnia only (control). Daphnia avoided the predators using the horizontal and vertical movements, indicating that Daphnia might have perceived a significant risk of predation. However, with citrate-nAg + predator treatment, Daphnia response did not differ from control in the vertical migration test, suggesting that Daphnia were unable to detect the presence of predator with citrate-nAg treatment and this may have potential implication on daphnids population structure owing to predation risk. The 48 h survival test showed a significant mortality of Daphnia individuals in the presence of predators, with or without citrate-nAg, in the test environment. Average reproduction of daphnids increased by 185% with low-concentration citrate-nAg treatment alone but was severely compromised in the presence of predators (decreased by 91.3%). Daphnia reproduction was slightly enhanced by approximately 128% with citrate-nAg + predator treatment. Potential mechanisms of these differential effects of low-concentration citrate-nAg, with or without predators, are discussed. Because silver dissolution was minimal, the observed toxicity could not be explained by dissolved Ag alone. These findings offer novel insights into how exposure to low-concentration silver nanoparticles could influence predator-prey interactions in the fresh water systems.

  7. The use of the cannibalistic habit and elevated relative humidity to improve the storage and shipment of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae).

    PubMed

    Ghazy, Noureldin Abuelfadl; Amano, Hiroshi

    2016-07-01

    This study investigated the feasibility of using the cannibalistic habits of the mite Neoseiulus californicus (McGregor) and controlling the relative humidity (RH) to prolong the survival time during the storage or shipment of this predatory mite. Three-day-old mated and unmated females were individually kept at 25 ± 1 °C in polypropylene vials (1.5 mL), each containing one of the following items or combinations of items: a kidney bean leaf disk (L), N. californicus eggs (E), and both a leaf disk and the eggs (LE). Because the leaf disk increased the RH in the vials, the RH was 95 ± 2 % under the L and LE treatments and 56 ± 6 % under the E treatment. The median lethal time (LT50) exceeded 50 days for the mated and unmated females under the LE treatment. However, it did not exceed 11 or 3 days for all females under the L or E treatments, respectively. Under the LE treatment, the mated and unmated females showed cannibalistic behavior and consumed an average of 5.2 and 4.6 eggs/female/10 days. Some of the females that survived for LT50 under each treatment were transferred and fed normally with a constant supply of Tetranychus urticae Koch. Unmated females were provided with adult males for 24 h for mating. Only females previously kept at LE treatment produced numbers of eggs equivalent to the control females (no treatment is applied). The results suggested that a supply of predator eggs and leaf material might have furnished nutrition and water vapor, respectively, and that this combination prolonged the survival time of N. californicus during storage. Moreover, this approach poses no risk of pest contamination in commercial products.

  8. Evidence for Avian Intrathoracic Air Sacs in a New Predatory Dinosaur from Argentina

    PubMed Central

    Sereno, Paul C.; Martinez, Ricardo N.; Wilson, Jeffrey A.; Varricchio, David J.; Alcober, Oscar A.; Larsson, Hans C. E.

    2008-01-01

    Background Living birds possess a unique heterogeneous pulmonary system composed of a rigid, dorsally-anchored lung and several compliant air sacs that operate as bellows, driving inspired air through the lung. Evidence from the fossil record for the origin and evolution of this system is extremely limited, because lungs do not fossilize and because the bellow-like air sacs in living birds only rarely penetrate (pneumatize) skeletal bone and thus leave a record of their presence. Methodology/Principal Findings We describe a new predatory dinosaur from Upper Cretaceous rocks in Argentina, Aerosteon riocoloradensis gen. et sp. nov., that exhibits extreme pneumatization of skeletal bone, including pneumatic hollowing of the furcula and ilium. In living birds, these two bones are pneumatized by diverticulae of air sacs (clavicular, abdominal) that are involved in pulmonary ventilation. We also describe several pneumatized gastralia (“stomach ribs”), which suggest that diverticulae of the air sac system were present in surface tissues of the thorax. Conclusions/Significance We present a four-phase model for the evolution of avian air sacs and costosternal-driven lung ventilation based on the known fossil record of theropod dinosaurs and osteological correlates in extant birds: (1) Phase I—Elaboration of paraxial cervical air sacs in basal theropods no later than the earliest Late Triassic. (2) Phase II—Differentiation of avian ventilatory air sacs, including both cranial (clavicular air sac) and caudal (abdominal air sac) divisions, in basal tetanurans during the Jurassic. A heterogeneous respiratory tract with compliant air sacs, in turn, suggests the presence of rigid, dorsally attached lungs with flow-through ventilation. (3) Phase III—Evolution of a primitive costosternal pump in maniraptoriform theropods before the close of the Jurassic. (4) Phase IV—Evolution of an advanced costosternal pump in maniraptoran theropods before the close of the

  9. A Novel Treatment Protects Chlorella at Commercial Scale from the Predatory Bacterium Vampirovibrio chlorellavorus

    PubMed Central

    Ganuza, Eneko; Sellers, Charles E.; Bennett, Braden W.; Lyons, Eric M.; Carney, Laura T.

    2016-01-01

    The predatory bacterium, Vampirovibrio chlorellavorus, can destroy a Chlorella culture in just a few days, rendering an otherwise robust algal crop into a discolored suspension of empty cell walls. Chlorella is used as a benchmark for open pond cultivation due to its fast growth. In nature, V. chlorellavorus plays an ecological role by controlling this widespread terrestrial and freshwater microalga, but it can have a devastating effect when it attacks large commercial ponds. We discovered that V. chlorellavorus was associated with the collapse of four pilot commercial-scale (130,000 L volume) open-pond reactors. Routine microscopy revealed the distinctive pattern of V. chlorellavorus attachment to the algal cells, followed by algal cell clumping, culture discoloration and ultimately, growth decline. The “crash” of the algal culture coincided with increasing proportions of 16s rRNA sequencing reads assigned to V. chlorellavorus. We designed a qPCR assay to predict an impending culture crash and developed a novel treatment to control the bacterium. We found that (1) Chlorella growth was not affected by a 15 min exposure to pH 3.5 in the presence of 0.5 g/L acetate, when titrated with hydrochloric acid and (2) this treatment had a bactericidal effect on the culture (2-log decrease in aerobic counts). Therefore, when qPCR results indicated a rise in V. chlorellavorus amplicons, we found that the pH-shock treatment prevented the culture crash and doubled the productive longevity of the culture. Furthermore, the treatment could be repeatedly applied to the same culture, at the beginning of at least two sequential batch cycles. In this case, the treatment was applied preventively, further increasing the longevity of the open pond culture. In summary, the treatment reversed the infection of V. chlorellavorus as confirmed by observations of bacterial attachment to Chlorella cells and by detection of V. chlorellavorus by 16s rRNA sequencing and qPCR assay. The p

  10. A trophic cascade induced by predatory ants in a fig-fig wasp mutualism.

    PubMed

    Wang, Bo; Geng, Xiang-Zong; Ma, Li-Bin; Cook, James M; Wang, Rui-Wu

    2014-09-01

    A trophic cascade occurs when predators directly decrease the densities, or change the behaviour, of herbivores and thus indirectly increase plant productivity. The predator-herbivore-plant context is well known, but some predators attack species beneficial to plants (e.g. pollinators) and/or enemies of herbivores (e.g. parasites), and their role in the dynamics of mutualisms remains largely unexplored. We surveyed the predatory ant species and studied predation by the dominant ant species, the weaver ant Oecophylla smaragdina, associated with the fig tree Ficus racemosa in southwest China. We then tested the effects of weaver ants on the oviposition behaviour of pollinating and non-pollinating fig wasps in an ant-exclusion experiment. The effects of weaver ants on fig wasp community structure and fig seed production were then compared between trees with and without O. smaragdina. Oecophylla smaragdina captured more non-pollinating wasps (Platyneura mayri) than pollinators as the insects arrived to lay eggs. When ants were excluded, more non-pollinators laid eggs into figs and fewer pollinators entered figs. Furthermore, trees with O. smaragdina produced more pollinator offspring and fewer non-pollinator offspring, shifting the community structure significantly. In addition, F. racemosa produced significantly more seeds on trees inhabited by weaver ants. Oecophylla smaragdina predation reverses the dominance of the two commonest wasp species at the egg-laying stage and favours the pollinators. This behavioural pattern is mirrored by wasp offspring production, with pollinators' offspring dominating figs produced by trees inhabited by weaver ants, and offspring of the non-pollinator P. mayri most abundant in figs on trees inhabited by other ants. Overall, our results suggest that predation by weaver ants limits the success of the non-pollinating P. mayri and therefore indirectly benefits the mutualism by increasing the reproductive success of both the

  11. Variation in trace-element accumulation in predatory fishes from a stream contaminated by coal combustion waste.

    PubMed

    Fletcher, Dean E; Lindell, Angela H; Stillings, Garrett K; Mills, Gary L; Blas, Susan A; McArthur, J Vaun

    2014-04-01

    Extensive and critical evaluation can be required to assess contaminant bioaccumulation in large predatory fishes. Species differences in habitat use, resource use, and trophic level, often influenced by body form, can result in diverging contaminant bioaccumulation patterns. Moreover, the broad size ranges inherent with large-bodied fish provide opportunity for trophic and habitat shifts within species that can further influence contaminant exposure. We compared contaminant bioaccumulation in four fish species, as well as two herbivorous invertebrates, from a coal combustion waste contaminated stream. Muscle, liver, and gonad tissue were analyzed from fish stratified across the broadest size ranges available. Effects of trophic position (δ (15)N), carbon sources (δ (13)C), and body size varied among and within species. Mercury and cesium concentrations were lowest in the invertebrates and increased with trophic level both among and within fish species. Other elements, such as vanadium, cadmium, barium, nickel, and lead, had greater levels in herbivorous invertebrates than in fish muscle. Sequestration by the fish livers averted accumulation in muscle. Consequently, fish liver tissue appeared to be a more sensitive indicator of bioavailability, but exceptions existed. Despite liver sequestration, within fishes, muscle concentrations of many elements still tended to increase by trophic level. Notable variation within some species was observed. These results illustrate the utility of stable isotope data in exploring differences of bioaccumulation within taxa. Our analyses suggest a need for further evaluation of the underlying sources of this variability to better understand contaminant bioaccumulation in large predatory fishes.

  12. Evaluation of the predatory mite, Neoseiulus californicus, for spider mite control on greenhouse sweet pepper under hot arid field conditions.

    PubMed

    Weintraub, P; Palevsky, E

    2008-06-01

    The efficacy of Neoseiulus californicus (a generalist predatory mite) for the biological control of Tetranychus urticae, was compared to release of Phytoseiulus persimilis (a specialist predatory mite) and an acaricide treatment in sweet pepper plants grown in greenhouse tunnels in a hot and arid climate. To ensure uniform pest populations, spider mites were spread on pepper plants in two seasons; a natural infestation occurred in one season. Predators were released prophylactically and curatively in separate tunnels when plants were artificially infested with spider mites, and at low and moderate spider mite populations when infestations occurred naturally. Although spider mite populations did not establish well the first year, fewer spider mites were recovered with release of N. californicus than with all other treatments. In the second year, spider mites established and the prophylactic release of N. californicus compared favorably with the acaricide-treated plants. In the course of monitoring arthropod populations, we observed a significant reduction in western flower thrips (Frankliniella occidentalis) populations in tunnels treated with N. californicus as compared with non-treated control tunnels. Our field trials validate results obtained from potted-plant experiments and confirm that N. californicus is a superior spider mite predator at high temperatures and low humidities.

  13. Driving factors of the communities of phytophagous and predatory mites in a physic nut plantation and spontaneous plants associated.

    PubMed

    Cruz, Wilton P; Sarmento, Renato A; Teodoro, Adenir V; Neto, Marçal P; Ignacio, Maíra

    2013-08-01

    Seasonal changes in climate and plant diversity are known to affect the population dynamics of both pests and natural enemies within agroecosystems. In Brazil, spontaneous plants are usually tolerated in small-scale physic nut plantations over the year, which in turn may mediate interactions between pests and natural enemies within this agroecosystem. Here, we aimed to access the influence of seasonal variation of abiotic (temperature, relative humidity and rainfall) and biotic (diversity of spontaneous plants, overall richness and density of mites) factors on the communities of phytophagous and predatory mites found in a physic nut plantation and its associated spontaneous plants. Mite sampling was monthly conducted in dicotyledonous and monocotyledonous leaves of spontaneous plants as well as in physic nut shrubs over an entire year. In the dry season there was a higher abundance of phytophagous mites (Tenuipalpidae, Tarsonemidae and Tetranychidae) on spontaneous plants than on physic nut shrubs, while predatory mites (Phytoseiidae) showed the opposite pattern. The overall density of mites on spontaneous plants increased with relative humidity and diversity of spontaneous plants. Rainfall was the variable that most influenced the density of mites inhabiting physic nut shrubs. Agroecosystems comprising spontaneous plants associated with crops harbour a rich mite community including species of different trophic levels which potentially benefit natural pest control due to increased diversity and abundance of natural enemies.

  14. Impact of factitious foods and prey on the oviposition of the predatory mites Gaeolaelaps aculeifer and Stratiolaelaps scimitus (Acari: Laelapidae).

    PubMed

    Navarro-Campos, C; Wäckers, F L; Pekas, A

    2016-09-01

    The soil-dwelling predatory mites Gaeolaelaps aculeifer and Stratiolaelaps scimitus (Mesostigmata: Laelapidae) are important biocontrol agents of several pests (Astigmata, Thysanoptera, Diptera). There is little information regarding the use of factitious foods that potentially improve their mass rearing and population development once released in the field. Here we tested the suitability of several types of factitious food and prey for G. aculeifer and S. scimitus. Factitious foods included eggs of Ephestia kuehniella (Lepidoptera: Pyralidae), hydrated encapsulated cysts of the brine shrimp Artemia sp. (Anostraca: Artemiidae), two species of saprophytic nematodes (Panagrellus redivivus and Panagrellus sp.) (Nematoda: Panagrolaimidae) and pollen of cattail Typha angustifolia (Poales: Typhaceae). Parameters tested were oviposition over a 3-day period compared with controls provided with either second instars of the thrips Frankliniella occidentalis (Thysanoptera: Thripidae) or a mix of instars of the commercially used prey mite Tyrophagus putrescentiae (Astigmatina: Acaridae) or the absence of food. Compared to the standard prey mite T. putrescentiae, G. aculeifer showed elevated oviposition when fed thrips larvae, E. kuehniella eggs, Artemia sp. cysts or the saprophytic P. redivivus. Oviposition by S. scimitus was high when provided with thrips larvae and P. redivivus, but not significantly different from oviposition on T. putrescentiae. Oviposition for both predatory mite species was very low or zero when provided with T. angustifolia pollen. Finally, G. aculeifer consumed significantly more thrips larvae than S. scimitus. The implication of these results for the mass-rearing of G. aculeifer and S. scimitus are discussed.

  15. The effect of a species-specific avoidance response to predatory starfish on the intertidal distribution of two gastropods.

    PubMed

    Phillips, David W

    1976-06-01

    The gastropodsAcmaea (Collisella) limatula andAcmaea (Notoacmea) scutum respond to water flowing over certain predatory starfish (i.e. to the scent of the starfish) by moving rapidly up a submerged, vertical surface. These limpets respond with upward movement to the scent ofPisaster ochraceus, Pisaster giganteus, Pycnopodia helianthoides, andLeptasterias aequalis. All of these starfish are predators on molluscs and at least occasionally inhabit the intertidal. In contrast, the limpets respond weakly or not at all to the scent ofPatiria miniata andPisaster brevispinus. Patiria is an omnivorous scavenger, andP. brevispinus is predaceous but strictly subtidal when it occurs on rocky shores. For the starfish tested, then, the limpets only give avoidance responses to starfish species naturally encountered as predators.The avoidance response ofA. limatula andA. scutum to predatory stafish can also be demonstrated in the field. When onePisaster ochraceus is placed beneath a population of limpets in the intertidal and confined so that contacts between the starfish and limpets are impossible, the limpet population is displaced significantly upward after one tidal cycle. In addition, the closer the limpets are to the starfish, the greater is their upward displacement.

  16. Chronic hypoxia and low salinity impair anti-predatory responses of the green-lipped mussel Perna viridis.

    PubMed

    Wang, Youji; Hu, Menghong; Cheung, S G; Shin, P K S; Lu, Weiqun; Li, Jiale

    2012-06-01

    The effects of chronic hypoxia and low salinity on anti-predatory responses of the green-lipped mussel Perna viridis were investigated. Dissolved oxygen concentrations ranged from hypoxic to normoxic (1.5 ± 0.3 mg l(-1), 3.0 ± 0.3 mg l(-1) and 6.0 ± 0.3 mg l(-1)), and salinities were selected within the variation during the wet season in Hong Kong coastal waters (15‰, 20‰, 25‰ and 30‰). The dissolved oxygen and salinity significantly affected some anti-predatory responses of mussel, including byssus production, shell thickness and shell weight, and the adductor diameter was only significantly affected by salinity. Besides, interactive effects of dissolved oxygen and salinity on the byssus production and shell thickness were also observed. In hypoxic and low salinity conditions, P. viridis produced fewer byssal threads, thinner shell and adductor muscle, indicating that hypoxia and low salinity are severe environmental stressors for self-defence of mussel, and their interactive effects further increase the predation risk.

  17. Etoxazole resistance in predatory mite Phytoseiulus persimilis A.-H. (Acari: Phytoseiidae): Cross-resistance, inheritance and biochemical resistance mechanisms.

    PubMed

    Yorulmaz Salman, Sibel; Aydınlı, Fatma; Ay, Recep

    2015-07-01

    Phytoseiulus persimilis of the family Phytoseiidae is an effective predatory mite species that is used to control pest mites. The LC50 and LC60 values of etoxazole were determined on P. persimilis using a leaf-disc method and spraying tower. A laboratory selection population designated ETO6 was found to have a 111.63-fold resistance to etoxazole following 6 selection cycles. This population developed low cross-resistance to spinosad, spiromesifen, acetamiprid, indoxacarb, chlorantraniliprole, milbemectin and moderate cross-resistance to deltamethrin. PBO, IBP and DEM synergised resistance 3.17-, 2.85- and 3.60-fold respectively. Crossing experiments revealed that etoxazole resistance in the ETO6 population was an intermediately dominant and polygenic. In addition, detoxifying enzyme activities were increased 2.71-fold for esterase, 3.09-fold for glutathione S-transferase (GST) and 2.76-fold for cytochrome P450 monooxygenase (P450) in the ETO6 population. Selection for etoxazole under laboratory conditions resulted in the development of etoxazole resistance in the predatory mite P. persimilis that are resistant to pesticides are considered valuable for use in resistance management programmes within integrated pest control strategies.

  18. Predatory behavior inTupinambis teguixin (Sauria: Teiidae). I. Tongue-flicking responses to chemical food stimuli.

    PubMed

    Yanosky, A A; Iriart, D E; Mercolli, C

    1993-02-01

    Black tegu lizards (Tupinambis teguixin) have the ability to detect food odors and discriminate between them and nonfood odors. This was tested by offering chemical stimuli on cotton-tipped applicators to the animals. Stimuli were from two plant and two animal species known to be principal items in these lizards' diets, demineralized water as an odorless control, and eaude-cologne as an odorous control lacking feeding or social importance. Tongueflick attack score, latency to attack, preattack tongue-flicks, and number of attacks were analyzed. The results clearly demonstrated that this species responds to chemical food stimuli, but does not respond to odorless nonfood stimuli. Responses differed among food types. There were no sex differences. These results are in agreement with the prediction that lizards having forked tongues and an active foraging mode rely on chemical cues for feeding.

  19. Functional responses and prey-stage preferences of a predatory gall midge and two predacious mites wtih twospotted spider mites, Tetranychus urticae as host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae), is an important pest of vegetables and other crops. This study was conducted to evaluate and compare the potential role of three commercially available predators, predatory gall midge, Feltiella acarisuga (Vallot) (Diptera: Ceci...

  20. Stethoconus praefectus (Hemiptera: Miridae): First North American records of an Old World predatory plant bug preying on avocado lace bug, Pseudascysta perseae (Hemiptera: Tingidae), in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant bug Stethoconus praefectus (Distant), a member of the subfamily Deraecorinae and tribe Hyaliodini, is reported in North America for the first time based on specimens collected on avocado, Persea americana L., in South Florida. This predatory mirid, observed feeding on the avocado lace b...

  1. Results from two years of field studies to determine Mancozeb based spray programmes with minimal impact on predatory mites in European vine cultivation.

    PubMed

    Miles, M; Kemmitt, G; Valverde, P

    2006-01-01

    Mancozeb is a dithiocarbamate fungicide with contact activity against a wide range of economically important fungal diseases. Its multi-site mode of action means that to date there have been no recorded incidences of resistance developing despite many years of use on high risk diseases. One such disease, Grape downy mildew (Plasmopara viticola) has developed resistance to a wide range of important oomycete specific fungicides following their introduction onto the market. The role of Mancozeb either as a mixing or alternation partner in helping to manage these resistance situations remains critically important. Historical use patterns for mancozeb in tree and vine crops involved many applications of product at high use rates. Although this gave excellent disease control, a negative impact on predatory mites was often reported by researchers. This has lead to the development of mancozeb spray programmes in vines and other crops with a much reduced impact on predatory mites. A range of field studies was conducted over two years in France, Germany, Italy, Portugal and Spain where 2, 3 or 4 applications of mancozeb containing products were made per season at different spray timings. In this paper findings from field studies over two years in five different vine growing regions in Europe indicated that two to four applications of mancozeb at 1.6 kg a.i./ha as part of a spray programme caused minimal impact on naturally occurring populations of predatory mites which in turn was compatible with Integrated Pest Management programmes and the conservation of predatory mites.

  2. Benefits and Limitations of factitious prey and artificial diets on life parameters of predatory beetles, bugs, and lacewings: A mini-review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary, peer-reviewed literature, published from 1998-2007, pertaining to rearing of predatory beetles, true bugs and lacewings was reviewed and synthesized. Advances in rearing were revealed in relation to the influence of factitious prey and artificial diets on predator life parameters. Egg...

  3. An aquatic light trap designed for live capture of predatory Tropisternus sp (Coleoptera: Hydrophilidae) larvae in Arkansas rice fields.

    PubMed

    Dennett, J A; Meisch, M V

    2001-12-01

    Construction of an aquatic light trap developed for the live capture of 3rd-stage larvae of predatory Tropisternus sp. for use in laboratory bioassays against larvae of Anopheles quadrimaculatus and Psorophora columbiae is described. On 10 occasions, an average of 5.2 traps was used per evening, resulting in 52 trap-nights that accumulated 106.7 h of trapping time, or an average of 10.6 h per trap. Use of 2 heavy-duty alkaline D-sized batteries and appropriate in-circuit resistance effectively increased bulb life and trap operating time, ranging from 22 to 36 h. During both seasons, approximately 3 wk after permanent flooding of large rice fields was the most productive period in which to capture larvae of Tropisternus sp. Live trapping worked well and provided numerous larvae of Tropisternus sp. for use in laboratory predation bioassays with An. quadrimaculatus and Ps. columbiae larvae. Six hundred fifteen 3rd-stage larvae of Tropisternus sp. and 740 adult Tropisternus lateralis were captured in aquatic light traps in 1999 and 2000. Of traps containing larval Tropisternus sp. and adult T. lateralis, average numbers of 15.3 and 19.4 were captured per trap, respectively. Among all traps, the largest nightly captures of larval Tropisternus sp. and adult T. lateralis consisted of 263 and 404 specimens, respectively. The largest single trap captures for larval Tropisternus sp. and adult T. lateralis were 94 and 184, respectively. Additionally, 478 rice water weevils (Lissorhoptrus oryzophilus) also were captured. Rice water weevils averaged 36.7 per trap, with the largest single trap capture of 102 weevils on an evening where 287 weevils were captured among all traps. Other predatory insect species were captured infrequently, consisting primarily of 3rd-stage larvae of Hydrophilus triangularis and adult belostomatids, dytiscids, and notonectids. Predatory larvae of H. triangularis may have been attracted to the traps by the presence of larval Tropisternus sp. Larval

  4. Ecological and spatial factors drive intra- and interspecific variation in exposure of subarctic predatory bird nestlings to persistent organic pollutants.

    PubMed

    Eulaers, Igor; Jaspers, Veerle L B; Bustnes, Jan O; Covaci, Adrian; Johnsen, Trond V; Halley, Duncan J; Moum, Truls; Ims, Rolf A; Hanssen, Sveinn A; Erikstad, Kjell E; Herzke, Dorte; Sonne, Christian; Ballesteros, Manuel; Pinxten, Rianne; Eens, Marcel

    2013-07-01

    Top predators in northern ecosystems may suffer from exposure to persistent organic pollutants (POPs) as this exposure may synergistically interact with already elevated natural stress in these ecosystems. In the present study, we aimed at identifying biological (sex, body condition), ecological (dietary carbon source, trophic level) and spatial factors (local habitat, regional nest location) that may influence intra- and interspecific variation in exposure of subarctic predatory bird nestlings to polychlorinated biphenyl 153 (CB 153), polybrominated diphenyl ether 47 (BDE 47), dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB). During three breeding seasons (2008-2010), we sampled body feathers from fully-grown nestlings of three ecologically distinct predatory bird species in subarctic Norway: Northern Goshawk (Accipiter gentilis), White-tailed Eagle (Haliaeetus albicilla) and Golden Eagle (Aquila chrysaetos). The present study analysed, for the first time, body feathers for both POPs and carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopes, thus integrating the dietary carbon source, trophic level and POP exposure for the larger part of the nestling stage. Intraspecific variation in exposure was driven by a combination of ecological and spatial factors, often different for individual compounds. In addition, combinations for individual compounds differed among species. Trophic level and local habitat were the predominant predictors for CB 153, p,p'-DDE and BDE 47, indicating their biomagnification and decreasing levels according to coast>fjord>inland. Variation in exposure may also have been driven by inter-annual variation arisen from primary sources (e.g. p,p'-DDE) and/or possible revolatilisation from secondary sources (e.g. HCB). Interspecific differences in POP exposure were best explained by a combination of trophic level (biomagnification), dietary carbon source (food chain discrimination) and regional nest location (historical POP

  5. Rattlesnake strike behavior: kinematics

    PubMed

    Kardong; v

    1998-03-01

    The predatory behavior of rattlesnakes includes many distinctive preparatory phases leading to an extremely rapid strike, during which venom is injected. The rodent prey is then rapidly released, removing the snake's head from retaliation by the prey. The quick action of the venom makes possible the recovery of the dispatched prey during the ensuing poststrike period. The strike is usually completed in less than 0.5 s, placing a premium on an accurate strike that produces no significant errors in fang placement that could result in poor envenomation and subsequent loss of the prey. To clarify the basis for effective strike performance, we examined the basic kinematics of the rapid strike using high-speed film analysis. We scored numerous strike variables. Four major results were obtained. (1) Neurosensory control of the strike is based primarily upon sensory inputs via the eyes and facial pits to launch the strike, and upon tactile stimuli after contact. Correction for errors in targeting occurs not by a change in strike trajectory, but by fang repositioning after the jaws have made contact with the prey. (2) The rattlesnake strike is based upon great versatility and variation in recruitment of body segments and body postures. (3) Forces generated during acceleration of the head are transferred to posterior body sections to decelerate the head before contact with the prey, thereby reducing impact forces upon the snake's jaws. (4) Body acceleration is based on two patterns of body displacement, one in which acute sections of the body open like a gate, the other in which body segments flow around postural curves similar to movements seen during locomotion. There is one major implication of these results: recruitment of body segments, launch postures and kinematic features of the strike may be quite varied from strike to strike, but the overall predatory success of each strike by a rattlesnake is very consistent.

  6. Toxicity effect of Delonix elata (Yellow Gulmohr) and predatory efficiency of Copepod, Mesocyclops aspericornis for the control of dengue vector, Aedes aegypti

    PubMed Central

    Vasugi, Chellamuthu; Kamalakannan, Siva; Murugan, Kadarkarai

    2013-01-01

    Objective To evaluate the toxicity, predatory efficiency of Delonix elata (D. elata) and Mesocyclops aspericornis (M. aspericornis) against dengue vector, Aedes aegypti (Ae. aegypti). Methods A mosquitocidal bioassay was conducted at different concentration of plant extract followed by WHO standard method. The probit analysis of each tested concentration and control were observed by using software SPSS 11 version package. The each tested concentration variable was assessed by DMRT method. The predatory efficiency of copepod was followed by Deo et al., 1988. The predator, M. aspericornis was observed for mortality, abnormalities, survival and swimming activity after 24 h treatment of plant and also predation on the mosquito larvae were observed. Results D. elata were tested for biological activity against the larvae, and pupae of Ae. aegypti. Significant mortality effects were observed in each life stage. The percentage of mortality was 100% in first and second instars whereas 96%, 92% in third and fourth instars. Fitted probit-mortality curves for larvae indicated the median and 90% lethal concentrations of D. elata for instars 1-4 to be 4.91 (8.13), 5.16 (8.44), 5.95 (7.76) and 6.87 (11.23), respectively. The results indicate that leaf extract exhibits significant biological activity against life stages. The present study revealed that D. elata is potentially important in the control of Ae. aegypti. Similar studies were conducted for predatory efficiency of Copepod, M. aspericornis against mosquito vector Ae. Aegypti. This study reported that the predatory copepod fed on 39% and 25% in I and III instar larvae of mosquito and in combined treatment of D. elata and copepod maximum control of mosquito larval states and at 83%, 80%, 75% and 53% in I, II, III and IV instars, respectively. Conclusions The combined action of plant extract and predatory copepod to effectively control mosquito population and reduce the dengue transmitting diseases.

  7. Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery: The case of the polyhydroxyalkanoates.

    PubMed

    Martínez, Virginia; Herencias, Cristina; Jurkevitch, Edouard; Prieto, M Auxiliadora

    2016-04-18

    This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered were polyhydroxyalkanoates (PHAs) produced naturally by Pseudomonas putida and Cupriavidus necator, or by recombinant Escherichia coli strains. B. bacteriovorus with a mutated PHA depolymerase gene to prevent the unwanted breakdown of the bio-product allowed the recovery of up to 80% of that accumulated by the prey bacteria, even at high biomass concentrations. This innovative downstream process highlights how B. bacteriovorus can be used as a novel, biological lytic agent for the inexpensive, industrial scale recovery of intracellular products from different Gram-negative prey cultures.

  8. Functional and Numerical Responses of the Predatory Mite, Neoseiulus longispinosus, to the Red Spider Mite, Oligonychus Coffeae, Infesting Tea

    PubMed Central

    Rahman, Vattakandy jasin; Babu, Azariah; Roobakkumar, Amsalingam; Perumalsamy, Kandasamy

    2012-01-01

    Functional and numerical responses of the predatory mite, Neoseiulus longispinosus (Evans) (Acari: Phytoseiidae) to the red spider mite, Oligonychus coffeae Nietner (Acari: Tetranychidae), infesting tea were determined in a laboratory on leaf discs. Prey consumption increased with increases in temperature and prey density. Handling time decreased and successful attack rate increased with increased temperature. N. longispinosus was more voracious on larvae and nymphs than on adults of O. coffeae. Handling time was higher on adult females than on larvae. Rate of predation leveled off at temperatures greater than 25° C. Functional responses to prey density at six temperatures and to each life stage of O. coffeae approximated the Holling type II model. The oviposition rate increased with prey consumption and temperature. On average, a predator consumed 1.62 adult female prey for every egg it laid. With a fixed number of prey available, predation rate per predator decreased with increased predator density. PMID:23452011

  9. Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery: The case of the polyhydroxyalkanoates

    PubMed Central

    Martínez, Virginia; Herencias, Cristina; Jurkevitch, Edouard; Prieto, M. Auxiliadora

    2016-01-01

    This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered were polyhydroxyalkanoates (PHAs) produced naturally by Pseudomonas putida and Cupriavidus necator, or by recombinant Escherichia coli strains. B. bacteriovorus with a mutated PHA depolymerase gene to prevent the unwanted breakdown of the bio-product allowed the recovery of up to 80% of that accumulated by the prey bacteria, even at high biomass concentrations. This innovative downstream process highlights how B. bacteriovorus can be used as a novel, biological lytic agent for the inexpensive, industrial scale recovery of intracellular products from different Gram-negative prey cultures. PMID:27087466

  10. Predatory efficiency of the water bug Sphaerodema annulatum on mosquito larvae (Culex quinquefasciatus) and its effect on the adult emergence.

    PubMed

    Aditya, G; Bhattacharyya, S; Kundu, N; Saha, G K; Raut, S K

    2004-11-01

    The daily number of IV instar larva of Culex quinquefasciatus killed, rate of pupation and adult emergence was noted in presence of the predatory water bug Sphaerodema annulatum for a period of seven consecutive days, experimentally, in the laboratory. The rate of IV instar larva killed by the water bugs on an average was 65.17 per day. The rate of pupation ranged between 7.6 and 48 in control while in presence of water bugs it ranged between 6 and 35. The rate of adult emergence in control experiments varied between 1.4 and 4.8 per day, which was reduced to only 0.4-28.8 per day in case of the water bugs. The results clearly indicate that the water bugs on its way of predation reduces the rate of pupation and adult emergence of Cx. quinquefasciatus significantly which calls for an extensive field trials.

  11. The spatial dynamics of crop and ground active predatory arthropods and their aphid prey in winter wheat.

    PubMed

    Holland, J M; Winder, L; Woolley, C; Alexander, C J; Perry, J N

    2004-10-01

    The distribution of aphid predators within arable fields has been previously examined using pitfall traps. With this technique predominantly larger invertebrate species are captured, especially Carabidae, but the technique provides no estimate of density unless mark-recapture is used. However, many other numerically important aphid predators occur in arable fields and relatively little is known about their distribution patterns nor whether they exhibit a density-dependent response to patches of cereal aphids. Identification of the most effective predators can allow management practices to be developed accordingly. In this study, the distribution of cereal aphids and their predators was examined by suction sampling within a field of winter wheat in Devon, UK, along with visual estimates of weed patchiness. Sampling was conducted on four occasions in 1999 across a grid of 128 sample locations. The distribution of 11 predatory taxa from the Carabidae, Staphylinidae and Linyphiidae was examined. Additionally, the total number of aphid predators and a predation index were used in these analyses. Carabid adults and larvae, along with staphylinid larvae showed the strongest aggregation into patches and the most temporal stability in their distribution. Other taxa had more ephemeral distributions as did the cereal aphids. The distribution of carabid larvae was disassociated from the distribution of cereal aphids for the first two sampling occasions indicating biocontrol was occurring. Other predatory groups showed both association and disassociation. Carabid larvae, Bathyphantes and total numbers of Linyphiidae showed a strong correlation with weed cover for two of the sample dates. Cereal aphids were disassociated from weed cover on three sampling occasions.

  12. Anti-predatory responses of the thick shell mussel Mytilus coruscus exposed to seawater acidification and hypoxia.

    PubMed

    Sui, Yanming; Hu, Menghong; Huang, Xizhi; Wang, Youji; Lu, Weiqun

    2015-08-01

    Ocean acidification and hypoxia, both caused by anthropogenic activities, have showed deleterious impacts on marine animals. However, their combined effect on the mussel's defence to its predator has been poorly understood, which hinders us to understand the prey-predator interaction in marine environment. The thick shell mussel Mytilus coruscus and its predator, the Asian paddle crab Charybdis japonica were exposed to three pH levels (7.3, 7.7, 8.1) at two concentrations of dissolved oxygen (2.0 mg L(-1), 6.0 mg L(-1)) seawater. The anti-predatory responses of mussels, in terms of byssus thread production were analyzed after 72 h exposure. During the experiment, frequency of shedding stalks (mussels shed their byssal stalks to release themselves from attachment and allow locomotion) and number of byssus threads increased with time, were significantly reduced by hypoxia and low pH levels, and some interactions among time, predator, DO and pH were observed. As expected, the presence of the crab induced an anti-predator response in M. coruscus (significant increases in most tested parameters except the byssus thread length). Acidification and hypoxia significantly reduced byssus thread diamter at the end of the experiment, but not the byssus thread length. Cumulative byssus thread length and volume were significantly impaired by hypoxia and acidification. Our results highlight the significance of anti-predatory responses for adult mussel M. coruscus even under a stressful environment in which stress occurs through ocean acidification and hypoxia. By decreasing the strength of byssus attachment, the chance of being dislodged and consumed by crabs is likely increased. Our data suggest that there are changes in byssus production induced by hypoxia and acidification, which may affect predation rates on M. coruscus in the field.

  13. Fine-scale analysis of an assassin bug's behaviour: predatory strategies to bypass the sensory systems of prey

    PubMed Central

    2016-01-01

    Some predators sidestep environments that render them conspicuous to the sensory systems of prey. However, these challenging environments are unavoidable for certain predators. Stenolemus giraffa is an assassin bug that feeds on web-building spiders; the web is the environment in which this predator finds its prey, but it also forms part of its preys' sophisticated sensory apparatus, blurring the distinction between environment and sensory systems. Stenolemus giraffa needs to break threads in the web that obstruct its path to the spiders, and such vibrations can alert the spiders. Using laser vibrometry, this study demonstrates how S. giraffa avoids alerting the spiders during its approach. When breaking threads, S. giraffa attenuates the vibrations produced by holding on to the loose ends of the broken thread and causing them to sag prior to release. In addition, S. giraffa releases the loose ends of a broken thread one at a time (after several seconds or minutes) and in this way spaces out the production of vibrations in time. Furthermore, S. giraffa was found to maximally reduce the amplitude of vibrations when breaking threads that are prone to produce louder vibrations. Finally, S. giraffa preferred to break threads in the presence of wind, suggesting that this araneophagic insect exploits environmental noise that temporarily impairs the spiders' ability to detect vibrations. The predatory behaviour of S. giraffa seems to be adaptated in intricate manner for bypassing the sophisticated sensory systems of web-building spiders. These findings illustrate how the physical characteristics of the environment, along with the sensory systems of prey can shape the predatory strategies of animals. PMID:27853576

  14. Stage-dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem.

    PubMed

    Liere, Heidi; Perfecto, Ivette; Vandermeer, John

    2014-08-01

    Interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. For example, stage-dependent vulnerability of a predatory lady beetle to aggression of the ant, Azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. Due to a mutualistic association between A. instabilis and the hemipteran Coccus viridis - which is A. orbigera main prey in the area - only plants around ant nests have high C. viridis populations. Here, we report on a series of surveys at three different scales aimed at detecting how the presence and clustered distribution of ant nests affect the distribution of the different life stages of this predatory lady beetle in a coffee farm in Chiapas, Mexico. Both beetle adults and larvae were more abundant in areas with ant nests, but adults were restricted to the peripheries of highest ant activity and outside the reach of coffee bushes containing the highest densities of lady beetle larvae. The abundance of adult beetles located around trees with ants increased with the size of the ant nest clusters but the relationship is not significant for larvae. Thus, we suggest that A. orbigera undergoes an ontogenetic niche shift, not through shifting prey species, but through stage-specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Together with evidence presented elsewhere, this study shows how an important predator is not only dependent on the existence of two qualitatively distinct habitat types, but also on the spatial distribution of these habitats. We suggest that this dependency arises due to the different responses that the predator's life stages have to this emergent spatial pattern.

  15. Association between shell morphology of micro-land snails (genus Plectostoma) and their predator’s predatory behaviour

    PubMed Central

    Schilthuizen, Menno

    2014-01-01

    Predator–prey interactions are among the main ecological interactions that shape the diversity of biological form. In many cases, the evolution of the mollusc shell form is presumably driven by predation. However, the adaptive significance of several uncommon, yet striking, shell traits of land snails are still poorly known. These include the distorted coiled “tuba” and the protruded radial ribs that can be found in micro-landsnails of the genus Plectostoma. Here, we experimentally tested whether these shell traits may act as defensive adaptations against predators. We characterised and quantified the possible anti-predation behaviour and shell traits of Plectostoma snails both in terms of their properties and efficiencies in defending against the Atopos slug predatory strategies, namely, shell-apertural entry and shell-drilling. The results showed that Atopos slugs would first attack the snail by shell-apertural entry, and, should this fail, shift to the energetically more costly shell-drilling strategy. We found that the shell tuba of Plectostoma snails is an effective defensive trait against shell-apertural entry attack. None of the snail traits, such as resting behaviour, shell thickness, shell tuba shape, shell rib density and intensity can fully protect the snail from the slug’s shell-drilling attack. However, these traits could increase the predation costs to the slug. Further analysis on the shell traits revealed that the lack of effectiveness in these anti-predation shell traits may be caused by a functional trade-off between shell traits under selection of two different predatory strategies. PMID:24749008

  16. Niche-specific cognitive strategies: object memory interferes with spatial memory in the predatory bat Myotis nattereri.

    PubMed

    Hulgard, Katrine; Ratcliffe, John M

    2014-09-15

    Related species with different diets are predicted to rely on different cognitive strategies: those best suited for locating available and appropriate foods. Here we tested two predictions of the niche-specific cognitive strategies hypothesis in bats, which suggests that predatory species should rely more on object memory than on spatial memory for finding food and that the opposite is true of frugivorous and nectivorous species. Specifically, we predicted that: (1) predatory bats would readily learn to associate shapes with palatable prey and (2) once bats had made such associations, these would interfere with their subsequent learning of a spatial memory task. We trained free-flying Myotis nattereri to approach palatable and unpalatable insect prey suspended below polystyrene objects. Experimentally naïve bats learned to associate different objects with palatable and unpalatable prey but performed no better than chance in a subsequent spatial memory experiment. Because experimental sequence was predicted to be of consequence, we introduced a second group of bats first to the spatial memory experiment. These bats learned to associate prey position with palatability. Control trials indicated that bats made their decisions based on information acquired through echolocation. Previous studies have shown that bat species that eat mainly nectar and fruit rely heavily on spatial memory, reflecting the relative consistency of distribution of fruit and nectar compared with insects. Our results support the niche-specific cognitive strategies hypothesis and suggest that for gleaning and clutter-resistant aerial hawking bats, learning to associate shape with food interferes with subsequent spatial memory learning.

  17. Exposure to a glyphosate-based herbicide affects agrobiont predatory arthropod behaviour and long-term survival.

    PubMed

    Evans, Samuel C; Shaw, Emma M; Rypstra, Ann L

    2010-10-01

    Humans commonly apply chemicals to manage agroecosystems. If those chemicals influence the behaviour or survival of non-target arthropods, the food web could be altered in unintended ways. Glyphosate-based herbicides are among the most ubiquitous pesticides used around the world, yet little is known about if and how they might affect the success of terrestrial predatory arthropods in agroecosystems. In this study, we quantified the effects of a commercial formulation of a glyphosate-based herbicide on the activity of three predatory arthropod species that inhabit agricultural fields in the eastern United States. We also measured the survival of the most common species. We tested the reactions of the wolf spider, Pardosa milvina, to either direct application (topical) or contact with a treated substrate (residual). We quantified the reactions of a larger wolf spider, Hogna helluo, and a ground beetle, Scarites quadriceps, to a compound (topical plus residual) exposure. Pardosa milvina reduced locomotion time and distance under topical herbicide exposure, but increased speed and non-locomotory activity time on exposed substrate. Both H. helluo and S. quadriceps increased non-locomotory activity time under compound herbicide exposure. Over a period of 60 days post-exposure, residually exposed P. milvina exhibited lower survivorship compared to topically exposed and control groups. Thus, exposure of terrestrial arthropods to glyphosate-based herbicides affects their behaviour and long-term survival. These results suggest that herbicides can affect arthropod community dynamics separate from their impact on the plant community and may influence biological control in agroecosystems.

  18. Stage-dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem

    PubMed Central

    Liere, Heidi; Perfecto, Ivette; Vandermeer, John

    2014-01-01

    Interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. For example, stage-dependent vulnerability of a predatory lady beetle to aggression of the ant, Azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. Due to a mutualistic association between A. instabilis and the hemipteran Coccus viridis – which is A. orbigera main prey in the area – only plants around ant nests have high C. viridis populations. Here, we report on a series of surveys at three different scales aimed at detecting how the presence and clustered distribution of ant nests affect the distribution of the different life stages of this predatory lady beetle in a coffee farm in Chiapas, Mexico. Both beetle adults and larvae were more abundant in areas with ant nests, but adults were restricted to the peripheries of highest ant activity and outside the reach of coffee bushes containing the highest densities of lady beetle larvae. The abundance of adult beetles located around trees with ants increased with the size of the ant nest clusters but the relationship is not significant for larvae. Thus, we suggest that A. orbigera undergoes an ontogenetic niche shift, not through shifting prey species, but through stage-specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Together with evidence presented elsewhere, this study shows how an important predator is not only dependent on the existence of two qualitatively distinct habitat types, but also on the spatial distribution of these habitats. We suggest that this dependency arises due to the different responses that the predator's life stages have to this emergent spatial pattern. PMID:25473473

  19. Fine-scale analysis of an assassin bug's behaviour: predatory strategies to bypass the sensory systems of prey.

    PubMed

    Soley, Fernando G

    2016-10-01

    Some predators sidestep environments that render them conspicuous to the sensory systems of prey. However, these challenging environments are unavoidable for certain predators. Stenolemus giraffa is an assassin bug that feeds on web-building spiders; the web is the environment in which this predator finds its prey, but it also forms part of its preys' sophisticated sensory apparatus, blurring the distinction between environment and sensory systems. Stenolemus giraffa needs to break threads in the web that obstruct its path to the spiders, and such vibrations can alert the spiders. Using laser vibrometry, this study demonstrates how S. giraffa avoids alerting the spiders during its approach. When breaking threads, S. giraffa attenuates the vibrations produced by holding on to the loose ends of the broken thread and causing them to sag prior to release. In addition, S. giraffa releases the loose ends of a broken thread one at a time (after several seconds or minutes) and in this way spaces out the production of vibrations in time. Furthermore, S. giraffa was found to maximally reduce the amplitude of vibrations when breaking threads that are prone to produce louder vibrations. Finally, S. giraffa preferred to break threads in the presence of wind, suggesting that this araneophagic insect exploits environmental noise that temporarily impairs the spiders' ability to detect vibrations. The predatory behaviour of S. giraffa seems to be adaptated in intricate manner for bypassing the sophisticated sensory systems of web-building spiders. These findings illustrate how the physical characteristics of the environment, along with the sensory systems of prey can shape the predatory strategies of animals.

  20. Metabarcoding dietary analysis of coral dwelling predatory fish demonstrates the minor contribution of coral mutualists to their highly partitioned, generalist diet

    PubMed Central

    Meyer, Christopher P.; Mills, Suzanne C.

    2015-01-01

    Understanding the role of predators in food webs can be challenging in highly diverse predator/prey systems composed of small cryptic species. DNA based dietary analysis can supplement predator removal experiments and provide high resolution for prey identification. Here we use a metabarcoding approach to provide initial insights into the diet and functional role of coral-dwelling predatory fish feeding on small invertebrates. Fish were collected in Moorea (French Polynesia) where the BIOCODE project has generated DNA barcodes for numerous coral associated invertebrate species. Pyrosequencing data revealed a total of 292 Operational Taxonomic Units (OTU) in the gut contents of the arc-eye hawkfish (Paracirrhites arcatus), the flame hawkfish (Neocirrhites armatus) and the coral croucher (Caracanthus maculatus). One hundred forty-nine (51%) of them had species-level matches in reference libraries (>98% similarity) while 76 additional OTUs (26%) could be identified to higher taxonomic levels. Decapods that have a mutualistic relationship with Pocillopora and are typically dominant among coral branches, represent a minor contribution of the predators’ diets. Instead, predators mainly consumed transient species including pelagic taxa such as copepods, chaetognaths and siphonophores suggesting non random feeding behavior. We also identified prey species known to have direct negative interactions with stony corals, such as Hapalocarcinus sp, a gall crab considered a coral parasite, as well as species of vermetid snails known for their deleterious effects on coral growth. Pocillopora DNA accounted for 20.8% and 20.1% of total number of sequences in the guts of the flame hawkfish and coral croucher but it was not detected in the guts of the arc-eye hawkfish. Comparison of diets among the three fishes demonstrates remarkable partitioning with nearly 80% of prey items consumed by only one predator. Overall, the taxonomic resolution provided by the metabarcoding approach

  1. [Pathophysiology of aggressive behavior: evaluation and management of pathological aggression].

    PubMed

    Pompili, E; Carlone, C; Silvestrini, C; Nicolò, G

    2016-01-01

    This work aims to define the aggression in all its forms, with notes on management and rapid tranquilization. The pathological aggression is described as a non-homogeneous phenomenon, it is variable in according to social, psychological and biological agents. The distinction of violence between affective aggression and predatory aggression can be functional to the prediction of outcome of any treatment. In general, a pattern of predatory violence tend to match with patients unresponsive and not compliant to treatment, a low probability to predict future violence and, therefore, a difficulty in managing risk. The affective aggressor, however, shows increased probability of treatment response, with more predictability of violent actions in reaction to situations perceived as threatening and, therefore, greater management of future violence risk. Those who act affective violence tend to show a wide range of emotional and cognitive problems, while those who act with predatory patterns show greater inclination to aggression and antisocial behavior. Aggression that occurs in psychiatry mostly appears to be affective, therefore susceptible to modulation through treatments.

  2. Flower-Visiting Butterflies Avoid Predatory Stimuli and Larger Resident Butterflies: Testing in a Butterfly Pavilion.

    PubMed

    Fukano, Yuya; Tanaka, Yosuke; Farkhary, Sayed Ibrahim; Kurachi, Takuma

    2016-01-01

    The flower-visiting behaviors of pollinator species are affected not only by flower traits but also by cues of predators and resident pollinators. There is extensive research into the effects of predator cues and resident pollinators on the flower-visiting behaviors of bee pollinators. However, there is relatively little research into their effects on butterfly pollinators probably because of the difficulty in observing a large number of butterfly pollination events. We conducted a dual choice experiment using artificial flowers under semi-natural conditions in the butterfly pavilion at Tama Zoological Park to examine the effects of the presence of a dead mantis and resident butterflies have on the flower-visiting behavior of several butterfly species. From 173 hours of recorded video, we observed 3235 visitations by 16 butterfly species. Statistical analysis showed that (1) butterflies avoided visiting flowers occupied by a dead mantis, (2) butterflies avoided resident butterflies that were larger than the visitor, and (3) butterflies showed greater avoidance of a predator when the predator was present together with the resident butterfly than when the predator was located on the opposite flower of the resident. Finally, we discuss the similarities and differences in behavioral responses of butterfly pollinators and bees.

  3. Direct injection of venom by a predatory wasp into cockroach brain.

    PubMed

    Haspel, Gal; Rosenberg, Lior Ann; Libersat, Frederic

    2003-09-05

    In this article, we provide direct evidence for injection of venom by a wasp into the central nervous system of its cockroach prey. Venomous predators use neurotoxins that generally act at the neuromuscular junction, resulting in different types of prey paralysis. The sting of the parasitoid wasp Ampulex compressa is unusual, as it induces grooming behavior, followed by a long-term lethargic state of its insect prey, thus ultimately providing a living meal for the newborn wasp larvae. These behavioral modifications are induced only when a sting is inflicted into the head. These unique effects of the wasp venom on prey behavior suggest that the venom targets the insect's central nervous system. The mechanism by which behavior modifying compounds in the venom transverse the blood-brain barrier to induce these central and long-lasting effects has been the subject of debate. In this article, we demonstrate that the wasp stings directly into the target ganglia in the head of its prey. To prove this assertion, we produced "hot" wasps by injecting them with (14)C radiolabeled amino acids and used a combination of liquid scintillation and light microscopy autoradiography to trace radiolabeled venom in the prey. To our knowledge, this is the first direct evidence documenting targeted delivery of venom by a predator into the brain of its prey.

  4. Flower-Visiting Butterflies Avoid Predatory Stimuli and Larger Resident Butterflies: Testing in a Butterfly Pavilion

    PubMed Central

    Fukano, Yuya; Tanaka, Yosuke; Farkhary, Sayed Ibrahim; Kurachi, Takuma

    2016-01-01

    The flower-visiting behaviors of pollinator species are affected not only by flower traits but also by cues of predators and resident pollinators. There is extensive research into the effects of predator cues and resident pollinators on the flower-visiting behaviors of bee pollinators. However, there is relatively little research into their effects on butterfly pollinators probably because of the difficulty in observing a large number of butterfly pollination events. We conducted a dual choice experiment using artificial flowers under semi-natural conditions in the butterfly pavilion at Tama Zoological Park to examine the effects of the presence of a dead mantis and resident butterflies have on the flower-visiting behavior of several butterfly species. From 173 hours of recorded video, we observed 3235 visitations by 16 butterfly species. Statistical analysis showed that (1) butterflies avoided visiting flowers occupied by a dead mantis, (2) butterflies avoided resident butterflies that were larger than the visitor, and (3) butterflies showed greater avoidance of a predator when the predator was present together with the resident butterfly than when the predator was located on the opposite flower of the resident. Finally, we discuss the similarities and differences in behavioral responses of butterfly pollinators and bees. PMID:27846252

  5. Parasites alter freshwater communities in mesocosms by modifying invasive crayfish behavior.

    PubMed

    Reisinger, Lindsey S; Lodge, David M

    2016-06-01

    Parasites can alter communities by reducing densities of keystone hosts, but few studies have examined how trait-mediated indirect effects of parasites can alter ecological communities. We test how trematode parasites (Microphallus spp.) that affect invasive crayfish (Orconectes rusticus) behavior alter how crayfish impact lake littoral communities. O. rusticus drive community composition in north temperate lakes, and predatory fish can reduce crayfish activity and feeding. In laboratory studies, Microphallus parasites also alter O. rusticus behavior: infected O. rusticus eat fewer macroinvertebrates and are bolder near predatory fish than uninfected individuals. We used a 2 x 2 factorial experiment to test how predatory fish and parasites affect O. rusticus impacts in large mesocosms over 4 weeks. We predicted (1) that when predators were absent, infected crayfish would have lower impacts than uninfected crayfish on macrophytes and macroinvertebrates (as well as reduced growth and higher mortality). However, (2) when predators were present but unable to consume crayfish, infected crayfish would have greater impacts (as well as greater growth and lower mortality) than uninfected crayfish because of increased boldness. Because of its effect on crayfish feeding behavior, we also predicted (3) that infection would alter macrophyte and macroinvertebrate community composition. In contrast to our first hypothesis, we found that infected and uninfected crayfish had similar impacts on lower trophic levels when predators were absent. Across all treatments, infected crayfish were more likely to be outside shelters and had greater growth than uninfected crayfish, suggesting that the reduced feeding observed in short-term experiments does not occur over longer timescales. However, in support of the second hypothesis, when predatory fish were present, infected crayfish ate more macroinvertebrates than did uninfected crayfish, likely due to increased boldness. We also observed a

  6. Egg hatching response to a range of ultraviolet-B (UV-B) radiation doses for four predatory mites and the herbivorous spider mite Tetranychus urticae.

    PubMed

    Koveos, Dimitrios S; Suzuki, Takeshi; Terzidou, Anastasia; Kokkari, Anastasia; Floros, George; Damos, Petros; Kouloussis, Nikos A

    2017-01-01

    Egg hatchability of four predatory mites-Phytoseiulus persimilis Athias-Henriot, Iphiseius [Amblyseius] degenerans Berlese, Amblyseius swirskii Athias-Henriot, and Euseius finlandicus Oudemans (Acari: Phytoseiidae)-and the spider mite Tetranychus urticae Koch (Acari: Tetranychidae) was determined under various UV-B doses either in constant darkness (DD) or with simultaneous irradiation using white light. Under UV-B irradiation and DD or simultaneous irradiation with white light, the predator's eggs hatched in significantly lower percentages than in the control non-exposed eggs, which indicates deleterious effects of UV-B on embryonic development. In addition, higher hatchability percentages were observed under UV-B irradiation and DD in eggs of the predatory mites than in eggs of T. urticae. This might be caused by a higher involvement of an antioxidant system, shield effects by pigments or a mere shorter duration of embryonic development in predatory mites than in T. urticae, thus avoiding accumulative effects of UV-B. Although no eggs of T. urticae hatched under UV-B irradiation and DD, variable hatchability percentages were observed under simultaneous irradiation with white light, which suggests the involvement of a photoreactivation system that reduces UV-B damages. Under the same doses with simultaneous irradiation with white light, eggs of T. urticae displayed higher photoreactivation and were more tolerant to UV-B than eggs of the predatory mites. Among predators variation regarding the tolerance to UV-B effects was observed, with eggs of P. persimilis and I. degenerans being more tolerant to UV-B radiation than eggs of A. swirskii and E. finlandicus.

  7. Beyond body size: muscle biochemistry and body shape explain ontogenetic variation of anti-predatory behaviour in the lizard Salvator merianae.

    PubMed

    de Barros, Fábio Cury; de Carvalho, José Eduardo; Abe, Augusto Shinya; Kohlsdorf, Tiana

    2016-06-01

    Anti-predatory behaviour evolves under the strong action of natural selection because the success of individuals avoiding predation essentially defines their fitness. Choice of anti-predatory strategies is defined by prey characteristics as well as environmental temperature. An additional dimension often relegated in this multilevel equation is the ontogenetic component. In the tegu Salvator merianae, adults run away from predators at high temperatures but prefer fighting when it is cold, whereas juveniles exhibit the same flight strategy within a wide thermal range. Here, we integrate physiology and morphology to understand ontogenetic variation in the temperature-dependent shift of anti-predatory behaviour in these lizards. We compiled data for body shape and size, and quantified enzyme activity in hindlimb and head muscles, testing the hypothesis that morphophysiological models explain ontogenetic variation in behavioural associations. Our prediction is that juveniles exhibit body shape and muscle biochemistry that enhance flight strategies. We identified biochemical differences between muscles mainly in the LDH:CS ratio, whereby hindlimb muscles were more glycolytic than the jaw musculature. Juveniles, which often use evasive strategies to avoid predation, have more glycolytic hindlimb muscles and are much smaller when compared with adults 1-2 years old. Ontogenetic differences in body shape were identified but marginally contributed to behavioural variation between juvenile and adult tegus, and variation in anti-predatory behaviour in these lizards resides mainly in associations between body size and muscle biochemistry. Our results are discussed in the ecological context of predator avoidance by individuals differing in body size living at temperature-variable environments, where restrictions imposed by the cold could be compensated by specific phenotypes.

  8. Effects of potential food sources on biological and demographic parameters of the predatory mites Kampimodromus aberrans, Typhlodromus pyri and Amblyseius andersoni.

    PubMed

    Lorenzon, Mauro; Pozzebon, Alberto; Duso, Carlo

    2012-11-01

    Kampimodromus aberrans, Typhlodromus pyri and Amblyseius andersoni are generalist predatory mites important in controlling tetranychid and eriophyoid mites in European vineyards. They can persist by exploiting various non-prey foods when their main prey is absent or scarce. A comparative analysis of the effects of various prey and non-prey foods on the life history of these predators is lacking. In the laboratory, predatory mites were reared on herbivorous mites (Panonychus ulmi, Eotetranychus carpini and Colomerus vitis), a potential alternative prey (Tydeus caudatus) and two non-prey foods, i.e. the pollen of Typha latifolia and the mycelium of Grape downy mildew (GDM) Plasmopara viticola. Developmental times, survival, sex ratio and fecundity as well as life table parameters were estimated. Kampimodromus aberrans developed faster on E. carpini, C. vitis or pollen than on P. ulmi and laid more eggs on pollen than on prey. Low numbers of this predator developed on GDM infected leaves. Tydeus caudatus was not suitable as prey for any of the three predatory mites. Kampimodromus aberrans showed the highest intrinsic rate of population increase when fed on pollen. Developmental times of T. pyri on prey or pollen were similar but fecundity was higher on pollen than on P. ulmi. Typhlodromus pyri had higher intrinsic rates of population increase on C. vitis and pollen than on P. ulmi; E. carpini showed intermediate values whereas GDM resulted in the lowest r ( m ) values. Development of A. andersoni females was faster on pollen and C. vitis than on P. ulmi and GDM. Fecundity was higher on pollen and mites compared to GDM. Life table parameters of A. andersoni did not differ when predators were fed with prey or pollen while GDM led to a lower r ( m ) value. On a specific diet A. andersoni exhibited faster development and higher fecundity than T. pyri and K. aberrans. These findings improve knowledge on factors affecting the potential of predatory mites in controlling

  9. The Potential Application and Risks Associated With the Use of Predatory Bacteria as a Bio-control Agent Against Wound Infections

    DTIC Science & Technology

    2015-10-01

    inhibition reduces innate immunity and improves isoniazid clearance of Mycobacterium tuberculosis in the lungs of infected mice. PLoS One 6, e17091, doi...Against Wound Infections PRINCIPAL INVESTIGATOR: Daniel E Kadouri, Ph.D CONTRACTING ORGANIZATION: Rutgers, The State University of New Jersey...SUBTITLE The Potential Application and Risks Associated With the Use of Predatory Bacteria as a Bio-control Agent Against Wound Infections 5c. PROGRAM

  10. Defensive responses of Brandt's voles (Lasiopodomys brandtii) to chronic predatory stress.

    PubMed

    Hegab, Ibrahim M; Shang, Guoshen; Ye, Manhong; Jin, Yajuan; Wang, Aiqin; Yin, Baofa; Yang, Shengmei; Wei, Wanhong

    2014-03-14

    Predator odors are non-intrusive natural stressors of high ethological relevance. The objective of this study was to investigate the processing of a chronic, life-threatening stimulus during repeated prolonged presentation to Brandt's voles. One hundred and twenty voles were tested by repeated presentation of cat feces in a defensive withdrawal apparatus. Voles exposed to feces for short periods showed more avoidance, more concealment in the hide box, less contact time with the odor source, more freezing behavior, less grooming, more jumping, and more vigilant rearing than did non-exposed voles, and those exposed for longer periods. Serum levels of adrenocorticotropic hormone and corticosterone increased significantly when animals were repeatedly exposed to cat feces for short periods. The behavioral and endocrine responses habituated during prolonged presentation of cat feces. ΔfosB mRNA expression level was highest in voles exposed to cat feces for 6 and 12 consecutive days, and subsequently declined in animals exposed to cat feces for 24 days. We therefore conclude that the behavioral and endocrine responses to repeated exposure to cat feces undergo a process of habituation, while ΔfosB changes in the medial hypothalamic region exhibit sensitization. We propose that habituation and sensitization are complementary rather than contradictory processes that occur in the same individual upon repeated presentation of the same stressor.

  11. Feeding Ecology of Predatory Fishes from Groote Eylandt in the Gulf of Carpentaria, Australia, with Special Reference to Predation on Penaeid Prawns

    NASA Astrophysics Data System (ADS)

    Brewer, D. T.; Blaber, S. J. M.; Salini, J. P.; Farmer, M. J.

    1995-05-01

    The aim of this study was to describe the feeding ecology of predatory fishes in the inshore waters of Groote Eylandt in the Gulf of Carpentaria, a large tropical bay in northern Australia. This knowledge will increase our understanding of trophic ecology of fishes in tropical waters and, in particular, their interactions with commercially important penaeid prawns. Several structurally complex habitats, including seagrass beds, mixed seagrass/reef habitats and mangrove areas, which support a diverse marine fauna, are found in these shallow waters. Consequently the diets of most predatory fishes in the region comprise a wide variety of fish and invertebrate prey. Juveniles of several species of penaeid live in seagrasses, where they are preyed on by, especially, Scomberoides commersonianusand the common shark species. However, the impact on juvenile penaeid populations is not as high as in the tropical estuaries of north-eastern Australia where fish abundances are lower. Many predatory fishes are size-selective and, in general, larger fish eat bigger penaeids. Seasonal and diel predation on penaeids is largely density-dependent. Evidence from this and previous studies indicates that individual species of tropical marine fishes eat similar prey (taxa and proportions) regardless of their habitat; any differences are chiefly only at the level of genus or species.

  12. Apple pollen as a supplemental food source for the control of western flower thrips by two predatory mites, Amblyseius swirskii and Neoseiulus cucumeris (Acari: Phytoseiidae), on potted chrysanthemum.

    PubMed

    Delisle, J F; Shipp, L; Brodeur, J

    2015-04-01

    It has been shown that pollen as a dietary supplement may increase the establishment (development and reproduction) and survival of phytoseiid predatory mites, and therefore the pest control these mites can provide. In this study, the role of apple pollen as a supplemental food source was assessed as a means to increase the efficiency of two predatory mite species, Neoseiulus cucumeris and Amblyseius swirskii, for control of western flower thrips, Frankliniella occidentalis, under greenhouse conditions. The impact of apple pollen on thrips populations and predator establishment on a greenhouse chrysanthemum crop was determined over a 4-week period. The two mite species were released separately and in combination with and without pollen with two control treatments (thrips only and thrips + pollen). The introduction of A. swirskii together with pollen application provided the best control of thrips (adults and immatures). The establishment of N. cucumeris was very low in the crop during the greenhouse trial. This could be attributable, in part, to their response to extreme temperature ranges that were encountered during the greenhouse cage trials. The use of A. swirskii alone and the mixed population of the two predatory mite species without pollen resulted in the lowest frequencies of plants with heavy damage, followed by the same treatments with the addition of apple pollen.

  13. Comparative study of predatory responses in blue mussels ( Mytilus edulis L.) produced in suspended long line cultures or collected from natural bottom mussel beds

    NASA Astrophysics Data System (ADS)

    Christensen, Helle Torp; Dolmer, Per; Petersen, Jens Kjerulf; Tørring, Ditte

    2012-03-01

    Blue mussels ( Mytilus edulis L.) are a valuable resource for commercial shellfish production and may also have uses as a tool in habitat improvement, because mussel beds can increase habitat diversity and complexity. A prerequisite for both commercial mussel production and habitat improvement is the availability of seed mussels collected with minimum impact on the benthic ecosystem. To examine whether mussels collected in suspended cultures can be used for bottom culture production and as tool in habitat improvement, the differences in predatory defence responses between suspended and bottom mussels exposed to the predatory shore crab ( Carcinus maenas L.) were tested in laboratory experiments and in the field. Predatory defence responses (byssal attachment and aggregation) and morphological traits were tested in laboratory, while growth and mortality were examined in field experiments. Suspended mussels had an active response in relation to the predator by developing a significantly firmer attachment to the substrate and a closer aggregated structure. Bottom mussels had a passive strategy by having a thicker shell and larger relative size of the adductor muscle. In a field experiment mussels originated from suspended cultures had a higher length increment and lower mortality when compared to bottom mussels. It is concluded that suspended mussels potentially are an alternative resource to bottom culture and can be used in habitat improvement of mussel beds, but that the use of suspended mussels has to be tested further in large-scale field experiments.

  14. [Effects of irrigation, environmental variability and predatory wasp on Leucoptera coffeella (Guérin-Méneville) (Lepidoptera: Lyonetiidae), in coffee plants].

    PubMed

    Fernandes, Flávio L; Mantovani, Everardo C; Bonfim Neto, Hermes; De V Nunes, Victor

    2009-01-01

    The population density of the coffee leaf miner Leucoptera coffeella (Guérin-Méneville) can be affected by environmental variables in irrigated agroecosystems and the occurrence of predatory wasps such as Vespidae. In here, we aimed to evaluate the effects of environmental variables, drip irrigation depths and predation by wasps on the population density of L. coffeella. The experiment was carried out during 2004 and 2005 in a Coffea arabica plantation cultivated in the county of Jaboticatubas, Minas Gerais State, Brazil. The different irrigation depths set through drip were established considering the daily depth required by the IRRIPLUS program, which was equal to 100%, and two other lower (51% and 72%) and higher (124% and 145%) values, having the control without irrigation. In order to evaluate the coffee leaf miner population density and predation, the number of active and preyed mines was determined on the fourth pair of leaves in a group of ten plants. For the study of interactions among the environmental variables, irrigation depths with the mine density of L. coffeella and predatory wasps, the following methods were used: multivariated analysis, simple linear regression and trail. We concluded that higher pluvial precipitation, solar radiation and irrigation depths would reduce population density of the coffee leaf miner. Furthermore, the increase in density of the predatory wasps was dependent on the population level of L. coffeella.

  15. The Interacting Effects of Ungulate Hoofprints and Predatory Native Ants on Metamorph Cane Toads in Tropical Australia

    PubMed Central

    Cabrera-Guzmán, Elisa; Crossland, Michael R.; González-Bernal, Edna; Shine, Richard

    2013-01-01

    Many invasive species exploit the disturbed habitats created by human activities. Understanding the effects of habitat disturbance on invasion success, and how disturbance interacts with other factors (such as biotic resistance to the invaders from the native fauna) may suggest new ways to reduce invader viability. In tropical Australia, commercial livestock production can facilitate invasion by the cane toad (Rhinella marina), because hoofprints left by cattle and horses around waterbody margins provide distinctive (cool, moist) microhabitats; nevertheless the same microhabitat can inhibit the success of cane toads by increasing the risks of predation or drowning. Metamorph cane toads actively select hoofprints as retreat-sites to escape dangerous thermal and hydric conditions in the surrounding landscape. However, hoofprint geometry is important: in hoofprints with steep sides the young toads are more likely to be attacked by predatory ants (Iridomyrmex reburrus) and are more likely to drown following heavy rain. Thus, anthropogenic changes to the landscape interact with predation by native taxa to affect the ability of cane toads in this vulnerable life-history stage to thrive in the harsh abiotic conditions of tropical Australia. PMID:24255703

  16. The Glutathione-S-Transferase, Cytochrome P450 and Carboxyl/Cholinesterase Gene Superfamilies in Predatory Mite Metaseiulus occidentalis

    PubMed Central

    Hoy, Marjorie A.

    2016-01-01

    Pesticide-resistant populations of the predatory mite Metaseiulus (= Typhlodromus or Galendromus) occidentalis (Arthropoda: Chelicerata: Acari: Phytoseiidae) have been used in the biological control of pest mites such as phytophagous Tetranychus urticae. However, the pesticide resistance mechanisms in M. occidentalis remain largely unknown. In other arthropods, members of the glutathione-S-transferase (GST), cytochrome P450 (CYP) and carboxyl/cholinesterase (CCE) gene superfamilies are involved in the diverse biological pathways such as the metabolism of xenobiotics (e.g. pesticides) in addition to hormonal and chemosensory processes. In the current study, we report the identification and initial characterization of 123 genes in the GST, CYP and CCE superfamilies in the recently sequenced M. occidentalis genome. The gene count represents a reduction of 35% compared to T. urticae. The distribution of genes in the GST and CCE superfamilies in M. occidentalis differs significantly from those of insects and resembles that of T. urticae. Specifically, we report the presence of the Mu class GSTs, and the J’ and J” clade CCEs that, within the Arthropoda, appear unique to Acari. Interestingly, the majority of CCEs in the J’ and J” clades contain a catalytic triad, suggesting that they are catalytically active. They likely represent two Acari-specific CCE clades that may participate in detoxification of xenobiotics. The current study of genes in these superfamilies provides preliminary insights into the potential molecular components that may be involved in pesticide metabolism as well as hormonal/chemosensory processes in the agriculturally important M. occidentalis. PMID:27467523

  17. Chromatin remodelling and antisense-mediated up-regulation of the developmental switch gene eud-1 control predatory feeding plasticity

    PubMed Central

    Serobyan, Vahan; Xiao, Hua; Namdeo, Suryesh; Rödelsperger, Christian; Sieriebriennikov, Bogdan; Witte, Hanh; Röseler, Waltraud; Sommer, Ralf J.

    2016-01-01

    Phenotypic plasticity has been suggested to act through developmental switches, but little is known about associated molecular mechanisms. In the nematode Pristionchus pacificus, the sulfatase eud-1 was identified as part of a developmental switch controlling mouth-form plasticity governing a predatory versus bacteriovorous mouth-form decision. Here we show that mutations in the conserved histone-acetyltransferase Ppa-lsy-12 and the methyl-binding-protein Ppa-mbd-2 mimic the eud-1 phenotype, resulting in the absence of one mouth-form. Mutations in both genes cause histone modification defects and reduced eud-1 expression. Surprisingly, Ppa-lsy-12 mutants also result in the down-regulation of an antisense-eud-1 RNA. eud-1 and antisense-eud-1 are co-expressed and further experiments suggest that antisense-eud-1 acts through eud-1 itself. Indeed, overexpression of the antisense-eud-1 RNA increases the eud-1-sensitive mouth-form and extends eud-1 expression. In contrast, this effect is absent in eud-1 mutants indicating that antisense-eud-1 positively regulates eud-1. Thus, chromatin remodelling and antisense-mediated up-regulation of eud-1 control feeding plasticity in Pristionchus. PMID:27487725

  18. Prey preference and life tables of the predatory mite Parasitus bituberosus (Acari: Parasitidae) when offered various prey combinations.

    PubMed

    Szafranek, Piotr; Lewandowski, Mariusz; Kozak, Marcin

    2013-09-01

    Parasitus bituberosus Karg (Acari: Parasitidae) is one of the predatory mite species inhabiting mushroom houses. It is known to accept a wide range of prey, suggesting that it may be a promising candidate for the biological control of key pests of mushroom culture. In our study it did not show any prey preference among four groups of small organisms often occurring in mushroom growth medium, namely rhabditid nematodes, pygmephorid mites, and sciarid and phorid fly larvae. Nevertheless, the type of food these predators fed on affects their development. The shortest egg-to-adult development time was obtained on a nematode diet. On a diet of phorid larvae, mite development stopped at the deutonymph stage; none reached adulthood. All other diets sufficed to reach the adult phase. Female fecundity when fed nematodes and sciarid larvae did not differ, but it was much lower when fed pygmephorid mites. Other life table parameters confirmed that pygmephorid mites constituted the worst diet for P. bituberosus. The highest intrinsic rate of population increase (r m = 0.34) was obtained on the nematode diet; when fed sciarid larvae and pygmephorid mites it was 0.25 and 0.14, respectively. Our study provides good reasons to further test P. bituberosus as biocontrol agent of especially sciarid flies and nematodes, especially when the compost is well colonized by mushroom mycelium (which retards nematode growth).

  19. Consequences of seasonal variation in reservoir water level for predatory fishes: linking visual foraging and prey densities

    USGS Publications Warehouse

    Klobucar, Stephen L.; Budy, Phaedra

    2016-01-01

    In reservoirs, seasonal drawdown can alter the physical environment and may influence predatory fish performance. We investigated the performance of lake trout (Salvelinus namaycush) in a western reservoir by coupling field measurements with visual foraging and bioenergetic models at four distinct states (early summer, mid-summer, late summer, and fall). The models suggested that lake trout prey, juvenile kokanee (Oncorhynchus nerka), are limited seasonally by suitable temperature and dissolved oxygen. Accordingly, prey densities were greatest in late summer when reservoir volume was lowest and fish were concentrated by stratification. Prey encounter rates (up to 68 fish·day−1) and predator consumption are also predicted to be greatest during late summer. However, our models suggested that turbidity negatively correlates with prey detection and consumption across reservoir states. Under the most turbid conditions, lake trout did not meet physiological demands; however, during less turbid periods, predator consumption reached maximum bioenergetic efficiency. Overall, our findings demonstrate that rapid reservoir fluctuations and associated abiotic conditions can influence predator–prey interactions, and our models describe the potential impacts of water level fluctuation on valuable sport fishes.

  20. Effect of temperature and photoperiod on the development, reproduction, and predation of the predatory ladybird Cheilomenes sexmaculata (Coleoptera: Coccinellidae).

    PubMed

    Wang, Su; Tan, Xiao-Ling; Guo, Xiao-Jun; Zhang, Fan

    2013-12-01

    The polyphagous predatory ladybird Cheilomenes. sexmaculata (F.) (Coleoptera: Coccinellidae) is distributed throughout southern China and has been investigated as a potential biological control agent against herbivorous insects in various agroecosystems. In the current study, we evaluated the preimaginal development, eclosion rate, reproduction, fertility, adult longevity, and prey consumption of C. sexmaculata under five temperature and five photoperiod regimens. The results showed that preadult developmental duration decreased significantly with increasing temperature and amount of daylight. Adult eclosion rate was highest at 35 degrees C and under conditions of complete darkness. Higher temperatures shortened the duration of copulation and preoviposition, prolonged the duration of oviposition, and increased the level of fecundity. Hatchability was highest at 30 degrees C. By contrast, the shortest copulation and oviposition duration and lowest level of fecundity and hatchability occurred with a completely dark photoperiod. Temperature and the gender of C. sexmaculata influenced adult longevity. In addition, there was a significant interaction effect of photoperiod and gender on adult longevity. Furthermore, prey consumption by fourth instar larvae and adult females both increased with increasing temperature and photoperiod. Our results reveal the high thermal and light sensitivities of C. sexmaculata, which highlight the importance of environment regulation in the mass rearing of this natural enemy for application as a biological control in agroecosystems in China.

  1. State-dependent and odour-mediated anemotactic responses of the predatory mite Phytoseiulus persimilis in a wind tunnel.

    PubMed

    Van Tilborg, Merijn; Sabelis, Maurice W; Roessingh, Peter

    2004-01-01

    Anemotaxis in the predatory mite Phytoseiulus persimilis (both well-fed and starved), has previously been studied on a wire grid under slight turbulent airflow conditions yielding weak, yet distinct, gradients in wind speed and odour concentration (Sabelis and Van der Weel 1993). Such conditions might have critically influenced the outcome of the study. We repeated these experiments, under laminar airflow conditions on a flat surface in a wind tunnel, thereby avoiding variation in wind speed and odour concentration. Treatments for starved and well-fed mites were (1) still-air without herbivore-induced plant volatiles (HIPV) (well-fed mites only), (2) an HIPV-free air stream, and (3) an air stream with HIPV (originating from Lima bean plants infested by two-spotted spider mites, Tetranychus urticae). Well-fed mites oriented in random directions in still-air without HIPV. In an air stream, starved mites always oriented upwind, whether plant odours were present or not. Well-fed mites oriented downwind in an HIPV-free air stream, but in random directions in an air stream with HIPV. Only under the last treatment our results differed from those of Sabelis and Van der Weel (1993).

  2. Pulsed-resource dynamics increase the asymmetry of antagonistic coevolution between a predatory protist and a prey bacterium.

    PubMed

    Friman, V-P; Laakso, J; Koivu-Orava, M; Hiltunen, T

    2011-12-01

    Temporal resource fluctuations could affect the strength of antagonistic coevolution through population dynamics and costs of adaptation. We studied this by coevolving the prey bacterium Serratia marcescens with the predatory protozoa Tetrahymena thermophila in constant and pulsed-resource environments for approximately 1300 prey generations. Consistent with arms race theory, the prey evolved to be more defended, whereas the predator evolved to be more efficient in consuming the bacteria. Coevolutionary adaptations were costly in terms of reduced prey growth in resource-limited conditions and less efficient predator growth on nonliving resource medium. However, no differences in mean coevolutionary changes or adaptive costs were observed between environments, even though resource pulses increased fluctuations and mean densities of coevolving predator populations. Interestingly, a surface-associated prey defence mechanism (bacterial biofilm), to which predators were probably unable to counter-adapt, evolved to be stronger in pulsed-resource environment. These results suggest that temporal resource fluctuations can increase the asymmetry of antagonistic coevolution by imposing stronger selection on one of the interacting species.

  3. Sex-specific developmental plasticity of generalist and specialist predatory mites (Acari: Phytoseiidae) in response to food stress.

    PubMed

    Walzer, Andreas; Schausberger, Peter

    2011-03-01

    We studied developmental plasticity under food stress in three female-biased size dimorphic predatory mite species, Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius andersoni. All three species prey on two-spotted spider mites but differ in the degree of adaptation to this prey. Phytoseiulus persimilis is a specialized spider mite predator, N. californicus is a generalist with a preference for spider mites, and A. andersoni is a broad generalist. Immature predators were offered prey patches of varying density and their survival chances, dispersal tendencies, age and size at maturity measured. Amblyseius andersoni dispersed earlier from and had lower survival chances in low density prey patches than N. californicus and P. persimilis. Age at maturity was not affected by prey density in the generalist A. andersoni, whereas both the specialist P. persimilis and the generalist N. californicus accelerated development at low prey densities. Species-specific plasticity in age at maturity reflects opposite survival strategies when confronted with limited prey: to prematurely leave and search for other food (A. andersoni) or to stay and accelerate development (P. persimilis, N. californicus). In all species, size at maturity was more plastic in females than males, indicating that males incur higher fitness costs from deviations from optimal body size.

  4. Selection of reference genes for RT-qPCR analysis in a predatory biological control agent, Coleomegilla maculata (Coleoptera: Coccinellidae).

    PubMed

    Yang, Chunxiao; Pan, Huipeng; Noland, Jeffrey Edward; Zhang, Deyong; Zhang, Zhanhong; Liu, Yong; Zhou, Xuguo

    2015-12-10

    Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is a reliable technique for quantifying gene expression across various biological processes, of which requires a set of suited reference genes to normalize the expression data. Coleomegilla maculata (Coleoptera: Coccinellidae), is one of the most extensively used biological control agents in the field to manage arthropod pest species. In this study, expression profiles of 16 housekeeping genes selected from C. maculata were cloned and investigated. The performance of these candidates as endogenous controls under specific experimental conditions was evaluated by dedicated algorithms, including geNorm, Normfinder, BestKeeper, and ΔCt method. In addition, RefFinder, a comprehensive platform integrating all the above-mentioned algorithms, ranked the overall stability of these candidate genes. As a result, various sets of suitable reference genes were recommended specifically for experiments involving different tissues, developmental stages, sex, and C. maculate larvae treated with dietary double stranded RNA. This study represents the critical first step to establish a standardized RT-qPCR protocol for the functional genomics research in a ladybeetle C. maculate. Furthermore, it lays the foundation for conducting ecological risk assessment of RNAi-based gene silencing biotechnologies on non-target organisms; in this case, a key predatory biological control agent.

  5. Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system.

    PubMed

    Nguyen, Hoang Minh; Rountrey, Adam N; Meeuwig, Jessica J; Coulson, Peter G; Feng, Ming; Newman, Stephen J; Waite, Anya M; Wakefield, Corey B; Meekan, Mark G

    2015-03-12

    The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats.

  6. Body size affects the predatory interactions between introduced American Bullfrogs (Rana catesbeiana) and native anurans in China: An experimental study

    USGS Publications Warehouse

    Wang, Y.; Guo, Z.; Pearl, C.A.; Li, Y.

    2007-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have established breeding populations in several provinces in China since their introduction in 1959. Although Bullfrogs are viewed as a potentially important predator of Chinese native anurans, their impacts in the field are difficult to quantify. We used two experiments to examine factors likely to mediate Bullfrog predation on native anurans. First, we examined effects of Bullfrog size and sex on daily consumption of a common Chinese native (Rana limnocharis). Second, we examined whether Bullfrogs consumed similar proportions of four Chinese natives: Black-Spotted Pond Frog (Rana nigromaculata), Green Pond Frog (Rana plancyi plancyi), Rice Frog (R. limnocharis), and Zhoushan Toad (Bufo bufo gargarizans). We found that larger Rana catesbeiana consumed more R. limnocharis per day than did smaller R. catesbeiana, and that daily consumption of R. limnocharis was positively related to R. catesbeiana body size. When provided with adults of four anurans that differed significantly in body size, R. catesbeiana consumed more individuals of the smallest species (R. limnocharis). However, when provided with similarly sized juveniles of the same four species, R. catesbeiana did not consume any species more than expected by chance. Our results suggest that body size plays an important role in the predatory interactions between R. catesbeiana and Chinese native anurans and that, other things being equal, smaller species and individuals are at greater risk of predation by R. catesbeiana. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  7. Selection of reference genes for RT-qPCR analysis in a predatory biological control agent, Coleomegilla maculata (Coleoptera: Coccinellidae)

    PubMed Central

    Yang, Chunxiao; Pan, Huipeng; Noland, Jeffrey Edward; Zhang, Deyong; Zhang, Zhanhong; Liu, Yong; Zhou, Xuguo

    2015-01-01

    Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is a reliable technique for quantifying gene expression across various biological processes, of which requires a set of suited reference genes to normalize the expression data. Coleomegilla maculata (Coleoptera: Coccinellidae), is one of the most extensively used biological control agents in the field to manage arthropod pest species. In this study, expression profiles of 16 housekeeping genes selected from C. maculata were cloned and investigated. The performance of these candidates as endogenous controls under specific experimental conditions was evaluated by dedicated algorithms, including geNorm, Normfinder, BestKeeper, and ΔCt method. In addition, RefFinder, a comprehensive platform integrating all the above-mentioned algorithms, ranked the overall stability of these candidate genes. As a result, various sets of suitable reference genes were recommended specifically for experiments involving different tissues, developmental stages, sex, and C. maculate larvae treated with dietary double stranded RNA. This study represents the critical first step to establish a standardized RT-qPCR protocol for the functional genomics research in a ladybeetle C. maculate. Furthermore, it lays the foundation for conducting ecological risk assessment of RNAi-based gene silencing biotechnologies on non-target organisms; in this case, a key predatory biological control agent. PMID:26656102

  8. Population structure of the predatory mite Neoseiulus womersleyi in a tea field based on an analysis of microsatellite DNA markers

    PubMed Central

    Todokoro, Yasuhiro; Higaki, Tomomi

    2010-01-01

    The predatory mite Neoseiulus womersleyi (Schicha) (Acari: Phytoseiidae) is an important natural enemy of the Kanzawa spider mite, Tetranychus kanzawaki Kishida (Acari: Tetranychidae), in tea fields. Attraction and preservation of natural enemies by habitat management to reduce the need for acaricide sprays is thought to enhance the activity of N. womersleyi. To better conserve N. womersleyi in the field, however, it is essential to elucidate the population genetic structure of this species. To this end, we developed ten microsatellite DNA markers for N. womersleyi. We then evaluated population structure of N. womersleyi collected from a tea field, where Mexican sunflower, Tithonia rotundifolia (Mill.), was planted to preserve N. womersleyi. Seventy-seven adult females were collected from four sites within 200 m. The fixation indexes FST among subpopulations were not significantly different. The kinship coefficients between individuals did not differ significantly within a site as a function of the sampling dates, but the coefficients gradually decreased with increasing distance. Bayesian clustering analysis revealed that the population consisted of three genetic clusters, and that subpopulations within 100 m, including those collected on T. rotundifolia, were genetically similar to each other. Given the previously observed population dynamics of N. womersleyi, it appears that the area inhabited by a given cluster of the mite did not exceed 100 m. The estimation of population structure using microsatellite markers will provide valuable information in conservation biological control. PMID:20625919

  9. Feeding on Beauveria bassiana-treated Frankliniella occidentalis causes negative effects on the predatory mite Neoseiulus barkeri

    PubMed Central

    Wu, Shengyong; Gao, Yulin; Xu, Xuenong; Wang, Dengjie; Li, Juan; Wang, Haihong; Wang, Endong; Lei, Zhongren

    2015-01-01

    The entomopathogenic fungus Beauveria bassiana and the predatory mite Neoseiulus barkeri are both potential biocontrol agents for their shared host/prey Frankliniella occidentalis. The combination of the two agents may enhance biological control of F. occidentalis if the fungus does not negatively affect N. barkeri. This study evaluated the indirect effects of B. bassiana strain SZ-26 on N. barkeri mediated by F. occidentalis using the age-stage, two-sex life table. When fed on the first instar larvae of F. occidentalis that had been exposed for 12 h to the SZ-26 suspension, the developmental time of preadult N. barkeri was significantly longer, and the longevity and fecundity were significantly lower than that of N. barkeri fed on untreated F. occidentalis. The mean generation time (T), net reproductive rate (R0), finite rate of increase (λ), intrinsic rate of natural increase (rm) and predation rates were correspondingly affected. The data showed that B. bassiana has indirect negative effects on N. barkeri population dynamics via influencing their prey F. occidentalis larvae, which indicates that there is a risk in combining B. bassiana with N. barkeri simultaneously for the biocontrol of F. occidentalis. The probable mechanism for the negative effects is discussed. PMID:26153532

  10. Interspecific and geographical differences in anticoagulant rodenticide residues of predatory wildlife from the Mediterranean region of Spain.

    PubMed

    López-Perea, Jhon J; Camarero, Pablo R; Molina-López, Rafael A; Parpal, Luis; Obón, Elena; Solá, Jessica; Mateo, Rafael

    2015-04-01

    We studied the prevalence of anticoagulant rodenticides (ARs) in the liver of 344 individuals representing 11 species of predatory wildlife that were found dead in the Mediterranean region of Spain (Catalonia and Majorca Island). Six different ARs (brodifacoum, bromadiolone, difenacoum, flocoumafen, difethialone, warfarin) were found in the liver of 216 (62.8%) animals and >1 AR co-occurred in 119 individuals (34.6%). The occurrence of ARs was positively correlated with the human population density. Catalonia and Majorca showed similar prevalence of AR detection (64.4 and 60.4%, respectively), but a higher prevalence was found in the resident population of Eurasian scops owl (Otus scops) from Majorca (57.7%) compared to the migratory population from Catalonia (14.3%). Birds of prey had lower levels of bromadiolone than hedgehogs, whereas no difference was found for other ARs. The risk of SGAR poisoning in wild predators in NE Spain is believed to be elevated, because 23.3% of the individuals exhibited hepatic concentration of ARs exceeding 200 ng/g.

  11. Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system

    PubMed Central

    Nguyen, Hoang Minh; Rountrey, Adam N.; Meeuwig, Jessica J.; Coulson, Peter G.; Feng, Ming; Newman, Stephen J.; Waite, Anya M.; Wakefield, Corey B.; Meekan, Mark G.

    2015-01-01

    The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats. PMID:25761975

  12. Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoang Minh; Rountrey, Adam N.; Meeuwig, Jessica J.; Coulson, Peter G.; Feng, Ming; Newman, Stephen J.; Waite, Anya M.; Wakefield, Corey B.; Meekan, Mark G.

    2015-03-01

    The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats.

  13. Similarity of cuticular lipids between a caterpillar and its host plant: a way to make prey undetectable for predatory ants?

    PubMed

    Portugal, Augusto Henrique Arantes; Trigo, José Roberto

    2005-11-01

    Ithomiine butterflies (Nymphalidae) have long-lived, aposematic, chemically protected adults. However, little is known about the defense mechanisms in larvae and other juvenile stages. We showed that larvae Mechanitis polymnia are defended from ants by a chemical similarity between their cuticular lipids and those of the host plant, Solanum tabacifolium (Solanaceae). This is a novel defense mechanism in phytophagous insects. A field survey during one season showed that larval survivorship was up to 80%, which is high when compared with other juvenile stages. In a laboratory bioassay, live larvae on their host plant were not attacked by the predatory ant Camponotus crassus (Formicidae). Two experiments showed that the similarity between the cuticular lipids of M. polymnia and S. tabacifolium protected the larvae from C. crassus: (a) when the caterpillar was switched from a host plant to a non-host plant, the predation rate increased, and (b) when a palatable larva (Spodoptera frugiperda, Noctuidae) was coated with the cuticular lipids of M. polymnia and placed on S. tabacifolium leaves, it no longer experienced a high predation rate. This defensive mechanism can be defined as chemical camouflage, and may have a double adaptive advantage, namely, protection against predation and a reduction in the cost of sequestering toxic compounds from the host plant.

  14. Arginine: A Potent Prey Attractant to Predatory Newts in Mountain Streams

    NASA Astrophysics Data System (ADS)

    Ferrer, R. P.; Zimmer, R. K.

    2005-05-01

    Chemoreception of aquatic organisms has been well-studied in the laboratory, but rarely in the field. The California newt, Taricha torosa, in natural stream habitats is an excellent animal for exploring behavioral responses to prey odors. Here, we selected 13 amino acids for field bioassays based on their concentrations in prey tissue extracts. Bioassays were calibrated for stimulus dilution by means of fluorescent dye releases and flow-through spectrofluorometry. Moreover, hydrodynamic properties of stream flows were determined using an electromagnetic current meter. Of all amino acids tested, only arginine, alanine and glycine were significantly attractive (relative to stream water controls). These three substances caused free-ranging newts to turn upstream and swim towards the odor sources. Additional experiments showed that arginine was the most effective attractant, evoking plume-tracking behavior at concentrations as low as 10 nM. In subsequent trials, nine arginine analogs were tested, but each compound failed to elicit a significant response. Even subtle changes to arginine, such as the addition of a single carbon to the side chain, destroyed all bioactivity. Within its natural habitat, the California newt thus exhibits keen sensitivity and narrow tuning to the free amino acid, arginine, a chemical signal of its prey.

  15. Hypoxic environments as refuge against predatory fish in the Amazonian floodplains.

    PubMed

    Anjos, M B; De Oliveira, R R; Zuanon, J

    2008-02-01

    Several groups of Amazonian fishes exhibit behavioral, morphological and physiological characteristics that allow occupying hypoxic environments, despite the energetic costs of living in such harsh conditions. One of the supposed advantages of occupying hypoxic habitats would be a lower predation pressure resulting from a lower number of piscivorous fishes in those environments. We tested this hypothesis in an area of the Amazon River floodplain through gill net fishing in normoxic and hypoxic habitats. From the 103 species caught, 38 were classified as piscivores. We found no difference in the number of piscivorous species captured in hypoxic and normoxic habitats (chi2 = 0.23; p = 0.63; df = 1) but piscivorous individuals were more numerous in normoxic than in hypoxic sampling stations (chi2 = 104.4; p < 0.001; df = 1). This indicates that environments submitted to low oxygen conditions may in fact function as refuges against piscivorous fishes in the Amazonian floodplains.

  16. Predatory threat of harpy eagles for yellow-breasted capuchin monkeys in the Atlantic Forest.

    PubMed

    Suscke, Priscila; Verderane, Michele; de Oliveira, Robson Santos; Delval, Irene; Fernández-Bolaños, Marcelo; Izar, Patrícia

    2017-01-01

    We describe seven encounters between different harpy eagle individuals (Harpia harpyja) and a group of yellow-breasted capuchin monkeys (Sapajus xanthosternos) in Una Biological Reserve. These interactions lasted 58 min on average. In each of those encounters, the capuchin monkeys used particular behavioral strategies against the harpy eagle that were not employed in reaction to other aerial predators. We did not observe any successful predation events, but after one of those encounters an infant disappeared from the capuchin group. As a whole, these observations indicate that the presence of harpy eagles in the group's home range increases predation risk for capuchin monkeys. The present report also suggests a reoccupation by H. harpyja of this area, as no previous recent records identify harpy eagle occurrence in Una Biological Reserve.

  17. Electric Organ Discharges of Mormyrid Fish as a Possible Cue for Predatory Catfish

    NASA Astrophysics Data System (ADS)

    Hanika, S.; Kramer, B.

    During reproductive migration the electroreceptive African sharptooth catfish, Clarias gariepinus (Siluriformes), preys mainly on a weakly electric fish, the bulldog Marcusenius macrolepidotus (Mormyridae; Merron 1993). This is puzzling because the electric organ discharges of known Marcusenius species are pulses of a duration (<1ms) too short for being detected by the catfishes' low-frequency electroreceptive system (optimum sensitivity, 10-30Hz Peters and Bretschneider 1981). On the recent discovery that M. macrolepidotus males emit discharges lasting approximately ten times longer than those of females (Kramer 1997a) we determined behavioral thresholds for discharges of both sexes, using synthetic playbacks of field-recorded discharges. C. gariepinus detected M. macrolepidotus male discharges down to a field gradient of 103μVpeak-peak/cm and up to a distance of 1.5m at natural field conditions. In contrast, thresholds for female discharges were not reached with our setup, and we presume the bulldogs eaten by catfish are predominantly male.

  18. Strategy Dependent Swimming Dynamics Change among a Predatory Algae Species with Different Strains

    NASA Astrophysics Data System (ADS)

    Katz, Joseph; Sheng, Jian; Malkiel, Edwin; Adolf, Jason; Place, Allen

    2008-11-01

    Digital holographic microscopic cinematography is used for measuring the 3D, time resolved, swimming behavior of toxic and non-toxic strains the marine dinoflagellate Karlodinium veneficum. We focus on the response of predators of the same species, but with different predation strategy, to the presence of prey, Storeatula major. Experiments are performed in a 3x3 mm cuvette, at densities extending to 100,000 cells/ml. Holograms are recorded at 60fps and at 20X magnification. In each case, we simultaneously track 200-500 cells in the 3mm deep sample, at a spatial resolution of 0.4x0.4x2 μm. We show that responses are largely dependent on the predation strategy. K. veneficum 2064, a toxic mixotroph, slows down and decreases the helix radius and clusters around the prey. Conversely, MD5, a non-toxic, autotrophic-like strain is completely oblivious to prey. Strain 1974, which is toxic and twice as motile, shows heterotrophic-like responses with characteristics of an active hunter. Also, on going spectral analysis of the 3-D motion provides quantitative insight on the swimming dynamics of microorganisms.

  19. When herbivores eat predators: predatory insects effectively avoid incidental ingestion by mammalian herbivores.

    PubMed

    Ben-Ari, Matan; Inbar, Moshe

    2013-01-01

    The direct trophic links between mammalian herbivores and plant-dwelling insects have been practically ignored. Insects are ubiquitous on plants consumed by mammalian herbivores and are thus likely to face the danger of being incidentally ingested by a grazing mammal. A few studies have shown that some herbivorous hemipterans are able to avoid this peril by dropping to the ground upon detecting the heat and humidity on the mammal's breath. We hypothesized that if this risk affects the entire plant-dwelling insect community, other insects that share this habitat are expected to develop similar escape mechanisms. We assessed the ability of three species (adults and larvae) of coccinellid beetles, important aphid predators, to avoid incidental ingestion. Both larvae and adults were able to avoid incidental ingestion effectively by goats by dropping to the ground, demonstrating the importance of this behavior in grazed habitats. Remarkably, all adult beetles escaped by dropping off the plant and none used their functional wings to fly away. In controlled laboratory experiments, we found that human breath caused 60-80% of the beetles to drop. The most important component of mammalian herbivore breath in inducing adult beetles and larvae to drop was the combination of heat and humidity. The fact that the mechanism of dropping in response to mammalian breath developed in distinct insect orders and disparate life stages accentuates the importance of the direct influence of mammalian herbivores on plant-dwelling insects. This direct interaction should be given its due place when discussing trophic interactions.

  20. When Herbivores Eat Predators: Predatory Insects Effectively Avoid Incidental Ingestion by Mammalian Herbivores

    PubMed Central

    Ben-Ari, Matan; Inbar, Moshe

    2013-01-01

    The direct trophic links between mammalian herbivores and plant-dwelling insects have been practically ignored. Insects are ubiquitous on plants consumed by mammalian herbivores and are thus likely to face the danger of being incidentally ingested by a grazing mammal. A few studies have shown that some herbivorous hemipterans are able to avoid this peril by dropping to the ground upon detecting the heat and humidity on the mammal's breath. We hypothesized that if this risk affects the entire plant-dwelling insect community, other insects that share this habitat are expected to develop similar escape mechanisms. We assessed the ability of three species (adults and larvae) of coccinellid beetles, important aphid predators, to avoid incidental ingestion. Both larvae and adults were able to avoid incidental ingestion effectively by goats by dropping to the ground, demonstrating the importance of this behavior in grazed habitats. Remarkably, all adult beetles escaped by dropping off the plant and none used their functional wings to fly away. In controlled laboratory experiments, we found that human breath caused 60–80% of the beetles to drop. The most important component of mammalian herbivore breath in inducing adult beetles and larvae to drop was the combination of heat and humidity. The fact that the mechanism of dropping in response to mammalian breath developed in distinct insect orders and disparate life stages accentuates the importance of the direct influence of mammalian herbivores on plant-dwelling insects. This direct interaction should be given its due place when discussing trophic interactions. PMID:23424674

  1. Predatory functional morphology in raptors: interdigital variation in talon size is related to prey restraint and immobilisation technique.

    PubMed

    Fowler, Denver W; Freedman, Elizabeth A; Scannella, John B

    2009-11-25

    Despite the ubiquity of raptors in terrestrial ecosystems, many aspects of their predatory behaviour remain poorly understood. Surprisingly little is known about the morphology of raptor talons and how they are employed during feeding behaviour. Talon size variation among digits can be used to distinguish families of raptors and is related to different techniques of prey restraint and immobilisation. The hypertrophied talons on digits (D) I and II in Accipitridae have evolved primarily to restrain large struggling prey while they are immobilised by dismemberment. Falconidae have only modest talons on each digit and only slightly enlarged D-I and II. For immobilisation, Falconini rely more strongly on strike impact and breaking the necks of their prey, having evolved a 'tooth' on the beak to aid in doing so. Pandionidae have enlarged, highly recurved talons on each digit, an adaptation for piscivory, convergently seen to a lesser extent in fishing eagles. Strigiformes bear enlarged talons with comparatively low curvature on each digit, part of a suite of adaptations to increase constriction efficiency by maximising grip strength, indicative of specialisation on small prey. Restraint and immobilisation strategy change as prey increase in size. Small prey are restrained by containment within the foot and immobilised by constriction and beak attacks. Large prey are restrained by pinning under the bodyweight of the raptor, maintaining grip with the talons, and immobilised by dismemberment (Accipitridae), or severing the spinal cord (Falconini). Within all raptors, physical attributes of the feet trade off against each other to attain great strength, but it is the variable means by which this is achieved that distinguishes them ecologically. Our findings show that interdigital talon morphology varies consistently among raptor families, and that this is directly correlative with variation in their typical prey capture and restraint strategy.

  2. Effects of air temperature and water vapor pressure deficit on storage of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae).

    PubMed

    Ghazy, Noureldin Abuelfadl; Suzuki, Takeshi; Amano, Hiroshi; Ohyama, Katsumi

    2012-10-01

    To determine the optimum air temperature and water vapor pressure deficit (VPD) for the storage of the predatory mite, Neoseiulus californicus, 3-day-old mated females were stored at air temperatures of 0, 5, 10, or 15 °C and VPDs of 0.1, 0.3, or 0.5 kPa for 10, 20, or 30 days. At 10 °C and 0.1 kPa, 83 % of females survived after 30 days of storage; this percentage was the highest among all conditions. VPDs of 0.3 and 0.5 kPa regardless of air temperature, and an air temperature of 0 °C regardless of VPD were detrimental to the survival of the females during storage. Since the highest survival was observed at 10 °C and 0.1 kPa, the effect of the storage duration on the post-storage quality of the stored females and their progeny was investigated at 25 °C to evaluate the effectiveness of the storage condition. The oviposition ability of the stored females, hatchability, and sex ratio of their progeny were not affected even when the storage duration was extended to 30 days. Although a slight decrease in the survival during the immature stages of progeny was observed when the storage duration was ≥20 days, the population growth of N. californicus may not be affected when individuals stored in these conditions are applied to greenhouses and agricultural fields. The results indicate that mated N. californicus females can be stored at 10 °C and 0.1 kPa VPD for at least 30 days.

  3. Distribution and Biology of Mallada desjardinsi (Neuroptera: Chrysopidae) in India and Its Predatory Potential Against Aleurodicus dispersus (Hemiptera: Aleyrodidae)

    PubMed Central

    Boopathi, T.; Singh, S. B.; Ravi, M.; Manju, T.

    2016-01-01

    In this study, we report the prevalence of Mallada desjardinsi (Navas) in seven geographical regions of India and provide the first report of its kind outlining the preying of all stages of the spiraling whitefly, Aleurodicus dispersus Russell, by M. desjardinsi. Sampling was conducted in seven regions of two provinces in India, Bengaluru (Karnataka) and Tiruppur (Tamil Nadu), which demonstrated that M. desjardinsi populations were most dense at the former and least at the later. To the best of our knowledge, this is the first report of its kind outlining observations regarding the biology and feeding potential of M. desjardinsi on A. dispersus under laboratory conditions. It was observed that the second nymphal stadium of A. dispersus was most preferred prey for M. desjardinsi and the least preferred was the A. dispersus adult. It was also seen that the third stadium of M. desjardinsi consumed more A. dispersus individuals than any other life stages. The longevity of female and the total developmental period of M. desjardinsi were computed as 27.6 ± 1.69 and 24.1 ± 0.99 d, respectively. The average total number of eggs laid by the M. desjardinsi female was 211.1 ± 6.35 eggs. M. desjardinsi was observed to be extremely efficient in terms of prey searching and predatory potential with respect to A. dispersus. The results of this study indicate strongly that M. desjardinsi has the potential to be used for the control of A. dispersus. PMID:27417642

  4. Optimization and evaluation of microencapsulated artificial diet for mass rearing the predatory ladybird Propylea japonica (Coleoptera: Coccinellidae).

    PubMed

    Tan, Xiao-Ling; Zhao, Jing; Wang, Su; Zhang, Fan

    2015-02-01

    Artificial diet optimization is a key aspect in mass rearing of natural enemies since it influences the quality and feeding effectiveness, and thus the success of the biological control program. Here, we introduced the microencapsulation method to package liquid artificial diet for feeding of the ladybird Propylea japonica. An orthogonal test of the quality of microencapsulated artificial diets (ADMs) was performed on key variables in production; Ca-alginate concentration, chitosan concentration and weight ratio of wall material to inner diet. We compared the development and reproduction of P. japonica fed on the ADMs under different cold-stored periods with those fed on fresh aphids and liquid artificial diets, in addition to a comparison of respiration, locomotion and predation. Our results indicated that chitosan concentration and ratio of shell to core significantly influence the quality of ADMs. The optimal recipe is 1.0% Ca-alginate, 1.6% chitosan and shell : core = 1 : 2. Insects reared on fresh optimized ADMs were similar to those fed on fresh prey in all developmental and reproductive characteristics except for survival ratio and female fertility. ADMs appeared more beneficial than using a liquid artificial diet, although this may decrease with the prolonging of the cold-storage period. P. japonica fed either on fresh ADMs or fresh prey showed improved respiration and predation abilities compared to where liquid artificial diet was used. Our study indicates advantages of microencapsulation in the production of artificial diet for predatory ladybird rearing. A microencapsulated diet can directly increase the efficiency and stability of mass rearing.

  5. The residual and direct effects of reduced-risk and conventional miticides on twospotted spider mites, Tetranychus urticae (Acari: Tetranychidae) and predatory mites (Acari: Phytoseiidae)

    SciTech Connect

    Liburd, O.E.; White, J.C.; Rhodes, E.M.; Browdy, A.A.

    2007-03-15

    The residual effects of several reduced-risk and conventional miticides were evaluated in strawberries (Fragaria z ananassa Duchesne) on the twospotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) and on 2 predatory mites, Neoseiulus californicus McGregor and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). Experiments were conducted in the laboratory and greenhouse. The greenhouse experiments also tested the direct effects of the miticides on TSSM. The efficacy of conventional and reduced-risk miticides was evaluated on strawberry leaf discs and on whole plants for control of TSSM. Furthermore, the residual effects of these miticides were evaluated on whole strawberry plants against selective predatory mites. For TSSM, 5 treatments were evaluated: a conventional miticide; fenbutatin-oxide (Vendex[reg]) and 3 reduced-risk miticides; binfenazate (Acramite 50WP[reg]), activated garlic extract (Repel[reg]), sesame seed and castor oil (Wipeout[reg]), and a water-treated control. For predatory mites, the residual effects of only Acramite[reg] and Vendex[reg] were evaluated. Acramite[reg] was the most effective acaricide in reducing TSSM populations in both the laboratory and greenhouse experiments. Vendex[reg] and Wipeout[reg] were also effective in the laboratory, but did not cause significant reduction of TSSM in the greenhouse. Repel[reg] was the least effective of the 4 pesticides evaluated. Neither Acramite[reg] nor Vendex[reg] had a significant effect on either predatory mite species. However, there appeared to be more predatory mites on the Vendex[reg]-treated plants than on the Acramite[reg]-treated plants. There were significantly more predatory mites of both species on the cue plants, which were inoculated with TSSM versus the non-cue plants, which were not inoculated. (author) [Spanish] Los efectos residuales en poblaciones de la 'arana roja', Tetranychus urticae Koch (Acari: Tetranichidae) y de los acaros predadores

  6. Maternal intraguild predation risk affects offspring anti-predator behavior and learning in mites

    PubMed Central

    Seiter, Michael; Schausberger, Peter

    2015-01-01

    Predation risk is a strong selective force shaping prey morphology, life history and behavior. Anti-predator behaviors may be innate, learned or both but little is known about the transgenerational behavioral effects of maternally experienced predation risk. We examined intraguild predation (IGP) risk-induced maternal effects on offspring anti-predator behavior, including learning, in the predatory mite Phytoseiulus persimilis. We exposed predatory mite mothers during egg production to presence or absence of the IG predator Amblyseius andersoni and assessed whether maternal stress affects the anti-predator behavior, including larval learning ability, of their offspring as protonymphs. Protonymphs emerging from stressed or unstressed mothers, and having experienced IGP risk as larvae or not, were subjected to choice situations with and without IG predator traces. Predator-experienced protonymphs from stressed mothers were the least active and acted the boldest in site choice towards predator cues. We argue that the attenuated response of the protonymphs to predator traces alone represents optimized risk management because no immediate risk existed. Such behavioral adjustment could reduce the inherent fitness costs of anti-predator behaviors. Overall, our study suggests that P. persimilis mothers experiencing IGP risk may prime their offspring to behave more optimally in IGP environments. PMID:26449645

  7. Maternal intraguild predation risk affects offspring anti-predator behavior and learning in mites.

    PubMed

    Seiter, Michael; Schausberger, Peter

    2015-10-09

    Predation risk is a strong selective force shaping prey morphology, life history and behavior. Anti-predator behaviors may be innate, learned or both but little is known about the transgenerational behavioral effects of maternally experienced predation risk. We examined intraguild predation (IGP) risk-induced maternal effects on offspring anti-predator behavior, including learning, in the predatory mite Phytoseiulus persimilis. We exposed predatory mite mothers during egg production to presence or absence of the IG predator Amblyseius andersoni and assessed whether maternal stress affects the anti-predator behavior, including larval learning ability, of their offspring as protonymphs. Protonymphs emerging from stressed or unstressed mothers, and having experienced IGP risk as larvae or not, were subjected to choice situations with and without IG predator traces. Predator-experienced protonymphs from stressed mothers were the least active and acted the boldest in site choice towards predator cues. We argue that the attenuated response of the protonymphs to predator traces alone represents optimized risk management because no immediate risk existed. Such behavioral adjustment could reduce the inherent fitness costs of anti-predator behaviors. Overall, our study suggests that P. persimilis mothers experiencing IGP risk may prime their offspring to behave more optimally in IGP environments.

  8. Multimodal communication, mismatched messages and the effects of turbidity on the antipredator behavior of the Barton Springs salamander, Eurycea sosorum.

    PubMed

    Zabierek, Kristina C; Gabor, Caitlin R

    2016-09-01

    Prey may use multiple sensory channels to detect predators, whose cues may differ in altered sensory environments, such as turbid conditions. Depending on the environment, prey may use cues in an additive/complementary manner or in a compensatory manner. First, to determine whether the purely aquatic Barton Springs salamander, Eurycea sosorum, show an antipredator response to visual cues, we examined their activity when exposed to either visual cues of a predatory fish (Lepomis cyanellus) or a non-predatory fish (Etheostoma lepidum). Salamanders decreased activity in response to predator visual cues only. Then, we examined the antipredator response of these salamanders to all matched and mismatched combinations of chemical and visual cues of the same predatory and non-predatory fish in clear and low turbidity conditions. Salamanders decreased activity in response to predator chemical cues matched with predator visual cues or mismatched with non-predator visual cues. Salamanders also increased latency to first move to predator chemical cues mismatched with non-predator visual cues. Salamanders decreased activity and increased latency to first move more in clear as opposed to turbid conditions in all treatment combinations. Our results indicate that salamanders under all conditions and treatments preferentially rely on chemical cues to determine antipredator behavior, although visual cues are potentially utilized in conjunction for latency to first move. Our results also have potential conservation implications, as decreased antipredator behavior was seen in turbid conditions. These results reveal complexity of antipredator behavior in response to multiple cues under different environmental conditions, which is especially important when considering endangered species.

  9. Effects of habitat age and plant species on predatory mites (Acari, Mesostigmata) in grassy arable fallows in Eastern Austria.

    PubMed

    Wissuwa, Janet; Salamon, Jörg-Alfred; Frank, Thomas

    2012-07-01

    Density, diversity and assemblage structure of Mesostigmata (cohorts Gamasina and Uropodina) were investigated in nine grassy arable fallows according to a factorial design with age class (2-3, 6-8, 12-15 years) and plant species (legume: Medicago sativa, herb: Taraxacum officinale, grass: Bromus sterilis) as factors. The response of Mesostigmata to habitat age and plant species was explored because this group belongs to the dominant acarine predators playing a crucial role in soil food webs and being important as biological control agents. To our knowledge, this combination of factors has never been studied before for Mesostigmata. A further rarely applied aspect of the present study is the micro-scale approach investigating the Mesostigmata assemblage of the soil associated with single plants. Four plots were randomly chosen at each fallow in May 2008. At each plot plant roots and the adjacent soil of five randomly selected plant individuals per plant species were dug out with steel cylinders for heat extraction of soil fauna and measurement of environmental parameters. In total, 83 mite taxa were identified, with 50 taxa being new to Austria. GLM analysis revealed a significant effect of plant species on mite density, with significantly more mites in B. sterilis than in T. officinale samples, and M. sativa samples being intermediate. This was in contrast to the assumption that the mite density is highest in M. sativa samples due to the propagation of plant quality effects to higher trophic levels. These results were probably caused by a higher amount of fine roots in grass samples leading to high densities of Collembola, which are preferred prey of predatory mites. Mite density did not significantly differ between the three age classes. A canonical analysis of principal coordinates (CAP) showed that the mite assemblage exhibited a weak yet significant separation between plant species, and a highly significant separation between age classes. Accordingly

  10. Is the relationship between body size and trophic niche position time-invariant in a predatory fish? First stable isotope evidence.

    PubMed

    Nakazawa, Takefumi; Sakai, Yoichiro; Hsieh, Chih-hao; Koitabashi, Tadatoshi; Tayasu, Ichiro; Yamamura, Norio; Okuda, Noboru

    2010-02-09

    Characterizing relationships between individual body size and trophic niche position is essential for understanding how population and food-web dynamics are mediated by size-dependent trophic interactions. However, whether (and how) intraspecific size-trophic relationships (i.e., trophic ontogeny pattern at the population level) vary with time remains poorly understood. Using archival specimens of a freshwater predatory fish Gymnogobius isaza (Tanaka 1916) from Lake Biwa, Japan, we assembled a long-term (>40 years) time-series of the size-dependence of trophic niche position by examining nitrogen stable isotope ratios (delta(15)N) of the fish specimens. The size-dependence of trophic niche position was defined as the slope of the relationship between delta(15)N and log body size. Our analyses showed that the slope was significantly positive in about 60% of years and null in other years, changing through time. This is the first quantitative (i.e., stable isotope) evidence of long-term variability in the size-trophic relationship in a predatory fish. This finding had implications for the fish trophic dynamics, despite that about 60% of the yearly values were not statistically different from the long-term average. We proposed hypotheses for the underlying mechanism of the time-varying size-trophic relationship.

  11. Potential of astigmatid mites (Acari: Astigmatina) as prey for rearing edaphic predatory mites of the families Laelapidae and Rhodacaridae (Acari: Mesostigmata).

    PubMed

    Barbosa, Marina F C; de Moraes, Gilberto J

    2016-07-01

    Laelapidae and Rhodacaridae are important families of edaphic predatory mites and species of these families have been considered for use in biological control programs of soil pests. Mites of Cohort Astigmatina (Acari: Sarcoptiformes) have been largely used as factitious prey in the mass rearing of various edaphic or plant-inhabiting predatory mites. Stratiolaelaps scimitus (Womersley) (Mesostigmata: Laelapidae) (widely commercialized for the control of fungus gnats and thrips) and Protogamasellopsis zaheri Abo-Shnaf, Castilho and Moraes (Mesostigmata: Rhodacaridae) (not available commercially but promising for the control of thrips and nematodes) are known to be reared on Tyrophagus putrescentiae (Schrank) (Astigmatina: Acaridae), but the possibility to find a perhaps more efficient prey has not been evaluated. The objective of this paper was to evaluate different astigmatid species as prey for these predators. S. scimitus and P. zaheri oviposited on all evaluated astigmatids and the acarid mites T. putrescentiae and Aleuroglyphus ovatus (Tropeau) were the most suitable prey; to confirm the effect of prey on oviposition rates, pregnant females of the predators were kept under starvation conditions and oviposition was negligible or null. Survivorship was always higher than 78 % and was not influenced by prey species or starvation.

  12. Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites.

    PubMed

    Aratchige, N S; Lesna, I; Sabelis, M W

    2004-01-01

    Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract predatory mites (Neoseiulus cucumeris). Since our aim was to demonstrate such odours and not their relevance under soil conditions, the experiments were carried out using a classic Y-tube olfactometer in which the predators moved on a Y-shaped wire in open air. We found that food-deprived female predators can discriminate between odours from infested bulbs and odours from uninfested bulbs or artificially wounded bulbs. No significant difference in attractiveness to predators was found between clean bulbs and bulbs either wounded 30 min or 3 h before the experiment. These results indicate that it may not be simply the wounding of the bulbs, but rather the feeding by rust mites, which causes the bulb to release odours that attract N. cucumeris. Since bulbs are belowground plant structures, the olfactometer results demonstrate the potential for odour-mediated interactions in the soil. However, their importance in the actual soil medium remains to be demonstrated.

  13. Predatory Journals in Dermatology.

    PubMed

    Maddy, A J; Tosti, A

    2016-09-17

    The "open-access" model increases the influence that a researcher has in his field, as his work is freely available to anyone with an Internet connection. In order for articles to be free to the reader, expenses of the publisher are covered by article processing charges (APCs) paid by the author or institution of the paper. The scientific community benefits as more readers have access to more papers, allowing ideas to grow and build one upon another. However, the disadvantages of open-access publishing have come to light in the past years as the number of publishers has increased exponentially and the open-access concept has been exploited. This article is protected by copyright. All rights reserved.

  14. "Freshwater killer whales": beaching behavior of an alien fish to hunt land birds.

    PubMed

    Cucherousset, Julien; Boulêtreau, Stéphanie; Azémar, Frédéric; Compin, Arthur; Guillaume, Mathieu; Santoul, Frédéric

    2012-01-01

    The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ(13)C and δ(15)N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

  15. “Freshwater Killer Whales”: Beaching Behavior of an Alien Fish to Hunt Land Birds

    PubMed Central

    Cucherousset, Julien; Boulêtreau, Stéphanie; Azémar, Frédéric; Compin, Arthur; Guillaume, Mathieu; Santoul, Frédéric

    2012-01-01

    The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ13C and δ15N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface. PMID:23227213

  16. Behavioral pieces of neuroethological puzzles.

    PubMed

    Catania, Kenneth C

    2017-03-04

    In this review, I give a first-person account of surprising insights that have come from the behavioral dimension of neuroethological studies in my laboratory. These studies include the early attempts to understand the function of the nose in star-nosed moles and to explore its representation in the neocortex. This led to the discovery of a somatosensory fovea that parallels the visual fovea of primates in several ways. Subsequent experiments to investigate the assumed superiority of star-nosed moles to their relatives when locating food led to the unexpected discovery of stereo olfaction in common moles. The exceptional olfactory abilities of common moles, in turn, helped to explain an unusual bait-collecting technique called "worm-grunting" in the American southeast. Finally, the predatory behavior of tentacled snakes was best understood not by exploring their nervous system, but rather by considering fish nervous systems. These experiences highlight the difficulty of predicting the abilities of animals that have senses foreign to the investigator, and also the rewards of discovering the unexpected.

  17. A parasite's modification of host behavior reduces predation on its host.

    PubMed

    Soghigian, John; Valsdottir, Linda R; Livdahl, Todd P

    2017-03-01

    Parasite modification of host behavior is common, and the literature is dominated by demonstrations of enhanced predation on parasitized prey resulting in transmission of parasites to their next host. We present a case in which predation on parasitized prey is reduced. Despite theoretical modeling suggesting that this phenomenon should be common, it has been reported in only a few host-parasite-predator systems. Using a system of gregarine endosymbionts in host mosquitoes, we designed experiments to compare the vulnerability of parasitized and unparasitized mosquito larvae to predation by obligate predatory mosquito larvae and then compared behavioral features known to change in the presence of predatory cues. We exposed Aedes triseriatus larvae to the parasite Ascogregarina barretti and the predator Toxohrynchites rutilus and assessed larval mortality rate under each treatment condition. Further, we assessed behavioral differences in larvae due to infection and predation stimuli by recording larvae and scoring behaviors and positions within microcosms. Infection with gregarines reduced cohort mortality in the presence of the predator, but the parasite did not affect mortality alone. Further, infection by parasites altered behavior such that infected hosts thrashed less frequently than uninfected hosts and were found more frequently on or in a refuge within the microcosm. By reducing predation on their host, gregarines may be acting as mutualists in the presence of predation on their hosts. These results illustrate a higher-order interaction, in which a relationship between a species pair (host-endosymbiont or predator-prey) is altered by the presence of a third species.

  18. Relationships between plant diversity and the abundance and α-diversity of predatory ground beetles (Coleoptera: Carabidae) in a mature Asian temperate forest ecosystem.

    PubMed

    Zou, Yi; Sang, Weiguo; Bai, Fan; Axmacher, Jan Christoph

    2013-01-01

    A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae) as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems.

  19. Relationships between Plant Diversity and the Abundance and α-Diversity of Predatory Ground Beetles (Coleoptera: Carabidae) in a Mature Asian Temperate Forest Ecosystem

    PubMed Central

    Zou, Yi; Sang, Weiguo; Bai, Fan; Axmacher, Jan Christoph

    2013-01-01

    A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae) as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems. PMID:24376582

  20. A linguistic analysis of grooming strategies of online child sex offenders: Implications for our understanding of predatory sexual behavior in an increasingly computer-mediated world.

    PubMed

    Black, Pamela J; Wollis, Melissa; Woodworth, Michael; Hancock, Jeffrey T

    2015-06-01

    There is a large body of evidence to suggest that child sex offenders engage in grooming to facilitate victimization. It has been speculated that this step-by-step grooming process is also used by offenders who access their underage victims online; however, little research has been done to examine whether there are unique aspects of computer-mediated communication that impact the traditional face-to-face grooming process. This study considered the similarities and differences in the grooming process in online environments by analyzing the language used by online offenders when communicating with their victims. The transcripts of 44 convicted online offenders were analyzed to assess a proposed theory of the online grooming process (O'Connell, 2003). Using a stage-based approach, computerized text analysis examined the types of language used in each stage of the offender-victim interaction. The transcripts also were content analyzed to examine the frequency of specific techniques known to be employed by both face-to-face and online offenders, such as flattery. Results reveal that while some evidence of the strategies used by offenders throughout the grooming process are present in online environments, the order and timing of these stages appear to be different. The types (and potential underlying pattern) of strategies used in online grooming support the development of a revised model for grooming in online environments.

  1. Acinonyx pardinensis (Carnivora, Felidae) from the Early Pleistocene of Pantalla (Italy): predatory behavior and ecological role of the giant Plio-Pleistocene cheetah

    NASA Astrophysics Data System (ADS)

    Cherin, Marco; Iurino, Dawid Adam; Sardella, Raffaele; Rook, Lorenzo

    2014-03-01

    The site of Pantalla (central Italy) yielded a rich late Villafranchian (Early Pleistocene) faunal assemblage, which includes some well-preserved large mammal skulls. We describe here two nearly complete crania and a left hemimandible of Acinonyx pardinensis from this locality, representing the most complete cranial material of this species in Europe. These finds allowed us to define more clearly the craniodental morphology of A. pardinensis. Similarly to the forms from North Africa and China, the giant cheetah from Pantalla has a more generalized skull than the living Acinonyx jubatus, showing some primitive, pantherine-like features such as the less domed dorsal outline of the cranium, the more developed sagittal and nuchal crests and the less bowed zygomatic arches. High-resolution CT scans of the specimens were used to obtain the first 3D model of a cranium with articulated mandible of A. pardinensis. Starting from the insertion areas on this model we reconstructed the jaw muscles of the Pantalla felid, confirming its affinities with pantherine felines. In the light of the musculoskeletal skull anatomy and the average body mass (about 80 kg), it is likely that A. pardinensis could kill large prey through a hunting strategy more similar to pantherine cats than to the living cheetah.

  2. A systematic survey of the integration of animal behavior into conservation

    USGS Publications Warehouse

    Berger-Tal, Oded; Blumstein, Daniel T.; Carroll, Scott; Fisher, Robert N.; Mesnick, Sarah L.; Owen, Megan A.; Saltz, David; St. Claire, Colleen Cassady; Swaisgood, Ronald R.

    2016-01-01

    The role of behavioral ecology in improving wildlife conservation and management has been the subject of much recent debate. We aim to answer two foundational questions about the current use of behavioral knowledge in conservation: 1. To what extent is behavioral knowledge used in wildlife conservation and management? 2. How does the use of behavior differ among conservation fields in both frequency and types of use? To answer these questions, we searched the literature for intersections between key fields of animal behavior and conservation biology and created a systematic ‘heat’ map to visualize relative efforts. Our analysis challenges previous suggestions that there is little association between the fields of behavioral ecology and conservation and reveals tremendous variation in the use of different behaviors in conservation. For instance, some behaviors, such as foraging and dispersal, are commonly considered, but other behaviors such as learning, social or anti-predatory behaviors are hardly considered. Our analysis suggests that in many cases awareness of the importance of behavior does not translate into applicable management tools. We recommend that researchers should focus on developing research in underutilized intersections of behavior and conservation themes for which preliminary work show a potential for improving conservation and management, on translating behavioral theory into applicable and testable predictions, and on creating systematic reviews to summarize the behavioral evidence within the behavior-conservation intersections for which many studies exist.

  3. Behavioral responses associated with a human-mediated predator shelter.

    PubMed

    Shannon, Graeme; Cordes, Line S; Hardy, Amanda R; Angeloni, Lisa M; Crooks, Kevin R

    2014-01-01

    Human activities in protected areas can affect wildlife populations in a similar manner to predation risk, causing increases in movement and vigilance, shifts in habitat use and changes in group size. Nevertheless, recent evidence indicates that in certain situations ungulate species may actually utilize areas associated with higher levels of human presence as a potential refuge from disturbance-sensitive predators. We now use four-years of behavioral activity budget data collected from pronghorn (Antilocapra americana) and elk (Cervus elephus) in Grand Teton National Park, USA to test whether predictable patterns of human presence can provide a shelter from predatory risk. Daily behavioral scans were conducted along two parallel sections of road that differed in traffic volume--with the main Teton Park Road experiencing vehicle use that was approximately thirty-fold greater than the River Road. At the busier Teton Park Road, both species of ungulate engaged in higher levels of feeding (27% increase in the proportion of pronghorn feeding and 21% increase for elk), lower levels of alert behavior (18% decrease for pronghorn and 9% decrease for elk) and formed smaller groups. These responses are commonly associated with reduced predatory threat. Pronghorn also exhibited a 30% increase in the proportion of individuals moving at the River Road as would be expected under greater exposure to predation risk. Our findings concur with the 'predator shelter hypothesis', suggesting that ungulates in GTNP use human presence as a potential refuge from predation risk, adjusting their behavior accordingly. Human activity has the potential to alter predator-prey interactions and drive trophic-mediated effects that could ultimately impact ecosystem function and biodiversity.

  4. Behavioral Responses Associated with a Human-Mediated Predator Shelter

    PubMed Central

    Shannon, Graeme; Cordes, Line S.; Hardy, Amanda R.; Angeloni, Lisa M.; Crooks, Kevin R.

    2014-01-01

    Human activities in protected areas can affect wildlife populations in a similar manner to predation risk, causing increases in movement and vigilance, shifts in habitat use and changes in group size. Nevertheless, recent evidence indicates that in certain situations ungulate species may actually utilize areas associated with higher levels of human presence as a potential refuge from disturbance-sensitive predators. We now use four-years of behavioral activity budget data collected from pronghorn (Antilocapra americana) and elk (Cervus elephus) in Grand Teton National Park, USA to test whether predictable patterns of human presence can provide a shelter from predatory risk. Daily behavioral scans were conducted along two parallel sections of road that differed in traffic volume - with the main Teton Park Road experiencing vehicle use that was approximately thirty-fold greater than the River Road. At the busier Teton Park Road, both species of ungulate engaged in higher levels of feeding (27% increase in the proportion of pronghorn feeding and 21% increase for elk), lower levels of alert behavior (18% decrease for pronghorn and 9% decrease for elk) and formed smaller groups. These responses are commonly associated with reduced predatory threat. Pronghorn also exhibited a 30% increase in the proportion of individuals moving at the River Road as would be expected under greater exposure to predation risk. Our findings concur with the ‘predator shelter hypothesis’, suggesting that ungulates in GTNP use human presence as a potential refuge from predation risk, adjusting their behavior accordingly. Human activity has the potential to alter predator-prey interactions and drive trophic-mediated effects that could ultimately impact ecosystem function and biodiversity. PMID:24718624

  5. Invader danger: lizards faced with novel predators exhibit an altered behavioral response to stress.

    PubMed

    Trompeter, Whitney P; Langkilde, Tracy

    2011-07-01

    Animals respond to stressors by producing glucocorticoid stress hormones, such as corticosterone (CORT). CORT acts too slowly to trigger immediate behavioral responses to a threat, but can change longer-term behavior, facilitating an individual's survival to subsequent threats. To be adaptive, the nature of an animal's behavior following elevated CORT levels should be matched to the predominant threats that they face. Seeking refuge following a stressful encounter could be beneficial if the predominant predator is a visual hunter, but may prove detrimental when the predominant predator is able to enter these refuge sites. As a result, an individual's behavior when their CORT levels are high may differ among populations of a single species. Invasive species impose novel pressures on native populations, which may select for a shift in their behavior when CORT levels are high. We tested whether the presence of predatory invasive fire ants (Solenopsis invicta) at a site affects the behavioral response of native eastern fence lizards (Sceloporus undulatus) to elevated CORT levels. Lizards from an uninvaded site were more likely to hide when their CORT levels were experimentally elevated; a response that likely provides a survival advantage for lizards faced with native predatory threats (e.g. birds and snakes). Lizards from a fire ant invaded site showed the opposite response; spending more time moving and up on the basking log when their CORT levels were elevated. Use of the basking log likely reflects a refuge-seeking behavior, rather than thermoregulatory activity, as selected body temperatures were not affected by CORT. Fleeing off the ground may prove more effective than hiding for lizards that regularly encounter small, terrestrially-foraging fire ant predators. This study suggests that invasive species may alter the relationship between the physiological and behavioral stress response of native species.

  6. CONTROLLING BEHAVIOR CHANGERS' BEHAVIOR.

    ERIC Educational Resources Information Center

    MARKLE, DAVID G.

    AN EMERGING METHODOLOGY OF PROGRAMING AVOIDS SOME OF THE UNFORTUNATE EFFECTS ON PROGRAMER BEHAVIOR PRODUCED BY INTERPRETATIONS OF TWO EARLIER METHODOLOGIES. WHILE SKINNERIAN PROGRAMING OFTEN HAS LED TO TRIVIAL PROGRAMS THROUGH PROBLEMS OF APPLICATION OF THE CRITERIA OF SPECIFIED BEHAVIORAL OBJECTIVES AND LOW ERROR RATES, CROWDERIAN PROGRAMING HAS…

  7. Evaluating the landscape of fear between apex predatory sharks and mobile sea turtles across a large dynamic seascape.

    PubMed

    Hammerschlag, Neil; Broderick, Annette C; Coker, John W; Coyne, Michael S; Dodd, Mark; Frick, Michael G; Godfrey, Matthew H; Godley, Brendan J; Griffin, DuBose B; Hartog, Kyra; Murphy, Sally R; Murphy, Thomas M; Nelson, Emily Rose; Williams, Kristina L; Witt, Matthew J; Hawkes, Lucy A

    2015-08-01

    The "landscape of fear" model has been proposed as a unifying concept in ecology, describing, in part, how animals behave and move about in their environment. The basic model predicts that as an animal's landscape changes from low to high risk of predation, prey species will alter their behavior to risk avoidance. However, studies investigating and evaluating the landscape of fear model across large spatial scales (tens to hundreds of thousands of square kilometers) in dynamic, open, aquatic systems involving apex predators and highly mobile prey are lacking. To address this knowledge gap, we investigated predator-prey relationships between. tiger sharks (Galeocerdo cuvier) and loggerhead turtles (Caretta caretta) in the North Atlantic Ocean. This included the use of satellite tracking to examine shark and turtle distributions as well as their surfacing behaviors under varying levels of home range overlap. Our findings revealed patterns that deviated from our a priori predictions based on the landscape of fear model. Specifically, turtles did not alter their surfacing behaviors to risk avoidance when overlap in shark-turtle core home range was high. However, in areas of high overlap with turtles, sharks exhibited modified surfacing behaviors that may enhance predation opportunity. We suggest that turtles may be an important factor in determining shark,distribution, whereas for turtles, other life history trade-offs may play a larger role in defining their habitat use. We propose that these findings are a result of both biotic and physically driven factors that independently or synergistically affect predator-prey interactions in this system. These results have implications for evolutionary biology, community ecology; and wildlife conservation. Further, given the difficulty in studying highly migratory marine species, our approach and conclusions may be applied to the study of other predator-prey systems.

  8. Vulnerability and behavioral response to ultraviolet radiation in the components of a foliar mite prey-predator system.

    PubMed

    Tachi, Fuyuki; Osakabe, Masahiro

    2012-12-01

    Ambient ultraviolet-B (UVB) radiation impacts plant-dwelling arthropods including herbivorous and predatory mites. However, the effects of UVB on prey-predator systems, such as that between the herbivorous spider mite and predatory phytoseiid mite, are poorly understood. A comparative study was conducted to determine the vulnerability and behavioral responses of these mites to ultraviolet (UV) radiation. First, we analyzed dose-response (cumulative irradiance-mortality) curves for the eggs of phytoseiid mites (Neoseiulus californicus, Neoseiulus womersleyi, and Phytoseiulus persimilis) and the spider mite (Tetranychus urticae) to UVB radiation from a UV lamp. This indicated that the phytoseiid mites were more vulnerable than the spider mite, although P. persimilis was slightly more tolerant than the other two phytoseiid mites. Second, we compared the avoidance behavior of adult female N. californicus and two spider mite species (T. urticae, a lower leaf surface user; Panonychus citri, an upper leaf surface user) in response to solar UV and visible light. N. californicus actively avoided both types of radiation, whereas P. citri showed only minimal avoidance behavior. T. urticae actively avoided UV as well as N. californicus but exhibited a slow response to visible light as well as P. citri. Such variation in vulnerability and avoidance behavior accounts for differences in the species adaptations to solar UVB radiation. This may be the primary factor determining habitat use among these mites on host plant leaves, subsequently affecting accessibility by predators and also intraguild competition.

  9. Vulnerability and behavioral response to ultraviolet radiation in the components of a foliar mite prey-predator system

    NASA Astrophysics Data System (ADS)

    Tachi, Fuyuki; Osakabe, Masahiro

    2012-12-01

    Ambient ultraviolet-B (UVB) radiation impacts plant-dwelling arthropods including herbivorous and predatory mites. However, the effects of UVB on prey-predator systems, such as that between the herbivorous spider mite and predatory phytoseiid mite, are poorly understood. A comparative study was conducted to determine the vulnerability and behavioral responses of these mites to ultraviolet (UV) radiation. First, we analyzed dose-response (cumulative irradiance-mortality) curves for the eggs of phytoseiid mites ( Neoseiulus californicus, Neoseiulus womersleyi, and Phytoseiulus persimilis) and the spider mite ( Tetranychus urticae) to UVB radiation from a UV lamp. This indicated that the phytoseiid mites were more vulnerable than the spider mite, although P. persimilis was slightly more tolerant than the other two phytoseiid mites. Second, we compared the avoidance behavior of adult female N. californicus and two spider mite species ( T. urticae, a lower leaf surface user; Panonychus citri, an upper leaf surface user) in response to solar UV and visible light. N. californicus actively avoided both types of radiation, whereas P. citri showed only minimal avoidance behavior. T. urticae actively avoided UV as well as N. californicus but exhibited a slow response to visible light as well as P. citri. Such variation in vulnerability and avoidance behavior accounts for differences in the species adaptations to solar UVB radiation. This may be the primary factor determining habitat use among these mites on host plant leaves, subsequently affecting accessibility by predators and also intraguild competition.

  10. Transfer and effects of cadmium in an experimental food chain involving the snail Helix aspersa and the predatory carabid beetle Chrysocarabus splendens.

    PubMed

    Scheifler, R; Gomot-de Vaufleury, A; Toussaint, M L; Badot, P M

    2002-08-01

    The transfer and the toxic effects of Cd were studied in an experimental food chain involving the snail Helix aspersa as prey organism and one of its natural predators, the carabid beetle Chrysocarabus splendens. Juvenile snails were fed plant-based food enriched with 0, 10, 50 and 100 microg g(-1) of Cd, then were offered as prey to beetle larvae from egg hatching to pupation stage. Cd concentrations in snail tissues increased with increasing Cd concentration in food and with duration of exposure. Bioaccumulation factors ranged from 1.87 to 3.39, showing that H. aspersa snails, even in their early life stages, belong to macroconcentrator species for Cd. No significant reduction of snail consumption by beetles was found in exposed groups. Cd concentrations in beetle larvae remained very low (lower than 1 microg g(-1) for all groups), demonstrating a very effective regulation capacity in beetle larvae. However, Cd concentrations in highest exposed groups were higher than those found in control groups. Cd contents in adult beetles were lower than in larvae, showing a loss of Cd during metamorphosis. Despite the low Cd concentrations found in beetles, their exposure to Cd contaminated snails led to 31% of mortality, which occurred only during pupation and for the highest exposure level. No clear sublethal effects were found. These results showed that snails inhabiting heavily polluted areas may represent a risk of secondary poisoning for predatory invertebrates and provided quantitative data on the transfer of Cd between two compartments of a terrestrial food chain.

  11. Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited

    PubMed Central

    Svendsen, Morten B. S.; Domenici, Paolo; Marras, Stefano; Krause, Jens; Boswell, Kevin M.; Rodriguez-Pinto, Ivan; Wilson, Alexander D. M.; Kurvers, Ralf H. J. M.; Viblanc, Paul E.; Finger, Jean S.; Steffensen, John F.

    2016-01-01

    ABSTRACT Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s−1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s−1), followed by barracuda (6.2±1.0 m s−1), little tunny (5.6±0.2 m s−1) and dorado (4.0±0.9 m s−1); although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s−1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues. PMID:27543056

  12. Molecular characterization and evolutionary insights into potential sex-determination genes in the western orchard predatory mite Metaseiulus occidentalis (Chelicerata: Arachnida: Acari: Phytoseiidae).

    PubMed

    Pomerantz, Aaron F; Hoy, Marjorie A; Kawahara, Akito Y

    2015-01-01

    Little is known about the process of sex determination at the molecular level in species belonging to the subclass Acari, a taxon of arachnids that contains mites and ticks. The recent sequencing of the transcriptome and genome of the western orchard predatory mite Metaseiulus occidentalis allows investigation of molecular mechanisms underlying the biological processes of sex determination in this predator of phytophagous pest mites. We identified four doublesex-and-mab-3-related transcription factor (dmrt) genes, one transformer-2 gene, one intersex gene, and two fruitless-like genes in M. occidentalis. Phylogenetic analyses were conducted to infer the molecular relationships to sequences from species of arthropods, including insects, crustaceans, acarines, and a centipede, using available genomic data. Comparative analyses revealed high sequence identity within functional domains and confirmed that the architecture for certain sex-determination genes is conserved in arthropods. This study provides a framework for identifying potential target genes that could be implicated in the process of sex determination in M. occidentalis and provides insight into the conservation and change of the molecular components of sex determination in arthropods.

  13. Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited.

    PubMed

    Svendsen, Morten B S; Domenici, Paolo; Marras, Stefano; Krause, Jens; Boswell, Kevin M; Rodriguez-Pinto, Ivan; Wilson, Alexander D M; Kurvers, Ralf H J M; Viblanc, Paul E; Finger, Jean S; Steffensen, John F

    2016-10-15

    Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s(-1) but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s(-1)), followed by barracuda (6.2±1.0 m s(-1)), little tunny (5.6±0.2 m s(-1)) and dorado (4.0±0.9 m s(-1)); although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s(-1), which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues.

  14. Validating the importance of two acetylcholinesterases in insecticide sensitivities by RNAi in Pardosa pseudoannulata, an important predatory enemy against several insect pests.

    PubMed

    Meng, Xiangkun; Li, Chunrui; Bao, Haibo; Fang, Jichao; Liu, Zewen; Zhang, Yixi

    2015-11-01

    The pond wolf spider (Pardosa pseudoannulata) is an important predatory enemy against several insect pests and showed relative different sensitivities to organophosphate and carbamate insecticides compared to insect pests. In our previous studies, two acetylcholinesterases were identified in P. pseudoannulata and played important roles in insecticide sensitivities. In order to understand the contributions of the two acetylcholinesterases to insecticide sensitivities, we firstly employed the RNAi technology in the spider. For a suitable microinjection RNAi method, the injection site, injection volume and interference time were optimized, which then demonstrated that the injection RNAi method was applicable in this spider. With the new RNAi method, it was revealed that both Pp-AChE1 and Pp-AChE2, encoded by genes Ppace1 and Ppace2, were the targets of organophosphate insecticides, but Pp-AChE1 would be more important. In contrast, the carbamate acted selectively on Pp-AChE1. The results showed that Pp-AChE1 was the major catalytic enzyme in P. pseudoannulata and the major target of organophosphate and carbamate insecticides. In a word, an RNAi method was established in the pond wolf spider, which further validated the importance of two acetylcholinesterases in insecticide sensitivities in this spider.

  15. Species richness and diversity of the parasites of two predatory fish species - perch (Perca fluviatilis Linnaeus, 1758) and zander (Sander lucioperca Linnaeus, 1758) from the Pomeranian Bay.

    PubMed

    Bielat, Iwona; Legierko, Monika; Sobecka, Ewa

    2015-01-01

    Pomeranian Bay as an ecotone is a transition zone between two different biocenoses, which is characterized by an increase in biodiversity and species density. Therefore, Pomeranian Bay is a destination of finding and reproductive migrations of fish from the rivers entered the area. The aim of the study was to compare parasitic fauna of two predatory fish species from the Pomeranian Bay, collected from the same fishing grounds at the same period. A total of 126 fish studied (53 perches and 73 zanders) were collected in the summer 2013. Parasitological examinations included: skin, fins, gills, vitreous humour and lens of the eye, mouth cavity, body cavity and internal organs. Apart from the prevalence and intensity of infection (mean, range) the parasite communities of both fish species were compared. European perch and zander were infected with parasites from five different taxonomic units. The most numerous parasites were Diplostomum spp. in European perch and Bucephalus polymorphus in zander. The prevalence of infection of European perch ranged from 5.7% (Diphyllobothrium latum) to 22.3% (Diplostomum spp.) and for zander from 1.4% (Ancyrocephalus paradoxus, Hysterothylacium aduncum) to 12.3% (Bucephalus polymorphus). Different composition of the parasitic fauna is likely due to the different biology of both fish species.

  16. Effects of neem oil (Azadirachta indica A. Juss) on midgut cells of predatory larvae Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae).

    PubMed

    Scudeler, Elton Luiz; dos Santos, Daniela Carvalho

    2013-01-01

    The effects of ingested neem oil, a botanical insecticide obtained from the seeds of the neem tree, Azadirachta indica, on the midgut cells of predatory larvae Ceraeochrysa claveri were analyzed. C. claveri were fed on eggs of Diatraea saccharalis treated with neem oil at a concentration of 0.5%, 1% and 2% during throughout the larval period. Light and electron microscopy showed severe damages in columnar cells, which had many cytoplasmic protrusions, clustering and ruptured of the microvilli, swollen cells, ruptured cells, dilatation and vesiculation of rough endoplasmic reticulum, development of smooth endoplasmic reticulum, enlargement of extracellular spaces of the basal labyrinth, intercellular spaces and necrosis. The indirect ingestion of neem oil with prey can result in severe alterations showing direct cytotoxic effects of neem oil on midgut cells of C. claveri larvae. Therefore, the safety of neem oil to non-target species as larvae of C. claveri was refuted, thus the notion that plants derived are safer to non-target species must be questioned in future ecotoxicological studies.

  17. The Mechanistic Basis of Myxococcus xanthus Rippling Behavior and Its Physiological Role during Predation

    PubMed Central

    Zhang, Haiyang; Vaksman, Zalman; Litwin, Douglas B.; Shi, Peng; Kaplan, Heidi B.; Igoshin, Oleg A.

    2012-01-01

    Myxococcus xanthus cells self-organize into periodic bands of traveling waves, termed ripples, during multicellular fruiting body development and predation on other bacteria. To investigate the mechanistic basis of rippling behavior and its physiological role during predation by this Gram-negative soil bacterium, we have used an approach that combines mathematical modeling with experimental observations. Specifically, we developed an agent-based model (ABM) to simulate rippling behavior that employs a new signaling mechanism to trigger cellular reversals. The ABM has demonstrated that three ingredients are sufficient to generate rippling behavior: (i) side-to-side signaling between two cells that causes one of the cells to reverse, (ii) a minimal refractory time period after each reversal during which cells cannot reverse again, and (iii) physical interactions that cause the cells to locally align. To explain why rippling behavior appears as a consequence of the presence of prey, we postulate that prey-associated macromolecules indirectly induce ripples by stimulating side-to-side contact-mediated signaling. In parallel to the simulations, M. xanthus predatory rippling behavior was experimentally observed and analyzed using time-lapse microscopy. A formalized relationship between the wavelength, reversal time, and cell velocity has been predicted by the simulations and confirmed by the experimental data. Furthermore, the results suggest that the physiological role of rippling behavior during M. xanthus predation is to increase the rate of spreading over prey cells due to increased side-to-side contact-mediated signaling and to allow predatory cells to remain on the prey longer as a result of more periodic cell motility. PMID:23028301

  18. The mechanistic basis of Myxococcus xanthus rippling behavior and its physiological role during predation.

    PubMed

    Zhang, Haiyang; Vaksman, Zalman; Litwin, Douglas B; Shi, Peng; Kaplan, Heidi B; Igoshin, Oleg A

    2012-01-01

    Myxococcus xanthus cells self-organize into periodic bands of traveling waves, termed ripples, during multicellular fruiting body development and predation on other bacteria. To investigate the mechanistic basis of rippling behavior and its physiological role during predation by this Gram-negative soil bacterium, we have used an approach that combines mathematical modeling with experimental observations. Specifically, we developed an agent-based model (ABM) to simulate rippling behavior that employs a new signaling mechanism to trigger cellular reversals. The ABM has demonstrated that three ingredients are sufficient to generate rippling behavior: (i) side-to-side signaling between two cells that causes one of the cells to reverse, (ii) a minimal refractory time period after each reversal during which cells cannot reverse again, and (iii) physical interactions that cause the cells to locally align. To explain why rippling behavior appears as a consequence of the presence of prey, we postulate that prey-associated macromolecules indirectly induce ripples by stimulating side-to-side contact-mediated signaling. In parallel to the simulations, M. xanthus predatory rippling behavior was experimentally observed and analyzed using time-lapse microscopy. A formalized relationship between the wavelength, reversal time, and cell velocity has been predicted by the simulations and confirmed by the experimental data. Furthermore, the results suggest that the physiological role of rippling behavior during M. xanthus predation is to increase the rate of spreading over prey cells due to increased side-to-side contact-mediated signaling and to allow predatory cells to remain on the prey longer as a result of more periodic cell motility.

  19. Behavioral and physiological antipredator responses of the San Marcos salamander, Eurycea nana.

    PubMed

    Davis, Drew R; Gabor, Caitlin R

    2015-02-01

    Exposure to predatory stimuli typically results in the elevation of circulating glucocorticoid levels and a behavioral response of freezing or escape behavior in many prey species. Corticosterone (CORT) is the main glucocorticoid in amphibians and is known to be important in modulating many behaviors and developmental functions. The federally threatened San Marcos salamander, Eurycea nana, decreases activity in response to both native and introduced predatory fish, however, experience may further influence these interactions. To better understand the indirect effects of fish predators on this salamander, we examined both the antipredator behavior and water-borne CORT release rates in response to chemical cues (kairomones) from two fish species that varied in temporal risk of predation: (1) a low encounter frequency predator (largemouth bass, Micropterus salmoides), (2) a high encounter frequency predator (redbreast sunfish, Lepomis auritus), and (3) a blank water control. Salamanders reduced activity (antipredator response) after exposure to both predator treatments, but not to the blank water control, and the response to M. salmoides was significantly stronger than that to L. auritus. The CORT response (post-stimulus/pre-stimulus release rates) did not differ between the blank water control and L. auritus treatments, and both were significantly less than the CORT response to M. salmoides. Overall, E. nana showed a decreased antipredator response and no CORT response towards the high encounter frequency L. auritus as compared to the low encounter frequency M. salmoides. Eurycea nana may mute antipredator and CORT responses to high temporal frequency predators. There was, however, no correlation between CORT release rates and antipredator behavior, which suggests that the presence of predators may be affecting CORT response and behavior independently.

  20. Do predator cues influence turn alternation behavior in terrestrial isopods Porcellio laevis Latreille and Armadillidium vulgare Latreille?

    PubMed

    Hegarty, Kevin G; Kight, Scott L

    2014-07-01

    Terrestrial isopods (Crustacea: Oniscidea) make more alternating maze turns in response to negative stimuli, a navigational behavior that corrects divergence from a straight line. The present study investigates this behavioral pattern in two species, Porcellio laevis Latreille and Armadillidium vulgare Latreille, in response to short-term vs. long-term exposure to indirect cues from predatory ants. Neither isopod species increased the number of alternating turns in response to short-term indirect exposure to ants, but both species made significantly more alternating turns following continuous indirect exposure to ants for a period of one-week. These results are surprising given differences in behavioral and morphological predator defenses between these species (the Armadillidiidae curl into defensive postures when attacked, whereas the Porcellionidae flee). The marked similarity in alternating turn behavior of the two families suggests evolutionary conservation of antipredator navigation mechanisms.

  1. Fishing indirectly structures macroalgal assemblages by altering herbivore behavior.

    PubMed

    Madin, Elizabeth M P; Gaines, Steven D; Madin, Joshua S; Warner, Robert R

    2010-12-01

    Fishing has clear direct effects on harvested species, but its cascading, indirect effects are less well understood. Fishing disproportionately removes larger, predatory fishes from marine food webs. Most studies of the consequent indirect effects focus on density-mediated interactions where predator removal alternately drives increases and decreases in abundances of successively lower trophic-level species. While prey may increase in number with fewer predators, they may also alter their behavior. When such behavioral responses impact the food resources of prey species, behaviorally mediated trophic cascades can dramatically shape landscapes. It remains unclear whether this pathway of change is typically triggered by ocean fishing. By coupling a simple foraging model with empirical observations from coral reefs, we provide a mechanistic basis for understanding and predicting how predator harvest can alter the landscape of risk for herbivores and consequently drive dramatic changes in primary producer distributions. These results broaden trophic cascade predictions for fisheries to include behavioral changes. They also provide a framework for detecting the presence and magnitude of behaviorally mediated cascades. This knowledge will help to reconcile the disparity between expected and observed patterns of fishing-induced cascades in the sea.

  2. Reducing the impact of pesticides on biological control in Australian vineyards: pesticide mortality and fecundity effects on an indicator species, the predatory mite Euseius victoriensis (Acari: Phytoseiidae).

    PubMed

    Bernard, Martina B; Cole, Peter; Kobelt, Amanda; Horne, Paul A; Altmann, James; Wratten, Stephen D; Yen, Alan L

    2010-12-01

    Laboratory bioassays on detached soybean, Glycine max (L.) Merr., leaves were used to test 23 fungicides, five insecticides, two acaricides, one herbicide, and two adjuvants on a key Australian predatory mite species Euseius victoriensis (Womersley) in "worst-case scenario" direct overspray assays. Zero- to 48-h-old juveniles, their initial food, and water supply were sprayed to runoff with a Potter tower; spinosad and wettable sulfur residues also were tested. Tests were standardized to deliver a pesticide dose comparable with commercial application of highest label rates at 1,000 liter/ha. Cumulative mortality was assessed 48 h, 4 d, and 7 d after spraying. Fecundity was assessed for 7 d from start of oviposition. No significant mortality or fecundity effects were detected for the following compounds at single-use application at 1,000 liter/ha: azoxystrobin, Bacillus thuringiensis (Bt) subsp. kurstaki, captan, chlorothalonil, copper hydroxide, fenarimol, glyphosate, hexaconazole, indoxacarb, metalaxyl/copper hydroxide, myclobutanil, nonyl phenol ethylene oxide, phosphorous acid, potassium bicarbonate, pyraclostrobin, quinoxyfen, spiroxamine, synthetic latex, tebufenozide, triadimenol, and trifloxystrobin. Iprodione and penconazole had some detrimental effect on fecundity. Canola oil as acaricide (2 liter/100 liter) and wettable sulfur (200 g/100 liter) had some detrimental effect on survival and fecundity and cyprodinil/fludioxonil on survivor. The following compounds were highly toxic (high 48-h mortality): benomyl, carbendazim, emamectin benzoate, mancozeb, spinosad (direct overspray and residue), wettable sulfur (> or = 400 g/100 liter), and pyrimethanil; pyrimethanil had no significant effect on fecundity of surviving females. Indoxacarb safety to E. victoriensis contrasts with its toxicity to key parasitoids and chrysopid predators. Potential impact of findings is discussed.

  3. Selection of nectar plants for use in ecological engineering to promote biological control of rice pests by the predatory bug, Cyrtorhinus lividipennis, (Heteroptera: Miridae).

    PubMed

    Zhu, Pingyang; Lu, Zhongxian; Heong, Kongluen; Chen, Guihua; Zheng, Xusong; Xu, Hongxing; Yang, Yajun; Nicol, Helen I; Gurr, Geoff M

    2014-01-01

    Ecological engineering for pest management involves the identification of optimal forms of botanical diversity to incorporate into a farming system to suppress pests, by promoting their natural enemies. Whilst this approach has been extensively researched in many temperate crop systems, much less has been done for rice. This paper reports the influence of various plant species on the performance of a key natural enemy of rice planthopper pests, the predatory mirid bug, Cyrtorhinus lividipennis. Survival of adult males and females was increased by the presence of flowering Tagetes erecta, Trida procumbens, Emilia sonchifolia (Compositae), and Sesamum indicum (Pedaliaceae) compared with water or nil controls. All flower treatments resulted in increased consumption of brown plant hopper, Nilaparvata lugens, and for female C. lividipennis, S. indicum was the most favorable. A separate study with a wider range of plant species and varying densities of prey eggs showed that S. indicum most strongly promoted predation by C. lividipennis. Reflecting this, S. indicum gave a relatively high rate of prey search and low prey handling time. On this basis, S. indicum was selected for more detailed studies to check if its potential incorporation into the farming system would not inadvertently benefit Cnaphalocrocis medinalis and Marasmia patnalis, serious Lepidoptera pests of rice. Adult longevity and fecundity of both pests was comparable for S. indicum and water treatments and significantly lower than the honey solution treatment. Findings indicate that S. indicumis well suited for use as an ecological engineering plant in the margins of rice crops. Sesame indicum can be a valuable crop as well as providing benefits to C. lividipennis whilst denying benefit to key pests.

  4. Morphological features of the tongue and laryngeal entrance in two predatory birds with similar feeding preferences: common kestrel (Falco tinnunculus) and Hume's tawny owl (Strix butleri).

    PubMed

    Abumandour, Mohamed M A; El-Bakary, Neveen E R

    2016-04-15

    The aim of this investigation was to describe the morphological characters of the tongue of two predatory birds with similar feeding preferences, i.e. the common kestrel and Hume's tawny owl. Descriptive information on the lingual morphology of these two birds, particularly Hume's tawny owl, is incomplete. We found that the lingual apex of the owl has an oval, concave, shovel-like form with a bifid lingual tip, while that of the kestrel has the shape of a horny tip-like spoon with a central process in addition to there being several filiform-like papillae on the dorsal surface of the apex and body. In the owl, the dorsal surface of the apex and body is subdivided into four U-shaped regions: lingual tip, two lateral regions and a median region. The two lateral regions are characterized by the presence of papillae and several openings of lingual glands, while the median region carries filiform-like papillae. In both birds, the papillary crest is located between the body and root. In the kestrel, there is an additional row of papillae rostral to crest, while in the owl there is a rostral lateral extension of papillae on the lateral lingual surface so the distribution pattern has a W-shape. In the kestrel, the posterior part of lingual body has several openings of glands, while the root lacks glands completely, although it has many taste buds. In the owl, the lingual root is folded and has a large number of gland openings. In the kestrel caudally to the glottis, there are two paramedian transverse rows of pharyngeal papillae with a pair of median huge papillae, while in the owl, there is only one transverse row of papillae. The dorsal and ventral lingual surfaces of both birds are lined with non-keratinized stratified squamous epithelium.

  5. Persistence and extirpation in invaded landscapes: patch characteristics and connectivity determine effects of non-native predatory fish on native salamanders

    USGS Publications Warehouse

    Pilliod, David S.; Arkle, Robert S.; Maxell, Bryce A.

    2012-01-01

    Studies have demonstrated negative effects of non-native, predatory fishes on native amphibians, yet it is still unclear why some amphibian populations persist, while others are extirpated, following fish invasion. We examined this question by developing habitat-based occupancy models for the long-toed salamander (Ambystoma macrodactylum) and nonnative fish using survey data from 1,749 water bodies across 470 catchments in the Northern Rocky Mountains, USA. We first modeled the habitat associations of salamanders at 468 fishless water bodies in 154 catchments where non-native fish were historically, and are currently, absent from the entire catchment. Wethen applied this habitat model to the complete data set to predict the probability of salamander occupancy in each water body, removing any effect of fish presence. Finally, we compared field-observed occurrences of salamanders and fish to modeled probability of salamander occupancy. Suitability models indicated that fish and salamanders had similar habitat preferences, possibly resulting in extirpations of salamander populations from entire catchments where suitable habitats were limiting. Salamanders coexisted with non-native fish in some catchments by using marginal quality, isolated (no inlet or outlet) habitats that remained fishless. They rarely coexisted with fish within individual water bodies and only where habitat quality was highest. Connectivity of water bodies via streams resulted in increased probability of fish invasion and consequently reduced probability of salamander occupancy.These results could be used to identify and prioritize catchments and water bodies where control measures would be most effective at restoring amphibian populations. Our approach could be useful as a framework for improved investigations into questions of persistence and extirpation of native species when non-native species have already become established.

  6. A Comprehensive Selection of Reference Genes for RT-qPCR Analysis in a Predatory Lady Beetle, Hippodamia convergens (Coleoptera: Coccinellidae)

    PubMed Central

    Siegfried, Blair D.; Zhou, Xuguo

    2015-01-01

    Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is a reliable, rapid, and reproducible technique for measuring and evaluating changes in gene expression. To facilitate gene expression studies and obtain more accurate RT-qPCR data, normalization relative to stable reference genes is required. In this study, expression profiles of seven candidate reference genes, including β-actin (Actin), elongation factor 1 α (EF1A), glyceralde hyde-3-phosphate dehydro-genase (GAPDH), cyclophilins A (CypA), vacuolar-type H+-ATPase (ATPase), 28S ribosomal RNA (28S), and 18S ribosomal RNA (18S) from Hippodamia convergens were investigated. H. convergens is an abundant predatory species in the New World, and has been widely used as a biological control agent against sap-sucking insect pests, primarily aphids. A total of four analytical methods, geNorm, Normfinder, BestKeeper, and the ΔCt method, were employed to evaluate the performance of these seven genes as endogenous controls under diverse experimental conditions. Additionally, RefFinder, a comprehensive evaluation platform integrating the four above mentioned algorithms, ranked the overall stability of these candidate genes. A suite of reference genes were specifically recommended for each experimental condition. Among them, 28S, EF1A, and CypA were the best reference genes across different development stages; GAPDH, 28S, and CypA were most stable in different tissues. GAPDH and CypA were most stable in female and male adults and photoperiod conditions, 28S and EF1A were most stable under a range of temperatures, Actin and CypA were most stable under dietary RNAi condition. This work establishes a standardized RT-qPCR analysis in H. convergens. Additionally, this study lays a foundation for functional genomics research in H. convergens and sheds light on the ecological risk assessment of RNAi-based biopesticides on this non-target biological control agent. PMID:25915640

  7. Laboratory studies on the use of two new arenas to evaluate the impact of the predatory mites Blattisocius tarsalis and Cheyletus eruditus on residual populations of the stored product mite Acarus siro.

    PubMed

    Thind, B B; Ford, H L

    2006-01-01

    Residual populations of storage mites sheltering in crevices and cracks escape conventional control treatments and are implicated in the infestation of newly harvested grain. In a series of 24 h laboratory tests, the performance of solitary adults of two predatory mite species, Cheyletus eruditus (Schrank) and Blattisocius tarsalis (Berlese), were assessed for controlling small numbers of the flour mite Acarus siro (L.). Tests were carried out in the presence or absence of prey refuges or grain debris to afford shelter to the flour mites. While C. eruditus had a significant effect on the motile stages of A. siro, in contrast B. tarsalis had a significant effect on the eggs. The maximum percentage of motile stages of A. siro eaten by C. eruditus was 82%, whereas the minimum percentage of A. siro eggs eaten by B. tarsalis was 99%. While the performance of C. eruditus in predating on motile stages of the flour mite was hindered by the presence of the prey refuge (38% eaten) and grain debris (25% eaten), the performance of B. tarsalis in predating on flour mite eggs was unaffected (100% eaten in presence of prey refuge or grain debris). In prolonged exposures (36 days) the performance of 2, 4 or 8 adult predators, either a single species or a combination of both, was assessed for their ability to control a population of the flour mite developing up to F(2) from an initial inoculum of 80 females and 20 males, allowed to oviposit for 72 h in the absence of predatory mites. The maximum reduction in prey population of 80% was achieved with eight B. tarsalis. Combining the two predatory species did not enhance the reduction of A. siro population.

  8. Ontogenic behavioral consistency, individual variation and fitness consequences among lady beetles.

    PubMed

    Rodrigues, Alice S; Botina, Lisbetd; Nascimento, Carolina P; Gontijo, Lessando M; Torres, Jorge B; Guedes, Raul Narciso C

    2016-10-01

    The potential relevance of complete metamorphosis for the individual variation in sets of behavioral traits and their fitness consequences in predatory species led to the present study. A set of nine behavioral traits were assessed for the larvae and adults of a pyrethroid-resistant and a susceptible population of the lady beetle Eriopis connexa. The aim was to assess: 1) the average individual behavioral (pheno)types and their within-population variation, 2) their ontogenic behavioral consistency from larva to adult, and 3) whether the observed correlated sets of behavioral traits can impact fitness. The average behavioral type differed between populations. The pyrethroid-resistant population consistently exhibited lower aggressiveness (as larvae) and exploration, but showed higher activity, as well as larva sociality, and sometimes boldness than the susceptible population. Behavioral trait variation was higher among pyrethroid-resistant individuals, particularly during the larval stage, but there was significant behavior correlation between larvae and adults, regardless of the insect population. Reduced aggressiveness, and to a lesser extent intermediate levels of boldness against heterospecific individuals were associated with higher population growth. Besides shedding light on the ontogenic consistency of behavioral traits and their fitness impact, our results also suggest that reduced aggressiveness is associated with predator population increase, but may compromise its effectiveness as a biocontrol agent.

  9. Behavioral dermatology.

    PubMed

    Virga, Vint

    2003-03-01

    The practice of behavioral dermatology encompasses the management of any dermatologic condition for which there is a substantial behavioral or emotional component. Commonly recognized behavioral dermatoses such as acral lick dermatitis, psychogenic alopecia, and hyperesthesia are syndromes rather than discrete diagnoses. Successful patient management is dependent upon integrating physiological, social, and environmental factors which contribute to the clinical manifestation of behavioral dermatoses.

  10. Factors affecting feeding behavior and survival of juvenile lake trout in the Great Lakes

    USGS Publications Warehouse

    Savino, Jacqueline F.; Henry, Mary G.; Kincaid, Harold L.

    1993-01-01

    We explored the importance of experience with feeding on live prey, of cataracts, of strain, and of maternally transferred contaminants for the feeding rate and predator avoidance behavior of young lake trout Salvelinus namaycush. Hatchery-reared and feral juvenile lake trout were tested separately as predators on lake trout fry in tanks with artificial cobble reefs. Feral fish captured more prey per day and more prey per strike than did hatchery lake trout. The predatory performance of hatchery and feral fish did not improve significantly with experience. Feeding rates did not differ between lake trout with unilateral cataracts and normal-eyed fish, but significantly diminished for lake trout with bilateral cataracts. Neither strain nor contaminant background affected the ability of fry to feed or to avoid predators. Of the factors studied, previous experience with live food under natural conditions (i.e., the experience of feral fish) was the most important factor affecting feeding behavior of young lake trout.

  11. A Robotics-Based Behavioral Paradigm to Measure Anxiety-Related Responses in Zebrafish

    PubMed Central

    Cianca, Valentina; Bartolini, Tiziana; Porfiri, Maurizio; Macrì, Simone

    2013-01-01

    Zebrafish are gaining momentum as a laboratory animal species for the study of anxiety-related disorders in translational research, whereby they serve a fundamental complement to laboratory rodents. Several anxiety-related behavioral paradigms, which rest upon the presentation of live predatorial stimuli, may yield inconsistent results due to fatigue, habituation, or idiosyncratic responses exhibited by the stimulus itself. To overcome these limitations, we designed and manufactured a fully controllable robot inspired by a natural aquatic predator (Indian leaf fish, Nandus nandus) of zebrafish. We report that this robot elicits aversive antipredatorial reactions in a preference test and that data obtained therein correlate with data observed in traditional anxiety- and fear-related tests (light/dark preference and shelter-seeking). Finally, ethanol administration (0.25; 0.50; 1.00%) exerts anxiolytic effects, thus supporting the view that robotic stimuli can be used in the analysis of anxiety-related behaviors in zebrafish. PMID:23922773

  12. A robotics-based behavioral paradigm to measure anxiety-related responses in zebrafish.

    PubMed

    Cianca, Valentina; Bartolini, Tiziana; Porfiri, Maurizio; Macrì, Simone

    2013-01-01

    Zebrafish are gaining momentum as a laboratory animal species for the study of anxiety-related disorders in translational research, whereby they serve a fundamental complement to laboratory rodents. Several anxiety-related behavioral paradigms, which rest upon the presentation of live predatorial stimuli, may yield inconsistent results due to fatigue, habituation, or idiosyncratic responses exhibited by the stimulus itself. To overcome these limitations, we designed and manufactured a fully controllable robot inspired by a natural aquatic predator (Indian leaf fish, Nandus nandus) of zebrafish. We report that this robot elicits aversive antipredatorial reactions in a preference test and that data obtained therein correlate with data observed in traditional anxiety- and fear-related tests (light/dark preference and shelter-seeking). Finally, ethanol administration (0.25; 0.50; 1.00%) exerts anxiolytic effects, thus supporting the view that robotic stimuli can be used in the analysis of anxiety-related behaviors in zebrafish.

  13. Cloning and differential expression of five heat shock protein genes associated with thermal stress and development in the polyphagous predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae).

    PubMed

    Chen, Wei; Li, Dunsong; Zhang, Min; Zhao, Yunlong; Wu, Wenjing; Zhang, Guren

    2015-09-01

    In order to explore the role of heat shock proteins (Hsps) during thermal stress and development in the predatory mite Neoseiulus cucumeris (Oudemans), we cloned and characterized five full-length Hsp genes. We investigated the expression levels of these genes by quantitative real-time PCR. The five genes characterized here were NcHsp90, NcHsp75, NcHsp70, NcHsp60, and NcHsp40. These Hsps showed high sequence conservation and had greatest identity with heat shock proteins of Metaseiulus occidentalis and other mite and insect species. All five NcHsp genes showed changes in their levels of expression during development. Higher levels of expression were observed in adult females than in adult males, but there were no significant changes between pre-oviposition and post-oviposition stages in the females. NcHsp90, NcHsp75, and NcHsp70 expression levels were up-regulated after a heat shock, and the increases in NcHsp75 and NcHsp70 expression levels were maintained for at least 3 h. Up-regulation of NcHsp60 and NcHsp40 was not detected after 1 h at a high temperature (35-45 °C); however, a significant down-regulation was observed after 3 h heat exposure at 35 °C and 3 h recovery at 25 °C. Cold shock treatment (-5 to 15 °C) for 1 h did not acute elicit changes in the expression levels of any of the genes. At 5 °C, the expression levels of NcHsp90 significantly increased after 6 or 24 h exposure compared to the levels after 1 h exposure. Thus, expression of Hsp genes in N. cucumeris reflected developmental changes, sexual difference, and variable induced response to thermal stress. Increased expression of Hsps might protect N. cucumeris individuals under extreme temperature conditions. Therefore, it may be possible to enhance the thermal tolerance of commercially available N. cucumeris using temperature acclimation. Treatment at 35 °C should be suitable for such acclimation.

  14. Temperature influences the toxicity of deltamethrin, chlorpyrifos and dimethoate to the predatory mite Hypoaspis aculeifer (Acari) and the springtail Folsomia candida (Collembola).

    PubMed

    Jegede, O O; Owojori, O J; Römbke, J

    2017-06-01

    In order to assess the influence of temperature on pesticide toxicity to soil fauna, specimens of the predatory mite Hypoaspis aculeifer and the springtail Folsomia candida were exposed in artificial soil spiked with different concentrations of three pesticides (dimethoate, chlorpyrifos and deltamethrin) at 20°C vs 28°C for the mites and 20°C vs 26°C for the springtails. All tests were carried out according to OECD guidelines. In the mite tests, the toxic effects of dimethoate and chlorpyrifos on survival was about two orders of magnitude more at 28°C than at 20°C. Mite reproduction decreased in the tests with chlorpyrifos and deltamethrin by about four to five orders of magnitude at 28°C than at 20°C. (EC5028°C =1.42 and 2.52mg/kg vs EC5020°C=6.18 and 10.09mg/kg) In the collembolan tests, the toxicity of dimethoate on survival was higher at 26°C than at 20°C (LC5026°C =0.17mg/kg vs LC5020°C =0.36mg/kg), while the opposite was detected for deltamethrin (LC5026°C =11.27mg/kg vs LC5020°C =6.84mg/kg). No difference was found in the test with chlorpyrifos. Effects of dimethoate and chlorpyrifos on reproduction were higher at 26°C than at 20°C (EC5026°C =0.11 and 0.018mg/kg vs EC5020°C =0.29 and 0.031mg/kg respectively), but in the case of deltamethrin the opposite was observed (EC5026°C =12.85mg/kg vs EC5020°C =2.77mg/kg). A preliminary risk assessment of the three pesticides at the two temperature regimes based on the Toxicity Exposure Ratio (TER) approach of the European Union, shows that in general there are few different outcomes when comparing data gained at different temperatures. However, in the light of the few comparisons made data gained in temperate regions should be used with caution in the tropics.

  15. Lateralized behavior in the attacks of largemouth bass on Rhinogobius gobies corresponding to their morphological antisymmetry.

    PubMed

    Yasugi, Masaki; Hori, Michio

    2012-07-15

    Vertebrates show left-right biases in turning direction, limb usage, predator-escape response and use of sensory organs. In particular, some fishes are known to have lateral biases in predatory behaviors corresponding to their morphological antisymmetry. To reveal the effects of these laterally biased behaviors on predator-prey interaction, we conducted behavioral tests of predatory events between largemouth bass, Micropterus salmoides, and freshwater gobies, Rhinogobius sp., both of which have individuals with a well-developed left side and individuals with a well-developed right side. The left-developed bass tended to approach the goby clockwise from behind, whereas right-developed individuals tended to approach counterclockwise. Congruently, left-developed gobies began their escape maneuvers at a longer distance from bass when they were approached clockwise than when they were approached counterclockwise, whereas right-developed gobies showed the reverse tendency. The longer the distance between bass and gobies at the start of goby escape, the more the subsequent bass strike or dash was delayed. Under these conditions, predation should be more successful when a left (right)-developed bass meets a right (left)-developed goby, and less successful when a left (right)-developed bass meets a left (right)-developed goby. This prediction was consistent with the difference in predation success in our test and in field data from Lake Biwa, Japan. We conclude that lateral biases in the behavioral direction of each morphological type will generate bias in predation success between different combinations of predator and prey types, leading to the maintenance of antisymmetric dimorphism through negative frequency-dependent natural selection.

  16. Mechanical properties of the cuticles of three cockroach species that differ in their wind-evoked escape behavior.

    PubMed

    Clark, Andrew J; Triblehorn, Jeffrey D

    2014-01-01

    The structural and material properties of insect cuticle remain largely unexplored, even though they comprise the majority (approximately 80%) of animals. Insect cuticle serves many functions, including protection against predatory attacks, which is especially beneficial to species failing to employ effective running escape responses. Despite recent advances in our understanding of insect escape behaviors and the biomechanics of insect cuticle, there are limited studies on the protective qualities of cuticle to extreme mechanical stresses and strains imposed by predatory attacks, and how these qualities vary between species employing different escape responses. Blattarians (cockroaches) provide an appropriate model system for such studies. Wind-evoked running escape responses are strong in Periplaneta americana, weak in Blaberus craniifer and absent in Gromphodorhina portentosa, putting the latter two species at greater risk of being struck by a predator. We hypothesized that the exoskeletons in these two larger species could provide more protection from predatory strikes relative to the exoskeleton of P. americana. We quantified the protective qualities of the exoskeletons by measuring the puncture resistance, tensile strength, strain energy storage, and peak strain in fresh samples of thoracic and abdominal cuticles from these three species. We found a continuum in puncture resistance, tensile strength, and strain energy storage between the three species, which were greatest in G. portentosa, moderate in B. craniifer, and smallest in P. americana. Histological measurements of total cuticle thickness followed this same pattern. However, peak strain followed a different trend between species. The comparisons in the material properties drawn between the cuticles of G. portentosa, B. craniifer, and P. americana demonstrate parallels between cuticular biomechanics and predator running escape responses.

  17. Mechanical properties of the cuticles of three cockroach species that differ in their wind-evoked escape behavior

    PubMed Central

    Clark, Andrew J.

    2014-01-01

    The structural and material properties of insect cuticle remain largely unexplored, even though they comprise the majority (approximately 80%) of animals. Insect cuticle serves many functions, including protection against predatory attacks, which is especially beneficial to species failing to employ effective running escape responses. Despite recent advances in our understanding of insect escape behaviors and the biomechanics of insect cuticle, there are limited studies on the protective qualities of cuticle to extreme mechanical stresses and strains imposed by predatory attacks, and how these qualities vary between species employing different escape responses. Blattarians (cockroaches) provide an appropriate model system for such studies. Wind-evoked running escape responses are strong in Periplaneta americana, weak in Blaberus craniifer and absent in Gromphodorhina portentosa, putting the latter two species at greater risk of being struck by a predator. We hypothesized that the exoskeletons in these two larger species could provide more protection from predatory strikes relative to the exoskeleton of P. americana. We quantified the protective qualities of the exoskeletons by measuring the puncture resistance, tensile strength, strain energy storage, and peak strain in fresh samples of thoracic and abdominal cuticles from these three species. We found a continuum in puncture resistance, tensile strength, and strain energy storage between the three species, which were greatest in G. portentosa, moderate in B. craniifer, and smallest in P. americana. Histological measurements of total cuticle thickness followed this same pattern. However, peak strain followed a different trend between species. The comparisons in the material properties drawn between the cuticles of G. portentosa, B. craniifer, and P. americana demonstrate parallels between cuticular biomechanics and predator running escape responses. PMID:25101230

  18. Activity cycles and foraging behaviors of free-ranging sidewinder rattlesnakes (Crotalus cerastes): the ontogeny of hunting in a precocial vertebrate.

    PubMed

    Clark, Rulon W; Dorr, Scott W; Whitford, Malachi D; Freymiller, Grace A; Putman, Breanna J

    2016-06-01

    Predators often employ a complex series of behaviors to overcome antipredator defenses and effectively capture prey. Although hunting behaviors can improve with age and experience, many precocial species are necessarily effective predators from birth. Additionally, many predators experience innate ontogenetic shifts in predatory strategies as they grow, allowing them to adapt to prey more appropriate for their increased size and energetic needs. Understanding how the relative roles of innate age-specific adaptation and learning have evolved requires information on how predation behavior develops in situ, in free-ranging predators. However, most of the research on the ontogeny of predation behavior is based on laboratory studies of captive animals, largely due to the difficulty of following newborn individuals in nature. Here, we take advantage of the unique tracks left by juveniles of a precocial viperid, the sidewinder rattlesnake (Crotalus cerastes), which we used to follow free-ranging snakes in the field. We recorded details of their ambush hunting behavior, and compared the behaviors of these juveniles to adult snakes that we monitored in the field via radio telemetry. Although juvenile and adult behaviors were similar in most respects, we did find that adults chose more effective ambush sites, which may be due to their increased experience. We also found that juveniles (but typically not adults) perform periodic tail undulations while in ambush, and that juveniles displayed slightly different activity cycles. Both of these latter differences are likely the result of age-specific adaptations for juveniles' greater reliance on lizards versus small mammals as prey. We also compared the general predatory behavior of sidewinders to that of other species in the genus Crotalus. These findings will provide important baseline field information for more detailed empirical research on the ontogeny of predation behavior in precocial vertebrates.

  19. Predatory Crime and Black Youth.

    ERIC Educational Resources Information Center

    Woodson, Robert L.

    1978-01-01

    While it is generally recognized that Blacks and other minorities are overrepresented as both crime victims and as those arrested for the commission of crimes, Blacks are underrepresented in framing the issues that address a solution to this problem. The input of minority researchers and policymakers is essential. (Author/RLV)

  20. Publishing corruption discussion: predatory journalism.

    PubMed

    Jones, James W; McCullough, Laurence B

    2014-02-01

    Dr Spock is a brilliant young vascular surgeon who is up for tenure next year. He has been warned by the chair of surgery that he needs to increase his list of publications to assure passage. He has recently had a paper reviewed by one of the top journals in his specialty, Journal X-special, with several suggestions for revision. He received an e-mail request for manuscript submission from a newly minted, open access, Journal of Vascular Disease Therapy, which promises a quick and likely favorable response for a fee. What should be done? A. Send the paper to another peer reviewed journal with the suggested revisions. B. Resubmit the paper to Journal X-special. C. Submit to the online journal as is to save time. D. Submit to the online journal and another regular journal. E. Look for another job.

  1. Behavioral Economics

    PubMed Central

    Reed, Derek D.; Niileksela, Christopher R.; Kaplan, Brent A.

    2013-01-01

    In recent years, behavioral economics has gained much attention in psychology and public policy. Despite increased interest and continued basic experimental studies, the application of behavioral economics to therapeutic settings remains relatively sparse. Using examples from both basic and applied studies, we provide an overview of the principles comprising behavioral economic perspectives and discuss implications for behavior analysts in practice. A call for further translational research is provided. PMID:25729506

  2. Verbal behavior.

    PubMed

    Michael, J

    1984-11-01

    THE RECENT HISTORY AND CURRENT STATUS OF THE AREA OF VERBAL BEHAVIOR ARE CONSIDERED IN TERMS OF THREE MAJOR THEMATIC LINES: the operant conditioning of adult verbal behavior, learning to be an effective speaker and listener, and developments directly related to Skinner's Verbal Behavior. Other topics not directly related to the main themes are also considered: the work of Kurt Salzinger, ape-language research, and human operant research related to rule-governed behavior.

  3. Behavioral Medicine.

    ERIC Educational Resources Information Center

    Garfield, Sol L., Ed.

    1982-01-01

    Contains 18 articles discussing the uses of behavioral medicine in such areas as obesity, smoking, hypertension, and headache. Reviews include discussions of behavioral medicine and insomnia, chronic pain, asthma, peripheral vascular disease, and coronary-prone behavior. Newly emerging topics include gastrointestinal disorders, arthritis,…

  4. Behaviorally Speaking.

    ERIC Educational Resources Information Center

    Porter, Elias H.; Dutton, Darell W. J.

    1987-01-01

    Consists of two articles focusing on (1) a modern behavioral model that takes cues from Hippocrates' Four Temperaments and (2) use of a behavioral approach to improve the effectiveness of meetings. Lists positive and negative behaviors within the meeting context. (CH)

  5. Evidence of cue synergism in termite corpse response behavior

    NASA Astrophysics Data System (ADS)

    Ulyshen, Michael D.; Shelton, Thomas G.

    2012-02-01

    Subterranean termites of the genus Reticulitermes are known to build walls and tubes and move considerable amounts of soil into wood but the causes of this behavior remain largely unexplored. In laboratory assays, we tested the hypothesis that Reticulitermes virginicus (Banks) would carry more sand into wooden blocks containing corpses compared to corpse-free controls. We further predicted that the corpses of predatory ants would elicit a stronger response than those of a benign beetle species or nestmates. As hypothesized, significantly more sand was carried into blocks containing corpses and this material was typically used to build partitions separating the dead from the rest of the colony. Contrary to expectations, however, this behavior did not vary among corpse types. We then tested the hypothesis that oleic acid, an unsaturated fatty acid released during arthropod decay and used by ants and other arthropod taxa in corpse recognition, would induce a similar building response in R. virginicus. To additionally determine the role of foreign objects in giving rise to this behavior, the experiment was carried out with and without imitation corpses (i.e., small glass beads). As predicted, oleic acid induced building (a tenfold increase) but only when applied to beads, suggesting strong synergism between tactile and chemical cues. Oleic acid also significantly reduced the amount of wood consumed by R. virginicus and may possess useful repellent properties.

  6. Piscivorous behavior of a temperate cone snail, Conus californicus.

    PubMed

    Stewart, Julia; Gilly, William F

    2005-10-01

    Most of the more than 500 species of predatory marine snails in the genus Conus are tropical or semitropical, and nearly all are thought to be highly selective regarding type of prey. Conus californicus Hinds, 1844, is unusual in that it is endemic to the North American Pacific coast and preys on a large variety of benthic organisms, primarily worms and other molluscs, and also scavenges. We studied the feeding behavior of C. californicus in captivity and found that it regularly killed and consumed live prickleback fishes (Cebidichthys violaceus and Xiphister spp.). Predation involved two behavioral methods similar to those employed by strictly piscivorous relatives. One method utilized stings delivered by radular teeth; the other involved engulfing the prey without stinging. Both methods were commonly used in combination, and individual snails sometimes employed multiple stings to subdue a fish. During the course of the study, snails became aroused by the presence of live fish more quickly, as evidenced by more rapid initiation of hunting behavior. Despite this apparent adaptation, details of prey-capture techniques and effectiveness of stings remained similar over the same period.

  7. Making Behavioral Activation More Behavioral

    ERIC Educational Resources Information Center

    Kanter, Jonathan W.; Manos, Rachel C.; Busch, Andrew M.; Rusch, Laura C.

    2008-01-01

    Behavioral Activation, an efficacious treatment for depression, presents a behavioral theory of depression--emphasizing the need for clients to contact positive reinforcement--and a set of therapeutic techniques--emphasizing provision of instructions rather than therapeutic provision of reinforcement. An integration of Behavioral Activation with…

  8. Psychological behaviorism and behaviorizing psychology

    PubMed Central

    Staats, Arthur W.

    1994-01-01

    Paradigmatic or psychological behaviorism (PB), in a four-decade history of development, has been shaped by its goal, the establishment of a behaviorism that can also serve as the approach in psychology (Watson's original goal). In the process, PB has become a new generation of behaviorism with abundant heuristic avenues for development in theory, philosophy, methodology, and research. Psychology has resources, purview and problem areas, and nascent developments of many kinds, gathered in chaotic diversity, needing unification (and other things) that cognitivism cannot provide. Behaviorism can, within PB's multilevel framework for connecting and advancing both psychology and behaviorism. PMID:22478175

  9. Psychological behaviorism and behaviorizing psychology.

    PubMed

    Staats, A W

    1994-01-01

    Paradigmatic or psychological behaviorism (PB), in a four-decade history of development, has been shaped by its goal, the establishment of a behaviorism that can also serve as the approach in psychology (Watson's original goal). In the process, PB has become a new generation of behaviorism with abundant heuristic avenues for development in theory, philosophy, methodology, and research. Psychology has resources, purview and problem areas, and nascent developments of many kinds, gathered in chaotic diversity, needing unification (and other things) that cognitivism cannot provide. Behaviorism can, within PB's multilevel framework for connecting and advancing both psychology and behaviorism.

  10. Teleological behaviorism.

    PubMed

    Rachlin, H

    1992-11-01

    A psychological science of efficient causes, using internal mechanisms to explain overt behavior, is distinguished from another psychological science, based on Aristotelian final causes, using external objects and goals to explain overt behavior. Efficient-cause psychology is designed to answer the question of how a particular act is emitted; final-cause psychology is designed to answer the question of why a particular act is emitted. Physiological psychology, modern cognitive psychology, and some parts of behaviorism including Skinnerian behaviorism are efficient-cause psychologies; final-cause psychology, a development of Skinnerian behaviorism, is here called teleological behaviorism. Each of these two conceptions of causality in psychology implies a different view of the mind, hence a different meaning of mental terms.

  11. Behavior modification.

    PubMed

    Pelham, W E; Fabiano, G A

    2000-07-01

    Attention deficit/hyperactivity disorder (ADHD) is a chronic and substantially impairing disorder. This means that treatment must also be chronic and substantial. Behavior Modification, and in many cases, the combination of behavior modification and stimulant medication, is a valid, useful treatment for reducing the pervasive impairment experienced by children with ADHD. Based on the research evidence reviewed, behavior modification should be the first line of treatment for children with ADHD.

  12. Do warning displays predict striking behavior in a viperid snake, the cottonmouth (Agkistrodon piscivorus)?

    SciTech Connect

    Glaudas, X. and C.T. Winne

    2007-01-01

    Warning displays are defined as signals designed to intimidate predators or indicate a proclivity to fight. However, support for the idea that warning behaviors signal an intent to fight is largely based on anecdotes and isolated observations, and a complete understanding of antipredator behavior will only be achieved if specific hypotheses are experimentally tested. Herein, we tested in a North American viperid snake, the cottonmouth (Agkistrodon piscivorus), the hypothesis that warning displays serve as a reliable signal to potential predators that a snake will strike. The cottonmouth exhibits two stereotypical warning displays during predator confrontation, i.e., mouth gaping and tail vibrations, making it an ideal study organism to experimentally test the relationship between warning displays and defensive striking. To test this idea, we recorded the sequence of defensive behavior--gaping, tail vibrating, and striking--of cottonmouths towards a standardized predatory stimulus in the laboratory. As predicted, snakes that gaped during the trials were subsequently more likely to strike than snakes that did not. In contrast, striking behavior was independent of the occurrence of tail vibrations. Our results suggest that gaping behavior--but not tail-vibrating behavior--may provide an honest signal to would-be predators.

  13. Sustained disruption of narwhal habitat use and behavior in the presence of Arctic killer whales.

    PubMed

    Breed, Greg A; Matthews, Cory J D; Marcoux, Marianne; Higdon, Jeff W; LeBlanc, Bernard; Petersen, Stephen D; Orr, Jack; Reinhart, Natalie R; Ferguson, Steven H

    2017-03-07

    Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an unprecedented dataset by synchronously tracking predator (killer whales, [Formula: see text] = 1; representing a family group) and prey (narwhal, [Formula: see text] = 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal. When killer whales were present (within about 100 km), narwhal moved closer to shore, where they were presumably less vulnerable. Under predation threat, narwhal movement patterns were more likely to be transiting, whereas in the absence of threat, more likely resident. Effects extended beyond discrete predatory events and persisted steadily for 10 d, the duration that killer whales remained in Admiralty Inlet. Our findings have two key consequences. First, given current reductions in sea ice and increases in Arctic killer whale sightings, killer whales have the potential to reshape Arctic marine mammal distributions and behavior. Second and of more general importance, predators have the potential to strongly affect movement behavior of tracked marine animals. Understanding predator effects may be as or more important than relating movement behavior to resource distribution or bottom-up drivers traditionally included in analyses of marine animal tracking data.

  14. Behavioral toxicology

    SciTech Connect

    Needleman, H.L.

    1995-09-01

    The new fields of behavioral toxicology and behavioral teratology investigate the outcome of specific toxic exposures in humans and animals on learning, memory, and behavioral characteristics. Three important classes of behavioral neurotoxicants are metals, solvents, and pesticides. The clearest data on the deleterious effects of prenatal exposure to toxicants comes from the study of two metals, lead and mercury, and form epidemiological investigations of the effects of alcohol taken during pregnancy. Less complete data are available for two other groups of agents, solvents, and pesticides. What we do know about their effects on the fetal brain is convincing enough to make us demand caution in their distribution. 15 refs.

  15. Decoding and Discrimination of Chemical Cues and Signals: Avoidance of Predation and Competition during Parental Care Behavior in Sympatric Poison Frogs.

    PubMed

    Schulte, Lisa M; Krauss, Martin; Lötters, Stefan; Schulze, Tobias; Brack, Werner

    2015-01-01

    The evolution of chemical communication and the discrimination between evolved functions (signals) and unintentional releases (cues) are among the most challenging issues in chemical ecology. The accurate classification of inter- or intraspecific chemical communication is often puzzling. Here we report on two different communication systems triggering the same parental care behavior in the poison frog Ranitomeya variabilis. This species deposits its tadpoles and egg clutches in phytotelmata and chemically recognizes and avoids sites with both predatory conspecific and non-predatory heterospecific tadpoles (of the species Hyloxalus azureiventris). Combining chemical analyses with in-situ bioassays, we identified the molecular formulas of the chemical compounds triggering this behavior. We found that both species produce distinct chemical compound combinations, suggesting two separate communication systems. Bringing these results into an ecological context, we classify the conspecific R. variabilis compounds as chemical cues, advantageous only to the receivers (the adult frogs), not the emitters (the tadpoles). The heterospecific compounds, however, are suggested to be chemical signals (or cues evolving into signals), being advantageous to the emitters (the heterospecific tadpoles) and likely also to the receivers (the adult frogs). Due to these assumed receiver benefits, the heterospecific compounds are possibly synomones which are advantageous to both emitter and receiver ‒ a very rare communication system between animal species, especially vertebrates.

  16. Decoding and Discrimination of Chemical Cues and Signals: Avoidance of Predation and Competition during Parental Care Behavior in Sympatric Poison Frogs

    PubMed Central

    Schulte, Lisa M.; Krauss, Martin; Lötters, Stefan; Schulze, Tobias; Brack, Werner

    2015-01-01

    The evolution of chemical communication and the discrimination between evolved functions (signals) and unintentional releases (cues) are among the most challenging issues in chemical ecology. The accurate classification of inter- or intraspecific chemical communication is often puzzling. Here we report on two different communication systems triggering the same parental care behavior in the poison frog Ranitomeya variabilis. This species deposits its tadpoles and egg clutches in phytotelmata and chemically recognizes and avoids sites with both predatory conspecific and non-predatory heterospecific tadpoles (of the species Hyloxalus azureiventris). Combining chemical analyses with in-situ bioassays, we identified the molecular formulas of the chemical compounds triggering this behavior. We found that both species produce distinct chemical compound combinations, suggesting two separate communication systems. Bringing these results into an ecological context, we classify the conspecific R. variabilis compounds as chemical cues, advantageous only to the receivers (the adult frogs), not the emitters (the tadpoles). The heterospecific compounds, however, are suggested to be chemical signals (or cues evolving into signals), being advantageous to the emitters (the heterospecific tadpoles) and likely also to the receivers (the adult frogs). Due to these assumed receiver benefits, the heterospecific compounds are possibly synomones which are advantageous to both emitter and receiver ‒ a very rare communication system between animal species, especially vertebrates. PMID:26132416

  17. Behavior Matters

    PubMed Central

    Fisher, Edwin B.; Fitzgibbon, Marian L.; Glasgow, Russell E.; Haire-Joshu, Debra; Hayman, Laura L.; Kaplan, Robert M.; Nanney, Marilyn S.; Ockene, Judith K.

    2011-01-01

    Behavior has a broad and central role in health. Behavioral interventions can be effectively used to prevent disease, improve management of existing disease, increase quality of life, and reduce healthcare costs. A summary is presented of evidence for these conclusions in cardiovascular disease/diabetes, cancer, and HIV/AIDS as well as with key risk factors: tobacco use, poor diet, physical inactivity, and excessive alcohol consumption. For each, documentation is made of (1) moderation of genetic and other fundamental biological influences by behaviors and social–environmental factors, (2) impacts of behaviors on health, (3) success of behavioral interventions in prevention, (4) disease management, (5) and quality of life, and (6) improvements in the health of populations through behavioral health promotion programs. Evidence indicates the cost effectiveness and value of behavioral interventions, especially relative to other common health services, as well as the value they add in terms of quality of life. Pertinent to clinicians and their patients as well as to health policy and population health, the benefits of behavioral interventions extend beyond impacts on a particular disease or risk factor. Rather, they include broad effects and benefits on prevention, disease management, and well-being across the life span. Among priorities for dissemination research, the application of behavioral approaches is challenged by diverse barriers, including socioeconomic barriers linked to health disparities. However, behavioral approaches including those emphasizing community and social influences appear to be useful in addressing such challenges. In sum, behavioral approaches should have a central place in prevention and health care of the 21st century. PMID:21496745

  18. Aggressive Behavior

    MedlinePlus

    ... Listen Español Text Size Email Print Share Aggressive Behavior Page Content Article Body My child is sometimes very aggressive. What is the best ... once they are quiet and still reinforces this behavior, so your child learns that time out means “quiet and still.” ...

  19. Behavioral economics.

    PubMed

    Camerer, Colin F

    2014-09-22

    Behavioral economics uses evidence from psychology and other social sciences to create a precise and fruitful alternative to traditional economic theories, which are based on optimization. Behavioral economics may interest some biologists, as it shifts the basis for theories of economic choice away from logical calculation and maximization and toward biologically plausible mechanisms.

  20. The Scent of Blood: A Driver of Human Behavior?

    PubMed

    Moran, James K; Dietrich, Daniel R; Elbert, Thomas; Pause, Bettina M; Kübler, Lisa; Weierstall, Roland

    2015-01-01

    The scent of blood is potentially one of the most fundamental and survival-relevant olfactory cues in humans. This experiment tests the first human parameters of perceptual threshold and emotional ratings in men and women of an artificially simulated smell of fresh blood in contact with the skin. We hypothesize that this scent of blood, with its association with injury, danger, death, and nutrition will be a critical cue activating fundamental motivational systems relating to either predatory approach behavior or prey-like withdrawal behavior, or both. The results show that perceptual thresholds are unimodally distributed for both sexes, with women being more sensitive. Furthermore, both women and men's emotional responses to simulated blood scent divide strongly into positive and negative valence ratings, with negative ratings in women having a strong arousal component. For women, this split is related to the phase of their menstrual cycle and oral contraception (OC). Future research will investigate whether this split in both genders is context-dependent or trait-like.

  1. Prey Capture Behavior in an Arboreal African Ponerine Ant

    PubMed Central

    Dejean, Alain

    2011-01-01

    I studied the predatory behavior of Platythyrea conradti, an arboreal ponerine ant, whereas most species in this subfamily are ground-dwelling. The workers, which hunt solitarily only around dusk, are able to capture a wide range of prey, including termites and agile, nocturnal insects as well as diurnal insects that are inactive at that moment of the Nyctemeron, resting on tree branches or under leaves. Prey are captured very rapidly, and the antennal palpation used by ground-dwelling ponerine species is reduced to a simple contact; stinging occurs immediately thereafter. The venom has an instant, violent effect as even large prey (up to 30 times the weight of a worker) never struggled after being stung. Only small prey are not stung. Workers retrieve their prey, even large items, singly. To capture termite workers and soldiers defending their nest entrances, ant workers crouch and fold their antennae backward. In their role as guards, the termites face the crouching ants and end up by rolling onto their backs, their legs batting the air. This is likely due to volatile secretions produced by the ants' mandibular gland. The same behavior is used against competing ants, including territorially-dominant arboreal species that retreat further and further away, so that the P. conradti finally drive them from large, sugary food sources. PMID:21589941

  2. The Scent of Blood: A Driver of Human Behavior?

    PubMed Central

    Moran, James K.; Dietrich, Daniel R.; Elbert, Thomas; Pause, Bettina M.; Kübler, Lisa; Weierstall, Roland

    2015-01-01

    The scent of blood is potentially one of the most fundamental and survival-relevant olfactory cues in humans. This experiment tests the first human parameters of perceptual threshold and emotional ratings in men and women of an artificially simulated smell of fresh blood in contact with the skin. We hypothesize that this scent of blood, with its association with injury, danger, death, and nutrition will be a critical cue activating fundamental motivational systems relating to either predatory approach behavior or prey-like withdrawal behavior, or both. The results show that perceptual thresholds are unimodally distributed for both sexes, with women being more sensitive. Furthermore, both women and men’s emotional responses to simulated blood scent divide strongly into positive and negative valence ratings, with negative ratings in women having a strong arousal component. For women, this split is related to the phase of their menstrual cycle and oral contraception (OC). Future research will investigate whether this split in both genders is context-dependent or trait-like. PMID:26397374

  3. Making behavioral activation more behavioral.

    PubMed

    Kanter, Jonathan W; Manos, Rachel C; Busch, Andrew M; Rusch, Laura C

    2008-11-01

    Behavioral Activation, an efficacious treatment for depression, presents a behavioral theory of depression--emphasizing the need for clients to contact positive reinforcement--and a set of therapeutic techniques--emphasizing provision of instructions rather than therapeutic provision of reinforcement. An integration of Behavioral Activation with another behavioral treatment, Functional Analytic Psychotherapy, addresses this mismatch. Functional Analytic Psychotherapy provides a process for the therapeutic provision of immediate and natural reinforcement. This article presents this integration and offers theoretical and practical therapist guidelines on its application. Although the integration is largely theoretical, empirical data are presented in its support when available. The article ends with a discussion of future research directions.

  4. Behavior change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This brief entry presents the mediating-moderating variable model as a conceptual framework for understanding behavior change in regard to physical activity/exercise and adiposity. The ideas are applied to real world situations....

  5. Animal Behavior: Electric Eels Amp Up for an Easy Meal.

    PubMed

    Carlson, Bruce A

    2015-11-16

    The high voltage discharge generated by electric eels is a powerful predatory weapon. A new study shows that eels exploit basic physics to increase the voltage delivered to prey, inducing muscle fatigue that turns challenging prey items into easy targets.

  6. Prey Capture Behavior Evoked by Simple Visual Stimuli in Larval Zebrafish

    PubMed Central

    Bianco, Isaac H.; Kampff, Adam R.; Engert, Florian

    2011-01-01

    Understanding how the nervous system recognizes salient stimuli in the environment and selects and executes the appropriate behavioral responses is a fundamental question in systems neuroscience. To facilitate the neuroethological study of visually guided behavior in larval zebrafish, we developed “virtual reality” assays in which precisely controlled visual cues can be presented to larvae whilst their behavior is automatically monitored using machine vision algorithms. Freely swimming larvae responded to moving stimuli in a size-dependent manner: they directed multiple low amplitude orienting turns (∼20°) toward small moving spots (1°) but reacted to larger spots (10°) with high-amplitude aversive turns (∼60°). The tracking of small spots led us to examine how larvae respond to prey during hunting routines. By analyzing movie sequences of larvae hunting paramecia, we discovered that all prey capture routines commence with eye convergence and larvae maintain their eyes in a highly converged position for the duration of the prey-tracking and capture swim phases. We adapted our virtual reality assay to deliver artificial visual cues to partially restrained larvae and found that small moving spots evoked convergent eye movements and J-turns of the tail, which are defining features of natural hunting. We propose that eye convergence represents the engagement of a predatory mode of behavior in larval fish and serves to increase the region of binocular visual space to enable stereoscopic targeting of prey. PMID:22203793

  7. Relating Sexual Sadism and Psychopathy to One Another, Non-Sexual Violence, and Sexual Crime Behaviors

    PubMed Central

    Robertson, Carrie A.; Knight, Raymond A.

    2014-01-01

    Sexual sadism and psychopathy have been theoretically, clinically, and empirically linked to violence. Although both constructs are linked to predatory violence, few studies have sought to explore the covariation of the two constructs, and even fewer have sought to conceptualize the similarities of violence prediction in each. The current study considered all four Psychopathy Checklist-Revised (PCL-R) facets and employed well-defined, validated measures of sadism to elucidate the relation between sadism and psychopathy, as well as to determine the role of each in the prediction of non-sexual violence and sexual crime behaviors. Study 1 assessed 314 adult, male sex offenders using archival ratings, as well as the self-report Multidimensional Inventory of Development, Sex, and Aggression (the MIDSA). Study 2 used archival ratings to assess 599 adult, male sex offenders. Exploratory and confirmatory factor analyses of crime scene descriptions yielded four sexual crime behavior factors: Violence, Physical Control, Sexual Behavior, and Paraphilic. Sadism and psychopathy covaried, but were not coextensive; sadism correlated with Total PCL-R, Facet 1, and Facet 4 scores. The constructs predicted all non-sexual violence measures, but predicted different sexual crime behavior factors. The PCL-R facets collectively predicted the Violence and Paraphilic factors, whereas sadism only predicted the Violence factor. PMID:24019144

  8. Variation in nesting behavior of eight species of spider mites, Stigmaeopsis having sociality

    NASA Astrophysics Data System (ADS)

    Saito, Yutaka; Zhang, Yan-Xuan; Mori, Kotaro; Ito, Katsura; Sato, Yukie; Chittenden, Anthony R.; Lin, Jian-Zhen; Chae, Younghae; Sakagami, Takane; Sahara, Ken

    2016-10-01

    Nesting behavior is considered to be an important element of social living in animals. The spider mites belonging to the genus Stigmaeopsis spend their lives within nests produced from silk threads. Several of these species show cooperative sociality, while the others are subsocial. In order to identify the origins of this social behavior, comparisons of nest sizes, nesting behaviors (making nests continuously or separately), and their associated traits (fecal deposition patterns) were made for eight cogeneric Stigmaeopsis species showing various levels of social development. All of these species inhabit bamboo plants (Poaceae). We initially addressed the proximate factor of nest size variation. The variation in nest size of the eight species corresponded well with the variation in dorsal seta sc1 length, suggesting that nest size variation among species may have a genetic basis. The time spent within a nest (nest duration) increased with nest size on the respective host plants. Nest arrangement patterns varied among species showing different sized nests: Large nest builders continuously extended their nests, while middle and small nest-building species built new separate nests, which resulted in different social interaction times among species, and is thought to be closely related to social development. Fecal deposition behaviors also varied among Stigmaeopsis species, suggesting diversity in anti-predatory adaptations. Finally, we discuss how the variation in sociality observed within this genus is likely the result of nest size variation that initially evolved as anti-predator strategies.

  9. Relating sexual sadism and psychopathy to one another, non-sexual violence, and sexual crime behaviors.

    PubMed

    Robertson, Carrie A; Knight, Raymond A

    2014-01-01

    Sexual sadism and psychopathy have been theoretically, clinically, and empirically linked to violence. Although both constructs are linked to predatory violence, few studies have sought to explore the covariation of the two constructs, and even fewer have sought to conceptualize the similarities of violence prediction in each. The current study considered all four Psychopathy Checklist-Revised (PCL-R) facets and employed well-defined, validated measures of sadism to elucidate the relation between sadism and psychopathy, as well as to determine the role of each in the prediction of non-sexual violence and sexual crime behaviors. Study 1 assessed 314 adult, male sex offenders using archival ratings, as well as the self-report Multidimensional Inventory of Development, Sex, and Aggression (the MIDSA). Study 2 used archival ratings to assess 599 adult, male sex offenders. Exploratory and confirmatory factor analyses of crime scene descriptions yielded four sexual crime behavior factors: Violence, Physical Control, Sexual Behavior, and Paraphilic. Sadism and psychopathy covaried, but were not coextensive; sadism correlated with Total PCL-R, Facet 1, and Facet 4 scores. The constructs predicted all non-sexual violence measures, but predicted different sexual crime behavior factors. The PCL-R facets collectively predicted the Violence and Paraphilic factors, whereas sadism only predicted the Violence factor.

  10. The genus Anthia Weber in the Republic of South Africa, Identification, distribution, biogeography, and behavior (Coleoptera, Carabidae)

    PubMed Central

    Mawdsley, Jonathan R.; Erwin, Terry L.; Sithole, Hendrik; Mawdsley, James L.; Mawdsley, Alice S.

    2011-01-01

    Abstract A key is presented for the identification of the four species of Anthia Weber (Coleoptera: Carabidae) recorded from the Republic of South Africa: Anthia cinctipennis Lequien, Anthia circumscripta Klug, Anthia maxillosa (Fabricius), and Anthia thoracica (Thunberg). For each of these species, illustrations are provided of adult beetles of both sexes as well as illustrations of male reproductive structures, morphological redescriptions, discussions of morphological variation, annual activity histograms, and maps of occurrence localities in the Republic of South Africa. Maps of occurrence localities for these species are compared against ecoregional and vegetation maps of southern Africa; each species of Anthia shows a different pattern of occupancy across the suite of ecoregions and vegetation types in the Republic of South Africa. Information about predatory and foraging behaviors, Müllerian mimicry, and small-scale vegetation community associations is presented for Anthia thoracica based on field and laboratory studies in Kruger National Park, South Africa. PMID:22144866

  11. Behavior subtraction

    NASA Astrophysics Data System (ADS)

    Jodoin, Pierre-Marc; Saligrama, Venkatesh; Konrad, Janusz

    2008-01-01

    Network video cameras, invented in the last decade or so, permit today pervasive, wide-area visual surveillance. However, due to the vast amounts of visual data that such cameras produce human-operator monitoring is not possible and automatic algorithms are needed. One monitoring task of particular interest is the detection of suspicious behavior, i.e., identification of individuals or objects whose behavior differs from behavior usually observed. Many methods based on object path analysis have been developed to date (motion detection followed by tracking and inferencing) but they are sensitive to motion detection and tracking errors and are also computationally complex. We propose a new surveillance method capable of abnormal behavior detection without explicit estimation of object paths. Our method is based on a simple model of video dynamics. We propose one practical implementation of this general model via temporal aggregation of motion detection labels. Our method requires little processing power and memory, is robust to motion segmentation errors, and general enough to monitor humans, cars or any other moving objects in uncluttered as well as highly-cluttered scenes. Furthermore, on account of its simplicity, our method can provide performance guarantees. It is also robust in harsh environments (jittery cameras, rain/snow/fog).

  12. Challenging Behavior.

    ERIC Educational Resources Information Center

    Reichle, Joe, Ed.; DePaepe, Paris, Ed.

    1991-01-01

    The articles in this feature or theme issue describe successful approaches to positive, community-based management of severe challenging behavior. Programs include: a train-the-trainer strategy for inservice training used across the country; the use of student volunteers as community integration facilitators; a school-based intervention project…

  13. Behavior Modification

    ERIC Educational Resources Information Center

    Boardman, Randolph M.

    2010-01-01

    In a perfect world, students would never talk back to school staff and never argue or fight with each other. They would complete all their assigned tasks, and disciplinary actions never would be needed. Unfortunately, people don't live in a perfect world. Student behavior is a daily concern. Teachers continue to refer students to the office as a…

  14. Model Behavior

    ERIC Educational Resources Information Center

    Holloway, John

    2006-01-01

    There are dozens of books and hundreds of resources that address the issue of character development in students: how to raise them to be good people, how to teach them to be good citizens, how to help them to make good decisions. Little is written, however, about the character development of principals and school leaders, whose behavior is a model…

  15. Ecotoxicity of cadmium in a soil collembolan-predatory mite food chain: Can we use the (15)N labeled litter addition method to assess soil functional change?

    PubMed

    Zhu, Dong; Ke, Xin; Wu, Longhua; Li, Zhu; Christie, Peter; Luo, Yongming

    2016-12-01

    Effects of cadmium (Cd) on predator-prey relationships and soil ecological function are poorly understood and there are few methods available to measure soil functional change. Thus, we structured a soil-dwelling food chain containing the predatory mite Hypoaspis aculeifer and its collembolan prey Folsomia candida to study the effects of Cd exposure for eight weeks in a spiked soil aged for five years. The (15)N labeled litter was added as food to analyze the change in nitrogen (N) transfer content. H. aculeifer reproduction and growth and the survival and reproduction of F. candida were all negatively affected by Cd exposure, and H. aculeifer reproduction was the most sensitive parameter. The sensitivity responses of F. candida and H. aculeifer were different from those using the previous single species test. The results suggest that predator-prey interactions might influence the toxicity of Cd by predation and food restriction. Cadmium lethal body concentrations of adults and juveniles of F. candida and H. aculeifer juveniles were 500-600, 180-270 and 8-10 μg g(-1), respectively. The content of N transfer from litter to animals in the food chain decreased significantly with increasing soil Cd concentration between 100 and 400 mg kg(-1). The results suggest that the (15)N labeled litter addition method is potentially useful for quantitative assessment of soil functional change for further risk assessment purposes.

  16. Tri-trophic effects of transgenic insect-resistant tobacco expressing a protease inhibitor or a biotin-binding protein on adults of the predatory carabid beetle Ctenognathus novaezelandiae.

    PubMed

    Burgess, E P J; Philip, B A; Christeller, J T; Page, N E M; Marshall, R K; Wohlers, M W

    2008-02-01

    Tri-trophic impacts on adult predatory carabid beetles, Ctenognathus novaezelandiae, of insect-resistant transgenic tobacco plants expressing a serine protease inhibitor, bovine spleen trypsin inhibitor (BSTI), or a biotin-binding protein, avidin, were investigated. Both proteins could potentially affect this beetle, since avidin is known to be insecticidal to many beetle species and C. novaezelandiae midguts were shown to contain high levels of trypsin, a protease powerfully inhibited by bovine pancreatic trypsin inhibitor (a BSTI homologue) in vitro. Newly emerged field-collected adult C. novaezelandiae were fed exclusively for 280 days on Spodoptera litura larvae raised either on non-transgenic control, transgenic avidin (55 ppm) or transgenic BSTI (68 ppm) tobacco. Despite this long-term exclusive diet, there was no treatment effect on survival or fecundity and only minor and transient effects on beetles were observed. Data pooled across time and genders showed control-prey-fed beetles weighed 3% more than BSTI-prey-fed beetles and avidin-prey-fed beetles consumed 3-4% fewer prey than control- or BSTI-prey-fed individuals. Females in all treatments gained more mass and survived longer than males. Low exposure to the proteins because of dilution and deactivation within the prey is the most likely explanation for the lack of tri-trophic effects observed. Aditionally, the presence of a digestive chymotrypsin only partially inhibited by BSTI may provide an alternative path for proteolysis.

  17. Rapid biosynthesis of silver nanoparticles using Crotalaria verrucosa leaves against the dengue vector Aedes aegypti: what happens around? An analysis of dragonfly predatory behaviour after exposure at ultra-low doses.

    PubMed

    Murugan, Kadarkarai; Sanoopa, C P; Madhiyazhagan, Pari; Dinesh, Devakumar; Subramaniam, Jayapal; Panneerselvam, Chellasamy; Roni, Mathath; Suresh, Udaiyan; Nicoletti, Marcello; Alarfaj, Abdullah A; Munusamy, Murugan A; Higuchi, Akon; Kumar, Suresh; Perumalsamy, Haribalan; Ahn, Young-Joon; Benelli, Giovanni

    2016-01-01

    Aedes aegypti is a primary vector of dengue, a mosquito-borne viral disease infecting 50-100 million people every year. Here, we biosynthesised mosquitocidal silver nanoparticles (AgNP) using the aqueous leaf extract of Crotalaria verrucosa. The green synthesis of AgNP was studied by UV-vis spectroscopy, SEM, EDX and FTIR. C. verrucosa-synthesised AgNPs were toxic against A. aegypti larvae and pupae. LC50 of AgNP ranged from 3.496 ppm (I instar larvae) to 17.700 ppm (pupae). Furthermore, we evaluated the predatory efficiency of dragonfly nymphs, Brachydiplax sobrina, against II and III instar larvae of A. aegypti in an aquatic environment contaminated with ultra-low doses of AgNP. Under standard laboratory conditions, predation after 24 h was 87.5% (II) and 54.7% (III). In an AgNP-contaminated environment, predation was 91 and 75.5%, respectively. Overall, C. verrucosa-synthesised AgNP could be employed at ultra-low doses to reduce larval population of dengue vectors enhancing predation rates of dragonfly nymphs.

  18. A key volatile infochemical that elicits a strong olfactory response of the predatory mite Neoseiulus californicus, an important natural enemy of the two-spotted spider mite Tetranychus urticae.

    PubMed

    Shimoda, Takeshi

    2010-01-01

    Herbivore-induced plant volatiles (HIPVs) emitted from lima bean leaves infested with the two-spotted spider mites Tetranychus urticae strongly attract the predatory mites Neoseiulus californicus. Among these HIPVs, methyl salicylate and linalool can attract the predators. Three green-leaf volatiles (GLVs) of (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate and (E)-2-hexenal, found in the odor blends from T. urticae-infested leaves and physically damaged leaves, can also attract the predators. To search for a strong predator attractant, the olfactory responses of N. californicus to each synthetic compound or their combinations were investigated in a Y-tube olfactometer. When presented a choice between a mixture of the five compounds (i.e. the two HIPVs and the three GLVs) and T. urticae-infested leaves, N. californicus did not discriminate between these odor sources. The same trend was observed when either a mixture of the two HIPVs or methyl salicylate vs. T. urticae-infested leaves were compared. In contrast, the predators preferred T. urticae-infested leaves to linalool, each of the three GLVs, or a mixture of the three GLVs. These results indicated that methyl salicylate is a strong predator attractant, and its potential attractiveness almost equaled that of the blend of HIPVs from T. urticae-infested leaves.

  19. Behavioral parasomnias.

    PubMed

    Brooks, Stephen; Kushida, Clete A

    2002-10-01

    Sleep is not a static state. During the sleep period, physiologic changes occur throughout the body and brain. This complex, dynamic process can, at times, result in episodes of unusual or undesirable behaviors. These phenomena are called parasomnias. The accurate diagnosis of this group of treatable disorders is important, because they can have a negative impact on sleep, health, and social function. In addition, some of the parasomnias may provide clues to the presence of other underlying pathologic conditions. The parasomnias may be categorized in more than one way, but any attempt to classify such a diverse collection of entities is likely to be somewhat arbitrary. This article discusses the parasomnias according to the classification of the International Classification of Sleep Disorders, with emphasis on those characterized by observable behavior. As the understanding of these disorders (and sleep, in general) continues to deepen, new entities and schemes of classification may emerge.

  20. Behavioral factors.

    PubMed

    Zero, D T; Lussi, A

    2006-01-01

    During and after an erosive challenge, behavioral factors play a role in modifying the extent of erosive tooth wear. The manner that dietary acids are introduced into the mouth (gulping, sipping, use of a straw) will affect how long the teeth are in contact with the erosive challenge. The frequency and duration of exposure to an erosive agent is of paramount importance. Night-time exposure (e.g. baby bottle-feeding) to erosive agents may be particularly destructive because of the absence of salivary flow. Health-conscious individuals tend to ingest acidic drinks and juices more frequently and tend to have higher than average oral hygiene. While good oral hygiene is of proven value in the prevention of periodontal disease and dental caries, frequent toothbrushing with abrasive oral hygiene products may enhance erosive tooth wear. Unhealthy lifestyles such as consumption of designer drugs, alcopops and alcohol abuse are other important behavioral factors.

  1. Crisis behavior

    SciTech Connect

    Grinspoon, L.

    1984-04-01

    The Department of Defense has rules and procedures to minimize the opportunity for error and improper behavior among those with access to strategic weapons, but no psychiatric screening system can predict with assurance who will or will not behave rationally during a crisis. Personal problems and institutional decision-making pressures may destroy nuclear deterrence. Certain features of military life, including drug and alcohol abuse, heavy responsibility, tension, and group decision making, can destreoy rationality. 12 references.

  2. Behavioral epigenetics.

    PubMed

    Moore, David S

    2017-01-01

    Why do we grow up to have the traits we do? Most 20th century scientists answered this question by referring only to our genes and our environments. But recent discoveries in the emerging field of behavioral epigenetics have revealed factors at the interface between genes and environments that also play crucial roles in development. These factors affect how genes work; scientists now know that what matters as much as which genes you have (and what environments you encounter) is how your genes are affected by their contexts. The discovery that what our genes do depends in part on our experiences has shed light on how Nature and Nurture interact at the molecular level inside of our bodies. Data emerging from the world's behavioral epigenetics laboratories support the idea that a person's genes alone cannot determine if, for example, he or she will end up shy, suffering from cardiovascular disease, or extremely smart. Among the environmental factors that can influence genetic activity are parenting styles, diets, and social statuses. In addition to influencing how doctors treat diseases, discoveries about behavioral epigenetics are likely to alter how biologists think about evolution, because some epigenetic effects of experience appear to be transmissible from generation to generation. This domain of research will likely change how we think about the origins of human nature. WIREs Syst Biol Med 2017, 9:e1333. doi: 10.1002/wsbm.1333 For further resources related to this article, please visit the WIREs website.

  3. OPEC behavior

    NASA Astrophysics Data System (ADS)

    Yang, Bo

    This thesis aims to contribute to a further understanding of the real dynamics of OPEC production behavior and its impacts on the world oil market. A literature review in this area shows that the existing studies on OPEC still have some major deficiencies in theoretical interpretation and empirical estimation technique. After a brief background review in chapter 1, chapter 2 tests Griffin's market-sharing cartel model on the post-Griffin time horizon with a simultaneous system of equations, and an innovative hypothesis of OPEC's behavior (Saudi Arabia in particular) is then proposed based on the estimation results. Chapter 3 first provides a conceptual analysis of OPEC behavior under the framework of non-cooperative collusion with imperfect information. An empirical model is then constructed and estimated. The results of the empirical studies in this thesis strongly support the hypothesis that OPEC has operated as a market-sharing cartel since the early 1980s. In addition, the results also provide some support of the theory of non-cooperative collusion under imperfect information. OPEC members collude under normal circumstances and behave competitively at times in response to imperfect market signals of cartel compliance and some internal attributes. Periodic joint competition conduct plays an important role in sustaining the collusion in the long run. Saudi Arabia acts as the leader of the cartel, accommodating intermediate unfavorable market development and punishing others with a tit-for-tat strategy in extreme circumstances.

  4. Role of Behavior Theory in Behavioral Medicine.

    ERIC Educational Resources Information Center

    Epstein, Leonard H.

    1992-01-01

    Defines behavioral medicine as multidisciplinary field that combines research methods from behavioral and biomedical sciences. Examines the role of behavior theory in behavioral medicine. Uses new advances in basic research on learning to illustrate that findings from behavioral science have implications for the field of contemporary behavioral…

  5. Moorea BIOCODE barcode library as a tool for understanding predator-prey interactions: insights into the diet of common predatory coral reef fishes

    NASA Astrophysics Data System (ADS)

    Leray, M.; Boehm, J. T.; Mills, S. C.; Meyer, C. P.

    2012-06-01

    Identifying species involved in consumer-resource interactions is one of the main limitations in the construction of food webs. DNA barcoding of prey items in predator guts provides a valuable tool for characterizing trophic interactions, but the method relies on the availability of reference sequences to which prey sequences can be matched. In this study, we demonstrate that the COI sequence library of the Moorea BIOCODE project, an ecosystem-level barcode initiative, enables the identification of a large proportion of semi-digested fish, crustacean and mollusks found in the guts of three Hawkfish and two Squirrelfish species. While most prey remains lacked diagnostic morphological characters, 94% of the prey found in 67 fishes had >98% sequence similarity with BIOCODE reference sequences. Using this species-level prey identification, we demonstrate how DNA barcoding can provide insights into resource partitioning, predator feeding behaviors and the consequences of predation on ecosystem function.

  6. Predator-induced fleeing behaviors in phytoplankton: a new mechanism for harmful algal bloom formation?

    PubMed

    Harvey, Elizabeth L; Menden-Deuer, Susanne

    2012-01-01

    In the plankton, heterotrophic microbes encounter and ingest phytoplankton prey, which effectively removes >50% of daily phytoplankton production in the ocean and influences global primary production and biochemical cycling rates. Factors such as size, shape, nutritional value, and presence of chemical deterrents are known to affect predation pressure. Effects of movement behaviors of either predator or prey on predation pressure, and particularly fleeing behaviors in phytoplankton are thus far unknown. Here, we quantified individual 3D movements, population distributions, and survival rates of the toxic phytoplankton species, Heterosigma akashiwo in response to a ciliate predator and predator-derived cues. We observed predator-induced defense behaviors previously unknown for phytoplankton. Modulation of individual phytoplankton movements during and after predator exposure resulted in an effective separation of predator and prey species. The strongest avoidance behaviors were observed when H. akashiwo co-occurred with an actively grazing predator. Predator-induced changes in phytoplankton movements resulted in a reduction in encounter rate and a 3-fold increase in net algal population growth rate. A spatially explicit population model predicted rapid phytoplankton bloom formation only when fleeing behaviors were incorporated. These model predictions reflected field observations of rapid H. akashiwo harmful algal bloom (HAB) formation in the coastal ocean. Our results document a novel behavior in phytoplankton that can significantly reduce predation pressure and suggests a new mechanism for HAB formation. Phytoplankton behaviors that minimize predatory losses, maximize resource acquisition, and alter community composition and distribution patterns could have major implications for our understanding and predictive capacity of marine primary production and biochemical cycling rates.

  7. Effect of downed woody debris on small mammal anti-predator behavior.

    SciTech Connect

    Hinkleman, Travis, M.; Orrock, John, L.; Loeb, Susan, C.

    2011-10-01

    Anti-predator behavior can affect prey growth, reproduction, survival, and generate emergent effects in food webs. Small mammals often lower the cost of predation by altering their behavior in response to shrubs,but the importance of other microhabitat features, such as downed woody debris, for anti-predator behavior is unknown. We used givingup densities to quantify the degree to which downed woody debris alters perceived predation risk by small mammals in southeastern pineforests. We placed 14 foraging trays next to large downed woody debris,shrubs, and in open areas for 12 consecutive nights. Moon illumination, a common indicator of predation risk, led to a similar reduction in small mammal foraging in all three microhabitats (open, downed woody debris,and shrub). Small mammals perceived open microhabitats as riskier than shrub microhabitats, with downed woody debris habitats perceived as being of intermediate risk between shrub and open microhabitats. Despite the presumed benefits of the protective cover of downed woody debris, small mammals may perceive downed woody debris as a relatively risky foraging site in southeastern pine forests where the high diversity and abundance of rodent-eating snakes may provide a primary predatory threat.

  8. Sharks modulate their escape behavior in response to predator size, speed and approach orientation.

    PubMed

    Seamone, Scott; Blaine, Tristan; Higham, Timothy E

    2014-12-01

    Escape responses are often critical for surviving predator-prey interactions. Nevertheless, little is known about how predator size, speed and approach orientation impact escape performance, especially in larger prey that are primarily viewed as predators. We used realistic shark models to examine how altering predatory behavior and morphology (size, speed and approach orientation) influences escape behavior and performance in Squalus acanthias, a shark that is preyed upon by apex marine predators. Predator models induced C-start escape responses, and increasing the size and speed of the models triggered a more intense response (increased escape turning rate and acceleration). In addition, increased predator size resulted in greater responsiveness from the sharks. Among the responses, predator approach orientation had the most significant impact on escapes, such that the head-on approach, as compared to the tail-on approach, induced greater reaction distances and increased escape turning rate, speed and acceleration. Thus, the anterior binocular vision in sharks renders them less effective at detecting predators approaching from behind. However, it appears that sharks compensate by performing high-intensity escapes, likely induced by the lateral line system, or by a sudden visual flash of the predator entering their field of view. Our study reveals key aspects of escape behavior in sharks, highlighting the modulation of performance in response to predator approach.

  9. A revised and dated phylogeny of cobweb spiders (Araneae, Araneoidea, Theridiidae): A predatory Cretaceous lineage diversifying in the era of the ants (Hymenoptera, Formicidae).

    PubMed

    Liu, Jie; May-Collado, Laura J; Pekár, Stano; Agnarsson, Ingi

    2016-01-01

    Cobweb spiders (Theridiidae) are highly diverse from the perspective of species richness, morphological diversity, variety of web architecture, and behavioral repertoires. The family includes over 50% of social spiders, a behavioral rarity among the order, and members of the family are furthermore the subject of research on venom, silk biomechanics, kleptoparasitism and web building, among other traits. Theridiidae is one of the most abundant groups of spiders, and thus key insect predators in many different ecosystems and is among relatively few spider families that show high degree of myrmecophagy. Modern comparative studies on all these fronts are best buttressed on a phylogenetic foundation. Our goal here is to offer a revised, dated, phylogenetic hypothesis for the family by summarizing previously published data from multiple molecular and morphological studies through data-mining, and adding novel data from several genera. We also test the hypothesis that the origin and diversification of cobweb spiders coincides with that of ants on which many species specialize as prey. The new phylogeny is largely congruent with prior studies and current taxonomy and should provide a useful tool for theridiid classification and for comparative analyses. Nevertheless, we also highlight the limitations of currently available data-the state of the art in Theridiidae phylogenetics-offering weak support for most of the deeper nodes in the phylogeny. Thus the need is clear for modern phylogenomic approaches to obtain a more solid understanding, especially of relationships among subfamilies. We recover the monophyly of currently recognized theridiid subfamilies with the exception of some enigmatic 'pholcommatines' (Styposis, Phoroncidia) and putative 'hadrotarsines' (Audifia, Tekellina) whose placement is uncertain in our analyses. Theridiidae dates back some 100 mya to the Cretaceous, a period of diversification in flowering plants and many groups of insects, including ants. The

  10. Persistent behavioral impairment caused by embryonic methylphenidate exposure in zebrafish.

    PubMed

    Levin, Edward D; Sledge, Damiyon; Roach, Stephanie; Petro, Ann; Donerly, Susan; Linney, Elwood

    2011-01-01

    As more adults take the stimulant medication methylphenidate to treat attention deficit hyperactivity disorder (ADHD) residual type, the risk arises with regard to exposure during early development if people taking the medication become pregnant. We studied the neurobehavioral effects of methylphenidate in zebrafish. Zebrafish offer cellular reporter systems, continuous visual access and molecular interventions such as morpholinos to help determine critical mechanisms underlying neurobehavioral teratogenicity. Previously, we had seen that persisting neurobehavioral impairment in zebrafish with developmental chlorpyrifos exposure was associated with disturbed dopamine systems. Because methylphenidate is an indirect dopamine agonist, it was thought that it might also cause persistent behavioral impairment after developmental exposure. Zebrafish embryos were exposed to the ADHD stimulant medication methylphenidate 0-5 days post fertilization (12.5-50mg/l). They were tested for long-term behavioral effects as adults. Methylphenidate exposure (50mg/l) caused significant increases in dopamine, norepinepherine and serotonin on day 6 but not day 30 after fertilization. In the novel tank diving test of predatory avoidance developmental methylphenidate (50mg/l) caused a significant reduction in the normal diving response. In the three-chamber spatial learning task early developmental methylphenidate (50mg/l) caused a significant impairment in choice accuracy. These data show that early developmental exposure of zebrafish to methylphenidate causes a long-term impairment in neurobehavioral plasticity. The identification of these functional deficits in zebrafish enables further studies with this model to determine how molecular and cellular mechanisms are disturbed to arrive at this compromised state.

  11. A novel paradigm for nonassociative long-term memory in Drosophila: predator-induced changes in oviposition behavior.

    PubMed

    Kacsoh, Balint Z; Bozler, Julianna; Hodge, Sassan; Ramaswami, Mani; Bosco, Giovanni

    2015-04-01

    Learning processes in Drosophila have been studied through the use of Pavlovian associative memory tests, and these paradigms have been extremely useful in identifying both genetic factors and neuroanatomical structures that are essential to memory formation. Whether these same genes and brain compartments also contribute to memory formed from nonassociative experiences is not well understood. Exposures to environmental stressors such as predators are known to induce innate behavioral responses and can lead to new memory formation that allows a predator response to persist for days after the predator threat has been removed. Here, we utilize a unique form of nonassociative behavior in Drosophila where female flies detect the presence of endoparasitoid predatory wasps and alter their oviposition behavior to lay eggs in food containing high levels of alcohol. The predator-induced change in fly oviposition preference is maintained for days after wasps are removed, and this persistence in behavior requires a minimum continuous exposure time of 14 hr. Maintenance of this behavior is dependent on multiple long-term memory genes, including orb2, dunce, rutabaga, amnesiac, and Fmr1. Maintenance of the behavior also requires intact synaptic transmission of the mushroom body. Surprisingly, synaptic output from the mushroom body (MB) or the functions of any of these learning and memory genes are not required for the change in behavior when female flies are in constant contact with wasps. This suggests that perception of this predator that leads to an acute change in oviposition behavior is not dependent on the MB or dependent on learning and memory gene functions. Because wasp-induced oviposition behavior can last for days and its maintenance requires a functional MB and the wild-type products of several known learning and memory genes, we suggest that this constitutes a paradigm for a bona fide form of nonassociative long-term memory that is not dependent on associated

  12. Behavior Modification is not...

    ERIC Educational Resources Information Center

    Tawney, James W.; And Others

    1973-01-01

    Identified are misconceptions of behavior modification procedures according to which behavior modification is connected mistakenly with noncontingent reinforcement, partial change of a teacher's behavior, decelerations of inappropriate behaviors only, dependency producing technology, teacher dominated activity, a single type of classroom…

  13. Behavior subtraction.

    PubMed

    Jodoin, Pierre-Marc; Saligrama, Venkatesh; Konrad, Janusz

    2012-09-01

    Background subtraction has been a driving engine for many computer vision and video analytics tasks. Although its many variants exist, they all share the underlying assumption that photometric scene properties are either static or exhibit temporal stationarity. While this works in many applications, the model fails when one is interested in discovering changes in scene dynamics instead of changes in scene's photometric properties; the detection of unusual pedestrian or motor traffic patterns are but two examples. We propose a new model and computational framework that assume the dynamics of a scene, not its photometry, to be stationary, i.e., a dynamic background serves as the reference for the dynamics of an observed scene. Central to our approach is the concept of an event, which we define as short-term scene dynamics captured over a time window at a specific spatial location in the camera field of view. Unlike in our earlier work, we compute events by time-aggregating vector object descriptors that can combine multiple features, such as object size, direction of movement, speed, etc. We characterize events probabilistically, but use low-memory, low-complexity surrogates in a practical implementation. Using these surrogates amounts to behavior subtraction, a new algorithm for effective and efficient temporal anomaly detection and localization. Behavior subtraction is resilient to spurious background motion, such as due to camera jitter, and is content-blind, i.e., it works equally well on humans, cars, animals, and other objects in both uncluttered and highly cluttered scenes. Clearly, treating video as a collection of events rather than colored pixels opens new possibilities for video analytics.

  14. Some verbal behavior about verbal behavior

    PubMed Central

    Salzinger, Kurt

    2003-01-01

    Beginning with behavior analysts' tendency to characterize verbal behavior as “mere” verbal behavior, the author reviews his own attempt to employ it to influence both his staff and policies of our government. He then describes its role in psychopathology, its effect on speakers in healing themselves and on engendering creativity. The paper ends by calling to our attention the role of verbal behavior in the construction of behavior analysis. PMID:22478393

  15. Agonistic behavior among three stocked trout species in a novel reservoir fish community

    USGS Publications Warehouse

    Budy, Phaedra; Hafen, Konrad

    2015-01-01

    The popularity of reservoirs to support sport fisheries has led to the stocking of species that did not co-evolve, creating novel reservoir fish communities. In Utah, the Bear Lake strain of Bonneville Cutthroat Trout Oncorhynchus clarkii utah and tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) are being more frequently added to a traditional stocking regimen consisting primarily of Rainbow TroutO. mykiss. Interactions between these three predatory species are not well understood, and studies evaluating community interactions have raised concern for an overall decrease of trout condition. To evaluate the potential for negative interactions among these species, we tested aggression in laboratory aquaria using three-species and pairwise combinations at three densities. Treatments were replicated before and after feeding. During the three-species trials Rainbow Trout initiated 24.8 times more aggressive interactions than Cutthroat Trout and 10.2 times more aggressive interactions than tiger trout, and tiger trout exhibited slightly (1.9 times) more aggressive initiations than Cutthroat Trout. There was no significant difference in behavior before versus after feeding for any species, and no indication of increased aggression at higher densities. Although Rainbow Trout in aquaria may benefit from their bold, aggressive behavior, given observations of decreased relative survival in the field, these benefits may be outweighed in reservoirs, possibly through unnecessary energy expenditure and exposure to predators.

  16. Structure and mechanical behaviors of protective armored pangolin scales and effects of hydration and orientation.

    PubMed

    Liu, Z Q; Jiao, D; Weng, Z Y; Zhang, Z F

    2016-03-01

    As natural flexible dermal armor, pangolin scales provide effective protection against predatory threats and possess other notable properties such as anti-adhesion and wear-resistance. In this study, the structure, mechanical properties, deformation and damage behaviors of pangolin scales were systematically investigated with the effects of hydration and orientation evaluated. The scales are divided into three macro-layers constituted by overlapping keratin tiles with distinct lamellar arrangements which are further composed of lower-ordered lamellae. Both hardness and strength are significantly decreased by hydration; while the plasticity is markedly improved concomitantly, and as such, the mechanical damages are mitigated. The tensile strength invariably approximates to one third of hardness in value. The tensile deformation is dominated by lamellae stretching and pulling out under wet condition, which is distinct from the trans-lamellar fracture in dry samples. The compressive behaviors are featured by pronounced plasticity in both dry and wet scales; and notable strain-hardening capacity is introduced by hydration, especially along the thickness direction wherein kinking occurs. Inter-lamellar cracking is effectively alleviated in wet samples compared with the dry ones and both of them deform by macroscopic buckling. This study may help stimulate possible inspiration for the design of high-performance synthetic armor materials by mimicking pangolin scales.

  17. Effect of ambient temperature in neonate aspic vipers: growth, locomotor performance and defensive behaviors.

    PubMed

    Aïdam, Aurélie; Michel, Catherine Louise; Bonnet, Xavier

    2013-07-01

    The impact of temperature during incubation and gestation has been tested in various reptiles; the postnatal period has been rarely investigated however. Three groups of newborn aspic vipers (Vipera aspis) were placed under contrasted thermal regimes during 7 months: (1) a cool 23°C constant regime, (2) a warm 28°C constant regime, and (3) an optimal regime with free-access to a wide range of temperatures. Later, all the snakes were placed under hibernation conditions (6°C) during 3 months. Finally all the snakes were placed in the optimal thermal regime during 2 additional months. The total duration of the experiment was of 12 months. Body mass and feeding rates were recorded weekly, body size was measured monthly. We also assessed locomotor performance and recorded several behavioral traits (e.g., defensive and predatory behaviors). As expected, snakes raised under cool temperatures exhibited low feeding rate, growth rate, body condition, and they exhibited poor locomotor performance; they also displayed marked defensive behaviors (e.g., high number of defensive bites) whilst hesitating during longer periods to bite a prey. Such behavioral effects were detected at the end of the experiment (i.e., 5 months after exposure to contrasted thermal treatments [3 months of hibernation plus 2 months of optimal regime]), revealing long term effects. Surprisingly, growth rate and locomotor performance were not different between the two other groups, warm constant 28°C versus optimal regimes (albeit several behavioral traits differed), suggesting that the access to a wide range of ambient temperatures was not a crucial factor.

  18. Threat-Sensitive Behavioral Responses to Concentrations of Water-Borne Cues from Predation.

    PubMed

    Kesavaraju, Banugopan; Damal, Kavitha; Juliano, Steven A

    2007-02-01

    Aquatic organisms often detect predators via water-borne chemical cues, and respond by showing reduced activity. Prey responses may be correlated with the concentration of predation cues, which would result in graded antipredator behavioral responses that adjust potentially costly behavioral changes to levels that are commensurate with the risk of predation. Larvae of the predatory mosquito Toxorhynchites rutilus prey upon other container-dwelling insects, including larvae of the mosquito Ochlerotatus triseriatus. Previous work has established that O. triseriatus reduce movement, foraging, and time below the surface, and increase the frequency of resting at the surface, in the presence of water-borne cues from predation by T. rutilus. We tested whether these responses by O. triseriatus are threat sensitive by recording behavior of fourth instar larvae in two runs of an experiment in which we created a series of concentrations (100, 10, 1, 0.1, and 0.01% and 100, 70, 40, 20, and 10%) of water that had held either O. triseriatus larvae alone (control) or a T. rutilus larva feeding on O. triseriatus (predation). We also tested whether associated effects on time spent feeding are threat sensitive by determining whether frequencies of filtering or browsing are also related to concentration of cues. The frequencies of resting and surface declined, whereas frequency of filtering (but not browsing) increased more rapidly with a decrease in concentration of predation cues compared with control cues. Thus, O. triseriatus shows a threat sensitive behavioral response to water-borne cues from this predator, adjusting its degree of behavioral response to the apparent risk of predation.

  19. From Behaviorism to Selectionism.

    ERIC Educational Resources Information Center

    Vargas, Ernest A.

    1993-01-01

    Discusses behaviorism and the gradual shift to a theory of selectionism. Highlights include the development of behaviorism as a part of psychology, including Skinner's theories; varieties of behaviorism, including behavioral analysis; behaviorology in other disciplinary settings; effects of contingencies upon behavior; and the prospects for…

  20. Autistic behavior, behavior analysis, and the gene

    PubMed Central

    Malott, Richard W.

    2004-01-01

    This article addresses the meaning of autism, the etiology of autistic behavior and values, the nature-nurture debate, contingencies vs. genes, and resistance to a behavioral analysis of autism. PMID:22477285

  1. The influence of ecology and genetics on behavioral variation in salamander populations across the Eastern Continental Divide.

    PubMed

    Rissler, Leslie J; Wilbur, Henry M; Taylor, Douglas R

    2004-08-01

    Understanding the unique contributions of ecology and history to the distribution of species within communities requires an integrative approach. The Eastern Continental Divide in southwestern Virginia separates river drainages that differ in species composition: the more aquatic, predatory Desmognathus quadramaculatus is present only in the New River drainage (which drains to the Gulf of Mexico), while Desmognathus monticola is present in both the New River drainage and the James River drainage (which drains to the Atlantic Ocean). We investigated natural distributions, behavioral variation in experimental mesocosms, population genetic, and phylogenetic implications of community structure. The presence of D. quadramaculatus increased the terrestriality of D. monticola in natural and experimental situations but to different degrees in allopatric and sympatric populations. Our ecological data suggest that the degree of terrestriality in D. monticola is a result of a balance between the optimal aquatic habitat and risks of predation. Our genetic analyses suggest that D. monticola has experienced a recent range expansion and has only a recent history of association with D. quadramaculatus in Virginia. This is surprising given the strong behavioral variation that exists in populations experiencing unique community compositions over a scale of meters. This study demonstrates the need to combine both ecology and genetics toward an understanding of the factors affecting species distributions, behavioral variation between populations, and patterns of genetic variation across a landscape.

  2. Positive Behavior Support and Applied Behavior Analysis

    ERIC Educational Resources Information Center

    Johnston, J. M.; Foxx, R. M.; Jacobson, J. W.; Green, G.; Mulick, J. A.

    2006-01-01

    This article reviews the origins and characteristics of the positive behavior support (PBS) movement and examines those features in the context of the field of applied behavior analysis (ABA). We raise a number of concerns about PBS as an approach to delivery of behavioral services and its impact on how ABA is viewed by those in human services. We…

  3. Behavioral technology and behavioral ecology1

    PubMed Central

    Willems, Edwin P.

    1974-01-01

    Applied behavior analysis, as a special case of behavioral technology, is discussed from the standpoint of behavioral ecology. The ecological orientation and its emphasis upon system-like interdependencies among environment, organism, and behavior are presented. The widespread possibilities for unintended effects of simple interventions provide the context for evaluating effective behavioral technology and calling for cooperation between the technologist and ecologist. Such cooperation, in the form of mutual and cooperative research efforts, should come naturally for the technologist and ecologist, because they share some fundamental values and assumptions, and each has much to offer the other. Several areas of such cooperative effort are spelled out. PMID:4465371

  4. Behavioral Health & Performance

    NASA Video Gallery

    Summary of the Behavioral Health and Performance Operations Group’s work including an overview of astronaut selection, behavioral health services provided to astronauts, the psychological aspects o...

  5. Inferring Predator Behavior from Attack Rates on Prey-Replicas That Differ in Conspicuousness

    PubMed Central

    2012-01-01

    Behavioral ecologists and evolutionary biologists have long studied how predators respond to prey items novel in color and pattern. Because a predatory response is influenced by both the predator’s ability to detect the prey and a post-detection behavioral response, variation among prey types in conspicuousness may confound inference about post-prey-detection predator behavior. That is, a relatively high attack rate on a given prey type may result primarily from enhanced conspicuousness and not predators’ direct preference for that prey. Few studies, however, account for such variation in conspicuousness. In a field experiment, we measured predation rates on clay replicas of two aposematic forms of the poison dart frog Dendrobates pumilio, one novel and one familiar, and two cryptic controls. To ask whether predators prefer or avoid a novel aposematic prey form independently of conspicuousness differences among replicas, we first modeled the visual system of a typical avian predator. Then, we used this model to estimate replica contrast against a leaf litter background to test whether variation in contrast alone could explain variation in predator attack rate. We found that absolute predation rates did not differ among color forms. Predation rates relative to conspicuousness did, however, deviate significantly from expectation, suggesting that predators do make post-detection decisions to avoid or attack a given prey type. The direction of this deviation from expectation, though, depended on assumptions we made about how avian predators discriminate objects from the visual background. Our results show that it is important to account for prey conspicuousness when investigating predator behavior and also that existing models of predator visual systems need to be refined. PMID:23119039

  6. Effects of behavioral and morphological plasticity on risk of predation in a Neotropical tadpole.

    PubMed

    McIntyre, Peter B; Baldwin, Sandra; Flecker, Alexander S

    2004-09-01

    Predator-induced phenotypic plasticity is widespread among aquatic animals, however the relative contributions of behavioral and morphological shifts to reducing risk of predation remain uncertain. We tested the phenotypic plasticity of a Neotropical tadpole ( Rana palmipes) in response to chemical cues from predatory Belostoma water bugs, and how phenotype affects risk of predation. Behavior, morphology, and pigmentation all were plastic, resulting in a predator-induced phenotype with lower activity, deeper tail fin and muscle, and darker pigmentation. Tadpoles in the predator cue treatment also grew more rapidly, possibly as a result of the nutrient subsidy from feeding the caged predator. For comparison to phenotypes induced in the experiment, we quantified the phenotype of tadpoles from a natural pool. Wild-caught tadpoles did not match either experimentally induced phenotype; their morphology was more similar to that produced in the control treatment, but their low swimming activity was similar to that induced by predator cues. Exposure of tadpoles from both experimental treatments and the natural pool to a free-ranging predator confirmed that predator-induced phenotypic plasticity reduces risk of predation. Risk of predation was comparable among wild-caught and predator-induced tadpoles, indicating that behavioral shifts can substantially alleviate risk in tadpoles that lack the typical suite of predator-induced morphological traits. The morphology observed in wild-caught tadpoles is associated with rapid growth and high competition in other tadpole species, suggesting that tadpoles may profitably combine a morphology suited to competition for food with behaviors that minimize risk of predation.

  7. Effects of behavioral and morphological plasticity on risk of predation in a Neotropical tadpole

    USGS Publications Warehouse

    McIntyre, P.B.; Baldwin, S.; Flecker, A.S.

    2004-01-01

    Predator-induced phenotypic plasticity is widespread among aquatic animals, however the relative contributions of behavioral and morphological shifts to reducing risk of predation remain uncertain. We tested the phenotypic plasticity of a Neotropical tadpole (Rana palmipes) in response to chemical cues from predatory Belostoma water bugs, and how phenotype affects risk of predation. Behavior, morphology, and pigmentation all were plastic, resulting in a predator-induced phenotype with lower activity, deeper tail fin and muscle, and darker pigmentation. Tadpoles in the predator cue treatment also grew more rapidly, possibly as a result of the nutrient subsidy from feeding the caged predator. For comparison to phenotypes induced in the experiment, we quantified the phenotype of tadpoles from a natural pool. Wildcaught tadpoles did not match either experimentally induced phenotype; their morphology was more similar to that produced in the control treatment, but their low swimming activity was similar to that induced by predator cues. Exposure of tadpoles from both experimental treatments and the natural pool to a free-ranging predator confirmed that predator-induced phenotypic plasticity reduces risk of predation. Risk of predation was comparable among wild-caught and predator-induced tadpoles, indicating that behavioral shifts can substantially alleviate risk in tadpoles that lack the typical suite of predator-induced morphological traits. The morphology observed in wild-caught tadpoles is associated with rapid growth and high competition in other tadpole species, suggesting that tadpoles may profitably combine a morphology suited to competition for food with behaviors that minimize risk of predation. ?? Springer-Verlag 2004.

  8. Predatorial borings in late precambrian mineralized exoskeletons.

    PubMed

    Bengtson, S; Zhao, Y

    1992-07-17

    The late Precambrian tube-forming Cloudina, the earliest known animal to produce a mineralized exoskeleton, shows evidence of having been attacked by shell-boring organisms. Of more than 500 tubes from Shaanxi Province, China, 2.7% have rounded holes 40 to 400 micrometers in diameter. The relation between the size of the holes and the width of the bored tubes suggests that the attacking organism was a predator, selecting its prey for size. If true, this would be the oldest case of predation in the fossil record and would support the hypothesis that selection pressures from predation was a significant factor in the evolution of animal skeletons around the Precambrian-Cambrian boundary.

  9. Applying the ethoexperimental approach to neurodevelopmental syndrome research reveals exaggerated defensive behavior in Mecp2 mutant mice.

    PubMed

    Pearson, Brandon L; Defensor, Erwin B; Blanchard, D Caroline; Blanchard, Robert J

    2015-07-01

    Rett syndrome is a Pervasive Developmental Disorder (PDD) associated with de novo mutations of the methyl CpG-binding protein 2 (MECP2) gene. Mecp2 functions as a transcription factor that regulates the expression of hundreds of genes. Identification of the role of Mecp2 in specific neurodevelopmental symptoms remains an important research aim. We previously demonstrated that male mice possessing a truncation mutation in Mecp2 are hyper-social. We predicted that reduced fear or anxiety might underlie this enhanced affiliation. In order to probe risk assessment and anxiety-like behavior, we compared Mecp2 truncation mutants to their wild-type littermates in the elevated plus maze and elevated zero maze. Additionally, subjects were administered the mouse defense test battery to evaluate unconditioned fear- and panic-like behavior to a graded set of threat scenarios and a predator stimulus. Mutant mice showed no significant changes in anxiety-like behavior. Yet, they displayed hyper-reactive escape and defensive behaviors to an animate predatory threat stimulus. Notably, mutant mice engaged in exaggerated active defense responding to threat stimuli at nearly all phases of the fear battery. These results reveal abnormalities in emotion regulation in Mecp2 mutants particularly in response to ecologically relevant threats. This hyper-responsivity suggests that transcriptional targets of Mecp2 are critical to emotion regulation. Moreover, we suggest that detailed analysis of defensive behavior and aggression with ethologically relevant tasks provides an avenue to interrogate gene-behavior mechanisms of neurodevelopmental and other psychiatric conditions.

  10. Basic Behavior Modification.

    ERIC Educational Resources Information Center

    Mehrabian, Albert

    This monograph examines the component parts of behavior modification, initially defining the problem behavior and drawing a difference between specific observable behaviors (the focus of behavior modification), and the interest of Freudian and similar psychologies in unobservable internal processes. Instrumental learning related to shaping in…

  11. Trophic ecology of the armadillo ant, Tatuidris tatusia, assessed by stable isotopes and behavioral observations.

    PubMed

    Jacquemin, Justine; Delsinne, Thibaut; Maraun, Mark; Leponce, Maurice

    2014-01-01

    Ants of the genus Tatuidris Brown and Kempf (Formicidae: Agroecomyrmecinae) generally occur at low abundances in forests of Central and South America. Their morphological peculiarities, such as mandibular brushes, are presumably linked with specialized predatory habits. Our aims were to (1) assess the Tatuidris abundance in an evergreen premontane forest of Ecuador; (2) detail morphological characteristics and feeding behavior of Tatuidris; and (3) define the position of Tatuidris in the food web. A total of 465 litter samples were collected. For the first time, live Tatuidris individuals were observed. Various potential food sources were offered to them. A nitrogen stable isotope ratio analysis ((15)N/(14)N) was conducted on Tatuidris tatusia, other ants, and common organisms from the leaf-litter mesofauna. We found a relatively high abundance of T. tatusia in the site. Live individuals did not feed on any of the food sources offered, as usually observed with diet specialist ants. The isotope analysis revealed that T. tatusia is one of the top predators of the leaf-litter food web.

  12. Density-dependent predation influences the evolution and behavior of masquerading prey

    PubMed Central

    Skelhorn, John; Rowland, Hannah M.; Delf, Jon; Speed, Michael P.; Ruxton, Graeme D.

    2011-01-01

    Predation is a fundamental process in the interaction between species, and exerts strong selection pressure. Hence, anti-predatory traits have been intensively studied. Although it has long been speculated that individuals of some species gain protection from predators by sometimes almost-uncanny resemblances to uninteresting objects in the local environment (such as twigs or stones), demonstration of antipredatory benefits to such “masquerade” have only very recently been demonstrated, and the fundamental workings of this defensive strategy remain unclear. Here we use laboratory experiments with avian predators and twig-mimicking caterpillars as masqueraders to investigate (i) the evolutionary dynamics of masquerade; and (ii) the behavioral adaptations associated with masquerade. We show that the benefit of masquerade declines as the local density of masqueraders relative to their models (twigs, in our system) increases. This occurs through two separate mechanisms: increasing model density both decreased predators’ motivation to search for masqueraders, and made masqueraders more difficult to detect. We further demonstrated that masquerading organisms have evolved complex microhabitat selection strategies that allow them to best exploit the density-dependent properties of masquerade. Our results strongly suggest the existence of opportunity costs associated with masquerade. Careful evaluation of such costs will be vital to the development of a fuller understanding of both the distribution of masquerade across taxa and ecosystems, and the evolution of the life history strategies of masquerading prey. PMID:21464318

  13. Density-dependent predation influences the evolution and behavior of masquerading prey.

    PubMed

    Skelhorn, John; Rowland, Hannah M; Delf, Jon; Speed, Michael P; Ruxton, Graeme D

    2011-04-19

    Predation is a fundamental process in the interaction between species, and exerts strong selection pressure. Hence, anti-predatory traits have been intensively studied. Although it has long been speculated that individuals of some species gain protection from predators by sometimes almost-uncanny resemblances to uninteresting objects in the local environment (such as twigs or stones), demonstration of antipredatory benefits to such "masquerade" have only very recently been demonstrated, and the fundamental workings of this defensive strategy remain unclear. Here we use laboratory experiments with avian predators and twig-mimicking caterpillars as masqueraders to investigate (i) the evolutionary dynamics of masquerade; and (ii) the behavioral adaptations associated with masquerade. We show that the benefit of masquerade declines as the local density of masqueraders relative to their models (twigs, in our system) increases. This occurs through two separate mechanisms: increasing model density both decreased predators' motivation to search for masqueraders, and made masqueraders more difficult to detect. We further demonstrated that masquerading organisms have evolved complex microhabitat selection strategies that allow them to best exploit the density-dependent properties of masquerade. Our results strongly suggest the existence of opportunity costs associated with masquerade. Careful evaluation of such costs will be vital to the development of a fuller understanding of both the distribution of masquerade across taxa and ecosystems, and the evolution of the life history strategies of masquerading prey.

  14. Trophic ecology of the armadillo ant,Tatuidris tatusia, assessed by stable isotopes and behavioral observations

    PubMed Central

    Jacquemin, Justine; Delsinne, Thibaut; Maraun, Mark; Leponce, Maurice

    2014-01-01

    Ants of the genus Tatuidris Brown and Kempf (Formicidae: Agroecomyrmecinae) generally occur at low abundances in forests of Central and South America. Their morphological peculiarities, such as mandibular brushes, are presumably linked with specialized predatory habits. Our aims were to (1) assess the Tatuidris abundance in an evergreen premontane forest of Ecuador; (2) detail morphological characteristics and feeding behavior of Tatuidris; and (3) define the position of Tatuidris in the food web. A total of 465 litter samples were collected. For the first time, live Tatuidris individuals were observed. Various potential food sources were offered to them. A nitrogen stable isotope ratio analysis (15N/14N) was conducted on Tatuidris tatusia, other ants, and common organisms from the leaf-litter mesofauna. We found a relatively high abundance of T. tatusia in the site. Live individuals did not feed on any of the food sources offered, as usually observed with diet specialist ants. The isotope analysis revealed that T. tatusia is one of the top predators of the leaf-litter food web. PMID:25199767

  15. Temperature rise and microplastics interact with the toxicity of the antibiotic cefalexin to juveniles of the common goby (Pomatoschistus microps): Post-exposure predatory behaviour, acetylcholinesterase activity and lipid peroxidation.

    PubMed

    Fonte, Elsa; Ferreira, Pedro; Guilhermino, Lúcia

    2016-11-01

    The goal of this study was to investigate the toxicity of cefalexin to Pomatoschistus microps juveniles in relation to the presence of microplastics in the water and temperature rise. After acclimatization, groups of wild juveniles were exposed for 96h to artificial salt water (control), microplastics alone (0.184mg/l), cefalexin alone (1.3-10mg/l) and in mixture with microplastics (cefalexin: 1.3-10mg/l; microplastics: 0.184mg/l) at 20 and 25°C. Effect criteria were mortality, post-exposure predatory performance (PEPP), acetylcholinesterase activity (AChE) and lipid peroxidation levels (LPO). At 20°C, concentrations of cefalexin alone≥5mg/l significantly reduced PEPP (up to 56%; 96h-EC50=8.4mg/l), indicating toxicity of the antibiotic to juveniles after short-term exposure to water concentrations in the low ppm range. At 20°C, fish exposed to microplastics alone did not have significant differences in any of the parameters tested relative to the control group but tended to have an inhibition of the PEPP (23%) and AChE (21%); at 25°C, microplastics alone caused mortality (33%) and PEPP inhibition (28%). Thus, microplastics are toxic to P. microps juveniles. At 20°C, under simultaneous exposure to cefalexin and microplastics, the PEPP was significantly reduced (at cefalexin concentrations≥1.25mg/l). Moreover, at 25°C, the toxicity curves of cefalexin (PEPP based), alone and in mixture with microplastics, were significantly different (p<0.05; 96h-EC50 of 3.8 and 5.2mg/l, respectively), and the integrated data analysis indicated significant interactions between the two substances for all biomarkers. Thus, the presence of microplastics in the water influenced the toxicity of cefalexin. The rise of water temperature (from 20°C to 25°C), increased the microplastics-induced mortality (from 8 to 33%), and the inhibitory effects of cefalexin on the PEPP (up to 70%). Significant differences (p<0.05) between the toxicity curves of cefalexin alone at distinct

  16. Behavior Management: Examining the Functions of Behavior

    ERIC Educational Resources Information Center

    Alstot, Andrew E.; Alstot, Crystal D.

    2015-01-01

    Appropriate student behavior is essential for the success of a physical education lesson. Despite using effective proactive management strategies, teachers may need to also use reactive techniques to reduce problem behaviors by applying suitable consequences. For these consequences to be effective, they must be aligned with the function, or cause,…

  17. Behaviorism and Cognitivism in Behavior Therapy.

    ERIC Educational Resources Information Center

    Levis, Donald J.

    The movement within behavior therapy to introduce cognitive terms, constructs, and techniques reflects and involves an extension of the pervasive cognitive movement within the experimental field and the long-standing cognitive approach of many clinicians. Modern day attacks on behaviorism by cognitivists have been almost exclusively geared to the…

  18. Genes and social behavior.

    PubMed

    Robinson, Gene E; Fernald, Russell D; Clayton, David F

    2008-11-07

    What genes and regulatory sequences contribute to the organization and functioning of neural circuits and molecular pathways in the brain that support social behavior? How does social experience interact with information in the genome to modulate brain activity? Here, we address these questions by highlighting progress that has been made in identifying and understanding two key "vectors of influence" that link genes, the brain, and social behavior: (i) Social information alters gene expression in the brain to influence behavior, and (ii) genetic variation influences brain function and social behavior. We also discuss how evolutionary changes in genomic elements influence social behavior and outline prospects for a systems biology of social behavior.

  19. Moving Forward: Positive Behavior Support and Applied Behavior Analysis

    ERIC Educational Resources Information Center

    Tincani, Matt

    2007-01-01

    A controversy has emerged about the relationship between positive behavior support and applied behavior analysis. Some behavior analysts suggest that positive behavior support and applied behavior analysis are the same (e.g., Carr & Sidener, 2002). Others argue that positive behavior support is harmful to applied behavior analysis (e.g., Johnston,…

  20. Behavioral Objectives?-No!

    ERIC Educational Resources Information Center

    Ferguson, Bill L.

    1971-01-01

    Discusses his reasons for objecting to the use of behavioral objectives in education. Article is in response to Robert Blake's article on Behavioral Objectives and the Teaching of English" in English Education, Winter 1971. (RB)

  1. Behavior Modification in Coaching.

    ERIC Educational Resources Information Center

    Lynch, Annette Rutt; Stillman, Stephen M.

    1979-01-01

    An example of behavior modification used in athletic coaching is presented. The case study involves a member of a women's basketball team and details the use of behavior modification for both weight reduction and skill improvement. (JMF)

  2. Behavioral Assessment: Questionnaires.

    ERIC Educational Resources Information Center

    Wilson, C. Chrisman

    1980-01-01

    This is a general discussion of the validity, reliability, function, and format of questionnaires designed to measure problem behavior, noncompliance, anxiety, social interaction, hyperactivity, drug use, and sexual behavior. Commonly used questionnaires are cited. (CP)

  3. Countercontrol in behavior analysis

    PubMed Central

    Delprato, Dennis J.

    2002-01-01

    Countercontrol is a functional class of behavior that is part of Skinner's analysis of social behavior. Countercontrol refers to behavioral episodes comprised of socially mediated aversive controlling conditions and escape or avoidance responses that do not reinforce, and perhaps even punish, controllers' responses. This paper suggests that neglect of countercontrol in modern behavior analysis is unfortunate because the concept applies to interpersonal and social relations the fundamental operant principle that human behavior is both controlled and controlling—humans are not passive and inflexible. Countercontrol is addressed here in terms of conceptual status, contemporary developments in behavior analysis, its importance in a behavior-analytic approach to freedom and cultural design, applications, and research. The main conclusion is that Skinner's formulation of counter-control is scientifically supported and worthy of increased prominence in behavior analysis. PMID:22478386

  4. Child Behavior Disorders

    MedlinePlus

    ... a death in the family may cause a child to act out. Behavior disorders are more serious. ... The behavior is also not appropriate for the child's age. Warning signs can include Harming or threatening ...

  5. Bridging Humanism and Behaviorism.

    ERIC Educational Resources Information Center

    Chu, Lily

    1980-01-01

    Humanistic behaviorism may provide the necessary bridge between behaviorism and humanism. Perhaps the most humanistic approach to teaching is to learn how certain changes will help students and how these changes can be accomplished. (Author/MLF)

  6. Humanism vs. Behaviorism

    ERIC Educational Resources Information Center

    Hunter, Madeline

    1977-01-01

    Author argues that humanism and behaviorism are not necessarily exclusive of one another, and that principles of behaviorism, when thoughtfully applied, can lead to the achievement of humanistic goals. (RW)

  7. Behaviorism and Neuroscience.

    ERIC Educational Resources Information Center

    Thompson, Richard F.

    1994-01-01

    The influence of behaviorism's methods and theories on theory and research in the neurosciences is examined, partly in light of John B. Watson's 1913 essay. An attempt is made to reconcile classical behaviorism and modern cognitive psychology and neuroscience. (SLD)

  8. Positive Behavior Support and Applied Behavior Analysis

    PubMed Central

    Johnston, J.M; Foxx, Richard M; Jacobson, John W; Green, Gina; Mulick, James A

    2006-01-01

    This article reviews the origins and characteristics of the positive behavior support (PBS) movement and examines those features in the context of the field of applied behavior analysis (ABA). We raise a number of concerns about PBS as an approach to delivery of behavioral services and its impact on how ABA is viewed by those in human services. We also consider the features of PBS that have facilitated its broad dissemination and how ABA might benefit from emulating certain practices of the PBS movement. PMID:22478452

  9. Teachers and Behavioral Objectives.

    ERIC Educational Resources Information Center

    Frey, Sherman

    A survey of 406 elementary, middle and secondary school teachers attending the 1973 summer session at Northern Illinois University was conducted to determine their familiarity with and exposure to behavioral objectives, their involvement in writing and using behavioral objectives, and their opinion of the effect of behavioral objectives on student…