understanding insect behavior: Topics by Science.gov

Sample records for understanding insect behavior

Olfactory Mechanisms for Discovery of Odorants to Reduce Insect-Host Contact

PubMed Central

Clark, Jonathan T.; Ray, Anandasankar

2016-01-01

Insects have developed highly sophisticated and sensitive olfactory systems to find animal or plant hosts for feeding. Some insects vector pathogens that cause diseases in hundreds of millions of people and destroy billions of dollars of food products every year. There is great interest, therefore, in understanding how the insect olfactory system can be manipulated to reduce their contact with hosts. Here, we review recent advances in our understanding of insect olfactory detection mechanisms, which may serve as a foundation for designing insect control programs based on manipulation of their behaviors by using odorants. Because every insect species has a unique set of olfactory receptors and olfactory-mediated behaviors, we focus primarily on general principles of odor detection that potentially apply to most insects. While these mechanisms have emerged from studies on model systems for study of insect olfaction, such as Drosophila melanogaster, they provide a foundation for discovery of odorants to repel insects or reduce host-seeking behavior. PMID:27628342
Behavior-based control of insect crop pests

USDA-ARS?s Scientific Manuscript database

Manipulation of insect behaviour can provide the foundation for effective strategies for control of insect crop pests. A detailed understanding of life cycles and the behavioural repertoires of insect pests is essential for development of this approach. A variety of strategies have been developed ...
Physical Processes and Real-Time Chemical Measurement of the Insect Olfactory Environment

PubMed Central

Abrell, Leif; Hildebrand, John G.

2009-01-01

Odor-mediated insect navigation in airborne chemical plumes is vital to many ecological interactions, including mate finding, flower nectaring, and host locating (where disease transmission or herbivory may begin). After emission, volatile chemicals become rapidly mixed and diluted through physical processes that create a dynamic olfactory environment. This review examines those physical processes and some of the analytical technologies available to characterize those behavior-inducing chemical signals at temporal scales equivalent to the olfactory processing in insects. In particular, we focus on two areas of research that together may further our understanding of olfactory signal dynamics and its processing and perception by insects. First, measurement of physical atmospheric processes in the field can provide insight into the spatiotemporal dynamics of the odor signal available to insects. Field measurements in turn permit aspects of the physical environment to be simulated in the laboratory, thereby allowing careful investigation into the links between odor signal dynamics and insect behavior. Second, emerging analytical technologies with high recording frequencies and field-friendly inlet systems may offer new opportunities to characterize natural odors at spatiotemporal scales relevant to insect perception and behavior. Characterization of the chemical signal environment allows the determination of when and where olfactory-mediated behaviors may control ecological interactions. Finally, we argue that coupling of these two research areas will foster increased understanding of the physicochemical environment and enable researchers to determine how olfactory environments shape insect behaviors and sensory systems. PMID:18548311
A review of chemosensation and related behavior in aquatic insects.

PubMed

Crespo, José G

2011-01-01

Insects that are secondarily adapted to aquatic environments are able to sense odors from a diverse array of sources. The antenna of these insects, as in all insects, is the main chemosensory structure and its input to the brain allows for integration of sensory information that ultimately ends in behavioral responses. Only a fraction of the aquatic insect orders have been studied with respect to their sensory biology and most of the work has centered either on the description of the different types of sensilla, or on the behavior of the insect as a whole. In this paper, the literature is exhaustively reviewed and ways in which antennal morphology, brain structure, and associated behavior can advance better understanding of the neurobiology involved in processing of chemosensory information are discussed. Moreover, the importance of studying such group of insects is stated, and at the same time it is shown that many interesting questions regarding olfactory processing can be addressed by looking into the changes that aquatic insects undergo when leaving their aquatic environment.
Behavioral Sabotage of Plant Defenses by Insect Folivores.

PubMed

Dussourd, David E

2017-01-31

Plant susceptibility to herbivore attack is determined not just by the suite of defenses present in different tissues of the plant, but also by the capabilities of the herbivore for tolerating, circumventing, or disarming the defenses. This article reviews the elaborate behaviors exhibited by leaf-chewing insects that appear to function specifically to deactivate hostplant defenses. Shortcomings in our understanding and promising areas for future research are highlighted. Behaviors covered include vein cutting, trenching, girdling, leaf clipping, and application of fluids from exocrine glands. Many of these behaviors have a widespread distribution, having evolved independently in multiple insect lineages. Insects utilizing the behaviors include significant agricultural, horticultural, and forestry pests, as well as numerous species important in natural ecosystems. Behavioral, ecological, and phylogenetic studies have documented the importance of the behaviors and their ancient history, but the molecular analysis of how the behaviors affect plant physiology has scarcely begun.
Behavioral Immunity in Insects

PubMed Central

de Roode, Jacobus C.; Lefèvre, Thierry

2012-01-01

Parasites can dramatically reduce the fitness of their hosts, and natural selection should favor defense mechanisms that can protect hosts against disease. Much work has focused on understanding genetic and physiological immunity against parasites, but hosts can also use behaviors to avoid infection, reduce parasite growth or alleviate disease symptoms. It is increasingly recognized that such behaviors are common in insects, providing strong protection against parasites and parasitoids. We review the current evidence for behavioral immunity in insects, present a framework for investigating such behavior, and emphasize that behavioral immunity may act through indirect rather than direct fitness benefits. We also discuss the implications for host-parasite co-evolution, local adaptation, and the evolution of non-behavioral physiological immune systems. Finally, we argue that the study of behavioral immunity in insects has much to offer for investigations in vertebrates, in which this topic has traditionally been studied. PMID:26466629
A Review of Chemosensation and Related Behavior in Aquatic Insects

PubMed Central

Crespo, José G.

2011-01-01

Insects that are secondarily adapted to aquatic environments are able to sense odors from a diverse array of sources. The antenna of these insects, as in all insects, is the main chemosensory structure and its input to the brain allows for integration of sensory information that ultimately ends in behavioral responses. Only a fraction of the aquatic insect orders have been studied with respect to their sensory biology and most of the work has centered either on the description of the different types of sensilla, or on the behavior of the insect as a whole. In this paper, the literature is exhaustively reviewed and ways in which antennal morphology, brain structure, and associated behavior can advance better understanding of the neurobiology involved in processing of chemosensory information are discussed. Moreover, the importance of studying such group of insects is stated, and at the same time it is shown that many interesting questions regarding olfactory processing can be addressed by looking into the changes that aquatic insects undergo when leaving their aquatic environment. PMID:21864156
Robust manipulations of pest insect behavior using repellents and practical application for integrated pest management

USDA-ARS?s Scientific Manuscript database

In agricultural settings, examples of effective control strategies using repellent chemicals in integrated pest management (IPM) are relatively scarce compared to those using attractants. This may be partly due to a poor understanding of how repellents affect insect behavior once they are deployed. ...
Levels of behavioral organization and the evolution of division of labor

NASA Astrophysics Data System (ADS)

Page, Robert E.; Erber, Joachim

2002-03-01

The major features of insect societies that fascinate biologists are the self-sacrificing altruism expressed by colony members, the complex division of labor, and the tremendous plasticity demonstrated in the face of changing environments. The social behavior of insects is a result of complex interactions at different levels of biological organization. Genes give rise to proteins and peptides that build the nervous and muscular systems, regulate their own synthesis, interact with each other, and affect the behavior of individuals. Social behavior emerges from the complex interactions of individuals that are themselves far removed from the direct effects of the genes. In order to understand how social organization evolves, we must understand the mechanisms that link the different levels of organization. In this review, we discuss how behavior is influenced by genes and the neural system and how social behavior emerges from the behavioral activities of individuals. We show how different levels of organization share common features and are linked through common mechanisms. We focus on the behavior of the honey bee, the best studied of all social insects.
A Proboscis Extension Response Protocol for Investigating Behavioral Plasticity in Insects: Application to Basic, Biomedical, and Agricultural Research

PubMed Central

Smith, Brian H.; Burden, Christina M.

2014-01-01

Insects modify their responses to stimuli through experience of associating those stimuli with events important for survival (e.g., food, mates, threats). There are several behavioral mechanisms through which an insect learns salient associations and relates them to these events. It is important to understand this behavioral plasticity for programs aimed toward assisting insects that are beneficial for agriculture. This understanding can also be used for discovering solutions to biomedical and agricultural problems created by insects that act as disease vectors and pests. The Proboscis Extension Response (PER) conditioning protocol was developed for honey bees (Apis mellifera) over 50 years ago to study how they perceive and learn about floral odors, which signal the nectar and pollen resources a colony needs for survival. The PER procedure provides a robust and easy-to-employ framework for studying several different ecologically relevant mechanisms of behavioral plasticity. It is easily adaptable for use with several other insect species and other behavioral reflexes. These protocols can be readily employed in conjunction with various means for monitoring neural activity in the CNS via electrophysiology or bioimaging, or for manipulating targeted neuromodulatory pathways. It is a robust assay for rapidly detecting sub-lethal effects on behavior caused by environmental stressors, toxins or pesticides. We show how the PER protocol is straightforward to implement using two procedures. One is suitable as a laboratory exercise for students or for quick assays of the effect of an experimental treatment. The other provides more thorough control of variables, which is important for studies of behavioral conditioning. We show how several measures for the behavioral response ranging from binary yes/no to more continuous variable like latency and duration of proboscis extension can be used to test hypotheses. And, we discuss some pitfalls that researchers commonly encounter when they use the procedure for the first time. PMID:25225822
Parasite-altered feeding behavior in insects: integrating functional and mechanistic research frontiers.

PubMed

Bernardo, Melissa A; Singer, Michael S

2017-08-15

Research on parasite-altered feeding behavior in insects is contributing to an emerging literature that considers possible adaptive consequences of altered feeding behavior for the host or the parasite. Several recent ecoimmunological studies show that insects can adaptively alter their foraging behavior in response to parasitism. Another body of recent work shows that infection by parasites can change the behavior of insect hosts to benefit the parasite; manipulations of host feeding behavior may be part of this phenomenon. Here, we address both the functional and the underlying physiological frontiers of parasite-altered feeding behavior in order to spur research that better integrates the two. Functional categories of parasite-altered behavior that are adaptive for the host include prophylaxis, therapy and compensation, while host manipulation is adaptive for the parasite. To better understand and distinguish prophylaxis, therapy and compensation, further study of physiological feedbacks affecting host sensory systems is especially needed. For host manipulation in particular, research on mechanisms by which parasites control host feedbacks will be important to integrate with functional approaches. We see this integration as critical to advancing the field of parasite-altered feeding behavior, which may be common in insects and consequential for human and environmental health. © 2017. Published by The Company of Biologists Ltd.
Neural and Hormonal Control of Postecdysial Behaviors in Insects

PubMed Central

White, Benjamin H.; Ewer, John

2016-01-01

The shedding of the old exoskeleton that occurs in insects at the end of a molt (a process called ecdysis) is typically followed by the expansion and tanning of a new one. At the adult molt, these postecdysial processes include expanding and hardening the wings. Here we describe recent advances in understanding the neural and hormonal control of wing expansion and hardening, focusing on work done in Drosophila where genetic manipulations have permitted a detailed investigation of postecdysial processes and their modulation by sensory input. To place this work in context, we briefly review recent progress in understanding the neuroendocrine regulation of ecdysis, which appears to be largely conserved across insect species. Investigations into the neuroendocrine networks that regulate ecdysial and postecdysial behaviors, will provide insights into how stereotyped, yet environmentally-responsive, sequences are generated, as well as into how they develop and evolve. PMID:24160420
Encyrtid parasitoids of soft scale insects: biology, behavior, and their use in biological control.

PubMed

Kapranas, Apostolos; Tena, Alejandro

2015-01-07

Parasitoids of the hymenopterous family Encyrtidae are one of the most important groups of natural enemies of soft scale insects and have been used extensively in biological control. We summarize existing knowledge of the biology, ecology, and behavior of these parasitoids and how it relates to biological control. Soft scale stage/size and phenology are important determinants of host range and host utilization, which are key aspects in understanding how control by these parasitoids is exerted. Furthermore, the nutritional ecology of encyrtids and their physiological interactions with their hosts affect soft scale insect population dynamics. Lastly, the interactions among encyrtids, heteronomous parasitoids, and ants shape parasitoid species complexes and consequently have a direct impact on the biological control of soft scale insects.
Corpse Management in Social Insects

PubMed Central

Sun, Qian; Zhou, Xuguo

2013-01-01

Undertaking behavior is an essential adaptation to social life that is critical for colony hygiene in enclosed nests. Social insects dispose of dead individuals in various fashions to prevent further contact between corpses and living members in a colony. Focusing on three groups of eusocial insects (bees, ants, and termites) in two phylogenetically distant orders (Hymenoptera and Isoptera), we review mechanisms of death recognition, convergent and divergent behavioral responses toward dead individuals, and undertaking task allocation from the perspective of division of labor. Distinctly different solutions (e.g., corpse removal, burial and cannibalism) have evolved, independently, in the holometabolous hymenopterans and hemimetabolous isopterans toward the same problem of corpse management. In addition, issues which can lead to a better understanding of the roles that undertaking behavior has played in the evolution of eusociality are discussed. PMID:23569436
Unraveling the neural basis of insect navigation.

PubMed

Heinze, Stanley

2017-12-01

One of the defining features of animals is their ability to navigate their environment. Using behavioral experiments this topic has been under intense investigation for nearly a century. In insects, this work has largely focused on the remarkable homing abilities of ants and bees. More recently, the neural basis of navigation shifted into the focus of attention. Starting with revealing the neurons that process the sensory signals used for navigation, in particular polarized skylight, migratory locusts became the key species for delineating navigation-relevant regions of the insect brain. Over the last years, this work was used as a basis for research in the fruit fly Drosophila and extraordinary progress has been made in illuminating the neural underpinnings of navigational processes. With increasingly detailed understanding of navigation circuits, we can begin to ask whether there is a fundamentally shared concept underlying all navigation behavior across insects. This review highlights recent advances and puts them into the context of the behavioral work on ants and bees, as well as the circuits involved in polarized-light processing. A region of the insect brain called the central complex emerges as the common substrate for guiding navigation and its highly organized neuroarchitecture provides a framework for future investigations potentially suited to explain all insect navigation behavior at the level of identified neurons. Copyright © 2017 Elsevier Inc. All rights reserved.
Neuroethology of Olfactory-Guided Behavior and Its Potential Application in the Control of Harmful Insects.

PubMed

Reisenman, Carolina E; Lei, Hong; Guerenstein, Pablo G

2016-01-01

Harmful insects include pests of crops and storage goods, and vectors of human and animal diseases. Throughout their history, humans have been fighting them using diverse methods. The fairly recent development of synthetic chemical insecticides promised efficient crop and health protection at a relatively low cost. However, the negative effects of those insecticides on human health and the environment, as well as the development of insect resistance, have been fueling the search for alternative control tools. New and promising alternative methods to fight harmful insects include the manipulation of their behavior using synthetic versions of "semiochemicals", which are natural volatile and non-volatile substances involved in the intra- and/or inter-specific communication between organisms. Synthetic semiochemicals can be used as trap baits to monitor the presence of insects, so that insecticide spraying can be planned rationally (i.e., only when and where insects are actually present). Other methods that use semiochemicals include insect annihilation by mass trapping, attract-and- kill techniques, behavioral disruption, and the use of repellents. In the last decades many investigations focused on the neural bases of insect's responses to semiochemicals. Those studies help understand how the olfactory system detects and processes information about odors, which could lead to the design of efficient control tools, including odor baits, repellents or ways to confound insects. Here we review our current knowledge about the neural mechanisms controlling olfactory responses to semiochemicals in harmful insects. We also discuss how this neuroethology approach can be used to design or improve pest/vector management strategies.
Neuroethology of Olfactory-Guided Behavior and Its Potential Application in the Control of Harmful Insects

PubMed Central

Reisenman, Carolina E.; Lei, Hong; Guerenstein, Pablo G.

2016-01-01

Harmful insects include pests of crops and storage goods, and vectors of human and animal diseases. Throughout their history, humans have been fighting them using diverse methods. The fairly recent development of synthetic chemical insecticides promised efficient crop and health protection at a relatively low cost. However, the negative effects of those insecticides on human health and the environment, as well as the development of insect resistance, have been fueling the search for alternative control tools. New and promising alternative methods to fight harmful insects include the manipulation of their behavior using synthetic versions of “semiochemicals”, which are natural volatile and non-volatile substances involved in the intra- and/or inter-specific communication between organisms. Synthetic semiochemicals can be used as trap baits to monitor the presence of insects, so that insecticide spraying can be planned rationally (i.e., only when and where insects are actually present). Other methods that use semiochemicals include insect annihilation by mass trapping, attract-and- kill techniques, behavioral disruption, and the use of repellents. In the last decades many investigations focused on the neural bases of insect's responses to semiochemicals. Those studies help understand how the olfactory system detects and processes information about odors, which could lead to the design of efficient control tools, including odor baits, repellents or ways to confound insects. Here we review our current knowledge about the neural mechanisms controlling olfactory responses to semiochemicals in harmful insects. We also discuss how this neuroethology approach can be used to design or improve pest/vector management strategies. PMID:27445858
A plausible neural circuit for decision making and its formation based on reinforcement learning.

PubMed

Wei, Hui; Dai, Dawei; Bu, Yijie

2017-06-01

A human's, or lower insects', behavior is dominated by its nervous system. Each stable behavior has its own inner steps and control rules, and is regulated by a neural circuit. Understanding how the brain influences perception, thought, and behavior is a central mandate of neuroscience. The phototactic flight of insects is a widely observed deterministic behavior. Since its movement is not stochastic, the behavior should be dominated by a neural circuit. Based on the basic firing characteristics of biological neurons and the neural circuit's constitution, we designed a plausible neural circuit for this phototactic behavior from logic perspective. The circuit's output layer, which generates a stable spike firing rate to encode flight commands, controls the insect's angular velocity when flying. The firing pattern and connection type of excitatory and inhibitory neurons are considered in this computational model. We simulated the circuit's information processing using a distributed PC array, and used the real-time average firing rate of output neuron clusters to drive a flying behavior simulation. In this paper, we also explored how a correct neural decision circuit is generated from network flow view through a bee's behavior experiment based on the reward and punishment feedback mechanism. The significance of this study: firstly, we designed a neural circuit to achieve the behavioral logic rules by strictly following the electrophysiological characteristics of biological neurons and anatomical facts. Secondly, our circuit's generality permits the design and implementation of behavioral logic rules based on the most general information processing and activity mode of biological neurons. Thirdly, through computer simulation, we achieved new understanding about the cooperative condition upon which multi-neurons achieve some behavioral control. Fourthly, this study aims in understanding the information encoding mechanism and how neural circuits achieve behavior control. Finally, this study also helps establish a transitional bridge between the microscopic activity of the nervous system and macroscopic animal behavior.
Morphological features of the ovaries during Oogenesis of the Oriental fruit fly (Bactrocera dorsalis Hendel) in relation to the physiological age

USDA-ARS?s Scientific Manuscript database

Determination of physiological state (age?) in insects is useful in furthering our understanding of how insect behavior changes with age. Central to this determination is the identification of characters that allow assessment of physiological age. While non-destructive measures are the most desired ...
Species-specific and female host-biased ectophoresy in the roundworm Caenorhabditis japonica

NASA Astrophysics Data System (ADS)

Yoshiga, Toyoshi; Ishikawa, Yuji; Tanaka, Ryusei; Hironaka, Mantaro; Okumura, Etsuko

2013-02-01

Caenorhabditis japonica is a bacteriophagous nematode species that was discovered on the semi-social burrower bug, Parastrachia japonensis, which demonstrates egg-guarding and provisioning behaviors. To understand the life history of C. japonica in relation to P. japonensis, we demonstrated the specificity of this association and fluctuations in nematode number on the insect throughout the year. C. japonica dauer larvae (DL), larvae in a nonfeeding diapause stage, were predominantly found as clumps on the adult female insects but rarely found on the male insects in all populations examined. This female-biased association was consistent throughout the year, but after the nymphs hatched, nematodes were not detected on the mother insects showing provisioning behavior. DL appeared on the nymphs, and the number of DL on the newly emerged female insects gradually increased thereafter. C. japonica has never been detected on other invertebrates collected from the P. japonensis habitat thus far. Our data suggest that the life cycles of C. japonica and P. japonensis are synchronized.

Knockdown of a metathoracic scent gland desaturase enhances the production of (E)-4-oxo-2-hexenal and suppresses female sexual attraction in the plant bug, Adelphocoris suturalis

USDA-ARS?s Scientific Manuscript database

Insect sex pheromones (SPs) are central to mate-finding behavior, and play an essential role in the survival and reproduction of organisms. Understanding the roles, biosynthetic pathways, and evolution of insect chemical communication systems has been an exciting challenge for biologists. Compared w...
Flight behavior of the rhinoceros beetle Trypoxylus dichotomus during electrical nerve stimulation.

PubMed

Van Truong, Tien; Byun, Doyoung; Lavine, Laura Corley; Emlen, Douglas J; Park, Hoon Cheol; Kim, Min Jun

2012-09-01

Neuronal stimulation is an intricate part of understanding insect flight behavior and control insect itself. In this study, we investigated the effects of electrical pulses applied to the brain and basalar muscle of the rhinoceros beetle (Trypoxylus dichotomus). To understand specific neuronal stimulation mechanisms, responses and flight behavior of the beetle, four electrodes were implanted into the two optic lobes, the brain's central complex and the ventral nerve cord in the posterior pronotum. We demonstrated flight initiation, turning and cessation by stimulating the brain. The change undergone by the wing flapping in response to the electrical signal was analyzed from a sequence of images captured by a high-speed camera. Here, we provide evidence to distinguish the important differences between neuronal and muscular flight stimulations in beetles. We found that in the neural potential stimulation, both the hind wing and the elytron were suppressed. Interestingly, the beetle stopped flying whenever a stimulus potential was applied between the pronotum and one side of the optic lobe, or between the ventral nerve cord in the posterior pronotum and the central complex. In-depth experimentation demonstrated the effective of neural stimulation over muscle stimulation for flight control. During electrical stimulation of the optic lobes, the beetle performed unstable flight, resulting in alternating left and right turns. By applying the electrical signal into both the optic lobes and the central complex of the brain, we could precisely control the direction of the beetle flight. This work provides an insight into insect flight behavior for future development of insect-micro air vehicle.
Insect-controlled Robot: A Mobile Robot Platform to Evaluate the Odor-tracking Capability of an Insect.

PubMed

Ando, Noriyasu; Emoto, Shuhei; Kanzaki, Ryohei

2016-12-19

Robotic odor source localization has been a challenging area and one to which biological knowledge has been expected to contribute, as finding odor sources is an essential task for organism survival. Insects are well-studied organisms with regard to odor tracking, and their behavioral strategies have been applied to mobile robots for evaluation. This "bottom-up" approach is a fundamental way to develop biomimetic robots; however, the biological analyses and the modeling of behavioral mechanisms are still ongoing. Therefore, it is still unknown how such a biological system actually works as the controller of a robotic platform. To answer this question, we have developed an insect-controlled robot in which a male adult silkmoth (Bombyx mori) drives a robot car in response to odor stimuli; this can be regarded as a prototype of a future insect-mimetic robot. In the cockpit of the robot, a tethered silkmoth walked on an air-supported ball and an optical sensor measured the ball rotations. These rotations were translated into the movement of the two-wheeled robot. The advantage of this "hybrid" approach is that experimenters can manipulate any parameter of the robot, which enables the evaluation of the odor-tracking capability of insects and provides useful suggestions for robotic odor-tracking. Furthermore, these manipulations are non-invasive ways to alter the sensory-motor relationship of a pilot insect and will be a useful technique for understanding adaptive behaviors.
The neural bases of host plant selection in a Neuroecology framework.

PubMed

Reisenman, Carolina E; Riffell, Jeffrey A

2015-01-01

Understanding how animals make use of environmental information to guide behavior is a fundamental problem in the field of neuroscience. Similarly, the field of ecology seeks to understand the role of behavior in shaping interactions between organisms at various levels of organization, including population-, community- and even ecosystem-level scales. Together, the newly emerged field of "Neuroecology" seeks to unravel this fundamental question by studying both the function of neurons at many levels of the sensory pathway and the interactions between organisms and their natural environment. The interactions between herbivorous insects and their host plants are ideal examples of Neuroecology given the strong ecological and evolutionary forces and the underlying physiological and behavioral mechanisms that shaped these interactions. In this review we focus on an exemplary herbivorous insect within the Lepidoptera, the giant sphinx moth Manduca sexta, as much is known about the natural behaviors related to host plant selection and the involved neurons at several level of the sensory pathway. We also discuss how herbivore-induced plant odorants and secondary metabolites in floral nectar in turn can affect moth behavior, and the underlying neural mechanisms.
Ant Trail Pheromone Biosynthesis Is Triggered by a Neuropeptide Hormone

PubMed Central

Choi, Man-Yeon; Vander Meer, Robert K.

2012-01-01

Our understanding of insect chemical communication including pheromone identification, synthesis, and their role in behavior has advanced tremendously over the last half-century. However, endocrine regulation of pheromone biosynthesis has progressed slowly due to the complexity of direct and/or indirect hormonal activation of the biosynthetic cascades resulting in insect pheromones. Over 20 years ago, a neurohormone, pheromone biosynthesis activating neuropeptide (PBAN) was identified that stimulated sex pheromone biosynthesis in a lepidopteran moth. Since then, the physiological role, target site, and signal transduction of PBAN has become well understood for sex pheromone biosynthesis in moths. Despite that PBAN-like peptides (∼200) have been identified from various insect Orders, their role in pheromone regulation had not expanded to the other insect groups except for Lepidoptera. Here, we report that trail pheromone biosynthesis in the Dufour's gland (DG) of the fire ant, Solenopsis invicta, is regulated by PBAN. RNAi knock down of PBAN gene (in subesophageal ganglia) or PBAN receptor gene (in DG) expression inhibited trail pheromone biosynthesis. Reduced trail pheromone was documented analytically and through a behavioral bioassay. Extension of PBAN's role in pheromone biosynthesis to a new target insect, mode of action, and behavioral function will renew research efforts on the involvement of PBAN in pheromone biosynthesis in Insecta. PMID:23226278
Morphology and physiology of the olfactory system of blood-feeding insects.

PubMed

Guidobaldi, F; May-Concha, I J; Guerenstein, P G

2014-01-01

Several blood-feeding (hematophagous) insects are vectors of a number of diseases including dengue, Chagas disease and leishmaniasis which persistently affect public health throughout Latin America. The vectors of those diseases include mosquitoes, triatomine bugs and sandflies. As vector control is an efficient way to prevent these illnesses it is important to understand the sensory biology of those harmful insects. We study the physiology of the olfactory system of those insects and apply that knowledge on the development of methods to manipulate their behavior. Here we review some of the latest information on insect olfaction with emphasis on hematophagous insects. The insect olfactory sensory neurons are housed inside hair-like organs called sensilla which are mainly distributed on the antenna and mouthparts. The identity of many of the odor compounds that those neurons detect are already known in hematophagous insects. They include several constituents of host (vertebrate) odor, sex, aggregation and alarm pheromones, and compounds related to egg-deposition behavior. Recent work has contributed significant knowledge on how odor information is processed in the insect first odor-processing center in the brain, the antennal lobe. The quality, quantity, and temporal features of the odor stimuli are encoded by the neural networks of the antennal lobe. Information regarding odor mixtures is also encoded. While natural mixtures evoke strong responses, synthetic mixtures that deviate from their natural counterparts in terms of key constituents or proportions of those constituents evoke weaker responses. The processing of olfactory information is largely unexplored in hematophagous insects. However, many aspects of their olfactory behavior are known. As in other insects, responses to relevant single odor compounds are weak while natural mixtures evoke strong responses. Future challenges include studying how information about odor mixtures is processed in their brain. This could help develop highly attractive synthetic odor blends to lure them into traps. Copyright © 2014 Elsevier Ltd. All rights reserved.
Investigating Crickets: Observing Animal Exploratory Behavior

ERIC Educational Resources Information Center

Bowen, G. M.

2008-01-01

For curriculum content-related reasons, inquiry activities can be difficult in classrooms unless the activities are approached in a manner that makes variations among student group findings understandable in the context of the study. Studies of individual animals and plant reactions to stimuli, such as insect exploratory behavior, allow the…
A conceptual framework that links pollinator foraging behavior to gene flow

USDA-ARS?s Scientific Manuscript database

In insect-pollinated crops such as alfalfa, a better understanding of how pollinator foraging behavior affects gene flow could lead to the development of management strategies to reduce gene flow and facilitate the coexistence of distinct seed-production markets. Here, we introduce a conceptual fram...
Evaluation of Possible Proximate Mechanisms Underlying the Kinship Theory of Intragenomic Conflict in Social Insects.

PubMed

Galbraith, David A; Yi, Soojin V; Grozinger, Christina M

2016-12-01

Kinship theory provides a universal framework in which to understand the evolution of altruism, but there are many molecular and genetic mechanisms that can generate altruistic behaviors. Interestingly, kinship theory specifically predicts intragenomic conflict between maternally-derived alleles (matrigenes) and paternally-derived alleles (patrigenes) over the generation of altruistic behavior in cases where the interests of the matrigenes and patrigenes are not aligned. Under these conditions, individual differences in selfish versus altruistic behavior are predicted to arise from differential expression of the matrigenes and patrigenes (parent-specific gene expression or PSGE) that regulate selfish versus altruistic behaviors. As one of the leading theories to describe PSGE and genomic imprinting, kinship theory has been used to generate predictions to describe the reproductive division of labor in social insect colonies, which represents an excellent model system to test the hypotheses of kinship theory and examine the underlying mechanisms driving it. Recent studies have confirmed the predicted differences in the influence of matrigenes and patrigenes on reproductive division of labor in social insects, and demonstrated that these differences are associated with differences in PSGE of key genes involved in regulating reproductive physiology, providing further support for kinship theory. However, the mechanisms mediating PSGE in social insects, and how PSGE leads to differences in selfish versus altruistic behavior, remain to be determined. Here, we review the available supporting evidence for three possible epigenetic mechanisms (DNA methylation, piRNAs, and histone modification) that may generate PSGE in social insects, and discuss how these may lead to variation in social behavior. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
Insect Immunity to Entomopathogenic Fungi.

PubMed

Lu, H-L; St Leger, R J

2016-01-01

The study of infection and immunity in insects has achieved considerable prominence with the appreciation that their host defense mechanisms share many fundamental characteristics with the innate immune system of vertebrates. Studies on the highly tractable model organism Drosophila in particular have led to a detailed understanding of conserved innate immunity networks, such as Toll. However, most of these studies have used opportunistic human pathogens and may not have revealed specialized immune strategies that have arisen through evolutionary arms races with natural insect pathogens. Fungi are the commonest natural insect pathogens, and in this review, we focus on studies using Metarhizium and Beauveria spp. that have addressed immune system function and pathogen virulence via behavioral avoidance, the use of physical barriers, and the activation of local and systemic immune responses. In particular, we highlight studies on the evolutionary genetics of insect immunity and discuss insect-pathogen coevolution. Copyright © 2016 Elsevier Inc. All rights reserved.
Mechanisms by which pesticides affect insect immunity.

PubMed

James, R R; Xu, J

2012-02-01

The current state of knowledge regarding the effect of pesticides on insect immunity is reviewed here. A basic understanding of these interactions is needed for several reasons, including to improve methods for controlling pest insects in agricultural settings, for controlling insect vectors of human diseases, and for reducing mortality in beneficial insects. Bees are particularly vulnerable to sublethal pesticide exposures because they gather nectar and pollen, concentrating environmental toxins in their nests in the process. Pesticides do have effects on immunity. Organophosphates and some botanicals have been found to impact hemocyte number, differentiation, and thus affect phagocytosis. The phenoloxidase cascade and malanization have also been shown to be affected by several insecticides. Many synthetic insecticides increase oxidative stress, and this could have severe impacts on the production of some antimicrobial peptides in insects, but research is needed to determine the actual effects. Pesticides can also affect grooming behaviors, rendering insects more susceptible to disease. Despite laboratory data documenting pesticide/pathogen interactions, little field data is available at the population level. Published by Elsevier Inc.
The Genome and Methylome of a Subsocial Small Carpenter Bee, Ceratina calcarata

PubMed Central

Rehan, Sandra M.; Glastad, Karl M.; Lawson, Sarah P.; Hunt, Brendan G.

2016-01-01

Understanding the evolution of animal societies, considered to be a major transition in evolution, is a key topic in evolutionary biology. Recently, new gateways for understanding social evolution have opened up due to advances in genomics, allowing for unprecedented opportunities in studying social behavior on a molecular level. In particular, highly eusocial insect species (caste-containing societies with nonreproductives that care for siblings) have taken center stage in studies of the molecular evolution of sociality. Despite advances in genomic studies of both solitary and eusocial insects, we still lack genomic resources for early insect societies. To study the genetic basis of social traits requires comparison of genomes from a diversity of organisms ranging from solitary to complex social forms. Here we present the genome of a subsocial bee, Ceratina calcarata. This study begins to address the types of genomic changes associated with the earliest origins of simple sociality using the small carpenter bee. Genes associated with lipid transport and DNA recombination have undergone positive selection in C. calcarata relative to other bee lineages. Furthermore, we provide the first methylome of a noneusocial bee. Ceratina calcarata contains the complete enzymatic toolkit for DNA methylation. As in the honey bee and many other holometabolous insects, DNA methylation is targeted to exons. The addition of this genome allows for new lines of research into the genetic and epigenetic precursors to complex social behaviors. PMID:27048475
A geometric model of mortality and crop protection for insects feeding on discrete toxicant deposits.

PubMed

Ebert, Timothy; Derksen, Richard

2004-04-01

Current theory governing the biological effectiveness of toxicants stresses the dose-response relationship and focuses on uniform toxicant distributions in the insect's environment. However, toxicants are seldom uniformly dispersed under field conditions. Toxicant distribution affects bioavailability, but the mechanics of such interactions is not well documented. We present a geometric model of the interactions between insects and heterogeneously distributed toxicants. From the model, we conclude the following: 1) There is an optimal droplet size, and droplets both smaller and larger than this optimum will decrease efficacy. 2) There is an ideal droplet distribution. Droplets should be spaced based on two criteria: calculate the allowable damage, double this quantity, and one lethal deposit should be placed in this area; and define the quantity of leaf the larva could eat before the toxicant decays below the lethal level and place one lethal deposit within this area. 3) Distributions of toxicant where deposits are sublethal will often be ineffective, but the application is wasteful if deposits contain more than a lethal dose. 4) Insect behavior both as individuals and collectively influences the level of crop production provided by an application. This conclusion has implications for both crop protection and natural plant-insect interactions. The effective utilization of new more environmentally sensitive toxicants may depend on how well we understand how heterogeneous toxicant distributions interact with insect behavior to determine the biological outcome.
Plant Tolerance: A Unique Approach to Control Hemipteran Pests.

PubMed

Koch, Kyle G; Chapman, Kaitlin; Louis, Joe; Heng-Moss, Tiffany; Sarath, Gautam

2016-01-01

Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant's ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest's physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented.
Application of synchrotron radiation phase-contrast microtomography with iodine staining to Rhodnius prolixus head during ecdysis period

NASA Astrophysics Data System (ADS)

Sena, G.; Nogueira, L. P.; Braz, D.; Colaço, M. V.; Azambuja, P.; Gonzalez, M. S.; Tromba, G.; Mantuano, A.; Costa, F. N.; Barroso, R. C.

2018-05-01

Synchrotron radiation phase-contrast microtomography (SR-PHC-CT) has become an important tool in studies of insects, mainly Rhodinius prolixus, the insect vector of Chagas disease. A previous work has shown that SR-PHC-CT is an excellent technique in studies about the ecdysis process of R.prolixus head. The term ecdysis refers to the set of behaviors by which an insect extracts itself from an old exoskeleton. The exoskeleton formation is indispensable for the evolutionary success of insect species, so failure to complete ecdysis will, in most cases result in death, making this process an excellent target in the search for new insect pest management strategies. Understanding the behavior of the ecdysis process is fundamental for the non-proliferation of Chagas disease. Despite it has been possible to identify the moulting process in the first work, main structures of the R.prolixus head could not be identified. In this work, it was developed a staining protocol which enabled the identification of these important structures using Iodine at SYRMEP beamline of ELETTRA. In the 3D images, it was possible to segment essential structures in the process of ecdysis. These structures have never been presented previously in the moulting period with SR-PHC-CT.
The Genome and Methylome of a Subsocial Small Carpenter Bee, Ceratina calcarata.

PubMed

Rehan, Sandra M; Glastad, Karl M; Lawson, Sarah P; Hunt, Brendan G

2016-05-13

Understanding the evolution of animal societies, considered to be a major transition in evolution, is a key topic in evolutionary biology. Recently, new gateways for understanding social evolution have opened up due to advances in genomics, allowing for unprecedented opportunities in studying social behavior on a molecular level. In particular, highly eusocial insect species (caste-containing societies with nonreproductives that care for siblings) have taken center stage in studies of the molecular evolution of sociality. Despite advances in genomic studies of both solitary and eusocial insects, we still lack genomic resources for early insect societies. To study the genetic basis of social traits requires comparison of genomes from a diversity of organisms ranging from solitary to complex social forms. Here we present the genome of a subsocial bee, Ceratina calcarata This study begins to address the types of genomic changes associated with the earliest origins of simple sociality using the small carpenter bee. Genes associated with lipid transport and DNA recombination have undergone positive selection in C. calcarata relative to other bee lineages. Furthermore, we provide the first methylome of a noneusocial bee. Ceratina calcarata contains the complete enzymatic toolkit for DNA methylation. As in the honey bee and many other holometabolous insects, DNA methylation is targeted to exons. The addition of this genome allows for new lines of research into the genetic and epigenetic precursors to complex social behaviors. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Host-Seeking Behavior in the Bed Bug, Cimex lectularius.

PubMed

Suchy, James T; Lewis, Vernard R

2011-03-07

The reemergence of the bed bug, Cimex lectularius Linnaeus, has recently spawned a frenzy of public, media, and academic attention. In response to the growing rate of infestation, considerable work has been focused on identifying the various host cues utilized by the bed bug in search of a meal. Most of these behavioral studies examine movement within a confined environment, such as a Petri dish. This has prevented a more complete understanding of the insect's host-seeking process. This work describes a novel method for studying host-seeking behavior, using various movement parameters, in a time-lapse photography system. With the use of human breath as an attractant, we qualitatively and quantitatively assessed how bed bugs navigate their environment between its harborage and the host. Levels of behavioral activity varied dramatically between bed bugs in the presence and absence of host odor. Bed bugs demonstrated not simply activation, but attraction to the chemical components of breath. Localized, stop-start host-seeking behavior or alternating periods of movement and pause were observed among bed bugs placed in the environment void of human breath, while those exposed to human breath demonstrated long range, stop-start host-seeking behavior. A more comprehensive understanding of bed bug host-seeking can lead to the development of traps and monitors that account for unique subtleties in their behavior. The time-lapse photography system uses a large, artificial environment and could also be employed to study other aspects of the insect's behavioral patterns.
[Research progress in chemical communication among insect-resistant genetically modified plants, insect pests and natural enemies].

PubMed

Liu, Qing-Song; Li, Yun-He; Chen, Xiu-Ping; Peng, Yu-Fa

2014-08-01

Semiochemicals released by plants or insects play an important role in the communication among plants, phytophagous insects and their natural enemies. They thus form a chemical information network which regulates intra- and inter-specific behaviors and sustains the composition and structure of plant and insect communities. The application of insect-resistant genetically modified (IRGM) crops may affect the chemical communication within and among the tritrophic levels, and thus cause disturbances to the biotic community structure and the stability of the farmland ecosystem. This has raised concerns about the environmental safety of IRGM crops and triggered research worldwide. In the current article we provided a brief summary of the chemical communication among plants, herbivores and natural enemies; analyzed the potential of IRGM crops to affect the chemical communication between plants and arthropods and the related mechanisms; and discussed the current research progress and the future prospects in this field. We hope that this will promote the research in this field by Chinese scientists and increase our understanding of the potential effects of growing of IRGM crops on the arthropod community structure.
Plant Tolerance: A Unique Approach to Control Hemipteran Pests

PubMed Central

Koch, Kyle G.; Chapman, Kaitlin; Louis, Joe; Heng-Moss, Tiffany; Sarath, Gautam

2016-01-01

Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant’s ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest’s physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented. PMID:27679643
Combinatorial Codes and Labeled Lines: How Insects Use Olfactory Cues to Find and Judge Food, Mates, and Oviposition Sites in Complex Environments

PubMed Central

Haverkamp, Alexander; Hansson, Bill S.; Knaden, Markus

2018-01-01

Insects, including those which provide vital ecosystems services as well as those which are devastating pests or disease vectors, locate their resources mainly based on olfaction. Understanding insect olfaction not only from a neurobiological but also from an ecological perspective is therefore crucial to balance insect control and conservation. However, among all sensory stimuli olfaction is particularly hard to grasp. Our chemical environment is made up of thousands of different compounds, which might again be detected by our nose in multiple ways. Due to this complexity, researchers have only recently begun to explore the chemosensory ecology of model organisms such as Drosophila, linking the tools of chemical ecology to those of neurogenetics. This cross-disciplinary approach has enabled several studies that range from single odors and their ecological relevance, via olfactory receptor genes and neuronal processing, up to the insects' behavior. We learned that the insect olfactory system employs strategies of combinatorial coding to process general odors as well as labeled lines for specific compounds that call for an immediate response. These studies opened new doors to the olfactory world in which insects feed, oviposit, and mate. PMID:29449815

Support for the reproductive ground plan hypothesis of social evolution and major QTL for ovary traits of Africanized worker honey bees (Apis mellifera L.)

PubMed Central

2011-01-01

Background The reproductive ground plan hypothesis of social evolution suggests that reproductive controls of a solitary ancestor have been co-opted during social evolution, facilitating the division of labor among social insect workers. Despite substantial empirical support, the generality of this hypothesis is not universally accepted. Thus, we investigated the prediction of particular genes with pleiotropic effects on ovarian traits and social behavior in worker honey bees as a stringent test of the reproductive ground plan hypothesis. We complemented these tests with a comprehensive genome scan for additional quantitative trait loci (QTL) to gain a better understanding of the genetic architecture of the ovary size of honey bee workers, a morphological trait that is significant for understanding social insect caste evolution and general insect biology. Results Back-crossing hybrid European x Africanized honey bee queens to the Africanized parent colony generated two study populations with extraordinarily large worker ovaries. Despite the transgressive ovary phenotypes, several previously mapped QTL for social foraging behavior demonstrated ovary size effects, confirming the prediction of pleiotropic genetic effects on reproductive traits and social behavior. One major QTL for ovary size was detected in each backcross, along with several smaller effects and two QTL for ovary asymmetry. One of the main ovary size QTL coincided with a major QTL for ovary activation, explaining 3/4 of the phenotypic variance, although no simple positive correlation between ovary size and activation was observed. Conclusions Our results provide strong support for the reproductive ground plan hypothesis of evolution in study populations that are independent of the genetic stocks that originally led to the formulation of this hypothesis. As predicted, worker ovary size is genetically linked to multiple correlated traits of the complex division of labor in worker honey bees, known as the pollen hoarding syndrome. The genetic architecture of worker ovary size presumably consists of a combination of trait-specific loci and general regulators that affect the whole behavioral syndrome and may even play a role in caste determination. Several promising candidate genes in the QTL intervals await further study to clarify their potential role in social insect evolution and the regulation of insect fertility in general. PMID:21489230
The draft genome of a socially polymorphic halictid bee, Lasioglossum albipes

PubMed Central

2013-01-01

Background Taxa that harbor natural phenotypic variation are ideal for ecological genomic approaches aimed at understanding how the interplay between genetic and environmental factors can lead to the evolution of complex traits. Lasioglossum albipes is a polymorphic halictid bee that expresses variation in social behavior among populations, and common-garden experiments have suggested that this variation is likely to have a genetic component. Results We present the L. albipes genome assembly to characterize the genetic and ecological factors associated with the evolution of social behavior. The de novo assembly is comparable to other published social insect genomes, with an N50 scaffold length of 602 kb. Gene families unique to L. albipes are associated with integrin-mediated signaling and DNA-binding domains, and several appear to be expanded in this species, including the glutathione-s-transferases and the inositol monophosphatases. L. albipes has an intact DNA methylation system, and in silico analyses suggest that methylation occurs primarily in exons. Comparisons to other insect genomes indicate that genes associated with metabolism and nucleotide binding undergo accelerated evolution in the halictid lineage. Whole-genome resequencing data from one solitary and one social L. albipes female identify six genes that appear to be rapidly diverging between social forms, including a putative odorant receptor and a cuticular protein. Conclusions L. albipes represents a novel genetic model system for understanding the evolution of social behavior. It represents the first published genome sequence of a primitively social insect, thereby facilitating comparative genomic studies across the Hymenoptera as a whole. PMID:24359881
Behavioral Evidence for Host Transitions in Plant, Plant Parasite, and Insect Interactions.

PubMed

Halbritter, Dale A; Willett, Denis S; Gordon, Johnalyn M; Stelinski, Lukasz L; Daniels, Jaret C

2018-06-06

Specialized herbivorous insects have the ability to transition between host plant taxa, and considering the co-evolutionary history between plants and the organisms utilizing them is important to understanding plant insect interactions. We investigated the role of a pine tree parasite, dwarf mistletoe (Arceuthobium spp.) M. Bieb. Santalales: Viscaceae, in mediating interactions between Neophasia (Lepidoptera: Pieridae) butterflies and pine trees, the butterflies' larval hosts. Mistletoe is considered the butterflies' ancestral host, and the evolutionary transition to pine may have occurred recently. In Arizona, United States, we studied six sites in pine forest habitats: three in Neophasia menapia (Felder and R. Felder, 1859) habitat and three in Neophasia terlooii Behr, 1869 habitat. Each site contained six stands of trees that varied in mistletoe infection severity. Butterfly behavior was observed and ranked at each stand. Volatile compounds were collected from trees at each site and analyzed using gas chromatography-mass spectroscopy. Female butterflies landed on or patrolled around pine trees (i.e., interacted) more than males, and N. terlooii interacted more with pine trees than N. menapia. Both butterfly species interacted more with tree stands harboring greater mistletoe infection, and N. terlooii interacted more with heavily infected tree stands than did N. menapia. The influence of mistletoe on Neophasia behavior may be mediated by differences in tree volatiles resulting from mistletoe infection. Volatile profiles significantly differed between infected and uninfected pine trees. The role of mistletoe in mediating butterfly interactions with pines has implications for conservation biology and forest management, and highlights the importance of understanding an organism's niche in an evolutionary context.
The trap of sex in social insects: from the female to the male perspective.

PubMed

Beani, Laura; Dessì-Fulgheri, Francesco; Cappa, Federico; Toth, Amy

2014-10-01

The phenotype of male Hymenoptera and the peculiar role of males has been neglected and greatly understudied, given the spectacular cooperative behavior of female social insects. In social insects there has been considerable progress in understanding the molecular mechanisms behind haplodiploid sex determination but, beyond that, very little is known concerning the neural, endocrine, and genetic correlates of sexual selection in males. An opportunity is being missed: the male phenotype in Hymenoptera is a natural experiment to compare the drives of natural versus sexual selection. In contrast to females, males do not work, they usually display far from the nest to gain mates, compete among rivals in nuptial flights or for a symbolic territory at leks, and engage in direct or ritualized conflicts. By comparing the available data on male paper wasps with studies on other social Hymenoptera, we summarize what we currently know about the physical, hormonal, neural and behavioral traits in a model system appropriate to examine current paradigms on sexual selection. Here we review male behavior in social Hymenoptera beyond sex stereotypes: the subtle role of "drones" in the colony, the lack of armaments and ornaments, the explosive mating crowds, the "endurance" race, the cognitive bases of the "choosy" male and his immune defense. Social insect males are not just simple-minded mating machines, they are shaped, constrained and perhaps trapped by sexual selection. Copyright © 2014 Elsevier Ltd. All rights reserved.
Debris-carrying camouflage among diverse lineages of Cretaceous insects.

PubMed

Wang, Bo; Xia, Fangyuan; Engel, Michael S; Perrichot, Vincent; Shi, Gongle; Zhang, Haichun; Chen, Jun; Jarzembowski, Edmund A; Wappler, Torsten; Rust, Jes

2016-06-01

Insects have evolved diverse methods of camouflage that have played an important role in their evolutionary success. Debris-carrying, a behavior of actively harvesting and carrying exogenous materials, is among the most fascinating and complex behaviors because it requires not only an ability to recognize, collect, and carry materials but also evolutionary adaptations in related morphological characteristics. However, the fossil record of such behavior is extremely scarce, and only a single Mesozoic example from Spanish amber has been recorded; therefore, little is known about the early evolution of this complicated behavior and its underlying anatomy. We report a diverse insect assemblage of exceptionally preserved debris carriers from Cretaceous Burmese, French, and Lebanese ambers, including the earliest known chrysopoid larvae (green lacewings), myrmeleontoid larvae (split-footed lacewings and owlflies), and reduviids (assassin bugs). These ancient insects used a variety of debris material, including insect exoskeletons, sand grains, soil dust, leaf trichomes of gleicheniacean ferns, wood fibers, and other vegetal debris. They convergently evolved their debris-carrying behavior through multiple pathways, which expressed a high degree of evolutionary plasticity. We demonstrate that the behavioral repertoire, which is associated with considerable morphological adaptations, was already widespread among insects by at least the Mid-Cretaceous. Together with the previously known Spanish specimen, these fossils are the oldest direct evidence of camouflaging behavior in the fossil record. Our findings provide a novel insight into early evolution of camouflage in insects and ancient ecological associations among plants and insects.
Plasticity in Insect Olfaction: To Smell or Not to Smell?

PubMed

Gadenne, Christophe; Barrozo, Romina B; Anton, Sylvia

2016-01-01

In insects, olfaction plays a crucial role in many behavioral contexts, such as locating food, sexual partners, and oviposition sites. To successfully perform such behaviors, insects must respond to chemical stimuli at the right moment. Insects modulate their olfactory system according to their physiological state upon interaction with their environment. Here, we review the plasticity of behavioral responses to different odor types according to age, feeding state, circadian rhythm, and mating status. We also summarize what is known about the underlying neural and endocrinological mechanisms, from peripheral detection to central nervous integration, and cover neuromodulation from the molecular to the behavioral level. We describe forms of olfactory plasticity that have contributed to the evolutionary success of insects and have provided them with remarkable tools to adapt to their ever-changing environment.
Mirid (Hemiptera: Heteroptera) specialists of sticky plants: adaptations, interactions, and ecological implications.

PubMed

Wheeler, Alfred G; Krimmel, Billy A

2015-01-07

Sticky plants-those having glandular trichomes (hairs) that produce adhesive, viscous exudates-can impede the movement of, and entrap, generalist insects. Disparate arthropod groups have adapted to these widespread and taxonomically diverse plants, yet their interactions with glandular hosts rarely are incorporated into broad ecological theory. Ecologists and entomologists might be unaware of even well-documented examples of insects that are sticky-plant specialists. The hemipteran family Miridae (more specifically, the omnivorous Dicyphini: Dicyphina) is the best-known group of arthropods that specializes on sticky plants. In the first synthesis of relationships with glandular plants for any insect family, we review mirid interactions with sticky hosts, including their adaptations (behavioral, morphological, and physiological) and mutualisms with carnivorous plants, and the ecological and agricultural implications of mirid-sticky plant systems. We propose that mirid research applies generally to tritrophic interactions on trichome-defended plants, enhances an understanding of insect-plant interactions, and provides information useful in managing crop pests.
Insect anaphylaxis: addressing clinical challenges.

PubMed

Tracy, James M; Lewis, Elena J; Demain, Jeffrey G

2011-08-01

Few allergic reactions are as potentially life-threatening, or frightening to the patient, as anaphylaxis. Food, medications, and insect stings are the three most common triggers of anaphylaxis, but insect allergy provides the best opportunity to understand the biology of anaphylaxis. If the physician can establish a diagnosis of insect allergy, treatment with nearly 98% effectiveness can be initiated. However, sometimes patients have a compelling history of insect sting anaphylaxis, but negative skin and blood tests. This situation presents us with a fascinating opportunity to understand the biology of insect anaphylaxis. Recent and ongoing work shows that occult mast cell disease may be critical in insect anaphylaxis. Mastocytosis, serum tryptase and basophil biology are key elements; genetic markers may potentially help us diagnose at-risk individuals and determine proper treatment. Understanding basophil activation may play an additional role both in diagnosis and knowing when therapy might be terminated. Mast cell disease, serum tryptase and basophil biology are providing an opportunity to better understand and manage insect allergy. This evolving understanding should improve long-term management of insect anaphylaxis and help us to better understand the clinical dilemma of appropriate management of the history-positive patient in which testing is unable to detect venom-specific IgE. Furthermore, omalizumab's immunomodulatory effects may play a role in difficult-to-treat insect allergy and mastocytosis. Finally, unrelated to these, but still important as an ongoing risk factor, is the continued underutilization of epinephrine for both acute and long-term management of insect anaphylaxis.
Bugs, butterflies, and spiders: children's understandings about insects

NASA Astrophysics Data System (ADS)

Shepardson, Daniel P.

2002-06-01

This article explores elementary children's ideas about insects. The study involved 20 children from each grade level, kindergarten through fifth-grade, for a total of 120 children. The data collection procedure was designed to investigate what an insect means to children, through the use of three different tasks: draw and explain, interview about instances, and the formulation of a general rule. Considering children's responses to the three tasks, I found that their ideas about insects reflect understandings based on physical characteristics of size and shape, arthropod characteristics, insect characteristics, human-insect interactions, life habits of insects, feeding habits of insects, and means of locomotion. Children's understandings are juxtaposed to that of a scientific perspective, elucidating implications for curriculum development and instructional practice.
Grooming Behavior as a Mechanism of Insect Disease Defense.

PubMed

Zhukovskaya, Marianna; Yanagawa, Aya; Forschler, Brian T

2013-11-04

Grooming is a well-recognized, multipurpose, behavior in arthropods and vertebrates. In this paper, we review the literature to highlight the physical function, neurophysiological mechanisms, and role that grooming plays in insect defense against pathogenic infection. The intricate relationships between the physical, neurological and immunological mechanisms of grooming are discussed to illustrate the importance of this behavior when examining the ecology of insect-pathogen interactions.
Chapter 13. Physiology and ecology of host defense against microbial invaders

USDA-ARS?s Scientific Manuscript database

Insects mount a complex hierarchy of defenses that pathogens must overcome before successful infection is achieved. Behavioral avoidance and antiseptic behaviors by host insects reduce the degree of encounters between the insect and pathogens. Any pathogen that contacts or establishes on a potentia...
Origins of Aminergic Regulation of Behavior in Complex Insect Social Systems

PubMed Central

Kamhi, J. Frances; Arganda, Sara; Moreau, Corrie S.; Traniello, James F. A.

2017-01-01

Neuromodulators are conserved across insect taxa, but how biogenic amines and their receptors in ancestral solitary forms have been co-opted to control behaviors in derived socially complex species is largely unknown. Here we explore patterns associated with the functions of octopamine (OA), serotonin (5-HT) and dopamine (DA) in solitary ancestral insects and their derived functions in eusocial ants, bees, wasps and termites. Synthesizing current findings that reveal potential ancestral roles of monoamines in insects, we identify physiological processes and conserved behaviors under aminergic control, consider how biogenic amines may have evolved to modulate complex social behavior, and present focal research areas that warrant further study. PMID:29066958
How Insects Survive Winter in the Midwest

USDA-ARS?s Scientific Manuscript database

Understanding how insects cope with cold temperatures can not only help entomologists more accurately forecast when and where insects are active, but it may also help us understand how climate change will influence insect pests. This newsletter article provides a comprehensive overview of how Midwes...
Simulating Flying Insects Using Dynamics and Data-Driven Noise Modeling to Generate Diverse Collective Behaviors

PubMed Central

Ren, Jiaping; Wang, Xinjie; Manocha, Dinesh

2016-01-01

We present a biologically plausible dynamics model to simulate swarms of flying insects. Our formulation, which is based on biological conclusions and experimental observations, is designed to simulate large insect swarms of varying densities. We use a force-based model that captures different interactions between the insects and the environment and computes collision-free trajectories for each individual insect. Furthermore, we model the noise as a constructive force at the collective level and present a technique to generate noise-induced insect movements in a large swarm that are similar to those observed in real-world trajectories. We use a data-driven formulation that is based on pre-recorded insect trajectories. We also present a novel evaluation metric and a statistical validation approach that takes into account various characteristics of insect motions. In practice, the combination of Curl noise function with our dynamics model is used to generate realistic swarm simulations and emergent behaviors. We highlight its performance for simulating large flying swarms of midges, fruit fly, locusts and moths and demonstrate many collective behaviors, including aggregation, migration, phase transition, and escape responses. PMID:27187068
Flight behavior and performance of Rhodnius pallescens (Hemiptera: Reduviidae) on a tethered flight mill.

PubMed

Castro, Lauren A; Peterson, Jennifer K; Saldana, Azael; Perea, Milixa Y; Calzada, Jose E; Pineda, Vanessa; Dobson, Andrew P; Gottdenker, Nicole L

2014-09-01

ABSTRACT Flight dispersal of the triatomine bug species Rhodnius pallescens Barber, the principal vector of Chagas disease in Panama, is an important mechanism for spreading Trypanosoma cruzi, causative agent of Chagas disease. This study measures R. pallescens flight performance using a tethered flight mill both when uninfected, and when infected with T. cruzi or Trypanosoma rangeli. Forty-four out of the 48 (91.7%) insects initiated flight across all treatments, and trypanosome infection did not significantly impact flight initiation. Insects from all treatments flew a cumulative distance ranging from 0.5 to 5 km before fatiguing. The median cumulative distance flown before insect fatigue was higher in T. cruzi- and T. rangeli-infected insects than in control insects; however, this difference was not statistically significant. There was a positive relationship between parasite load ingested and time until flight initiation in T. rangeli-infected bugs, and T. rangeli- and T. cruzi-infected females flew significantly faster than males at different time points. These novel findings allow for a better understanding of R. pallescens dispersal ability and peridomestic management strategies for the prevention of Chagas disease in Panama.
Birds Bug on Indirect Plant Defenses to Locate Insect Prey.

PubMed

Hiltpold, Ivan; Shriver, W Gregory

2018-06-01

It has long been thought that most birds do not use volatile cues to perceive their environment. Aside from some scavenging birds, this large group of vertebrates was believed to mostly rely on highly developed vision while foraging and there are relatively few studies exploring bird response to volatile organic compounds. In response to insect herbivory, plants release volatile organic compounds to attract parasitoids and predators of the pests. To test if insectivorous birds use herbivore-induced plant volatiles (HIPV), dispensers emitting a synthetic blend of HIPV typically emitted after insect herbivory were deployed in a maize field along with imitation clay caterpillars. Significantly more imitation insects were attacked by birds when located close to dispensers releasing HIPV than close to dispenser with organic solvent only. Seven times more peck marks, an index of avian predation, were counted on caterpillars in the vicinity of the HIPV dispensers than on insects close to control dispensers. This is the first field demonstration that insectivorous birds cue on HIPV to locate prey in agricultural settings. These results support the growing evidence that foraging birds exploit volatile cues. This more accurate understanding of their behavior will be important when implementing pest management program involving insectivorous birds.
The evolutionary diversity of insect retinal mosaics: Common design principles and emerging molecular logic

PubMed Central

Wernet, Mathias F.; Perry, Michael W.; Desplan, Claude

2015-01-01

Independent evolution has resulted in a vast diversity of eyes. Despite the lack of a common Bauplan or ancestral structure, similar developmental strategies are used. For instance, different classes of photoreceptor cells (PRs) are distributed stochastically and/or localized in different regions of the retina. Here we focus on recent progress made towards understanding the molecular principles behind patterning retinal mosaics of insects, one of the most diverse groups of animals adapted to life on land, in the air, under water, or on the water surface. Morphological, physiological, and behavioral studies from many species provide detailed descriptions of the vast variation in retinal design and function. By integrating this knowledge with recent progress in the characterization of insect Rhodopsins as well as insight from the model organism Drosophila melanogaster, we seek to identify the molecular logic behind the adaptation of retinal mosaics to an animal’s habitat and way of life. PMID:26025917
Certain applied electrical signals during EPG cause negative effects on stylet probing behaviors by adult Lygus lineolaris (Hemiptera: Miridae)

USDA-ARS?s Scientific Manuscript database

This study is the first to fully evaluate whether electrical signals applied to insects during electropenetrography (EPG; also called electrical penetration graph) affect insect behavior. During EPG, electrical signals are applied to plants, and thus to the gold-wire-tethered insects feeding on elec...
The first fossil leaf insect: 47 million years of specialized cryptic morphology and behavior

PubMed Central

Wedmann, Sonja; Bradler, Sven; Rust, Jes

2007-01-01

Stick and leaf insects (insect order Phasmatodea) are represented primarily by twig-imitating slender forms. Only a small percentage (≈1%) of extant phasmids belong to the leaf insects (Phylliinae), which exhibit an extreme form of morphological and behavioral leaf mimicry. Fossils of phasmid insects are extremely rare worldwide. Here we report the first fossil leaf insect, Eophyllium messelensis gen. et sp. nov., from 47-million-year-old deposits at Messel in Germany. The new specimen, a male, is exquisitely preserved and displays the same foliaceous appearance as extant male leaf insects. Clearly, an advanced form of extant angiosperm leaf mimicry had already evolved early in the Eocene. We infer that this trait was combined with a special behavior, catalepsy or “adaptive stillness,” enabling Eophyllium to deceive visually oriented predators. Potential predators reported from the Eocene are birds, early primates, and bats. The combination of primitive and derived characters revealed by Eophyllium allows the determination of its exact phylogenetic position and illuminates the evolution of leaf mimicry for this insect group. It provides direct evidence that Phylliinae originated at least 47 Mya. Eophyllium enlarges the known geographical range of Phylliinae, currently restricted to southeast Asia, which is apparently a relict distribution. This fossil leaf insect bears considerable resemblance to extant individuals in size and cryptic morphology, indicating minimal change in 47 million years. This absence of evolutionary change is an outstanding example of morphological and, probably, behavioral stasis. PMID:17197423
Walking Drosophila align with the e-vector of linearly polarized light through directed modulation of angular acceleration

PubMed Central

Velez, Mariel M.; Wernet, Mathias F.; Clark, Damon A.

2014-01-01

Understanding the mechanisms that link sensory stimuli to animal behavior is a central challenge in neuroscience. The quantitative description of behavioral responses to defined stimuli has led to a rich understanding of different behavioral strategies in many species. One important navigational cue perceived by many vertebrates and insects is the e-vector orientation of linearly polarized light. Drosophila manifests an innate orientation response to this cue (‘polarotaxis’), aligning its body axis with the e-vector field. We have established a population-based behavioral paradigm for the genetic dissection of neural circuits guiding polarotaxis to both celestial as well as reflected polarized stimuli. However, the behavioral mechanisms by which flies align with a linearly polarized stimulus remain unknown. Here, we present a detailed quantitative description of Drosophila polarotaxis, systematically measuring behavioral parameters that are modulated by the stimulus. We show that angular acceleration is modulated during alignment, and this single parameter may be sufficient for alignment. Furthermore, using monocular deprivation, we show that each eye is necessary for modulating turns in the ipsilateral direction. This analysis lays the foundation for understanding how neural circuits guide these important visual behaviors. PMID:24810784

Insect anaphylaxis: where are we? The stinging facts 2012.

PubMed

Tracy, James M; Khan, Fatima S; Demain, Jeffrey G

2012-08-01

Insect allergy remains an important cause of morbidity and mortality in the United States. In 2011, the third iteration of the stinging insect hypersensitivity practice parameter was published, the first being published in 1999 and the second in 2004. Since the 2004 edition, our understanding of insect hypersensitivity has continued to expand and has been incorporated into the 2011 edition. This work will review the relevant changes in the management of insect hypersensitivity occurring since 2004 and present our current understanding of the insect hypersensitivity diagnosis and management. Since the 2004 commissioning by the Joint Task Force (JTF) on Practice Parameters of 'Stinging insect hypersensitivity: a practice parameter update', there have been important contributions to our understanding of insect allergy. These contributions were incorporated into the 2011 iteration. Similar efforts were made by the European Allergy Asthma and Clinical Immunology Interest Group in 2005 and most recently in 2011 by the British Society of Allergy and Clinical Immunology. Our understanding of insect allergy, including the natural history, epidemiology, diagnostic testing, and risk factors, has greatly expanded. This evolution of knowledge should provide improved long-term management of stinging insect hypersensitivity. This review will focus primarily on the changes between the 2004 and 2011 stinging insect practice parameter commissioned by the JTF on Practice Parameters, but will, where appropriate, highlight the differences between working groups.
Four Forensic Entomology Case Studies: Records and Behavioral Observations on Seldom Reported Cadaver Fauna With Notes on Relevant Previous Occurrences and Ecology.

PubMed

Lindgren, Natalie K; Sisson, Melissa S; Archambeault, Alan D; Rahlwes, Brent C; Willett, James R; Bucheli, Sibyl R

2015-03-01

A yearlong survey of insect taxa associated with human decomposition was conducted at the Southeast Texas Applied Forensic Science (STAFS) facility located in the Center for Biological Field Studies of Sam Houston State University in Huntsville, TX. During this study, four insect-cadaver interactions were observed that represent previously poorly documented yet forensically significant interactions: Syrphidae maggots colonized a corpse in an aquatic situation; Psychodidae adults mated and oviposited on an algal film that was present on a corpse that had been recently removed from water; several Panorpidae were the first insects to feed upon a freshly placed corpse in the autumn; and a noctuid caterpillar was found chewing and ingesting dried human skin. Baseline knowledge of insect-cadaver interactions is the foundation of forensic entomology, and unique observations have the potential to expand our understanding of decomposition ecology. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
The Dilemmas of the Gourmet Fly: The Molecular and Neuronal Mechanisms of Feeding and Nutrient Decision Making in Drosophila

PubMed Central

Itskov, Pavel M.; Ribeiro, Carlos

2012-01-01

To survive and successfully reproduce animals need to maintain a balanced intake of nutrients and energy. The nervous system of insects has evolved multiple mechanisms to regulate feeding behavior. When animals are faced with the choice to feed, several decisions must be made: whether or not to eat, how much to eat, what to eat, and when to eat. Using Drosophila melanogaster substantial progress has been achieved in understanding the neuronal and molecular mechanisms controlling feeding decisions. These feeding decisions are implemented in the nervous system on multiple levels, from alterations in the sensitivity of peripheral sensory organs to the modulation of memory systems. This review discusses methodologies developed in order to study insect feeding, the effects of neuropeptides and neuromodulators on feeding behavior, behavioral evidence supporting the existence of internal energy sensors, neuronal and molecular mechanisms controlling protein intake, and finally the regulation of feeding by circadian rhythms and sleep. From the discussed data a conceptual framework starts to emerge which aims to explain the molecular and neuronal processes maintaining the stability of the internal milieu. PMID:23407678
Using new technology and insect behavior in novel terrestrial and flying insect traps

USDA-ARS?s Scientific Manuscript database

Insect traps are commonly used for both population sampling and insect control, the former as part of an integrated pest management (IPM) program. We developed traps for two insects, one as part of a pesticide based IPM system and the other for population control. Our IPM trap is for crawling insect...
Peptide neuromodulation in invertebrate model systems

PubMed Central

Taghert, Paul H.; Nitabach, Michael N.

2012-01-01

Neuropeptides modulate neural circuits controlling adaptive animal behaviors and physiological processes, such as feeding/metabolism, reproductive behaviors, circadian rhythms, central pattern generation, and sensorimotor integration. Invertebrate model systems have enabled detailed experimental analysis using combined genetic, behavioral, and physiological approaches. Here we review selected examples of neuropeptide modulation in crustaceans, mollusks, insects, and nematodes, with a particular emphasis on the genetic model organisms Drosophila melanogaster and Caenorhabditis elegans, where remarkable progress has been made. On the basis of this survey, we provide several integrating conceptual principles for understanding how neuropeptides modulate circuit function, and also propose that continued progress in this area requires increased emphasis on the development of richer, more sophisticated behavioral paradigms. PMID:23040808
Target detection in insects: optical, neural and behavioral optimizations.

PubMed

Gonzalez-Bellido, Paloma T; Fabian, Samuel T; Nordström, Karin

2016-12-01

Motion vision provides important cues for many tasks. Flying insects, for example, may pursue small, fast moving targets for mating or feeding purposes, even when these are detected against self-generated optic flow. Since insects are small, with size-constrained eyes and brains, they have evolved to optimize their optical, neural and behavioral target visualization solutions. Indeed, even if evolutionarily distant insects display different pursuit strategies, target neuron physiology is strikingly similar. Furthermore, the coarse spatial resolution of the insect compound eye might actually be beneficial when it comes to detection of moving targets. In conclusion, tiny insects show higher than expected performance in target visualization tasks. Copyright Â© 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Hearing in Insects.

PubMed

Göpfert, Martin C; Hennig, R Matthias

2016-01-01

Insect hearing has independently evolved multiple times in the context of intraspecific communication and predator detection by transforming proprioceptive organs into ears. Research over the past decade, ranging from the biophysics of sound reception to molecular aspects of auditory transduction to the neuronal mechanisms of auditory signal processing, has greatly advanced our understanding of how insects hear. Apart from evolutionary innovations that seem unique to insect hearing, parallels between insect and vertebrate auditory systems have been uncovered, and the auditory sensory cells of insects and vertebrates turned out to be evolutionarily related. This review summarizes our current understanding of insect hearing. It also discusses recent advances in insect auditory research, which have put forward insect auditory systems for studying biological aspects that extend beyond hearing, such as cilium function, neuronal signal computation, and sensory system evolution.
SwarmSight: Real-time Tracking of Insect Antenna Movements and Proboscis Extension Reflex Using a Common Preparation and Conventional Hardware

PubMed Central

Birgiolas, Justas; Jernigan, Christopher M.; Gerkin, Richard C.; Smith, Brian H.; Crook, Sharon M.

2017-01-01

Many scientifically and agriculturally important insects use antennae to detect the presence of volatile chemical compounds and extend their proboscis during feeding. The ability to rapidly obtain high-resolution measurements of natural antenna and proboscis movements and assess how they change in response to chemical, developmental, and genetic manipulations can aid the understanding of insect behavior. By extending our previous work on assessing aggregate insect swarm or animal group movements from natural and laboratory videos using the video analysis software SwarmSight, we developed a novel, free, and open-source software module, SwarmSight Appendage Tracking (SwarmSight.org) for frame-by-frame tracking of insect antenna and proboscis positions from conventional web camera videos using conventional computers. The software processes frames about 120 times faster than humans, performs at better than human accuracy, and, using 30 frames per second (fps) videos, can capture antennal dynamics up to 15 Hz. The software was used to track the antennal response of honey bees to two odors and found significant mean antennal retractions away from the odor source about 1 s after odor presentation. We observed antenna position density heat map cluster formation and cluster and mean angle dependence on odor concentration. PMID:29364251
Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits.

PubMed

Heinloth, Tanja; Uhlhorn, Juliane; Wernet, Mathias F

2018-01-01

The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the "Dorsal Rim Area" (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster , we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision.
Respiration in Aquatic Insects.

ERIC Educational Resources Information Center

MacFarland, John

1985-01-01

This article: (1) explains the respiratory patterns of several freshwater insects; (2) describes the differences and mechanisms of spiracular cutaneous, and gill respiration; and (3) discusses behavioral aspects of selected aquatic insects. (ML)
Learning and cognition in insects.

PubMed

Giurfa, Martin

2015-01-01

Insects possess small brains but exhibit sophisticated behavioral performances. Recent works have reported the existence of unsuspected cognitive capabilities in various insect species, which go beyond the traditional studied framework of simple associative learning. In this study, I focus on capabilities such as attention, social learning, individual recognition, concept learning, and metacognition, and discuss their presence and mechanistic bases in insects. I analyze whether these behaviors can be explained on the basis of elemental associative learning or, on the contrary, require higher-order explanations. In doing this, I highlight experimental challenges and suggest future directions for investigating the neurobiology of higher-order learning in insects, with the goal of uncovering l architectures underlying cognitive processing. © 2015 John Wiley & Sons, Ltd.
Certain applied electrical signals during EPG cause negative effects on stylet probing behaviors by adult Lygus lineolaris (Hemiptera: Miridae).

PubMed

Backus, Elaine A; Cervantes, Felix A; Godfrey, Larry; Akbar, Waseem; Clark, Thomas L; Rojas, Maria G

This study is the first to fully evaluate whether electrical signals applied to large insects during electropenetrography (EPG; also called electrical penetration graph) negatively affect insect behavior. During EPG, electrical signals are applied to plants, and thus to the gold-wire-tethered insects feeding on them. The insect completes an electrical circuit whose changes in voltage reflect the insect's stylet probing/penetration behaviors, recorded as waveform output. For nearly 50 years of EPG science, evidence has supported that there are no or negligible effects on tiny insects from applied electricity during EPG. Recently however, EPG studies of large-bodied hemipterans such as heteropterans and sharpshooter leafhoppers have been published. The wider stylet diameters of such large insects cause them to have lower inherent resistances to applied signals compared with smaller insects, conveying more electrical current. The present study asked whether such increased currents would affect insect stylet probing, by comparing Lygus lineolaris behaviors on pin-head cotton squares using an AC-DC electropenetrograph. Effects of AC or DC applied signals were separately examined in two factorial studies, each comparing four input resistor (Ri) levels (10 6 , 10 7 , 10 8 and 10 9  Ω) and four applied voltage levels (2, 60, 150 and 250 mV). Results showed that changes in both probing and non-probing behaviors were indeed caused by changing signal type, Ri level, or applied voltage. Negative effects on feeding were numerically greater overall for DC than AC applied signals, perhaps due to muscular tetany from DC; however, AC versus DC could not be statistically tested. Results strongly support the need for flexible Ri and applied voltage levels and types, to tailor instrument settings to the size and special needs of each insect subject. Our findings will facilitate further EPG studies of Lygus spp., such as host plant resistance or insecticidal assays/bioassays to assess mode of action and appropriate dosage. It is hoped that this study will also inform EPG studies of similar, large heteropterans in the future. Published by Elsevier Ltd.
Drosophila TRP channels and animal behavior

PubMed Central

Fowler, Melissa A.; Montell, Craig

2012-01-01

Multiple classes of cell surface receptors and ion channels participate in the detection of changes in environmental stimuli, and thereby influence animal behavior. Among the many classes of ion channels, Transient Receptor Potential (TRP) cation channels are notable in contributing to virtually every sensory modality, and in controlling a daunting array of behaviors. TRP channels appear to be conserved in all metazoan organisms including worms, insects and humans. Flies encode 13 TRPs, most of which are expressed and function in sensory neurons, and impact behaviors ranging from phototaxis to thermotaxis, gravitaxis, the avoidance of noxious tastants and smells and proprioception. Multiple diseases result from defects in TRPs, and flies provide an excellent animal model for dissecting the mechanisms underlying “TRPopathies.” Drosophila TRPs also function in the sensation of botanically derived insect repellents, and related TRPs in insect pests are potential targets for the development of improved repellents to combat insect-borne diseases. PMID:22877650
Effects of temporal variation in temperature and density dependence on insect population dynamics

USDA-ARS?s Scientific Manuscript database

Understanding effects of environmental variation on insect populations is important in light of predictions about increasing future climatic variability. In order to understand the effects of changing environmental variation on population dynamics and life history evolution in insects one would need...
The evolutionary diversity of insect retinal mosaics: common design principles and emerging molecular logic.

PubMed

Wernet, Mathias F; Perry, Michael W; Desplan, Claude

2015-06-01

Independent evolution has resulted in a vast diversity of eyes. Despite the lack of a common Bauplan or ancestral structure, similar developmental strategies are used. For instance, different classes of photoreceptor cells (PRs) are distributed stochastically and/or localized in different regions of the retina. Here, we focus on recent progress made towards understanding the molecular principles behind patterning retinal mosaics of insects, one of the most diverse groups of animals adapted to life on land, in the air, under water, or on the water surface. Morphological, physiological, and behavioral studies from many species provide detailed descriptions of the vast variation in retinal design and function. By integrating this knowledge with recent progress in the characterization of insect Rhodopsins as well as insight from the model organism Drosophila melanogaster, we seek to identify the molecular logic behind the adaptation of retinal mosaics to the habitat and way of life of an animal. Copyright © 2015 Elsevier Ltd. All rights reserved.
Insect Control (1): Use of Pheromones

ERIC Educational Resources Information Center

Marx, Jean L.

1973-01-01

Discusses current research relating to the use of pheromones as a means of controlling insect pests. These chemicals, which are secreted by insects to affect the behavior of other individuals of the same species, may be used to eliminate pests without destroying their predators and other beneficial insects. (JR)
Optic flow-based collision-free strategies: From insects to robots.

PubMed

Serres, Julien R; Ruffier, Franck

2017-09-01

Flying insects are able to fly smartly in an unpredictable environment. It has been found that flying insects have smart neurons inside their tiny brains that are sensitive to visual motion also called optic flow. Consequently, flying insects rely mainly on visual motion during their flight maneuvers such as: takeoff or landing, terrain following, tunnel crossing, lateral and frontal obstacle avoidance, and adjusting flight speed in a cluttered environment. Optic flow can be defined as the vector field of the apparent motion of objects, surfaces, and edges in a visual scene generated by the relative motion between an observer (an eye or a camera) and the scene. Translational optic flow is particularly interesting for short-range navigation because it depends on the ratio between (i) the relative linear speed of the visual scene with respect to the observer and (ii) the distance of the observer from obstacles in the surrounding environment without any direct measurement of either speed or distance. In flying insects, roll stabilization reflex and yaw saccades attenuate any rotation at the eye level in roll and yaw respectively (i.e. to cancel any rotational optic flow) in order to ensure pure translational optic flow between two successive saccades. Our survey focuses on feedback-loops which use the translational optic flow that insects employ for collision-free navigation. Optic flow is likely, over the next decade to be one of the most important visual cues that can explain flying insects' behaviors for short-range navigation maneuvers in complex tunnels. Conversely, the biorobotic approach can therefore help to develop innovative flight control systems for flying robots with the aim of mimicking flying insects' abilities and better understanding their flight. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Isolongifolenone: A Novel Sesquiterpene Repellent of Ticks and Mosquitoes

DTIC Science & Technology

2009-01-01

Invasive Insect Biocontrol and Behavior Laboratory, Beltsville Agricultural Research Center-West, Beltsville, MD 20705. 2 Corresponding author, e-mail...AND ADDRESS(ES) U.S. Department of Agriculture -Agricultural Research Center,Invasive Insect Biocontrol and Behavior Laboratory,Beltsville
Insect antiviral innate immunity: pathways, effectors, and connections

PubMed Central

Kingsolver, Megan B.; Huang, Zhijing; Hardy, Richard W.

2014-01-01

Insects are infected by a wide array of viruses some of which are insect-restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the siRNA pathway that responds through the detection of virus-derived dsRNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, Jak-STAT, and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses. PMID:24120681
Adult Tea Green Leafhoppers, Empoasca onukii (Matsuda), Change Behaviors under Varying Light Conditions

PubMed Central

Shi, Longqing; Vasseur, Liette; Huang, Huoshui; Zeng, Zhaohua; Hu, Guiping; Liu, Xin; You, Minsheng

2017-01-01

Insect behaviors are often influenced by light conditions including photoperiod, light intensity, and wavelength. Understanding pest insect responses to changing light conditions may help with developing alternative strategies for pest control. Little is known about the behavioral responses of leafhoppers (Hemiptera: Cicadellidae) to light conditions. The behavior of the tea green leafhopper, Empoasca onukii Matsuda, was examined when exposed to different light photoperiods or wavelengths. Observations included the frequency of locomotion and cleaning activities, and the duration of time spent searching. The results suggested that under normal photoperiod both female and male adults were generally more active in darkness (i.e., at night) than in light. In continuous darkness (DD), the locomotion and cleaning events in Period 1 (7:00–19:00) were significantly increased, when compared to the leafhoppers under normal photoperiod (LD). Leafhoppers, especially females, changed their behavioral patterns to a two day cycle under DD. Under continuous illumination (continuous quartz lamp light, yellow light at night, and green light at night), the activities of locomotion, cleaning, and searching were significantly suppressed during the night (19:00–7:00) and locomotion activities of both females and males were significantly increased during the day (7:00–19:00), suggesting a shift in circadian rhythm. Our work suggests that changes in light conditions, including photoperiod and wavelength, can influence behavioral activities of leafhoppers, potentially affecting other life history traits such as reproduction and development, and may serve as a method for leafhopper behavioral control. PMID:28103237

Adult Tea Green Leafhoppers, Empoasca onukii (Matsuda), Change Behaviors under Varying Light Conditions.

PubMed

Shi, Longqing; Vasseur, Liette; Huang, Huoshui; Zeng, Zhaohua; Hu, Guiping; Liu, Xin; You, Minsheng

2017-01-01

Insect behaviors are often influenced by light conditions including photoperiod, light intensity, and wavelength. Understanding pest insect responses to changing light conditions may help with developing alternative strategies for pest control. Little is known about the behavioral responses of leafhoppers (Hemiptera: Cicadellidae) to light conditions. The behavior of the tea green leafhopper, Empoasca onukii Matsuda, was examined when exposed to different light photoperiods or wavelengths. Observations included the frequency of locomotion and cleaning activities, and the duration of time spent searching. The results suggested that under normal photoperiod both female and male adults were generally more active in darkness (i.e., at night) than in light. In continuous darkness (DD), the locomotion and cleaning events in Period 1 (7:00-19:00) were significantly increased, when compared to the leafhoppers under normal photoperiod (LD). Leafhoppers, especially females, changed their behavioral patterns to a two day cycle under DD. Under continuous illumination (continuous quartz lamp light, yellow light at night, and green light at night), the activities of locomotion, cleaning, and searching were significantly suppressed during the night (19:00-7:00) and locomotion activities of both females and males were significantly increased during the day (7:00-19:00), suggesting a shift in circadian rhythm. Our work suggests that changes in light conditions, including photoperiod and wavelength, can influence behavioral activities of leafhoppers, potentially affecting other life history traits such as reproduction and development, and may serve as a method for leafhopper behavioral control.
Insect Responses to Linearly Polarized Reflections: Orphan Behaviors Without Neural Circuits

PubMed Central

Heinloth, Tanja; Uhlhorn, Juliane; Wernet, Mathias F.

2018-01-01

The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the “Dorsal Rim Area” (DRA), a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster, we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision. PMID:29615868
Insect-machine interface based neurocybernetics.

PubMed

Bozkurt, Alper; Gilmour, Robert F; Sinha, Ayesa; Stern, David; Lal, Amit

2009-06-01

We present details of a novel bioelectric interface formed by placing microfabricated probes into insect during metamorphic growth cycles. The inserted microprobes emerge with the insect where the development of tissue around the electronics during the pupal development allows mechanically stable and electrically reliable structures coupled to the insect. Remarkably, the insects do not react adversely or otherwise to the inserted electronics in the pupae stage, as is true when the electrodes are inserted in adult stages. We report on the electrical and mechanical characteristics of this novel bioelectronic interface, which we believe would be adopted by many investigators trying to investigate biological behavior in insects with negligible or minimal traumatic effect encountered when probes are inserted in adult stages. This novel insect-machine interface also allows for hybrid insect-machine platforms for further studies. As an application, we demonstrate our first results toward navigation of flight in moths. When instrumented with equipment to gather information for environmental sensing, such insects potentially can assist man to monitor the ecosystems that we share with them for sustainability. The simplicity of the optimized surgical procedure we invented allows for batch insertions to the insect for automatic and mass production of such hybrid insect-machine platforms. Therefore, our bioelectronic interface and hybrid insect-machine platform enables multidisciplinary scientific and engineering studies not only to investigate the details of insect behavioral physiology but also to control it.
Physics-based Morphology Analysis and Adjoint Optimization of Flexible Flapping Wings

DTIC Science & Technology

2016-08-30

understand the underlying physics of flexible wings in flying insects and birds towards the bio -inspired wing designs with superior aerodynamic...flapping flights have been developed to understand the underlying physics of flexible wings in flying insects and birds towards the bio -inspired wing...been developed to understand the underlying physics of flexible wings in flying insects and birds towards the bio -inspired wing designs with superior
Diaphorina citri Induces Huanglongbing-Infected Citrus Plant Volatiles to Repel and Reduce the Performance of Propylaea japonica.

PubMed

Lin, Yongwen; Lin, Sheng; Akutse, Komivi S; Hussain, Mubasher; Wang, Liande

2016-01-01

Transmission of plant pathogens through insect vectors is a complex biological process involving interactions between the host plants, insects, and pathogens. Simultaneous impact of the insect damage and pathogenic bacteria in infected host plants induce volatiles that modify not only the behavior of its insect vector but also of their natural enemies, such as parasitoid wasps. Therefore, it is essential to understand how insects such as the predator ladybird beetle responds to volatiles emitted from a host plant and how the disease transmission alters the interactions between predators, vector, pathogens, and plants. In this study, we investigated the response of Propylaea japonica to volatiles from citrus plants damaged by Diaphorina citri and Candidatus Liberibacter asiaticus through olfactometer bioassays. Synthetic chemical blends were also used to determine the active compounds in the plant volatile. The results showed that volatiles emitted by healthy plants attracted more P. japonica than other treatments, due to the presence of high quantities of D-limonene and beta-ocimene, and the lack of methyl salicylate. When using synthetic chemicals in the olfactory tests, we found that D-limonene attracted P. japonica while methyl salicylate repelled the predator. However, beta-ocimene attracted the insects at lower concentrations but repelled them at higher concentrations. These results indicate that P. japonica could not efficiently search for its host by using volatile cues emitted from psyllids- and Las bacteria-infected citrus plants.
Electric ants: A cross-disciplinary approach to understanding insect behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slowik, T.J.; Thorvilson, H.G.; Green, B.L.

1996-12-31

The response and attraction of the red imported fire ant, Solenopsis invicta, to electrical equipment was examined using an interdisciplinary approach. Entomologists specializing in fire ant behavior combined expertise with electrical engineers to investigate the economically damaging interaction of fire ants with electrical circuitry. Knowledge from the realms of physics, engineering, and biology were integrated in experimentation to test for a fire ant response to electric fields and magnetic fields associated with electrical equipment. It was determined that fire ants react to electrified conductive material and the alternating-current magnetic fields associated with electricity.
The gram-negative sensing receptor PGRP-LC contributes to grooming induction in Drosophila

PubMed Central

Neyen, Claudine; Lemaitre, Bruno; Marion-Poll, Frédéric

2017-01-01

Behavioral resistance protects insects from microbial infection. However, signals inducing insect hygiene behavior are still relatively unexplored. Our previous study demonstrated that olfactory signals from microbes enhance insect hygiene behavior, and gustatory signals even induce the behavior. In this paper, we postulated a cross-talk between behavioral resistance and innate immunity. To examine this hypothesis, we employed a previously validated behavioral test to examine the function of taste signals in inducing a grooming reflex in decapitated flies. Microbes, which activate different pattern recognition systems upstream of immune pathways, were applied to see if there was any correlation between microbial perception and grooming reflex. To narrow down candidate elicitors, the grooming induction tests were conducted with highly purified bacterial components. Lastly, the role of DAP-type peptidoglycan in grooming induction was confirmed. Our results demonstrate that cleaning behavior can be triggered through recognition of DAP-type PGN by its receptor PGRP-LC. PMID:29121087
Perspectives on the behavior of entomopathogenic nematodes from dispersal to reproduction: traits contributing to nematode fitness and biocontrol efficacy.

PubMed

Griffin, Christine T

2012-06-01

The entomopathogenic nematodes (EPN) Heterorhabditis and Steinernema are widely used for the biological control of insect pests and are gaining importance as model organisms for studying parasitism and symbiosis. In this paper recent advances in the understanding of EPN behavior are reviewed. The "foraging strategy" paradigm (distinction between species with ambush and cruise strategies) as applied to EPN is being challenged and alternative paradigms proposed. Infection decisions are based on condition of the potential host, and it is becoming clear that already-infected and even long-dead hosts may be invaded, as well as healthy live hosts. The state of the infective juvenile (IJ) also influences infection, and evidence for a phased increase in infectivity of EPN species is mounting. The possibility of social behavior - adaptive interactions between IJs outside the host - is discussed. EPNs' symbiotic bacteria (Photorhabdus and Xenorhabdus) are important for killing the host and rendering it suitable for nematode reproduction, but may reduce survival of IJs, resulting in a trade-off between survival and reproduction. The symbiont also contributes to defence of the cadaver by affecting food-choice decisions of insect and avian scavengers. I review EPN reproductive behavior (including sperm competition, copulation and evidence for attractive and organizational effects of pheromones), and consider the role of endotokia matricida as parental behavior exploited by the symbiont for transmission.
Shape-and-behavior encoded tracking of bee dances.

PubMed

Veeraraghavan, Ashok; Chellappa, Rama; Srinivasan, Mandyam

2008-03-01

Behavior analysis of social insects has garnered impetus in recent years and has led to some advances in fields like control systems, flight navigation etc. Manual labeling of insect motions required for analyzing the behaviors of insects requires significant investment of time and effort. In this paper, we propose certain general principles that help in simultaneous automatic tracking and behavior analysis with applications in tracking bees and recognizing specific behaviors exhibited by them. The state space for tracking is defined using position, orientation and the current behavior of the insect being tracked. The position and orientation are parametrized using a shape model while the behavior is explicitly modeled using a three-tier hierarchical motion model. The first tier (dynamics) models the local motions exhibited and the models built in this tier act as a vocabulary for behavior modeling. The second tier is a Markov motion model built on top of the local motion vocabulary which serves as the behavior model. The third tier of the hierarchy models the switching between behaviors and this is also modeled as a Markov model. We address issues in learning the three-tier behavioral model, in discriminating between models, detecting and in modeling abnormal behaviors. Another important aspect of this work is that it leads to joint tracking and behavior analysis instead of the traditional track and then recognize approach. We apply these principles for tracking bees in a hive while they are executing the waggle dance and the round dance.
Social Insects: A Model System for Network Dynamics

NASA Astrophysics Data System (ADS)

Charbonneau, Daniel; Blonder, Benjamin; Dornhaus, Anna

Social insect colonies (ants, bees, wasps, and termites) show sophisticated collective problem-solving in the face of variable constraints. Individuals exchange information and materials such as food. The resulting network structure and dynamics can inform us about the mechanisms by which the insects achieve particular collective behaviors and these can be transposed to man-made and social networks. We discuss how network analysis can answer important questions about social insects, such as how effective task allocation or information flow is realized. We put forward the idea that network analysis methods are under-utilized in social insect research, and that they can provide novel ways to view the complexity of collective behavior, particularly if network dynamics are taken into account. To illustrate this, we present an example of network tasks performed by ant workers, linked by instances of workers switching from one task to another. We show how temporal network analysis can propose and test new hypotheses on mechanisms of task allocation, and how adding temporal elements to static networks can drastically change results. We discuss the benefits of using social insects as models for complex systems in general. There are multiple opportunities emergent technologies and analysis methods in facilitating research on social insect network. The potential for interdisciplinary work could significantly advance diverse fields such as behavioral ecology, computer sciences, and engineering.
Use of habitat odour by host-seeking insects.

PubMed

Webster, Ben; Cardé, Ring T

2017-05-01

Locating suitable feeding or oviposition sites is essential for insect survival. Understanding how insects achieve this is crucial, not only for understanding the ecology and evolution of insect-host interactions, but also for the development of sustainable pest-control strategies that exploit insects' host-seeking behaviours. Volatile chemical cues are used by foraging insects to locate and recognise potential hosts but in nature these resources usually are patchily distributed, making chance encounters with host odour plumes rare over distances greater than tens of metres. The majority of studies on insect host-seeking have focussed on short-range orientation to easily detectable cues and it is only recently that we have begun to understand how insects overcome this challenge. Recent advances show that insects from a wide range of feeding guilds make use of 'habitat cues', volatile chemical cues released over a relatively large area that indicate a locale where more specific host cues are most likely to be found. Habitat cues differ from host cues in that they tend to be released in larger quantities, are more easily detectable over longer distances, and may lack specificity, yet provide an effective way for insects to maximise their chances of subsequently encountering specific host cues. This review brings together recent advances in this area, discussing key examples and similarities in strategies used by haematophagous insects, soil-dwelling insects and insects that forage around plants. We also propose and provide evidence for a new theory that general and non-host plant volatiles can be used by foraging herbivores to locate patches of vegetation at a distance in the absence of more specific host cues, explaining some of the many discrepancies between laboratory and field trials that attempt to make use of plant-derived repellents for controlling insect pests. © 2016 Cambridge Philosophical Society.
A persistent homology approach to collective behavior in insect swarms

NASA Astrophysics Data System (ADS)

Sinhuber, Michael; Ouellette, Nicholas T.

Various animals from birds and fish to insects tend to form aggregates, displaying self-organized collective swarming behavior. Due to their frequent occurrence in nature and their implications for engineered, collective systems, these systems have been investigated and modeled thoroughly for decades. Common approaches range from modeling them with coupled differential equations on the individual level up to continuum approaches. We present an alternative, topology-based approach for describing swarming behavior at the macroscale rather than the microscale. We study laboratory swarms of Chironomus riparius, a flying, non-biting midge. To obtain the time-resolved three-dimensional trajectories of individual insects, we use a multi-camera stereoimaging and particle-tracking setup. To investigate the swarming behavior in a topological sense, we employ a persistent homology approach to identify persisting structures and features in the insect swarm that elude a direct, ensemble-averaging approach. We are able to identify features of sub-clusters in the swarm that show behavior distinct from that of the remaining swarm members. The coexistence of sub-swarms with different features resembles some non-biological systems such as active colloids or even thermodynamic systems.
Genes, enzymes and chemicals of terpenoid diversity in the constitutive and induced defence of conifers against insects and pathogens.

PubMed

Keeling, Christopher I; Bohlmann, Jörg

2006-01-01

Insects select their hosts, but trees cannot select which herbivores will feed upon them. Thus, as long-lived stationary organisms, conifers must resist the onslaught of varying and multiple attackers over their lifetime. Arguably, the greatest threats to conifers are herbivorous insects and their associated pathogens. Insects such as bark beetles, stem- and wood-boring insects, shoot-feeding weevils, and foliage-feeding budworms and sawflies are among the most devastating pests of conifer forests. Conifer trees produce a great diversity of compounds, such as an enormous array of terpenoids and phenolics, that may impart resistance to a variety of herbivores and microorganisms. Insects have evolved to specialize in resistance to these chemicals -- choosing, feeding upon, and colonizing hosts they perceive to be best suited to reproduction. This review focuses on the plant-insect interactions mediated by conifer-produced terpenoids. To understand the role of terpenoids in conifer-insect interactions, we must understand how conifers produce the wide diversity of terpenoids, as well as understand how these specific compounds affect insect behaviour and physiology. This review examines what chemicals are produced, the genes and proteins involved in their biosynthesis, how they work, and how they are regulated. It also examines how insects and their associated pathogens interact with, elicit, and are affected by conifer-produced terpenoids.
Scaling up our understanding of non-consumptive effects in insect systems

DOE PAGES

Hermann, Sara L.; Landis, Douglas A.

2017-04-06

Here, non-consumptive effects (NCEs) of predators on prey is an important topic in insect ecology with potential applications for pest management. NCEs are changes in prey behavior and physiology that aid in predation avoidance. While NCEs can have positive outcomes for prey survival there may also be negative consequences including increased stress and reduced growth. These effects can cascade through trophic systems influencing ecosystem function. Most NCEs have been studied at small spatial and temporal scales. However, recent studies show promise for the potential to manipulate NCEs for pest management. We suggest the next frontier for NCE studies includes manipulatingmore » the landscape of fear to improve pest control, which requires scaling-up to field and landscape levels, over ecologically relevant time frames.« less
Scaling up our understanding of non-consumptive effects in insect systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hermann, Sara L.; Landis, Douglas A.

Here, non-consumptive effects (NCEs) of predators on prey is an important topic in insect ecology with potential applications for pest management. NCEs are changes in prey behavior and physiology that aid in predation avoidance. While NCEs can have positive outcomes for prey survival there may also be negative consequences including increased stress and reduced growth. These effects can cascade through trophic systems influencing ecosystem function. Most NCEs have been studied at small spatial and temporal scales. However, recent studies show promise for the potential to manipulate NCEs for pest management. We suggest the next frontier for NCE studies includes manipulatingmore » the landscape of fear to improve pest control, which requires scaling-up to field and landscape levels, over ecologically relevant time frames.« less
How Far is Far Enough? Invertebrate Responses to Physical Constraints on Drift Distance

NASA Astrophysics Data System (ADS)

Hoover, T. M.; Yonemitsu, N.; Richardson, J. S.

2005-05-01

Many stream insects enter the drift and disperse downstream. Once entrained, however, the probability of settling in a patch of suitable habitat is a function of the physical properties and behavior of the drifting insect, as well as the hydrodynamic characteristics of the habitat through which the insect is drifting. The roles that taxa-specific morphology and behavior play in determining drift distance were examined for four mayflies with different habitat requirements; two rheophilous taxa (Baetis and Epeorus) and two pool-dwelling taxa (Ameletus and Paraleptophlebia). Larvae were released in an experimental channel in low and high water velocities. The total distances traveled by live mayfly larvae (+ behavior, + morphology) were compared to heat-killed larvae (- behavior, + morphology), and a series of low-density tracer particles (- behavior, - morphology). Live Baetis and Epeorus drifted similar distances, whereas the drift distances of the two pool taxa differed substantially (Ameletus < Epeorus, Baetis < Paraleptophlebia). The settlement distributions of dead larvae and passive tracer particles show that settlement behaviors allow drifting larvae to avoid becoming entrained in large-scale turbulent flow structures. These results suggest that stream insects have evolved strategies that facilitate dispersal between patches of suitable habitat.
Insect antiviral innate immunity: pathways, effectors, and connections.

PubMed

Kingsolver, Megan B; Huang, Zhijing; Hardy, Richard W

2013-12-13

Insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the small, interfering RNA pathway that responds through the detection of virus-derived double-stranded RNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, and Jak-STAT and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review, we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses. © 2013.
For a Limited Time Only? How Long Can Trees Maintain Enhanced Chemical Defenses During Pre-Mortality Heat and Drought Stress

NASA Astrophysics Data System (ADS)

Trowbridge, A.; Adams, H. D.; Cook, A. A.; Hofland, M.; Weaver, D.; McDowell, N. G.

2016-12-01

The relative contribution of forest pests to climate and drought-induced tree mortality is complex and largely absent from current process-based models. Recent efforts have focused on developing frameworks to integrate insects into models of tree mortality, citing the need for a better mechanistic understanding of the links between stress-induced tree physiology and insect behavior and population dynamics. Secondary plant metabolites (SPMs) play a critical role in plant resistance and their synthesis and mobilization are coupled to carbon assimilation, hydraulic conductivity, and herbivory itself. Insect host choice also depends in part on behavioral responses to host SPMs. Monoterpenes are the dominant SPMs in conifers, and while high concentrations of monoterpenes are toxic to bark beetles, lower concentrations serve as precursors for a number of aggregation pheromones. Thus, the impact of monoterpenes on bark beetle behavior is complex and is impacted by environmental effects on primary metabolism including heat and drought stress. Here, we quantify the dynamics of piñon pine monoterpene chemistry as a function of predicted and prolonged drought stress implemented at the SUrvival MOrtality (SUMO) experimental site at the Los Alamos National Laboratory, NM, USA. In both woody and needle tissues, total monoterpene concentrations in ambient trees were not significantly different from those observed in trees exposed to heat stress, but drought trees showed higher total concentration while heat+drought trees were observed to have the highest levels (2 fold increase over ambient). These treatment effects were sustained over a two-year period despite seasonal variation in tree water status; however, total concentration in the xylem and phloem were closely coupled to tree water potential and treatment effects took longer to manifest relative to the needles. Individual compounds responded differently to the treatments, suggesting cyclase-level enzyme regulation, while α-pinene - an important bark beetle aggregate pheromone precursor - dominated total monoterpene concentration dynamics. These results have important implications for piñon-bark beetle interactions during drought and provide a missing link between drought-induced physiology and insect behavior.
Digestive enzyme activity and trophic behavior in two predator aquatic insects (Plecoptera, Perlidae): a comparative study.

PubMed

López-Rodríguez, M J; Trenzado, C E; Tierno de Figueroa, J M; Sanz, A

2012-05-01

Plecoptera (Perlidae) are among the major macroinvertebrate predators in stream ecosystems and one of the insect families with lower tolerance to environmental alterations, being usually employed as bioindicators of high water ecological quality. The differences in the trophic roles of the coexisting species have been exclusively studied from their gut contents, while no data are available on the comparative digestive capacity. In the present paper, we make a comparative study of the activity of several digestive enzymes, namely proteases (at different pH), amylase, lipase, trypsin and chymotrypsin, in two species of stoneflies, Perla bipunctata and Dinocras cephalotes, which cohabit in the same stream. The study of digestive enzyme activity together with the analysis of gut contents can contribute to a better understanding of the ecology of these aquatic insects and their role in freshwater food webs. Thus, our results show that the two studied predator species inhabiting in the same stream present specializations on their feeding behaviors, facilitating their coexistence, and also differences in their capacity of use the resources. One of the main findings of this study is that D. cephalotes is able to assimilate a wider trophic resource spectrum and this could be one of the reasons why this species has a wider global distribution in all its geographical range. Copyright Â© 2012 Elsevier Inc. All rights reserved.
Development of mimetic analogs of pyrokinin-like neuropeptides to disrupt pest insect physiology/behavior

USDA-ARS?s Scientific Manuscript database

Pyrokinin (FXPRLamide) neuropeptides regulate a variety of critical processes and behaviors in insects, though they are unsuitable as tools to arthropod endocrinologists and/or as pest management agents due to sub-optimal biostability and/or bioavailability characteristics. Peptidomimetic analogs c...

A New SAS program for behavioral analysis of electrical penetration graph data

USDA-ARS?s Scientific Manuscript database

Monitoring feeding behaviors of insects whose piercing-sucking mouthparts are inserted into plant tissue is done by making the insect part of an electronic circuit, using electropenetrography (EPG). Fluctuating voltage signals in the circuit are graphed, and resulting waveforms are interpreted as sp...
Insects in the Classroom: A Study of Animal Behavior

ERIC Educational Resources Information Center

Miller, Jon S.

2004-01-01

These activities allow students to investigate behavioral responses of the large Milkweed bug, "Oncopeltus fasciatus," and the mealworm, "Tenebrio molitor" or "Tenebrio obscurus," to external stimuli of light, color, and temperature. During the activities, students formulate hypotheses to research questions presented. They also observe insects for…
Identifying behavioral circuits in Drosophila melanogaster: moving targets in a flying insect.

PubMed

Griffith, Leslie C

2012-08-01

Drosophila melanogaster has historically been the premier model system for understanding the molecular and genetic bases of complex behaviors. In the last decade technical advances, in the form of new genetic tools and electrophysiological and optical methods, have allowed investigators to begin to dissect the neuronal circuits that generate behavior in the adult. The blossoming of circuit analysis in this organism has also reinforced our appreciation of the inadequacy of wiring diagrams for specifying complex behavior. Neuromodulation and neuronal plasticity act to reconfigure circuits on both short and long time scales. These processes act on the connectome, providing context by integrating external and internal cues that are relevant for behavioral choices. New approaches in the fly are providing insight into these basic principles of circuit function. Copyright © 2012 Elsevier Ltd. All rights reserved.
Induced Release of a Plant-Defense Volatile ‘Deceptively’ Attracts Insect Vectors to Plants Infected with a Bacterial Pathogen

PubMed Central

Mann, Rajinder S.; Ali, Jared G.; Hermann, Sara L.; Tiwari, Siddharth; Pelz-Stelinski, Kirsten S.; Alborn, Hans T.; Stelinski, Lukasz L.

2012-01-01

Transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. Pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. Experiments were conducted to understand how a plant pathogenic bacterium, Candidatus Liberibacter asiaticus (Las), affects host preference behavior of its psyllid (Diaphorina citri Kuwayama) vector. D. citri were attracted to volatiles from pathogen-infected plants more than to those from non-infected counterparts. Las-infected plants were more attractive to D. citri adults than non-infected plants initially; however after feeding, psyllids subsequently dispersed to non-infected rather than infected plants as their preferred settling point. Experiments with Las-infected and non-infected plants under complete darkness yielded similar results to those recorded under light. The behavior of psyllids in response to infected versus non-infected plants was not influenced by whether or not they were carriers of the pathogen. Quantification of volatile release from non-infected and infected plants supported the hypothesis that odorants mediate psyllid preference. Significantly more methyl salicylate, yet less methyl anthranilate and D-limonene, was released by infected than non-infected plants. Methyl salicylate was attractive to psyllids, while methyl anthranilate did not affect their behavior. Feeding on citrus by D. citri adults also induced release of methyl salicylate, suggesting that it may be a cue revealing location of conspecifics on host plants. Infected plants were characterized by lower levels of nitrogen, phosphorus, sulfur, zinc, and iron, as well as, higher levels of potassium and boron than non-infected plants. Collectively, our results suggest that host selection behavior of D. citri may be modified by bacterial infection of plants, which alters release of specific headspace volatiles and plant nutritional contents. Furthermore, we show in a laboratory setting that this apparent pathogen-mediated manipulation of vector behavior may facilitate pathogen spread. PMID:22457628
Assessment of Potential Sublethal Effects of Various Insecticides on Key Biological Traits of The Tobacco Whitefly, Bemisia tabaci

PubMed Central

He, Yuxian; Zhao, Jianwei; Zheng, Yu; Weng, Qiyong; Biondi, Antonio; Desneux, Nicolas; Wu, Kongming

2013-01-01

The tobacco whitefly Bemisia tabaci is one of the most devastating pests worldwide. Current management of B. tabaci relies upon the frequent applications of insecticides. In addition to direct mortality by typical acute toxicity (lethal effect), insecticides may also impair various key biological traits of the exposed insects through physiological and behavioral sublethal effects. Identifying and characterizing such effects could be crucial for understanding the global effects of insecticides on the pest and therefore for optimizing its management in the crops. We assessed the effects of sublethal and low-lethal concentrations of four widely used insecticides on the fecundity, honeydew excretion and feeding behavior of B. tabaci adults. The probing activity of the whiteflies feeding on treated cotton seedlings was recorded by an Electrical Penetration Graph (EPG). The results showed that imidacloprid and bifenthrin caused a reduction in phloem feeding even at sublethal concentrations. In addition, the honeydew excretions and fecundity levels of adults feeding on leaf discs treated with these concentrations were significantly lower than the untreated ones. While, sublethal concentrations of chlorpyrifos and carbosulfan did not affect feeding behavior, honeydew excretion and fecundity of the whitefly. We demonstrated an antifeedant effect of the imidacloprid and bifenthrin on B. tabaci, whereas behavioral changes in adults feeding on leaves treated with chlorpyrifos and carbosulfan were more likely caused by the direct effects of the insecticides on the insects' nervous system itself. Our results show that aside from the lethal effect, the sublethal concentration of imidacloprid and bifenthrin impairs the phloem feeding, i.e. the most important feeding trait in a plant protection perspective. Indeed, this antifeedant property would give these insecticides potential to control insect pests indirectly. Therefore, the behavioral effects of sublethal concentrations of imidacloprid and bifenthrin may play an important role in the control of whitefly pests by increasing the toxicity persistence in treated crops. PMID:23494876
Induced release of a plant-defense volatile 'deceptively' attracts insect vectors to plants infected with a bacterial pathogen.

PubMed

Mann, Rajinder S; Ali, Jared G; Hermann, Sara L; Tiwari, Siddharth; Pelz-Stelinski, Kirsten S; Alborn, Hans T; Stelinski, Lukasz L

2012-01-01

Transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. Pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. Experiments were conducted to understand how a plant pathogenic bacterium, Candidatus Liberibacter asiaticus (Las), affects host preference behavior of its psyllid (Diaphorina citri Kuwayama) vector. D. citri were attracted to volatiles from pathogen-infected plants more than to those from non-infected counterparts. Las-infected plants were more attractive to D. citri adults than non-infected plants initially; however after feeding, psyllids subsequently dispersed to non-infected rather than infected plants as their preferred settling point. Experiments with Las-infected and non-infected plants under complete darkness yielded similar results to those recorded under light. The behavior of psyllids in response to infected versus non-infected plants was not influenced by whether or not they were carriers of the pathogen. Quantification of volatile release from non-infected and infected plants supported the hypothesis that odorants mediate psyllid preference. Significantly more methyl salicylate, yet less methyl anthranilate and D-limonene, was released by infected than non-infected plants. Methyl salicylate was attractive to psyllids, while methyl anthranilate did not affect their behavior. Feeding on citrus by D. citri adults also induced release of methyl salicylate, suggesting that it may be a cue revealing location of conspecifics on host plants. Infected plants were characterized by lower levels of nitrogen, phosphorus, sulfur, zinc, and iron, as well as, higher levels of potassium and boron than non-infected plants. Collectively, our results suggest that host selection behavior of D. citri may be modified by bacterial infection of plants, which alters release of specific headspace volatiles and plant nutritional contents. Furthermore, we show in a laboratory setting that this apparent pathogen-mediated manipulation of vector behavior may facilitate pathogen spread.
Post-molting development of wind-elicited escape behavior in the cricket.

PubMed

Sato, Nodoka; Shidara, Hisashi; Ogawa, Hiroto

2017-11-01

Arthropods including insects grow through several developmental stages by molting. The abrupt changes in their body size and morphology accompanying the molting are responsible for the developmental changes in behavior. While in holometabolous insects, larval behaviors are transformed into adult-specific behaviors with drastic changes in nervous system during the pupal stage, hemimetabolous insects preserve most innate behaviors whole life long, which allow us to trace the maturation process of preserved behaviors after the changes in body. Wind-elicited escape behavior is one of these behaviors and mediated by cercal system, which is a mechanosensory organ equipped by all stages of nymph in orthopteran insects like crickets. However, the maturation process of the escape behavior after the molt is unclear. In this study, we examined time-series of changes in the wind-elicited escape behavior just after the imaginal molt in the cricket. The locomotor activities are developed over the elapsed time, and matured 24h after the molt. In contrast, a stimulus-angle dependency of moving direction was unchanged over time, meaning that the cercal sensory system detecting airflow direction was workable immediately after the molt, independent from the behavioral maturation. The post-molting development of the wind-elicited behavior was considered to result not simply from maturation of the exoskeleton or musculature because the escape response to heat-shock stimulus did not change after the molt. No effect of a temporal immobilization after the imaginal molt on the maturation of the wind-elicited behavior also implies that the maturation may be innately programmed without experience of locomotion. Copyright © 2017 Elsevier Ltd. All rights reserved.
Weevil x Insecticide: Does 'Personality' Matter?

PubMed

Morales, Juliana A; Cardoso, Danúbia G; Della Lucia, Terezinha Maria C; Guedes, Raul Narciso C

2013-01-01

An insect's behavior is the expression of its integrated physiology in response to external and internal stimuli, turning insect behavior into a potential determinant of insecticide exposure. Behavioral traits may therefore influence insecticide efficacy against insects, compromising the validity of standard bioassays of insecticide activity, which are fundamentally based on lethality alone. By extension, insect 'personality' (i.e., an individual's integrated set of behavioral tendencies that is inferred from multiple empirical measures) may also be an important determinant of insecticide exposure and activity. This has yet to be considered because the behavioral studies involving insects and insecticides focus on populations rather than on individuals. Even among studies of animal 'personality', the relative contributions of individual and population variation are usually neglected. Here, we assessed behavioral traits (within the categories: activity, boldness/shyness, and exploration/avoidance) of individuals from 15 populations of the maize weevil (Sitophilus zeamais), an important stored-grain pest with serious problems of insecticide resistance, and correlated the behavioral responses with the activity of the insecticide deltamethrin. This analysis was performed at both the population and individual levels. There was significant variation in weevil 'personality' among individuals and populations, but variation among individuals within populations accounted for most of the observed variation (92.57%). This result emphasizes the importance of individual variation in behavioral and 'personality' studies. When the behavioral traits assessed were correlated with median lethal time (LT50) at the population level and with the survival time under insecticide exposure, activity traits, particularly the distance walked, significantly increased survival time. Therefore, behavioral traits are important components of insecticide efficacy, and individual variation should be considered in such studies. This is so because population differences provided only crude approximation of the individual personality in a restrained experimental setting likely to restrict individual behavior favoring the transposition of the individual variation to the population.
A Sequential Insect Dispenser for Behavioral Experiments

ERIC Educational Resources Information Center

Gans, Carl; Mix, Harold

1974-01-01

Describes the construction and operation of an automatic insect dispenser suitable for feeding small vertebrates that are being maintained for behavioral experiments. The food morsels are squirted from their chambers an an air jet, and may be directed at a particluar portion of the cage or distributed to different areas. (JR)
Insect neurotoxicity and physiological mode of action of basic amines

USDA-ARS?s Scientific Manuscript database

The basic amines 1-methylpiperazine and 1-methylpyrrolidine have been proposed as chemicals that interfere with insect host-seeking behavior with a possible anosmia, or narcotizing effect on Aedes aegypti. In this study, the behavior and toxicity, as well as the electrophysiology effects of these b...
Laboratory and Field Evaluation of SS220 and Deet Against Mosquitoes in Queensland, Australia

DTIC Science & Technology

2009-01-01

Australian Army Malaria Institute, Gallipoli Bar- racks, Enoggera, Queensland 4051, Australia. 2 Invasive Insect Biocontrol and Behavior Laborato- ry...Invasive Insect Biocontrol and Behavior Laboratory (Beltsville, MD; Klun et al. 2003). A 20% solution (V/V) of each chemical in absolute ethanol was used
Forest structure affects trophic linkages: How silvicultural disturbance impacts bats and their insect prey

USGS Publications Warehouse

Dodd, L.E.; Lacki, M.J.; Britzke, E.R.; Buehler, D.A.; Keyser, P.D.; Larkin, J.L.; Rodewald, A.D.; Wigley, T.B.; Wood, P.B.; Rieske, L.K.

2012-01-01

Vertebrate insectivores such as bats are a pervasive top-down force on prey populations in forest ecosystems. Conservation focusing on forest-dwelling bats requires understanding of community-level interactions between these predators and their insect prey. Our study assessed bat activity and insect occurrence (abundance and diversity) across a gradient of forest disturbance and structure (silvicultural treatments) in the Central Appalachian region of North America. We conducted acoustic surveys of bat echolocation concurrent with insect surveys using blacklight and malaise traps over 2 years. Predator activity, prey occurrence and prey biomass varied seasonally and across the region. The number of bat echolocation pulses was positively related with forest disturbance, whereas prey demonstrated varied trends. Lepidopteran abundance was negatively related with disturbance, while dipteran abundance and diversity was positively related with disturbance. Coleoptera were unaffected. Neither bat nor insect response variables differed between plot interiors and edges. Correlations between bat activity and vegetative structure reflected differences in foraging behavior among ensembles. Activity of myotine bats was correlated with variables describing sub-canopy vegetation, whereas activity of lasiurine bats was more closely correlated with canopy-level vegetation. Lepidopteran abundance was correlated with variables describing canopy and sub-canopy vegetation, whereas coleopteran and dipteran occurrence were more closely correlated with canopy-level vegetative structure. Our study demonstrates regional variation in bat activity and prey occurrence across a forested disturbance gradient. Land management and conservation efforts should consider the importance of vegetation structure and plant species richness to sustain forest-dwelling bats and their insect prey.
Jaburetox-induced toxic effects on the hemocytes of Rhodnius prolixus (Hemiptera: Reduviidae).

PubMed

Moyetta, Natalia R; Broll, Valquiria; Perin, Ana Paula A; Uberti, Augusto F; Coste Grahl, Matheus V; Staniscuaski, Fernanda; Carlini, Celia R; Fruttero, Leonardo L

2017-10-01

Jaburetox is a recombinant peptide derived from a Canavalia ensiformis urease that presents toxic effects upon several species of insects, phytopathogenic fungi and yeasts of medical importance. So far, no toxicity of Jaburetox to mammals has been shown. Previous reports have identified biochemical targets of this toxic peptide in insect models, although its mechanism of action is not completely understood. In this work, we aimed to characterize the effects of Jaburetox in hemolymphatic insect cells. For this purpose, the model insect and Chagas' disease vector Rhodnius prolixus was used. In vivo and in vitro experiments indicated that Jaburetox interacts with a subset of hemocytes and it can be found in various subcellular compartments. In insects injected with Jaburetox there was an increase in the gene expression of the enzymes UDP-N-acetylglucosamine pyrophosphorylase (UAP), chitin synthase and nitric oxide synthase (NOS). Nevertheless, the expression of NOS protein, the enzyme activities of UAP and acid phosphatase (a possible link between UAP and NOS) as well as the phosphorylation state of proteins remained unchanged upon the in vivo Jaburetox treatment. Nitric oxide (NO) imaging using fluorescent probes showed that Jaburetox augmented NO production in the hemocyte aggregates when compared to controls. Even though Jaburetox activated the hemocytes, as demonstrated by wheat germ agglutinin binding assays, the peptide did not lead to an increase of their phagocytic behavior. Taken together, these findings contribute to our understanding of toxic effects of Jaburetox, a peptide with biotechnological applications and a prospective tool for rational insect control. Copyright © 2017 Elsevier Inc. All rights reserved.
Comparative analysis of behavioral and transcriptional variation underlying CO2 sensory neuron function and development in Drosophila.

PubMed

Pan, Jia Wern; McLaughlin, Joi; Yang, Haining; Leo, Charles; Rambarat, Paula; Okuwa, Sumie; Monroy-Eklund, Anaïs; Clark, Sabrina; Jones, Corbin D; Volkan, Pelin Cayirlioglu

2017-10-02

Carbon dioxide is an important environmental cue for many insects, regulating many behaviors including some that have direct human impacts. To further improve our understanding of how this system varies among closely related insect species, we examined both the behavioral response to CO 2 as well as the transcriptional profile of key developmental regulators of CO 2 sensory neurons in the olfactory system across the Drosophila genus. We found that CO 2 generally evokes repulsive behavior across most of the Drosophilids we examined, but this behavior has been lost or reduced in several lineages. Comparisons of transcriptional profiles from the developing and adult antennae for subset these species suggest that behavioral differences in some species may be due to differences in the expression of the CO 2 co-receptor Gr63a. Furthermore, these differences in Gr63a expression are correlated with changes in the expression of a few genes known to be involved in the development of the CO 2 circuit, namely dac, an important regulator of sensilla fate for sensilla that house CO 2 ORNs, and mip120, a member of the MMB/dREAM epigenetic regulatory complex that regulates CO 2 receptor expression. In contrast, most of the other known structural, molecular, and developmental components of the peripheral Drosophila CO 2 olfactory system seem to be well-conserved across all examined lineages. These findings suggest that certain components of CO 2 sensory ORN development may be more evolutionarily labile, and may contribute to differences in CO 2 -evoked behavioral responses across species.
Multiple activities of insect repellents on odorant receptors in mosquitoes

USDA-ARS?s Scientific Manuscript database

Several lines of evidence suggest that insect repellent molecules reduce mosquito-host contacts by interacting with odorants and odorant receptors (ORs) ultimately affecting olfactory-driven behaviors. We describe the molecular effects of ten insect repellents and a pyrethroid insecticide with known...
Effects of temperature on development, survival and reproduction of insects: Experimental design, data analysis and modeling

Treesearch

Jacques Regniere; James Powell; Barbara Bentz; Vincent Nealis

2012-01-01

The developmental response of insects to temperature is important in understanding the ecology of insect life histories. Temperature-dependent phenology models permit examination of the impacts of temperature on the geographical distributions, population dynamics and management of insects. The measurement of insect developmental, survival and reproductive responses to...
Hijacked: Co-option of host behavior by entomophthoralean fungi

USDA-ARS?s Scientific Manuscript database

Over 700 species of fungi are known to infect and cause disease in insects and other arthropods. The majority of insect pathogenic fungi are classified in the phyla Entomophthoromycotina and Ascomycotina, and many are ecologically important in regulating insect populations. To summarize fungal-inse...
Aggregative group behavior in insect parasitic nematode dispersal.

PubMed

Shapiro-Ilan, David I; Lewis, Edwin E; Schliekelman, Paul

2014-01-01

Movement behavior of foraging animals is critical to the determination of their spatial ecology and success in exploiting resources. Individuals sometimes gain advantages by foraging in groups to increase their efficiency in garnering these resources. Group movement behavior has been studied in various vertebrates. In this study we explored the propensity for innate group movement behavior among insect parasitic nematodes. Given that entomopathogenic nematodes benefit from group attack and infection, we hypothesised that the populations would tend to move in aggregate in the absence of extrinsic cues. Movement patterns of entomopathogenic nematodes in sand were investigated when nematodes were applied to a specific locus or when the nematodes emerged naturally from infected insect hosts; six nematode species in two genera were tested (Heterorhabditis bacteriophora, Heterorhabditis indica, Steinernema carpocapsae, Steinernema feltiae, Steinernema glaseri and Steinernema riobrave). Nematodes were applied in aqueous suspension via filter paper discs or in infected insect host cadavers (to mimic emergence in nature). We discovered that nematode dispersal resulted in an aggregated pattern rather than a random or uniform distribution; the only exception was S. glaseri when emerging directly from infected hosts. The group movement may have been continuous from the point of origin, or it may have been triggered by a propensity to aggregate after a short period of random movement. To our knowledge, this is the first report of group movement behavior in parasitic nematodes in the absence of external stimuli (e.g., without an insect or other apparent biotic or abiotic cue). These findings have implications for nematode spatial distribution and suggest that group behavior is involved in nematode foraging. Published by Elsevier Ltd.
Unexpected Effects of Low Doses of a Neonicotinoid Insecticide on Behavioral Responses to Sex Pheromone in a Pest Insect

PubMed Central

Rabhi, Kaouther K.; Esancy, Kali; Voisin, Anouk; Crespin, Lucille; Le Corre, Julie; Tricoire-Leignel, Hélène; Anton, Sylvia; Gadenne, Christophe

2014-01-01

In moths, which include many agricultural pest species, males are attracted by female-emitted sex pheromones. Although integrated pest management strategies are increasingly developed, most insect pest treatments rely on widespread use of neurotoxic chemicals, including neonicotinoid insecticides. Residual accumulation of low concentrations of these insecticides in the environment is known to be harmful to beneficial insects such as honey bees. This environmental stress probably acts as an “info-disruptor” by modifying the chemical communication system, and therefore decreases chances of reproduction in target insects that largely rely on olfactory communication. However, low doses of pollutants could on the contrary induce adaptive processes in the olfactory pathway, thus enhancing reproduction. Here we tested the effects of acute oral treatments with different low doses of the neonicotinoid clothianidin on the behavioral responses to sex pheromone in the moth Agrotis ipsilon using wind tunnel experiments. We show that low doses of clothianidin induce a biphasic effect on pheromone-guided behavior. Surprisingly, we found a hormetic-like effect, improving orientation behavior at the LD20 dose corresponding to 10 ng clothianidin. On the contrary, a negative effect, disturbing orientation behavior, was elicited by a treatment with a dose below the LD0 dose corresponding to 0.25 ng clothianidin. No clothianidin effect was observed on behavioral responses to plant odor. Our results indicate that risk assessment has to include unexpected effects of residues on the life history traits of pest insects, which could then lead to their adaptation to environmental stress. PMID:25517118
Plant Virus–Insect Vector Interactions: Current and Potential Future Research Directions

PubMed Central

Dietzgen, Ralf G.; Mann, Krin S.; Johnson, Karyn N.

2016-01-01

Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus–insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors. PMID:27834855

Plant Virus-Insect Vector Interactions: Current and Potential Future Research Directions.

PubMed

Dietzgen, Ralf G; Mann, Krin S; Johnson, Karyn N

2016-11-09

Acquisition and transmission by an insect vector is central to the infection cycle of the majority of plant pathogenic viruses. Plant viruses can interact with their insect host in a variety of ways including both non-persistent and circulative transmission; in some cases, the latter involves virus replication in cells of the insect host. Replicating viruses can also elicit both innate and specific defense responses in the insect host. A consistent feature is that the interaction of the virus with its insect host/vector requires specific molecular interactions between virus and host, commonly via proteins. Understanding the interactions between plant viruses and their insect host can underpin approaches to protect plants from infection by interfering with virus uptake and transmission. Here, we provide a perspective focused on identifying novel approaches and research directions to facilitate control of plant viruses by better understanding and targeting virus-insect molecular interactions. We also draw parallels with molecular interactions in insect vectors of animal viruses, and consider technical advances for their control that may be more broadly applicable to plant virus vectors.
Feeding behavior of the stink bug Bagrada hilaris is changed by the electrical signals applied during EPG recordings

USDA-ARS?s Scientific Manuscript database

Feeding behavior of piercing-sucking insects is most rigorously studied using eletropenetrography (EPG). This technique utilizes an electrical circuit to record waveforms caused by voltage fluctuations when a wired insect inserts its stylet into an electrified plant. Past researchers have asserted t...
Modeling and regression analysis of semiochemical dose-response curves of insect antennal reception and behavior

USDA-ARS?s Scientific Manuscript database

Dose-response curves with semiochemicals are reported in many articles in insect chemical ecology regarding neurophysiology and behavioral bioassays. Most such curves are shown in figures where the x-axis has order of magnitude increases in dosages versus responses on the y-axis represented by point...
New technologies in electrical penetration graph (EPG) monitors of insect feeding and their applications for 21st century entomology

USDA-ARS?s Scientific Manuscript database

Electrical penetration graph (EPG) monitoring of insect feeding is a rigorous means of observing and quantifying feeding behaviors of piercing-sucking arthropods, as well as fine details of chewing and oviposition behaviors not observable visually. While EPG was originally invented nearly 50 years ...
Effects of Essential Oil from Hinoki Cypress, Chamaecyparis obtusa, on Physiology and Behavior of Flies

PubMed Central

Min, Kyung-Jin

2015-01-01

Phytoncides, which are volatile substances emitted from plants for protection against plant pathogens and insects, are known to have insecticidal, antimicrobial, and antifungal activities. In contrast to their negative effects on microorganisms and insects, phytoncides have been shown to have beneficial effects on human health. Essential oil from Hinoki cypress (Chamaecyparis obtusa) is mostly used in commercial products such as air purifiers. However, the physiological/behavioral impact of essential oil from C. obtusa on insects is not established. In this study, we tested the effects of essential oil extracted from C. obtusa on the physiologies and behaviors of Drosophila melanogaster and Musca domestica. Exposure to essential oil from C. obtusa decreased the lifespan, fecundity, locomotive activity, and developmental success rate of D. melanogaster. In addition, both fruit flies and house flies showed strong repellent behavioral responses to the essential oil, with duration times of about 5 hours at 70 μg/ml. These results suggest that essential oil from C. obtusa can be used as a ‘human-friendly’ alternative insect repellent. PMID:26624577
The role of the Drosophila lateral horn in olfactory information processing and behavioral response.

PubMed

Schultzhaus, Janna N; Saleem, Sehresh; Iftikhar, Hina; Carney, Ginger E

2017-04-01

Animals must rapidly and accurately process environmental information to produce the correct behavioral responses. Reactions to previously encountered as well as to novel but biologically important stimuli are equally important, and one understudied region in the insect brain plays a role in processing both types of stimuli. The lateral horn is a higher order processing center that mainly processes olfactory information and is linked via olfactory projection neurons to another higher order learning center, the mushroom body. This review focuses on the lateral horn of Drosophila where most functional studies have been performed. We discuss connectivity between the primary olfactory center, the antennal lobe, and the lateral horn and mushroom body. We also present evidence for the lateral horn playing roles in innate behavioral responses by encoding biological valence to novel odor cues and in learned responses to previously encountered odors by modulating neural activity within the mushroom body. We describe how these processes contribute to acceptance or avoidance of appropriate or inappropriate mates and food, as well as the identification of predators. The lateral horn is a sexually dimorphic and plastic region of the brain that modulates other regions of the brain to ensure that insects produce rapid and effective behavioral responses to both novel and learned stimuli, yet multiple gaps exist in our knowledge of this important center. We anticipate that future studies on olfactory processing, learning, and innate behavioral responses will include the lateral horn in their examinations, leading to a more comprehensive understanding of olfactory information relay and resulting behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.
Molecular structure and diversity of PBAN/Pyrokinin family peptides in ants

USDA-ARS?s Scientific Manuscript database

Neuropeptides are the largest group of insect hormones. They are produced in the central and peripheral nervous systems and affect insect development, reproduction, feeding and behavior. A variety of neuropeptide families have been identified in insects. One of these families is the PBAN/Pyrokinin f...
Neurophysiological and behavioral responses of gypsy moth larvae to insect repellents

USDA-ARS?s Scientific Manuscript database

The interactions between insect repellents and the olfactory system have been widely studied, however relatively little is known about the effects of repellents on the gustatory system of insects. In this study, we show that the gustatory receptor neuron (GRN) located in the medial styloconic sensi...
Identification of methyl farnesoate from the hemolymph of insects

USDA-ARS?s Scientific Manuscript database

Juvenile hormones (JH) have been a focal point of study in insect endocrinology for more than 80 years and are implicated in regulation of more physiological and behavioral functions than any other insect hormone. Indeed, evidence has suggested that JHs are the only sesquiterpene hormone products s...
Multidimensional approaches for studying plant defence against insects: from ecology to omics and synthetic biology.

PubMed

Barah, Pankaj; Bones, Atle M

2015-02-01

The biggest challenge for modern biology is to integrate multidisciplinary approaches towards understanding the organizational and functional complexity of biological systems at different hierarchies, starting from the subcellular molecular mechanisms (microscopic) to the functional interactions of ecological communities (macroscopic). The plant-insect interaction is a good model for this purpose with the availability of an enormous amount of information at the molecular and the ecosystem levels. Changing global climatic conditions are abruptly resetting plant-insect interactions. Integration of discretely located heterogeneous information from the ecosystem to genes and pathways will be an advantage to understand the complexity of plant-insect interactions. This review will present the recent developments in omics-based high-throughput experimental approaches, with particular emphasis on studying plant defence responses against insect attack. The review highlights the importance of using integrative systems approaches to study plant-insect interactions from the macroscopic to the microscopic level. We analyse the current efforts in generating, integrating and modelling multiomics data to understand plant-insect interaction at a systems level. As a future prospect, we highlight the growing interest in utilizing the synthetic biology platform for engineering insect-resistant plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Protection via parasitism: Datura odors attract parasitoid flies, which inhibit Manduca larvae from feeding and growing but may not help plants.

PubMed

Wilson, J K; Woods, H A

2015-12-01

Insect carnivores frequently use olfactory cues from plants to find prey or hosts. For plants, the benefits of attracting parasitoids have been controversial, partly because parasitoids often do not kill their host insect immediately. Furthermore, most research has focused on the effects of solitary parasitoids on growth and feeding of hosts, even though many parasitoids are gregarious (multiple siblings inhabit the same host). Here, we examine how a gregarious parasitoid, the tachinid fly Drino rhoeo, uses olfactory cues from the host plant Datura wrightii to find the sphingid herbivore Manduca sexta, and how parasitism affects growth and feeding of host larvae. In behavioral trials using a Y-olfactometer, female flies were attracted to olfactory cues emitted by attacked plants and by cues emitted from the frass produced by larval Manduca sexta. M. sexta caterpillars that were parasitized by D. rhoeo grew to lower maximum weights, grew more slowly, and ate less of their host plant. We also present an analytical model to predict how tri-trophic interactions change with varying herbivory levels, parasitization rates and plant sizes. This model predicted that smaller plants gain a relatively greater benefit compared to large plants in attracting D. rhoeo. By assessing the behavior, the effects of host performance, and the variation in ecological parameters of the system, we can better understand the complex interactions between herbivorous insects, the plants they live on and the third trophic level members that attack them.
Harnessing insect-microbe chemical communications to control insect pest of agricultural systems

USDA-ARS?s Scientific Manuscript database

Insect pests have long been known to impose serious yield, economic, and food safety problems to managed crops worldwide, and are known to vector microbes, many of which are pathogenic or toxigenic. At the heart of many of these studies has been the vital understanding of the plant-insect interactio...
Towards the elements of successful insect RNAi.

PubMed

Scott, Jeffrey G; Michel, Kristin; Bartholomay, Lyric C; Siegfried, Blair D; Hunter, Wayne B; Smagghe, Guy; Zhu, Kun Yan; Douglas, Angela E

2013-12-01

RNA interference (RNAi), the sequence-specific suppression of gene expression, offers great opportunities for insect science, especially to analyze gene function, manage pest populations, and reduce disease pathogens. The accumulating body of literature on insect RNAi has revealed that the efficiency of RNAi varies between different species, the mode of RNAi delivery, and the genes being targeted. There is also variation in the duration of transcript suppression. At present, we have a limited capacity to predict the ideal experimental strategy for RNAi of a particular gene/insect because of our incomplete understanding of whether and how the RNAi signal is amplified and spread among insect cells. Consequently, development of the optimal RNAi protocols is a highly empirical process. This limitation can be relieved by systematic analysis of the molecular physiological basis of RNAi mechanisms in insects. An enhanced conceptual understanding of RNAi function in insects will facilitate the application of RNAi for dissection of gene function, and to fast-track the application of RNAi to both control pests and develop effective methods to protect beneficial insects and non-insect arthropods, particularly the honey bee (Apis mellifera) and cultured Pacific white shrimp (Litopenaeus vannamei) from viral and parasitic diseases. Copyright © 2013 Elsevier Ltd. All rights reserved.
Neuropeptides as Regulators of Behavior in Insects.

PubMed

Schoofs, Liliane; De Loof, Arnold; Van Hiel, Matthias Boris

2017-01-31

Neuropeptides are by far the largest and most diverse group of signaling molecules in multicellular organisms. They are ancient molecules important in regulating a multitude of processes. Their small proteinaceous character allowed them to evolve and radiate quickly into numerous different molecules. On average, hundreds of distinct neuropeptides are present in animals, sometimes with unique classes that do not occur in distantly related species. Acting as neurotransmitters, neuromodulators, hormones, or growth factors, they are extremely diverse and are involved in controlling growth, development, ecdysis, digestion, diuresis, and many more physiological processes. Neuropeptides are also crucial in regulating myriad behavioral actions associated with feeding, courtship, sleep, learning and memory, stress, addiction, and social interactions. In general, behavior ensures that an organism can survive in its environment and is defined as any action that can change an organism's relationship to its surroundings. Even though the mode of action of neuropeptides in insects has been vigorously studied, relatively little is known about most neuropeptides and only a few model insects have been investigated. Here, we provide an overview of the roles neuropeptides play in insect behavior. We conclude that multiple neuropeptides need to work in concert to coordinate certain behaviors. Additionally, most neuropeptides studied to date have more than a single function.
Distributed power and control actuation in the thoracic mechanics of a robotic insect.

PubMed

Finio, Benjamin M; Wood, Robert J

2010-12-01

Recent advances in the understanding of biological flight have inspired roboticists to create flapping-wing vehicles on the scale of insects and small birds. While our understanding of the wing kinematics, flight musculature and neuromotor control systems of insects has expanded, in practice it has proven quite difficult to construct an at-scale mechanical device capable of similar flight performance. One of the key challenges is the development of an effective and efficient transmission mechanism to control wing motions. Here we present multiple insect-scale robotic thorax designs capable of producing asymmetric wing kinematics similar to those observed in nature and utilized by dipteran insects to maneuver. Inspired by the thoracic mechanics of dipteran insects, which entail a morphological separation of power and control muscles, these designs show that such distributed actuation can also modulate wing motion in a robotic design.
Insect vision as model for machine vision

NASA Astrophysics Data System (ADS)

Osorio, D.; Sobey, Peter J.

1992-11-01

The neural architecture, neurophysiology and behavioral abilities of insect vision are described, and compared with that of mammals. Insects have a hardwired neural architecture of highly differentiated neurons, quite different from the cerebral cortex, yet their behavioral abilities are in important respects similar to those of mammals. These observations challenge the view that the key to the power of biological neural computation is distributed processing by a plastic, highly interconnected, network of individually undifferentiated and unreliable neurons that has been a dominant picture of biological computation since Pitts and McCulloch's seminal work in the 1940's.
Affective and Cognitive Responses to Insects and Other Arthropods

ERIC Educational Resources Information Center

Lorenz-Reaves, Amanda R.

2017-01-01

Insects are the most abundant and diverse group of animals on Earth. Though as a group they do far more ecological good than harm, previous studies have shown that human attitudes toward insects are mainly negative. Attitudes have affective (emotions) and cognitive (beliefs, mental representations) components that interact to influence behavior.…
Host plants impact courtship vibration transmission and mating success of a parasitoid wasp, Cotesia flavipes (Hymenoptera: Braconidae)

USDA-ARS?s Scientific Manuscript database

Host plants provide food, shelter and mating habitats for herbivorous and parasitoid insects. Yet each plant species is a distinct microhabitat and insects must adapt to its chemical and physical attributes in order to survive, mate and reproduce. Behavioral and genetic divergence between insect pop...
Insulin-like peptide genes in honey bee fat body respond differently to manipulation of social behavioral physiology.

PubMed

Nilsen, Kari-Anne; Ihle, Kate E; Frederick, Katy; Fondrk, M Kim; Smedal, Bente; Hartfelder, Klaus; Amdam, Gro V

2011-05-01

Nutrient sensitive insulin-like peptides (ILPs) have profound effects on invertebrate metabolism, nutrient storage, fertility and aging. Many insects transcribe ILPs in specialized neurosecretory cells at changing levels correlated with life history. However, the major site of insect metabolism and nutrient storage is not the brain, but rather the fat body, where functions of ILP expression are rarely studied and poorly understood. Fat body is analogous to mammalian liver and adipose tissue, with nutrient stores that often correlate with behavior. We used the honey bee (Apis mellifera), an insect with complex behavior, to test whether ILP genes in fat body respond to experimentally induced changes of behavioral physiology. Honey bee fat body influences endocrine state and behavior by secreting the yolk protein precursor vitellogenin (Vg), which suppresses lipophilic juvenile hormone and social foraging behavior. In a two-factorial experiment, we used RNA interference (RNAi)-mediated vg gene knockdown and amino acid nutrient enrichment of hemolymph (blood) to perturb this regulatory module. We document factor-specific changes in fat body ilp1 and ilp2 mRNA, the bee's ILP-encoding genes, and confirm that our protocol affects social behavior. We show that ilp1 and ilp2 are regulated independently and differently and diverge in their specific expression-localization between fat body oenocyte and trophocyte cells. Insect ilp functions may be better understood by broadening research to account for expression in fat body and not only brain.
Insulin-like peptide genes in honey bee fat body respond differently to manipulation of social behavioral physiology

PubMed Central

Nilsen, Kari-Anne; Ihle, Kate E.; Frederick, Katy; Fondrk, M. Kim; Smedal, Bente; Hartfelder, Klaus; Amdam, Gro V.

2011-01-01

SUMMARY Nutrient sensitive insulin-like peptides (ILPs) have profound effects on invertebrate metabolism, nutrient storage, fertility and aging. Many insects transcribe ILPs in specialized neurosecretory cells at changing levels correlated with life history. However, the major site of insect metabolism and nutrient storage is not the brain, but rather the fat body, where functions of ILP expression are rarely studied and poorly understood. Fat body is analogous to mammalian liver and adipose tissue, with nutrient stores that often correlate with behavior. We used the honey bee (Apis mellifera), an insect with complex behavior, to test whether ILP genes in fat body respond to experimentally induced changes of behavioral physiology. Honey bee fat body influences endocrine state and behavior by secreting the yolk protein precursor vitellogenin (Vg), which suppresses lipophilic juvenile hormone and social foraging behavior. In a two-factorial experiment, we used RNA interference (RNAi)-mediated vg gene knockdown and amino acid nutrient enrichment of hemolymph (blood) to perturb this regulatory module. We document factor-specific changes in fat body ilp1 and ilp2 mRNA, the bee's ILP-encoding genes, and confirm that our protocol affects social behavior. We show that ilp1 and ilp2 are regulated independently and differently and diverge in their specific expression-localization between fat body oenocyte and trophocyte cells. Insect ilp functions may be better understood by broadening research to account for expression in fat body and not only brain. PMID:21490257

Sensorimotor Integration of Antennal Positioning in Flying Insects

DTIC Science & Technology

2015-02-23

eclectic approach is necessary for a deeper understanding of the physics and biology of insect flight, its role in evolution and its influence upon ecology ...Sane, in preparation; Saxena, Natesan and Sane, in preparation) Natural history of plant -insect interactions in the oleander hawk moth, Daphnis...distances. We are interested in the following broad questions relating migration to insect- plant interactions : 1. How do small insects, with a limited fuel
Deriving neural network controllers from neuro-biological data: implementation of a single-leg stick insect controller.

PubMed

von Twickel, Arndt; Büschges, Ansgar; Pasemann, Frank

2011-02-01

This article presents modular recurrent neural network controllers for single legs of a biomimetic six-legged robot equipped with standard DC motors. Following arguments of Ekeberg et al. (Arthropod Struct Dev 33:287-300, 2004), completely decentralized and sensori-driven neuro-controllers were derived from neuro-biological data of stick-insects. Parameters of the controllers were either hand-tuned or optimized by an evolutionary algorithm. Employing identical controller structures, qualitatively similar behaviors were achieved for robot and for stick insect simulations. For a wide range of perturbing conditions, as for instance changing ground height or up- and downhill walking, swing as well as stance control were shown to be robust. Behavioral adaptations, like varying locomotion speeds, could be achieved by changes in neural parameters as well as by a mechanical coupling to the environment. To a large extent the simulated walking behavior matched biological data. For example, this was the case for body support force profiles and swing trajectories under varying ground heights. The results suggest that the single-leg controllers are suitable as modules for hexapod controllers, and they might therefore bridge morphological- and behavioral-based approaches to stick insect locomotion control.
The Amateur Scientist.

ERIC Educational Resources Information Center

Walker, Jearl

1983-01-01

Water striders are insects that walk and run on the surface of water. Discusses the morphology, physiology, and behavior of these insects. Includes diagrams of stages in the movement of a typical strider. (JN)
Lessons from Studying Insect Symbioses

PubMed Central

Douglas, Angela E.

2011-01-01

As for mammals, insect health is strongly influenced by the composition and activities of resident microorganisms. However, the microbiota of insects is generally less diverse than that of mammals, allowing microbial function in insects to be coupled to individual, identified microbial species. This trait of insect symbioses facilitates our understanding of the mechanisms that promote insect-microbial coexistence and the processes by which the microbiota affect insect wellbeing. As a result, insects are potentially ideal models to study various aspects of interactions between the host and its resident microorganisms that are impractical or unfeasible in mammals and to generate hypotheses for subsequent testing in mammalian models. PMID:22018236
Linking Insects with Crustacea: Physiology of the Pancrustacea: An Introduction to the Symposium.

PubMed

Tamone, Sherry L; Harrison, Jon F

2015-11-01

Insects and crustaceans represent critical, dominant animal groups (by biomass and species number) in terrestrial and aquatic systems, respectively. Insects (hexapods) and crustaceans are historically grouped under separate taxonomic classes within the Phylum Arthropoda, and the research communities studying hexapods and crustaceans are quite distinct. More recently, the hexapods have been shown to be evolutionarily derived from basal crustaceans, and the clade Pancrustacea recognizes this relationship. This recent evolutionary perspective, and the fact that the Society for Integrative and Comparative Biology has strong communities in both invertebrate biology and insect physiology, provides the motivation for this symposium. Speakers in this symposium were selected because of their expertise in a particular field of insect or crustacean physiology, and paired in such a way as to provide a comparative view of the state of the current research in their respective fields. Presenters discussed what aspects of the physiological system are clearly conserved across insects and crustaceans and how cross-talk between researchers utilizing insects and crustaceans can fertilize understanding of such conserved systems. Speakers were also asked to identify strategies that would enable improved understanding of the evolution of physiological systems of the terrestrial insects from the aquatic crustaceans. The following collection of articles describes multiple recent advances in our understanding of Pancrustacean physiology. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
Variation in the susceptibility of Drosophila to different entomopathogenic nematodes.

PubMed

Peña, Jennifer M; Carrillo, Mayra A; Hallem, Elissa A

2015-03-01

Entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema are lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species of Drosophila fruit flies as model hosts. We show that the EPN Steinernema carpocapsae, which is widely used for insect control, is capable of infecting and killing D. melanogaster larvae. S. carpocapsae is associated with the bacterium Xenorhabdus nematophila, and we show that X. nematophila induces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence toward D. melanogaster and that Drosophila species vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Vector-Borne Bacterial Plant Pathogens: Interactions with Hemipteran Insects and Plants

PubMed Central

Perilla-Henao, Laura M.; Casteel, Clare L.

2016-01-01

Hemipteran insects are devastating pests of crops due to their wide host range, rapid reproduction, and ability to transmit numerous plant-infecting pathogens as vectors. While the field of plant–virus–vector interactions has flourished in recent years, plant–bacteria–vector interactions remain poorly understood. Leafhoppers and psyllids are by far the most important vectors of bacterial pathogens, yet there are still significant gaps in our understanding of their feeding behavior, salivary secretions, and plant responses as compared to important viral vectors, such as whiteflies and aphids. Even with an incomplete understanding of plant–bacteria–vector interactions, some common themes have emerged: (1) all known vector-borne bacteria share the ability to propagate in the plant and insect host; (2) particular hemipteran families appear to be incapable of transmitting vector-borne bacteria; (3) all known vector-borne bacteria have highly reduced genomes and coding capacity, resulting in host-dependence; and (4) vector-borne bacteria encode proteins that are essential for colonization of specific hosts, though only a few types of proteins have been investigated. Here, we review the current knowledge on important vector-borne bacterial pathogens, including Xylella fastidiosa, Spiroplasma spp., Liberibacter spp., and ‘Candidatus Phytoplasma spp.’. We then highlight recent approaches used in the study of vector-borne bacteria. Finally, we discuss the application of this knowledge for control and future directions that will need to be addressed in the field of vector–plant–bacteria interactions. PMID:27555855
Colony social structure in native and invasive populations of the social wasp Vespula pensylvanica

USGS Publications Warehouse

Hanna, Cause; Cook, Erin D.; Thompson, Ariel R.; Dare, Lyndzey E.; Palaski, Amanda L.; Foote, David; Goodisman, Michael A. D.

2014-01-01

Social insects rank among the most invasive of terrestrial species. The success of invasive social insects stems, in part, from the flexibility derived from their social behaviors. We used genetic markers to investigate if the social system of the invasive wasp, Vespula pensylvanica, differed in its introduced and native habitats in order to better understand variation in social phenotype in invasive social species. We found that (1) nestmate workers showed lower levels of relatedness in introduced populations than native populations, (2) introduced colonies contained workers produced by multiple queens whereas native colonies contained workers produced by only a single queen, (3) queen mate number did not differ significantly between introduced and native colonies, and (4) workers from introduced colonies were frequently produced by queens that originated from foreign nests. Thus, overall, native and introduced colonies differed substantially in social phenotype because introduced colonies more frequently contained workers produced by multiple, foreign queens. In addition, the similarity in levels of genetic variation in introduced and native habitats, as well as observed variation in colony social phenotype in native populations, suggest that colony structure in invasive populations may be partially associated with social plasticity. Overall, the differences in social structure observed in invasive V. pensylvanica parallel those in other, distantly related invasive social insects, suggesting that insect societies often develop similar social phenotypes upon introduction into new habitats.
The age for the fossil-bearing Tabbowa beds in Sri Lanka

NASA Astrophysics Data System (ADS)

Chang, S. C.; Dassanayake, S.; Wang, J.

2014-12-01

Well-preserved terrestrial fossils, mainly including conifers, cycads and ferns, were discovered from the Tabbowa beds in northwestern Sri Lanka. The high diversity and abundance of plants and insects from these Jurassic sediments provide a unique window to understand floral evolution and plant-insect co-evolution in the Mesozoic. For example, unearthed fossils from the Tabbowa beds indicate that leaf feeding and dwelling insects played a significant role in the Jurassic ecosystem. For another example, feeding and chewing marks on leaves allow studying insect behavior and paleo-ecology. Additionally, the recent discoveries of Otozamites latiphyllus and Otozamites tabbowensis from these sediments provide evidence that Bennettitales, an extinct order of seed plants, widely spread in the Gondwana during the Jurassic period. Although most fossils are yet to be well studied, and only few of the fossil occurrences have been published in western journals, plant fossils from the Tabbowa beds have great potential for substantially increasing our knowledge of Jurassic terrestrial ecosystems. The fossil-bearing Tabbowa beds are mainly composed of sandstone, siltstone, and mudstone with occasional thin bands of nodular limestone. Until now, radio-isotopic age determinations for the fossil-rich Tabbowa beds are lacking. In this study, we investigate the geological and geochronological setting of this area by dating detrital zircons from the Tabbowa beds. The age data will allow testing several hypotheses regarding the plant evolution, the basin development of this region.
Repellent and deterrent effects of SS220, Picaridin, and Deet suppress human blood feeding by Aedes aegypti, Anopheles stephensi, and Phlebotomus papatasi.

PubMed

Klun, Jerome A; Khrimian, Ashot; Debboun, Mustapha

2006-01-01

A series of behavioral tests with Aedes aegypti (L.), Anopheles stephensi Liston, mosquitoes, and the sand fly Phlebotomus papatasi Scopoli in the presence of Deet, SS220, and Picaridin topically applied to the skin of human volunteers showed that the insects were deterred from feeding on and repelled from surfaces emanating the compounds. When offered a 12- or 24-cm2 area of skin, one-half treated with compound and one-half untreated, the insects fed almost exclusively on untreated skin. The sand flies and mosquitoes did not at any time physically contact chemically treated surfaces. When treated and untreated skin areas were covered with cloth, insects contacted, landed, and bit only through cloth covering untreated skin. These observations provided evidence that the compounds deterred feeding and repelled insects from treated surfaces primarily as a result of olfactory sensing. When cloth, one-half untreated and one-half treated with chemical, was placed over untreated skin, insects only touched and specifically bit through the untreated cloth. This showed that the activity of the chemicals does not involve a chemical x skin interaction. In the presence of any of the three chemicals, no matter how they were presented to the insects, overall population biting activity was reduced by about one-half relative to controls. This reduction showed a true repellent effect for the compounds. Results clearly showed that Deet, SS220, and Picaridin exert repellent and deterrent effects upon the behavior of mosquitoes and sand flies. Heretofore, the combined behavioral effects of these compounds upon mosquito and sand fly behavior were unknown. Moreover, protection afforded by Deet, SS220, and Picaridin against the feeding of these three disease vectors on humans is mechanistically a consequence of the two chemical effects.
Practical applications of insects' sexual development for pest control.

PubMed

Koukidou, M; Alphey, L

2014-01-01

Elucidation of the sex differentiation pathway in insects offers an opportunity to understand key aspects of evolutionary developmental biology. In addition, it provides the understanding necessary to manipulate insects in order to develop new synthetic genetics-based tools for the control of pest insects. Considerable progress has been made in this, especially in improvements to the sterile insect technique (SIT). Large scale sex separation is considered highly desirable or essential for most SIT targets. This separation can be provided by genetic methods based on sex-specific gene expression. Investigation of sex determination by many groups has provided molecular components and methods for this. Though the primary sex determination signal varies considerably, key regulatory genes and mechanisms remain surprisingly similar. In most cases studied so far, a primary signal is transmitted to a basal gene at the bottom of the hierarchy (dsx) through an alternative splicing cascade; dsx is itself differentially spliced in males and females. A sex-specific alternative splicing system therefore offers an attractive route to achieve female-specific expression. Experience has shown that alternative splicing modules can be developed with cross-species function; modularity and standardisation and re-use of parts are key principles of synthetic biology. Both female-killing and sex reversal (XX females to phenotypic males) can in principle also be used as efficient alternatives to sterilisation in SIT-like methods. Sexual maturity is yet another area where understanding of sexual development may be applied to insect control programmes. Further detailed understanding of this crucial aspect of insect biology will undoubtedly continue to underpin innovative practical applications. © 2014 S. Karger AG, Basel.
Strategic and tactical use of movement information in pest management

NASA Technical Reports Server (NTRS)

Knipling, E. F.

1979-01-01

Several insect movement problems are discussed. Much more information is needed to make a better appraisal of the practical significance of the insect dispersal problem. Data on the time, rate, and extent of movement of insects are provided. Better techniques for measuring insect movement are developed. A better understanding of the importance of insect movement in the development and implementation of more effective and ecologically acceptable pest management strategies and tactics was proved.
Odorant-binding proteins display high affinities for behavioral attractants and repellents in the natural predator Chrysopa pallens.

PubMed

Li, Zhao-Qun; Zhang, Shuai; Luo, Jun-Yu; Wang, Si-Bao; Dong, Shuang-Lin; Cui, Jin-Jie

2015-07-01

Chrysopa pallens is an important natural predator of various pests in many different cropping systems. Understanding the sophisticated olfactory system of insect antennae is crucial for studying the physiological bases of olfaction and could also help enhance the effectiveness of C. pallens in biological control. However, functional studies of the olfactory genes in C. pallens are still lacking. In this study, we cloned five odorant-binding protein (OBP) genes from C. pallens (CpalOBPs). Quantitative RT-PCR results indicated that the five CpalOBPs had different tissue expression profiles. Ligand-binding assays showed that farnesol, farnesene, cis-3-hexenyl hexanoate, geranylacetone, beta-ionone, octyl aldehyde, decanal, nerolidol (Ki<20 μM), and especially 2-pentadecanone (Ki=1.19 μM) and 2-hexyl-1-decanol (Ki=0.37 μM) strongly bound to CpalOBP2. CpalOBP15 exhibited high binding affinities for beta-ionone, 2-tridecanone, trans-nerolidol, and dodecyl aldehyde. Behavioral trials using the 14 compounds exhibiting high binding affinities for the CpalOBPs revealed that nine were able to elicit significant behavioral responses from C. pallens. Among them, farnesene and its corresponding alcohol, farnesol, elicited remarkable repellent behavioral responses from C. pallens. Our study provides several compounds that could be selected to develop slow-release agents that attract/repel C. pallens and to improve the search for strategies to eliminate insect pests. Copyright © 2015 Elsevier Inc. All rights reserved.
Ethanol-Induced Effects on Sting Extension Response and Punishment Learning in the Western Honey Bee (Apis mellifera)

PubMed Central

Giannoni-Guzmán, Manuel A.; Giray, Tugrul; Agosto-Rivera, Jose Luis; Stevison, Blake K.; Freeman, Brett; Ricci, Paige; Brown, Erika A.; Abramson, Charles I.

2014-01-01

Acute ethanol administration is associated with sedation and analgesia as well as behavioral disinhibition and memory loss but the mechanisms underlying these effects remain to be elucidated. During the past decade, insects have emerged as important model systems to understand the neural and genetic bases of alcohol effects. However, novel assays to assess ethanol's effects on complex behaviors in social or isolated contexts are necessary. Here we used the honey bee as an especially relevant model system since bees are typically exposed to ethanol in nature when collecting standing nectar crop of flowers, and there is recent evidence for independent biological significance of this exposure for social behavior. Bee's inhibitory control of the sting extension response (SER) and a conditioned-place aversion assay were used to study ethanol effects on analgesia, behavioral disinhibition, and associative learning. Our findings indicate that although ethanol, in a dose-dependent manner, increases SER thresholds (analgesic effects), it disrupts the ability of honey bees to inhibit SER and to associate aversive stimuli with their environment. These results suggest that ethanol's effects on analgesia, behavioral disinhibition and associative learning are common across vertebrates and invertebrates. These results add to the use of honey bees as an ethanol model to understand ethanol's effects on complex, socially relevant behaviors. PMID:24988309
Precocene-I inhibits juvenile hormone biosynthesis, ovarian activation, aggression and alters sterility signal production in bumble bee (Bombus terrestris) workers

USDA-ARS?s Scientific Manuscript database

Juvenile hormone (JH) is an important regulator of development and physiology in insects. While in many insect species, including bumble bees, JH function as gonadotropin in adults, in some highly eusocial insects its role has shifted to regulate social behavior including division of labor, dominanc...
Odorant receptor modulation: Ternary paradigm for mode of action of insect repellents

USDA-ARS?s Scientific Manuscript database

The modulation of insect behavior for the purpose of controlling the spread of infectious diseases has been the task of a few insect repellents for which the mechanistic modes of action on odorant receptors (ORs) are unclear. Here, we study the effects of the repellents DEET and IR3535, and a novel ...
Uncovering the novel characteristics of Asian honey bee, Apis cerana, by whole genome sequencing.

PubMed

Park, Doori; Jung, Je Won; Choi, Beom-Soon; Jayakodi, Murukarthick; Lee, Jeongsoo; Lim, Jongsung; Yu, Yeisoo; Choi, Yong-Soo; Lee, Myeong-Lyeol; Park, Yoonseong; Choi, Ik-Young; Yang, Tae-Jin; Edwards, Owain R; Nah, Gyoungju; Kwon, Hyung Wook

2015-01-02

The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A.cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory.
Movement and Orientation Decision Modeling of Rhyzopertha dominica (Coleoptera: Bostrichidae) in the Grain Mass.

PubMed

Cordeiro, Erick M G; Campbell, James F; Phillips, Thomas W

2016-04-01

Grain stored in bins is initially a relatively homogenous resource patch for stored-product insects, but over time, spatial pattern in insect distribution can form, due in part to insect movement patterns. However, the factors that influence stored-product insect movement patterns in grain are not well-understood. This research focused on the movement of the lesser grain borer, Rhyzopertha dominica (F.), within a simulated wheat grain mass (vertical monolayer of wheat) and the identification of factors that contribute to overall and upward movement (age since adult emergence from an infested kernel [1, 7, and 14 d], sex, strain, and different levels of environment quality). We also used the model selection approach to select the most relevant factors and determine the relationships among them. Three-week-old adults tended to stay closer to the surface compared with 1- or 2-wk-old insects. Also, females tended to be more active and to explore a larger area compared with males. Explored area and daily displacement were also significantly strain-dependent, and increasing grain infestation level decreased daily displacement and explored area. Variation in movement pattern is likely to influence the formation of spatial pattern and affect probability to disperse. Understanding movement behavior within a grain bin is crucial to designing better strategies to implement and interpret monitoring programs and to target control tactics. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.
Measuring individual locomotor rhythms in honey bees, paper wasps and other similar-sized insects

PubMed Central

Giannoni-Guzmán, Manuel A.; Avalos, Arian; Perez, Jaime Marrero; Loperena, Eduardo J. Otero; Kayım, Mehmet; Medina, Jose Alejandro; Massey, Steve E.; Kence, Meral; Kence, Aykut; Giray, Tugrul; Agosto-Rivera, José L.

2014-01-01

Circadian rhythms in social insects are highly plastic and are modulated by multiple factors. In addition, complex behaviors such as sun-compass orientation and time learning are clearly regulated by the circadian system in these organisms. Despite these unique features of social insect clocks, the mechanisms as well as the functional and evolutionary relevance of these traits remain largely unknown. Here we show a modification of the Drosophila activity monitoring (DAM) system that allowed us to measure locomotor rhythms of the honey bee, Apis mellifera (three variants; gAHB, carnica and caucasica), and two paper wasps (Polistes crinitus and Mischocyttarus phthisicus). A side-by-side comparison of the endogenous period under constant darkness (free-running period) led us to the realization that these social insects exhibit significant deviations from the Earth's 24 h rotational period as well as a large degree of inter-individual variation compared with Drosophila. Experiments at different temperatures, using honey bees as a model, revealed that testing the endogenous rhythm at 35°C, which is the hive's core temperature, results in average periods closer to 24 h compared with 25°C (23.8 h at 35°C versus 22.7 h at 25°C). This finding suggests that the degree of tuning of circadian temperature compensation varies among different organisms. We expect that the commercial availability, cost-effectiveness and integrated nature of this monitoring system will facilitate the growth of the circadian field in these social insects and catalyze our understanding of the mechanisms as well as the functional and evolutionary relevance of circadian rhythms. PMID:24436380
Interactive effects of large herbivores and plant diversity on insect abundance in a meadow steppe in China

Treesearch

Hui Zhu; Deli Wang; Qinfeng Guo; Jun Liu; Ling Wang

2015-01-01

The structure and dynamics of insect community in grasslands can be influenced by grazing management via altered characteristics of plant community. However, attempts to better understand the complex relationships among plants, insects, and large herbivores is still hampered largely by the interactive effects of plants, insects, and large grazers on each other. In this...

Fir sawyer beetle-Siberian fir interaction modeling: resistance of fir stands to insect outbreaks

Treesearch

Tamara M. Ovtchinnikova; Victor V. Kiselev

1991-01-01

Entomological monitoring is part of a total ecological monitoring system. Its purpose is the identification, prognosis, and estimation of forest ecosystem impacts induced by insects. The entomological monitoring of a forest is based on a clear understanding of the role played by insects in forest ecosystems. The patterns of insect population dynamics in space and time...
Adult-specific insulin-producing neurons in Drosophila melanogaster.

PubMed

Ohhara, Yuya; Kobayashi, Satoru; Yamakawa-Kobayashi, Kimiko; Yamanaka, Naoki

2018-06-01

Holometabolous insects undergo metamorphosis to reorganize their behavioral and morphological features into adult-specific ones. In the central nervous system (CNS), some larval neurons undergo programmed cell death, whereas others go through remodeling of axonal and dendritic arbors to support functions of re-established adult organs. Although there are multiple neuropeptides that have stage-specific roles in holometabolous insects, the reorganization pattern of the entire neuropeptidergic system through metamorphosis still remains largely unclear. In this study, we conducted a mapping and lineage tracing of peptidergic neurons in the larval and adult CNS by using Drosophila genetic tools. We found that Diuretic hormone 44-producing median neurosecretory cells start expressing Insulin-like peptide 2 in the pharate adult stage. This neuronal cluster projects to the corpora cardiaca and dorsal vessel in both larval and adult stages, and also innervates an adult-specific structure in the digestive tract, the crop. We propose that the adult-specific insulin-producing cells may regulate functions of the digestive system in a stage-specific manner. Our study provides a neuroanatomical basis for understanding remodeling of the neuropeptidergic system during insect development and evolution. © 2018 Wiley Periodicals, Inc.
Organization of descending neurons in Drosophila melanogaster

PubMed Central

Hsu, Cynthia T.; Bhandawat, Vikas

2016-01-01

Neural processing in the brain controls behavior through descending neurons (DNs) - neurons which carry signals from the brain to the spinal cord (or thoracic ganglia in insects). Because DNs arise from multiple circuits in the brain, the numerical simplicity and availability of genetic tools make Drosophila a tractable model for understanding descending motor control. As a first step towards a comprehensive study of descending motor control, here we estimate the number and distribution of DNs in the Drosophila brain. We labeled DNs by backfilling them with dextran dye applied to the neck connective and estimated that there are ~1100 DNs distributed in 6 clusters in Drosophila. To assess the distribution of DNs by neurotransmitters, we labeled DNs in flies in which neurons expressing the major neurotransmitters were also labeled. We found DNs belonging to every neurotransmitter class we tested: acetylcholine, GABA, glutamate, serotonin, dopamine and octopamine. Both the major excitatory neurotransmitter (acetylcholine) and the major inhibitory neurotransmitter (GABA) are employed equally; this stands in contrast to vertebrate DNs which are predominantly excitatory. By comparing the distribution of DNs in Drosophila to those reported previously in other insects, we conclude that the organization of DNs in insects is highly conserved. PMID:26837716
Organization of descending neurons in Drosophila melanogaster.

PubMed

Hsu, Cynthia T; Bhandawat, Vikas

2016-02-03

Neural processing in the brain controls behavior through descending neurons (DNs) - neurons which carry signals from the brain to the spinal cord (or thoracic ganglia in insects). Because DNs arise from multiple circuits in the brain, the numerical simplicity and availability of genetic tools make Drosophila a tractable model for understanding descending motor control. As a first step towards a comprehensive study of descending motor control, here we estimate the number and distribution of DNs in the Drosophila brain. We labeled DNs by backfilling them with dextran dye applied to the neck connective and estimated that there are ~1100 DNs distributed in 6 clusters in Drosophila. To assess the distribution of DNs by neurotransmitters, we labeled DNs in flies in which neurons expressing the major neurotransmitters were also labeled. We found DNs belonging to every neurotransmitter class we tested: acetylcholine, GABA, glutamate, serotonin, dopamine and octopamine. Both the major excitatory neurotransmitter (acetylcholine) and the major inhibitory neurotransmitter (GABA) are employed equally; this stands in contrast to vertebrate DNs which are predominantly excitatory. By comparing the distribution of DNs in Drosophila to those reported previously in other insects, we conclude that the organization of DNs in insects is highly conserved.
Differential gene expression in Xylella fastidiosa 9a5c during co-cultivation with the endophytic bacterium Methylobacterium mesophilicum SR1.6/6.

PubMed

Dourado, Manuella Nóbrega; Santos, Daiene Souza; Nunes, Luiz Roberto; Costa de Oliveira, Regina Lúcia Batista da; de Oliveira, Marcus Vinicius; Araújo, Welington Luiz

2015-12-01

Xylella fastidiosa, the causal agent of citrus variegated chlorosis (CVC), colonizes plant xylem, reducing sap flow, and inducing internerval chlorosis, leaf size reduction, necrosis, and harder and smaller fruits. This bacterium may be transmitted from plant to plant by sharpshooter insects, including Bucephalogonia xanthopis. The citrus endophytic bacterium Methylobacterium mesophilicum SR1.6/6 colonizes citrus xylem and previous studies showed that this strain is also transferred from plant to plant by B. xanthopis (Insecta), suggesting that this endophytic bacterium may interact with X. fastidiosa in planta and inside the insect vector during co-transmission by the same insect vector. To better understand the X. fastidiosa behavior in the presence of M. mesophilicum, we evaluated the X. fastidiosa transcriptional profile during in vitro interaction with M. mesophilicum SR1.6/6. The results showed that during co-cultivation, X. fastidiosa down-regulated genes related to growth and up-regulated genes related to energy production, stress, transport, and motility, suggesting the existence of a specific adaptive response to the presence of M. mesophilicum in the culture medium. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Magnetic compasses in insects

USDA-ARS?s Scientific Manuscript database

The use of magnetic information for orientation and navigation is a widespread phenomenon in animals. In contrast to navigational systems in vertebrates, our understanding of the mechanisms underlying the insect magnetic perception and use of the information is at an early stage. Some insects use ma...
The Mantis Project.

ERIC Educational Resources Information Center

Palopoli, Maria L.

1998-01-01

Explains an integrated insect unit in which students learn about the characteristics, life cycle, and environment of an organism; learn about specific body structures; and make inferences about the body structure and behaviors of the insects. (DDR)
Explaining the host-finding behavior of blood-sucking insects: computerized simulation of the effects of habitat geometry on tsetse fly movement.

PubMed

Vale, Glyn A; Hargrove, John W; Solano, Philippe; Courtin, Fabrice; Rayaisse, Jean-Baptiste; Lehane, Michael J; Esterhuizen, Johan; Tirados, Inaki; Torr, Stephen J

2014-06-01

Male and female tsetse flies feed exclusively on vertebrate blood. While doing so they can transmit the diseases of sleeping sickness in humans and nagana in domestic stock. Knowledge of the host-orientated behavior of tsetse is important in designing bait methods of sampling and controlling the flies, and in understanding the epidemiology of the diseases. For this we must explain several puzzling distinctions in the behavior of the different sexes and species of tsetse. For example, why is it that the species occupying savannahs, unlike those of riverine habitats, appear strongly responsive to odor, rely mainly on large hosts, are repelled by humans, and are often shy of alighting on baits? A deterministic model that simulated fly mobility and host-finding success suggested that the behavioral distinctions between riverine, savannah and forest tsetse are due largely to habitat size and shape, and the extent to which dense bushes limit occupiable space within the habitats. These factors seemed effective primarily because they affect the daily displacement of tsetse, reducing it by up to ∼70%. Sex differences in behavior are explicable by females being larger and more mobile than males. Habitat geometry and fly size provide a framework that can unify much of the behavior of all sexes and species of tsetse everywhere. The general expectation is that relatively immobile insects in restricted habitats tend to be less responsive to host odors and more catholic in their diet. This has profound implications for the optimization of bait technology for tsetse, mosquitoes, black flies and tabanids, and for the epidemiology of the diseases they transmit.
Nocturnal insect availability in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley

USGS Publications Warehouse

Loraine Ketzler,; Christopher Comer,; Twedt, Daniel J.

2017-01-01

Silviculture used to alter forest structure and thereby enhance wildlife habitat has been advocated for bottomland hardwood forest management on public conservation lands in the Mississippi Alluvial Valley. Although some songbirds respond positively to these management actions to attain desired forest conditions for wildlife, the response of other species, is largely unknown. Nocturnal insects are a primary prey base for bats, thereby influencing trophic interactions within hardwood forests. To better understand how silviculture influences insect availability for bats, we conducted vegetation surveys and sampled insect biomass within silviculturally treated bottomland hardwood forest stands. We used passive blacklight traps to capture nocturnal flying insects in 64 treated and 64 untreated reference stands, located on 15 public conservation areas in Arkansas, Louisiana, and Mississippi. Dead wood and silvicultural treatments were positively associated with greater biomass of macro-Lepidoptera, macro-Coleoptera, and all insect taxa combined. Biomass of micro-Lepidoptera was negatively associated with silvicultural treatment but comprised only a small proportion of total biomass. Understanding the response of nocturnal insects to wildlife-forestry silviculture provides insight for prescribed silvicultural management affecting bat species.
Mixture and odorant processing in the olfactory systems of insects: a comparative perspective.

PubMed

Clifford, Marie R; Riffell, Jeffrey A

2013-11-01

Natural olfactory stimuli are often complex mixtures of volatiles, of which the identities and ratios of constituents are important for odor-mediated behaviors. Despite this importance, the mechanism by which the olfactory system processes this complex information remains an area of active study. In this review, we describe recent progress in how odorants and mixtures are processed in the brain of insects. We use a comparative approach toward contrasting olfactory coding and the behavioral efficacy of mixtures in different insect species, and organize these topics around four sections: (1) Examples of the behavioral efficacy of odor mixtures and the olfactory environment; (2) mixture processing in the periphery; (3) mixture coding in the antennal lobe; and (4) evolutionary implications and adaptations for olfactory processing. We also include pertinent background information about the processing of individual odorants and comparative differences in wiring and anatomy, as these topics have been richly investigated and inform the processing of mixtures in the insect olfactory system. Finally, we describe exciting studies that have begun to elucidate the role of the processing of complex olfactory information in evolution and speciation.
Issues of convection in insect respiration: Insights from synchrotron X-ray imaging and beyond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Socha, John J.; Förster, Thomas D.; Greenlee, Kendra J.

2010-11-01

While it has long been known that in small animals, such as insects, sufficient gas transport could be provided by diffusion, it is now recognized that animals generate and control convective flows to improve oxygen delivery across a range of body sizes and taxa. However, size-based methodological limitations have constrained our understanding of the mechanisms that underlie the production of these convective flows. Recently, new techniques have enabled the elucidation of the anatomical structures and physiological processes that contribute to creating and maintaining bulk flow in small animals. In particular, synchrotron X-ray imaging provides unprecedented spatial and temporal resolution ofmore » internal functional morphology and is changing the way we understand gas exchange in insects. This symposium highlights recent efforts towards understanding the relationship between form, function, and control in the insect respiratory system.« less
Uncontrolled Stability in Freely Flying Insects

NASA Astrophysics Data System (ADS)

Melfi, James, Jr.; Wang, Z. Jane

2015-11-01

One of the key flight modes of a flying insect is longitudinal flight, traveling along a localized two-dimensional plane from one location to another. Past work on this topic has shown that flying insects, unless stabilized by some external stimulus, are typically unstable to a well studied pitching instability. In our work, we examine this instability in a computational study to understand whether it is possible for either evolution or an aero-vehicle designer to stabilize longitudinal flight through changes to insect morphology, kinematics, or aerodynamic quantities. A quasi-steady wingbeat averaged flapping flight model is used to describe the insect. From this model, a number of non-dimensional parameters are identified. The effect of these parameters was then quantified using linear stability analysis, applied to various translational states of the insect. Based on our understanding of these parameters, we demonstrate how to find an intrinsically stable flapping flight sequence for a dragonfly-like flapping flier in an instantaneous flapping flight model.
Velocity correlations in laboratory insect swarms

NASA Astrophysics Data System (ADS)

Ni, R.; Ouellette, N. T.

2015-12-01

In contrast to animal groups such as bird flocks or migratory herds that display net, directed motion, insect swarms do not possess global order. Without such order, it is difficult to define and characterize the transition to collective behavior in swarms; nevertheless, visual observation of swarms strongly suggests that swarming insects do behave collectively. It has recently been suggested that correlation rather than order is the hallmark of emergent collective behavior. Here, we report measurements of spatial velocity correlation functions in laboratory mating swarms of the non-biting midge Chironomus riparius. Although we find some correlation at short distances, our swarms are in general only weakly correlated, in contrast to what has been observed in field studies. Our results hint at the potentially important role of environmental conditions on collective behavior, and suggest that general indicators of the collective nature of swarming are still needed.
Mechanosensation and Adaptive Motor Control in Insects.

PubMed

Tuthill, John C; Wilson, Rachel I

2016-10-24

The ability of animals to flexibly navigate through complex environments depends on the integration of sensory information with motor commands. The sensory modality most tightly linked to motor control is mechanosensation. Adaptive motor control depends critically on an animal's ability to respond to mechanical forces generated both within and outside the body. The compact neural circuits of insects provide appealing systems to investigate how mechanical cues guide locomotion in rugged environments. Here, we review our current understanding of mechanosensation in insects and its role in adaptive motor control. We first examine the detection and encoding of mechanical forces by primary mechanoreceptor neurons. We then discuss how central circuits integrate and transform mechanosensory information to guide locomotion. Because most studies in this field have been performed in locusts, cockroaches, crickets, and stick insects, the examples we cite here are drawn mainly from these 'big insects'. However, we also pay particular attention to the tiny fruit fly, Drosophila, where new tools are creating new opportunities, particularly for understanding central circuits. Our aim is to show how studies of big insects have yielded fundamental insights relevant to mechanosensation in all animals, and also to point out how the Drosophila toolkit can contribute to future progress in understanding mechanosensory processing. Copyright © 2016 Elsevier Ltd. All rights reserved.
Snowy Entomology

ERIC Educational Resources Information Center

Schmidt, Pamela; Chadde, Joan Schumaker; Buenzli, Michael

2003-01-01

Insects can be useful for investigations because they are numerous, relatively easy to find, and fascinating to students. Most elementary students have limited understandings of what exactly becomes of insects during the winter, often guessing that insects must "go to sleep" or "they just die." In this winter activity, students learn about insect…
An Automated Approach to Map the History of Forest Disturbance from Insect Mortality and Harvest with Landsat Time-Series Data

NASA Technical Reports Server (NTRS)

Rudasill-Neigh, Christopher S.; Bolton, Douglas K.; Diabate, Mouhamad; Williams, Jennifer J.; Carvalhais, Nuno

2014-01-01

Forests contain a majority of the aboveground carbon (C) found in ecosystems, and understanding biomass lost from disturbance is essential to improve our C-cycle knowledge. Our study region in the Wisconsin and Minnesota Laurentian Forest had a strong decline in Normalized Difference Vegetation Index (NDVI) from 1982 to 2007, observed with the National Ocean and Atmospheric Administration's (NOAA) series of Advanced Very High Resolution Radiometer (AVHRR). To understand the potential role of disturbances in the terrestrial C-cycle, we developed an algorithm to map forest disturbances from either harvest or insect outbreak for Landsat time-series stacks. We merged two image analysis approaches into one algorithm to monitor forest change that included: (1) multiple disturbance index thresholds to capture clear-cut harvest; and (2) a spectral trajectory-based image analysis with multiple confidence interval thresholds to map insect outbreak. We produced 20 maps and evaluated classification accuracy with air-photos and insect air-survey data to understand the performance of our algorithm. We achieved overall accuracies ranging from 65% to 75%, with an average accuracy of 72%. The producer's and user's accuracy ranged from a maximum of 32% to 70% for insect disturbance, 60% to 76% for insect mortality and 82% to 88% for harvested forest, which was the dominant disturbance agent. Forest disturbances accounted for 22% of total forested area (7349 km2). Our algorithm provides a basic approach to map disturbance history where large impacts to forest stands have occurred and highlights the limited spectral sensitivity of Landsat time-series to outbreaks of defoliating insects. We found that only harvest and insect mortality events can be mapped with adequate accuracy with a non-annual Landsat time-series. This limited our land cover understanding of NDVI decline drivers. We demonstrate that to capture more subtle disturbances with spectral trajectories, future observations must be temporally dense to distinguish between type and frequency in heterogeneous landscapes.
Tick Haller's Organ, a New Paradigm for Arthropod Olfaction: How Ticks Differ from Insects.

PubMed

Carr, Ann L; Mitchell, Robert D; Dhammi, Anirudh; Bissinger, Brooke W; Sonenshine, Daniel E; Roe, R Michael

2017-07-18

Ticks are the vector of many human and animal diseases; and host detection is critical to this process. Ticks have a unique sensory structure located exclusively on the 1st pairs of legs; the fore-tarsal Haller's organ, not found in any other animals, presumed to function like the insect antennae in chemosensation but morphologically very different. The mechanism of tick chemoreception is unknown. Utilizing next-generation sequencing and comparative transcriptomics between the 1st and 4th legs (the latter without the Haller's organ), we characterized 1st leg specific and putative Haller's organ specific transcripts from adult American dog ticks, Dermacentor variabilis . The analysis suggested that the Haller's organ is involved in olfaction, not gustation. No known odorant binding proteins like those found in insects, chemosensory lipocalins or typical insect olfactory mechanisms were identified; with the transcriptomic data only supporting a possible olfactory G-protein coupled receptor (GPCR) signal cascade unique to the Haller's organ. Each component of the olfactory GPCR signal cascade was identified and characterized. The expression of GPCR, G αo and β-arrestin transcripts identified exclusively in the 1st leg transcriptome, and putatively Haller's organ specific, were examined in unfed and blood-fed adult female and male D. variabilis . Blood feeding to repletion in adult females down-regulated the expression of all three chemosensory transcripts in females but not in males; consistent with differences in post-feeding tick behavior between sexes and an expected reduced chemosensory function in females as they leave the host. Data are presented for the first time of the potential hormonal regulation of tick chemosensation; behavioral assays confirmed the role of the Haller's organ in N , N -diethyl-meta-toluamide (DEET) repellency but showed no role for the Haller's organ in host attachment. Further research is needed to understand the potential role of the GPCR cascade in olfaction.
Tick Haller’s Organ, a New Paradigm for Arthropod Olfaction: How Ticks Differ from Insects

PubMed Central

Carr, Ann L.; Mitchell III, Robert D.; Dhammi, Anirudh; Bissinger, Brooke W.; Sonenshine, Daniel E.; Roe, R. Michael

2017-01-01

Ticks are the vector of many human and animal diseases; and host detection is critical to this process. Ticks have a unique sensory structure located exclusively on the 1st pairs of legs; the fore-tarsal Haller’s organ, not found in any other animals, presumed to function like the insect antennae in chemosensation but morphologically very different. The mechanism of tick chemoreception is unknown. Utilizing next-generation sequencing and comparative transcriptomics between the 1st and 4th legs (the latter without the Haller’s organ), we characterized 1st leg specific and putative Haller’s organ specific transcripts from adult American dog ticks, Dermacentor variabilis. The analysis suggested that the Haller’s organ is involved in olfaction, not gustation. No known odorant binding proteins like those found in insects, chemosensory lipocalins or typical insect olfactory mechanisms were identified; with the transcriptomic data only supporting a possible olfactory G-protein coupled receptor (GPCR) signal cascade unique to the Haller’s organ. Each component of the olfactory GPCR signal cascade was identified and characterized. The expression of GPCR, Gαo and β-arrestin transcripts identified exclusively in the 1st leg transcriptome, and putatively Haller’s organ specific, were examined in unfed and blood-fed adult female and male D. variabilis. Blood feeding to repletion in adult females down-regulated the expression of all three chemosensory transcripts in females but not in males; consistent with differences in post-feeding tick behavior between sexes and an expected reduced chemosensory function in females as they leave the host. Data are presented for the first time of the potential hormonal regulation of tick chemosensation; behavioral assays confirmed the role of the Haller’s organ in N,N-diethyl-meta-toluamide (DEET) repellency but showed no role for the Haller’s organ in host attachment. Further research is needed to understand the potential role of the GPCR cascade in olfaction. PMID:28718821
Stereotyped responses of Drosophila peptidergic neuronal ensemble depend on downstream neuromodulators

PubMed Central

Mena, Wilson; Diegelmann, Sören; Wegener, Christian; Ewer, John

2016-01-01

Neuropeptides play a key role in the regulation of behaviors and physiological responses including alertness, social recognition, and hunger, yet, their mechanism of action is poorly understood. Here, we focus on the endocrine control ecdysis behavior, which is used by arthropods to shed their cuticle at the end of every molt. Ecdysis is triggered by ETH (Ecdysis triggering hormone), and we show that the response of peptidergic neurons that produce CCAP (crustacean cardioactive peptide), which are key targets of ETH and control the onset of ecdysis behavior, depends fundamentally on the actions of neuropeptides produced by other direct targets of ETH and released in a broad paracrine manner within the CNS; by autocrine influences from the CCAP neurons themselves; and by inhibitory actions mediated by GABA. Our findings provide insights into how this critical insect behavior is controlled and general principles for understanding how neuropeptides organize neuronal activity and behaviors. DOI: http://dx.doi.org/10.7554/eLife.19686.001 PMID:27976997
A Bio-inspired Collision Avoidance Model Based on Spatial Information Derived from Motion Detectors Leads to Common Routes

PubMed Central

Bertrand, Olivier J. N.; Lindemann, Jens P.; Egelhaaf, Martin

2015-01-01

Avoiding collisions is one of the most basic needs of any mobile agent, both biological and technical, when searching around or aiming toward a goal. We propose a model of collision avoidance inspired by behavioral experiments on insects and by properties of optic flow on a spherical eye experienced during translation, and test the interaction of this model with goal-driven behavior. Insects, such as flies and bees, actively separate the rotational and translational optic flow components via behavior, i.e. by employing a saccadic strategy of flight and gaze control. Optic flow experienced during translation, i.e. during intersaccadic phases, contains information on the depth-structure of the environment, but this information is entangled with that on self-motion. Here, we propose a simple model to extract the depth structure from translational optic flow by using local properties of a spherical eye. On this basis, a motion direction of the agent is computed that ensures collision avoidance. Flying insects are thought to measure optic flow by correlation-type elementary motion detectors. Their responses depend, in addition to velocity, on the texture and contrast of objects and, thus, do not measure the velocity of objects veridically. Therefore, we initially used geometrically determined optic flow as input to a collision avoidance algorithm to show that depth information inferred from optic flow is sufficient to account for collision avoidance under closed-loop conditions. Then, the collision avoidance algorithm was tested with bio-inspired correlation-type elementary motion detectors in its input. Even then, the algorithm led successfully to collision avoidance and, in addition, replicated the characteristics of collision avoidance behavior of insects. Finally, the collision avoidance algorithm was combined with a goal direction and tested in cluttered environments. The simulated agent then showed goal-directed behavior reminiscent of components of the navigation behavior of insects. PMID:26583771

Selectivity of odorant receptors in insects

USDA-ARS?s Scientific Manuscript database

Insect olfactory receptors (ORs) detect chemical signals, shape neuronal physiology and regulate behavior. Although ORs have been categorized as generalists and specialists based on their ligand spectrum, both electrophysiological studies and recent pharmacological investigations show that ORs spec...
Boomeranging in structural defense: phytophagous insect uses cycad trichomes to defend against entomophagy.

PubMed

Marler, Thomas E

2012-11-01

Plant defensive behaviors that resist arthropod herbivory include trichome-mediated defenses, and variation in plant trichome morphology and abundance provides examples of the mechanistic complexities of insect-plant interactions. Trichomes were removed from Cycas revoluta cataphylls on the island of Guam to reveal Aulacaspis yasumatsui scale infestation, and predation of the newly exposed insects by pre-existing Rhyzobius lophanthae beetles commenced within one day. The quotient of predated/total scale insects was 0.5 by day 4 and stabilized at that found on adjacent glabrous leaves in about one week. The trichome phenotype covering the C. revoluta cataphyll complex offers the invasive A. yasumatsui armored scale effectual enemy-free space in this system. This pest and predator share no known evolutionary history with C. revoluta, therefore, the adaptive significance of this plant behavior in natural habitat is not yet known.
Extracellular wire tetrode recording in brain of freely walking insects.

PubMed

Guo, Peiyuan; Pollack, Alan J; Varga, Adrienn G; Martin, Joshua P; Ritzmann, Roy E

2014-04-01

Increasing interest in the role of brain activity in insect motor control requires that we be able to monitor neural activity while insects perform natural behavior. We previously developed a technique for implanting tetrode wires into the central complex of cockroach brains that allowed us to record activity from multiple neurons simultaneously while a tethered cockroach turned or altered walking speed. While a major advance, tethered preparations provide access to limited behaviors and often lack feedback processes that occur in freely moving animals. We now present a modified version of that technique that allows us to record from the central complex of freely moving cockroaches as they walk in an arena and deal with barriers by turning, climbing or tunneling. Coupled with high speed video and cluster cutting, we can now relate brain activity to various parameters of the movement of freely behaving insects.
Design tools for complex dynamic security systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrne, Raymond Harry; Rigdon, James Brian; Rohrer, Brandon Robinson

2007-01-01

The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systemsmore » are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle.« less
A Non-lethal water-based removal-reapplication technique for behavioral analysis of cuticular compounds of ants.

PubMed

Roux, Olivier; Martin, Jean-Michel; Ghomsi, Nathan Tene; Dejean, Alain

2009-08-01

Interspecific relationships among insects are often mediated by chemical cues, including non-volatile cuticular compounds. Most of these compounds are hydrocarbons that necessitate the use of solvents for their extraction, identification, and manipulation during behavioral assays. The toxicity of these solvents often precludes the removal and reapplication of hydrocarbons from and to live insects. As a consequence, dummies often are used in behavioral assays, but their passivity can bias the behavior of the responding insects. To overcome these limitations, we propose a method where cuticular compounds are extracted from live ants by placing them into glass vials half-filled with tepid water (ca. 34 degrees C) and vigorously shaking the vials to form an emulsion whose supernatant can be analyzed and/or reapplied to other ants. We demonstrate that cuticular compounds can be extracted from workers of the red fire ant, Solenopsis saevissima, and reapplied to the cuticle of workers from a sympatric species, Camponotus blandus (both Hymenoptera: Formicidae), while keeping the ants alive. Gas chromatographic-mass spectrometric analysis and behavioral assays were used to confirm the successful transfer of the behaviorally active compounds.
Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects

USGS Publications Warehouse

Buchwalter, D.B.; Cain, D.J.; Clements, W.H.; Luoma, S.N.

2007-01-01

Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. ?? 2007 American Chemical Society.
Infrared absorption characteristics of Culicoides sonorensis in relation to insect age

USDA-ARS?s Scientific Manuscript database

Biting midges can transmit diseases that significantly impact livestock in many parts of the world. The age structure of an insect vector population determines its likelihood of transmitting pathogens because the older insects are more likely to be infected than younger ones. Understanding the insec...
The Insect SNMP Gene Family

DTIC Science & Technology

2009-01-01

The insect SNMP gene family Richard G. Vogt a,*,1, Natalie E. Miller a, Rachel Litvack a, Richard A. Fandino a, Jackson Sparks a, Jon Staples a...Wallace Beltsville Agricultural Research Center Plant Sciences Institute, Invasive Insect Biocontrol and Behavior Laboratory, Bldg. 007, Rm. 030...keywords: Pheromone Receptors Olfactory Gustatory Chemosensory Gustatory Mosquito Fly a b s t r a c t SNMPs are membrane proteins observed to associate with
Harnessing Host-Vector Microbiome for Sustainable Plant Disease Management of Phloem-Limited Bacteria.

PubMed

Trivedi, Pankaj; Trivedi, Chanda; Grinyer, Jasmine; Anderson, Ian C; Singh, Brajesh K

2016-01-01

Plant health and productivity is strongly influenced by their intimate interaction with deleterious and beneficial organisms, including microbes, and insects. Of the various plant diseases, insect-vectored diseases are of particular interest, including those caused by obligate parasites affecting plant phloem such as Candidatus ( Ca .) Phytoplasma species and several species of Ca. Liberibacter. Recent studies on plant-microbe and plant-insect interactions of these pathogens have demonstrated that plant-microbe-insect interactions have far reaching consequences for the functioning and evolution of the organisms involved. These interactions take place within complex pathosystems and are shaped by a myriad of biotic and abiotic factors. However, our current understanding of these processes and their implications for the establishment and spread of insect-borne diseases remains limited. This article highlights the molecular, ecological, and evolutionary aspects of interactions among insects, plants, and their associated microbial communities with a focus on insect vectored and phloem-limited pathogens belonging to Ca. Phytoplasma and Ca. Liberibacter species. We propose that innovative and interdisciplinary research aimed at linking scales from the cellular to the community level will be vital for increasing our understanding of the mechanisms underpinning plant-insect-microbe interactions. Examination of such interactions could lead us to applied solutions for sustainable disease and pest management.
Genomics of adaptation to host-plants in herbivorous insects.

PubMed

Simon, Jean-Christophe; d'Alençon, Emmanuelle; Guy, Endrick; Jacquin-Joly, Emmanuelle; Jaquiéry, Julie; Nouhaud, Pierre; Peccoud, Jean; Sugio, Akiko; Streiff, Réjane

2015-11-01

Herbivorous insects represent the most species-rich lineages of metazoans. The high rate of diversification in herbivorous insects is thought to result from their specialization to distinct host-plants, which creates conditions favorable for the build-up of reproductive isolation and speciation. These conditions rely on constraints against the optimal use of a wide range of plant species, as each must constitute a viable food resource, oviposition site and mating site for an insect. Utilization of plants involves many essential traits of herbivorous insects, as they locate and select their hosts, overcome their defenses and acquire nutrients while avoiding intoxication. Although advances in understanding insect-plant molecular interactions have been limited by the complexity of insect traits involved in host use and the lack of genomic resources and functional tools, recent studies at the molecular level, combined with large-scale genomics studies at population and species levels, are revealing the genetic underpinning of plant specialization and adaptive divergence in non-model insect herbivores. Here, we review the recent advances in the genomics of plant adaptation in hemipterans and lepidopterans, two major insect orders, each of which includes a large number of crop pests. We focus on how genomics and post-genomics have improved our understanding of the mechanisms involved in insect-plant interactions by reviewing recent molecular discoveries in sensing, feeding, digesting and detoxifying strategies. We also present the outcomes of large-scale genomics approaches aimed at identifying loci potentially involved in plant adaptation in these insects. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Integrating sensorimotor systems in a robot model of cricket behavior

NASA Astrophysics Data System (ADS)

Webb, Barbara H.; Harrison, Reid R.

2000-10-01

The mechanisms by which animals manage sensorimotor integration and coordination of different behaviors can be investigated in robot models. In previous work the first author has build a robot that localizes sound based on close modeling of the auditory and neural system in the cricket. It is known that the cricket combines its response to sound with other sensorimotor activities such as an optomotor reflex and reactions to mechanical stimulation for the antennae and cerci. Behavioral evidence suggests some ways these behaviors may be integrated. We have tested the addition of an optomotor response, using an analog VLSI circuit developed by the second author, to the sound localizing behavior and have shown that it can, as in the cricket, improve the directness of the robot's path to sound. In particular it substantially improves behavior when the robot is subject to a motor disturbance. Our aim is to better understand how the insect brain functions in controlling complex combinations of behavior, with the hope that this will also suggest novel mechanisms for sensory integration on robots.
Extracellular ice phase transitions in insects.

PubMed

Hawes, T C

2014-01-01

At temperatures below their temperature of crystallization (Tc), the extracellular body fluids of insects undergo a phase transition from liquid to solid. Insects that survive the transition to equilibrium (complete freezing of the body fluids) are designated as freeze tolerant. Although this phenomenon has been reported and described in many Insecta, current nomenclature and theory does not clearly delineate between the process of transition (freezing) and the final solid phase itself (the frozen state). Thus freeze tolerant insects are currently, by convention, described in terms of the temperature at which the crystallization of their body fluids is initiated, Tc. In fact, the correct descriptor for insects that tolerate freezing is the temperature of equilibrium freezing, Tef. The process of freezing is itself a separate physical event with unique physiological stresses that are associated with ice growth. Correspondingly there are a number of insects whose physiological cryo-limits are very specifically delineated by this transitional envelope. The distinction also has considerable significance for our understanding of insect cryobiology: firstly, because the ability to manage endogenous ice growth is a fundamental segregator of cryotype; and secondly, because our understanding of internal ice management is still largely nascent.
Eyes Matched to the Prize: The State of Matched Filters in Insect Visual Circuits.

PubMed

Kohn, Jessica R; Heath, Sarah L; Behnia, Rudy

2018-01-01

Confronted with an ever-changing visual landscape, animals must be able to detect relevant stimuli and translate this information into behavioral output. A visual scene contains an abundance of information: to interpret the entirety of it would be uneconomical. To optimally perform this task, neural mechanisms exist to enhance the detection of important features of the sensory environment while simultaneously filtering out irrelevant information. This can be accomplished by using a circuit design that implements specific "matched filters" that are tuned to relevant stimuli. Following this rule, the well-characterized visual systems of insects have evolved to streamline feature extraction on both a structural and functional level. Here, we review examples of specialized visual microcircuits for vital behaviors across insect species, including feature detection, escape, and estimation of self-motion. Additionally, we discuss how these microcircuits are modulated to weigh relevant input with respect to different internal and behavioral states.
Insect odorant receptors are molecular targets of the insect repellent DEET.

PubMed

Ditzen, Mathias; Pellegrino, Maurizio; Vosshall, Leslie B

2008-03-28

DEET (N,N-diethyl-meta-toluamide) is the world's most widely used topical insect repellent, with broad effectiveness against most insects. Its mechanism of action and molecular target remain unknown. Here, we show that DEET blocks electrophysiological responses of olfactory sensory neurons to attractive odors in Anopheles gambiae and Drosophila melanogaster. DEET inhibits behavioral attraction to food odors in Drosophila, and this inhibition requires the highly conserved olfactory co-receptor OR83b. DEET inhibits odor-evoked currents mediated by the insect odorant receptor complex, comprising a ligand-binding subunit and OR83b. We conclude that DEET masks host odor by inhibiting subsets of heteromeric insect odorant receptors that require the OR83b co-receptor. The identification of candidate molecular targets for the action of DEET may aid in the design of safer and more effective insect repellents.
Quantity over quality: light intensity, but not red/far-red ratio, affects extrafloral nectar production in Senna mexicana var. chapmanii.

PubMed

Jones, Ian M; Koptur, Suzanne

2015-09-01

Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and insects and provides plants with a form of indirect defense against herbivory. Understanding sources of variation in EFN production is important because such variations affect the number and identity of insect visitors and the effectiveness of plant defense. Light represents a potentially crucial tool for regulating resource allocation to defense, as it not only contributes energy but may help plants to anticipate future conditions. Low red/far-red (R/FR) light ratios can act as a signal of the proximity of competing plants. Exposure to such light ratios has been shown to promote competitive behaviors that coincide with reduced resource allocation to direct chemical defenses. Little is known, however, about how such informational light signals might affect indirect defenses such as EFN, and the interactions that they mediate. Through controlled glasshouse experiments, we investigated the effects of light intensity, and R/FR light ratios, on EFN production in Senna mexicana var. chapmanii. Plants in light-limited conditions produced significantly less EFN, and leaf damage elicited increased EFN production regardless of light conditions. Ratios of R/FR light, however, did not appear to affect EFN production in either damaged or undamaged plants. Understanding the effects of light on indirect defenses is of particular importance for plants in the threatened pine rockland habitats of south Florida, where light conditions are changing in predictable ways following extensive fragmentation and subsequent mismanagement. Around 27% of species in these habitats produce EFN and may rely on insect communities for defense.
An experimental study of the unsteady vortex structures in the wake of a root-fixed flapping wing

NASA Astrophysics Data System (ADS)

Hu, Hui; Clemons, Lucas; Igarashi, Hirofumi

2011-08-01

An experimental study was conducted to characterize the evolution of the unsteady vortex structures in the wake of a root-fixed flapping wing with the wing size, stroke amplitude, and flapping frequency within the range of insect characteristics for the development of novel insect-sized nano-air-vehicles (NAVs). The experiments were conducted in a low-speed wing tunnel with a miniaturized piezoelectric wing (i.e., chord length, C = 12.7 mm) flapping at a frequency of 60 Hz (i.e., f = 60 Hz). The non-dimensional parameters of the flapping wing are chord Reynolds number of Re = 1,200, reduced frequency of k = 3.5, and non-dimensional flapping amplitude at wingtip h = A/C = 1.35. The corresponding Strouhal number (Str) is 0.33 , which is well within the optimal range of 0.2 < Str < 0.4 used by flying insects and birds and swimming fishes for locomotion. A digital particle image velocimetry (PIV) system was used to achieve phased-locked and time-averaged flow field measurements to quantify the transient behavior of the wake vortices in relation to the positions of the flapping wing during the upstroke and down stroke flapping cycles. The characteristics of the wake vortex structures in the chordwise cross planes at different wingspan locations were compared quantitatively to elucidate underlying physics for a better understanding of the unsteady aerodynamics of flapping flight and to explore/optimize design paradigms for the development of novel insect-sized, flapping-wing-based NAVs.
Identification and Characterization of Odorant Binding Proteins in the Forelegs of Adelphocoris lineolatus (Goeze)

PubMed Central

Sun, Liang; Wang, Qian; Wang, Qi; Dong, Kun; Xiao, Yong; Zhang, Yong-Jun

2017-01-01

The chemosensory system is essential for insects to detect exogenous compounds, and odorant binding proteins (OBPs) play crucial roles in odorant binding and transduction. In the alfalfa plant bug Adelphocoris lineolatus, an important pest of multiple crops, our understanding of the physiological roles of antenna-biased OBPs has increased dramatically, whereas OBPs related to gustation have remained mostly unexplored. In this study, we employed RNA sequencing and RACE PCR methods to identify putative OBPs from the adult forelegs of both sexes. Eight candidate OBPs were identified, and three OBPs (AlinOBP15, 16, and 17) were novel. Full-length sequence alignment and phylogenetic analyses suggested that these three candidate OBPs had characteristics typical of the insect OBP family. AlinOBP16 and 17 displayed six highly conserved cysteines, placing them in the classic OBP subfamily, whereas AlinOBP15 resembled AlinOBP14 and clustered with the Plus-C clade. Quantitative real-time PCR (qRT-PCR) revealed distinct and significant tissue- and sex-biased expression patterns. AlinOBP15 was highly expressed in female heads, and AlinOBP16 and 17 were strongly expressed in female antennae. In particular, AlinOBP11, the most abundant OBP gene in our foreleg transcriptome dataset, was predominately expressed in adult legs. Furthermore, four types of sensilla hairs were observed on the forelegs of adult A. lineolatus, including sensilla trichodea, setae, and two types of sensilla chaetica (Sch1 and Sch2). Anti-AlinOBP11 antiserum strongly labeled the outer sensillum lymph of Sch2, implying that it has important gustatory functions in A. lineolatus. Our current findings provide evidence that OBPs can be functionally expressed in the tarsal gustatory sensilla of hemipteran mirid species, broadening our understanding of OBP chemosensory function in insects and facilitating the discovery of new functional targets for the regulation of insect host-searching behaviors. PMID:29018358
Molecular dissection of nutrient exchange at the insect-microbial interface.

PubMed

Douglas, Angela E

2014-10-01

Genome research is transforming our understanding of nutrient exchange between insects and intracellular bacteria. A key characteristic of these bacteria is their small genome size and gene content. Their fastidious and inflexible nutritional requirements are met by multiple metabolites from the insect host cell. Although the bacteria have generally retained genes coding the synthesis of nutrients required by the insect, some apparently critical genes have been lost, and compensated for by shared metabolic pathways with the insect host or supplementary bacteria with complementary metabolic capabilities. Copyright © 2014 Elsevier Inc. All rights reserved.
Dispersal behavior of yellowjacket (Vespula germanica) queens.

PubMed

Masciocchi, Maité; Martinez, Andrés S; Pereira, Ana J; Villacide, José M; Corley, Juan C

2018-02-01

Understanding the factors that affect animal dispersal behavior is important from both fundamental and applied perspectives. Dispersal can have clear evolutionary and ecological consequences, but for nonnative insect pests, dispersal capacity can also help to explain invasion success. Vespula germanica is a social wasp that, in the last century, has successfully invaded several regions of the world, showing one of the highest spread rates reported for a nonnative insect. In contrast with nonsocial wasps, in social species, queens are responsible for population redistribution and spread, as workers are sterile. For V. germanica, it has been observed that queen flight is limited to 2 distinct periods: early autumn, when new queens leave the nest to mate and find sheltered places in which to hibernate, and spring when new colonies are founded. Our aim was to study the flight behavior of V. germanica queens by focusing on the different periods in which dispersal occurs, characterizing as well the potential contribution of queen flight (i.e., distance) to the observed geographical spread. Our results suggest that the distances flown by nonoverwintered queens is greater than that flown by overwintered individuals, suggesting that the main queen dispersal events would occur before queens enter hibernation. This could relate to a behavioral trait of the queens to avoid the inbreeding with related drones. Additionally, given the short distances flown and remarkable geographical spread observed, we provide evidence showing that queen dispersal by flight is likely to contribute proportionately less to population spread than human-aided factors. © 2016 Institute of Zoology, Chinese Academy of Sciences.
Application of genomics for understanding plant virus-insect vector interactions and insect vector control

USDA-ARS?s Scientific Manuscript database

The ability to decipher DNA sequences provides new insights into the study of plant viruses and their interactions with host plants, including the intricate interactions that allow a virus to be transmitted by an insect vector. Next generation sequencing (NGS) provides a wealth of genetic informati...

Insects and Spiders. Environmental Education Curriculum.

ERIC Educational Resources Information Center

Topeka Public Schools, KS.

This unit is designed to provide information on insects and spiders that special education students are capable of understanding. The activities are aimed at level 2 and level 3 educable mentally retarded classes. There are four topics: (1) Characteristics and Life Cycles of Insects; (2) Characteristics of Spiders; (3) Habitats and Food Sources of…
Core RNAi machinery and gene knockdown in the emerald ash borer (Agrilus planipennis)

Treesearch

Chaoyang Zhao; Miguel A. Alvarez Gonzales; Therese M. Poland; Omprakash Mittapalli

2015-01-01

The RNA interference (RNAi) technology has been widely used in insect functional genomics research and provides an alternative approach for insect pest management. To understand whether the emerald ash borer (Agrilus planipennis), an invasive and destructive coleopteran insect pest of ash tree (Fraxinus spp.), possesses a strong...
INSECT FAT BODY: ENERGY, METABOLISM, AND REGULATION

PubMed Central

Arrese, Estela L.; Soulages, Jose L.

2010-01-01

The fat body plays major roles in the life of insects. It is a dynamic tissue involved in multiple metabolic functions. One of these functions is to store and release energy in response to the energy demands of the insect. Insects store energy reserves in the form of glycogen and triglycerides in the adipocytes, the main fat body cell. Insect adipocytes can store a great amount of lipid reserves as cytoplasmic lipid droplets. Lipid metabolism is essential for growth and reproduction and provides energy needed during extended nonfeeding periods. This review focuses on energy storage and release and summarizes current understanding of the mechanisms underlying these processes in insects. PMID:19725772
Solutions Network Formulation Report. Using NASA Sensors to Perform Crop Type Assessment for Monitoring Insect Resistance in Corn

NASA Technical Reports Server (NTRS)

Lewis, David; Copenhaver, Ken; Anderson, Daniel; Hilbert, Kent

2007-01-01

The EPA (U.S. Environmental Protection Agency) is tasked to monitor for insect pest resistance to transgenic crops. Several models have been developed to understand the resistance properties of insects. The Population Genetics Simulator model is used in the EPA PIRDSS (Pest Infestation and Resistance Decision Support System). The EPA Office of Pesticide Programs uses the DSS to help understand the potential for insect pest resistance development and the likelihood that insect pest resistance will negatively affect transgenic corn. Once the DSS identifies areas of concern, crews are deployed to collect insect pest samples, which are tested to identify whether they have developed resistance to the toxins in transgenic corn pesticides. In this candidate solution, VIIRS (Visible/Infrared Imager/Radiometer Suite) vegetation index products will be used to build hypertemporal layerstacks for crop type and phenology assessment. The current phenology attribute is determined by using the current time of year to index the expected growth stage of the crop. VIIRS might provide more accurate crop type assessment and also might give a better estimate on the crop growth stage.
An Ecological Perspective on Sleep Disruption.

PubMed

Tougeron, Kévin; Abram, Paul K

2017-09-01

Despite its evolutionary importance and apparent ubiquity among animals, the ecological significance of sleep is largely unresolved. The ecology of sleep has been particularly neglected in invertebrates. In insects, recent neurobehavioral research convincingly demonstrates that resting behavior shares several common characteristics with sleep in vertebrates. Laboratory studies have produced compelling evidence that sleep disruption can cause changes in insect daily activity patterns (via "sleep rebound") and have consequences for behavioral performance during active periods. However, factors that could cause insect sleep disruption in nature have not been considered nor have the ecological consequences. Drawing on evidence from laboratory studies, we argue that sleep disruption may be an overlooked component of insect ecology and could be caused by a variety of anthropogenic and nonanthropogenic factors in nature. We identify several candidate sleep-disrupting factors and provide new insights on the potential consequences of sleep disruption on individual fitness, species interactions, and ecosystem services. We propose an experimental framework to bridge the current gap in knowledge between laboratory and field studies. We conclude that sleep disruption is a potential mechanism underpinning variation in behavioral, population, and community-level processes associated with several aspects of global change.
Hunger and thirst interact to regulate ingestive behavior in flies and mammals.

PubMed

Jourjine, Nicholas

2017-05-01

In animals, nervous systems regulate the ingestion of food and water in a manner that reflects internal metabolic need. While the coordination of these two ingestive behaviors is essential for homeostasis, it has been unclear how internal signals of hunger and thirst interact to effectively coordinate food and water ingestion. In the last year, work in insects and mammals has begun to elucidate some of these interactions. As reviewed here, these studies have identified novel molecular and neural mechanisms that coordinate the regulation of food and water ingestion behaviors. These mechanisms include peptide signals that modulate neural circuits for both thirst and hunger, neurons that regulate both food and water ingestion, and neurons that integrate sensory information about both food and water in the external world. These studies argue that a deeper understanding of hunger and thirst will require closer examination of how these two biological drives interact. © 2017 WILEY Periodicals, Inc.
Genetic structure and breeding system in a social wasp and its social parasite

PubMed Central

2008-01-01

Background Social insects dominate ecological communities because of their sophisticated group behaviors. However, the intricate behaviors of social insects may be exploited by social parasites, which manipulate insect societies for their own benefit. Interactions between social parasites and their hosts lead to unusual coevolutionary dynamics that ultimately affect the breeding systems and population structures of both species. This study represents one of the first attempts to understand the population and colony genetic structure of a parasite and its host in a social wasp system. Results We used DNA microsatellite markers to investigate gene flow, genetic variation, and mating behavior of the facultative social parasite Vespula squamosa and its primary host, V. maculifrons. Our analyses of genetic variability uncovered that both species possessed similar amounts of genetic variation and failed to show genetic structure over the sampling area. Our analysis of mating system of V. maculifrons and V. squamosa revealed high levels of polyandry and no evidence for inbreeding in the two species. Moreover, we found no significant differences between estimates of worker relatedness in this study and a previous investigation conducted over two decades ago, suggesting that the selective pressures operating on queen mate number have remained constant. Finally, the distribution of queen mate number in both species deviated from simple expectations suggesting that mate number may be under stabilizing selection. Conclusion The general biology of V. squamosa has not changed substantially from that of a typical, nonparasitic Vespula wasp. For example, population sizes of the host and its parasite appear to be similar, in contrast to other social parasites, which often display lower population sizes than their hosts. In addition, parasitism has not caused the mating behavior of V. squamosa queens to deviate from the high levels of multiple mating that typify Vespula wasps. This stands in contrast to some socially parasitic ants, which revert to mating with few males. Overall, the general similarity of the genetic structure of V. maculifrons and V. squamosa presumably reflects the fact that V. squamosa is still capable of independent colony founding and thus reflects an intermediate stage in the evolution of social parasitism. PMID:18715511
Increased expression of a cGMP-dependent protein kinase in rotation-adapted western corn rootworm (Diabrotica virgifera virgifera L.).

PubMed

Garabagi, Freydoun; Wade French, B; Schaafsma, Arthur W; Peter Pauls, K

2008-07-01

A new 'variant' behavior in western corn rootworm (WCR) has resulted in egg-laying into non-cornfields, compared to 'normal' deposition of eggs in cornfields, allowing these insects to circumvent crop rotation. No morphological or genetic characteristics have been defined to differentiate between the normal and variant biotypes. Cyclic GMP-dependent protein kinases (PKG) have been implicated in the regulation of behaviors in vertebrates, insects, and nematodes, including foraging behavior in Drosophila. A cDNA with homology to the Drosophila melanogaster foraging gene (called Dvfor1) was cloned from WCR. The deduced DvFOR1 protein is approximately 70% similar to FOR proteins in Drosophila, silkworm (Bombyx mori) and honeybee (Apis mellifera). It contains a coiled-coil region, two tandem cyclic nucleotide-binding domains, a serine/threonine kinase catalytic domain, and a serine/threonine kinase catalytic domain extension, which are all characteristically found in PKG proteins. Real-time PCR assays of foraging transcript levels in heads of normal and rotation adapted females of WCR obtained from lab-reared insect colonies indicated that the variants had higher levels (25%) of PKG expression than normals. The magnitude of this increase is similar to that observed in Drosophila rover phenotypes compared to sitter phenotypes. However, Diabrotica contains at least two different foraging gene transcripts, which complicates establishing a direct link between the level of gene expression and insect behavior.
Perception of solar UVB radiation by phytophagous insects: Behavioral responses and ecosystem implications

PubMed Central

Mazza, Carlos A.; Zavala, Jorge; Scopel, Ana L.; Ballaré, Carlos L.

1999-01-01

Most of our present knowledge about the impacts of solar UVB radiation on terrestrial ecosystems comes from studies with plants. Recently, the effects of UVB on the growth and survival of consumer species have begun to receive attention, but very little is known about UVB impacts on animal behavior. Here we report that manipulations of the flux of solar UVB received by field-grown soybean crops had large and consistent effects on the density of the thrips (Caliothrips phaseoli, Thysanoptera: Thripidae) populations that invaded the canopies, as well as on the amount of leaf damage caused by the insects. Solar UVB strongly reduced thrips herbivory. Thrips not only preferred leaves from plants that were not exposed to solar UVB over leaves from UVB-exposed plants in laboratory and field choice experiments, but they also appeared to directly sense and avoid exposure to solar UVB. Additional choice experiments showed that soybean leaf consumption by the late-season soybean worm Anticarsia gemmatalis (Lepidoptera: Noctuidae) was much less intense in leaves with even slight symptoms of an early thrips attack than in undamaged leaves. These experiments suggest that phytophagous insects can present direct and indirect behavioral responses to solar UVB. The indirect responses are mediated by changes in the plant host that are induced by UVB and, possibly, by other insects whose behavior is affected by UVB. PMID:9927679
Will climate change affect insect pheromonal communication?

PubMed

Boullis, Antoine; Detrain, Claire; Francis, Frédéric; Verheggen, François J

2016-10-01

Understanding how climate change will affect species interactions is a challenge for all branches of ecology. We have only limited understanding of how increasing temperature and atmospheric CO 2 and O 3 levels will affect pheromone-mediated communication among insects. Based on the existing literature, we suggest that the entire process of pheromonal communication, from production to behavioural response, is likely to be impacted by increases in temperature and modifications to atmospheric CO 2 and O 3 levels. We argue that insect species relying on long-range chemical signals will be most impacted, because these signals will likely suffer from longer exposure to oxidative gases during dispersal. We provide future directions for research programmes investigating the consequences of climate change on insect pheromonal communication. Copyright © 2016 Elsevier Inc. All rights reserved.
Colors of attraction: Modeling insect flight to light behavior.

PubMed

Donners, Maurice; van Grunsven, Roy H A; Groenendijk, Dick; van Langevelde, Frank; Bikker, Jan Willem; Longcore, Travis; Veenendaal, Elmar

2018-06-26

Light sources attract nocturnal flying insects, but some lamps attract more insects than others. The relation between the properties of a light source and the number of attracted insects is, however, poorly understood. We developed a model to quantify the attractiveness of light sources based on the spectral output. This model is fitted using data from field experiments that compare a large number of different light sources. We validated this model using two additional datasets, one for all insects and one excluding the numerous Diptera. Our model facilitates the development and application of light sources that attract fewer insects without the need for extensive field tests and it can be used to correct for spectral composition when formulating hypotheses on the ecological impact of artificial light. In addition, we present a tool allowing the conversion of the spectral output of light sources to their relative insect attraction based on this model. © 2018 Wiley Periodicals, Inc.
Interfacing insect brain for space applications.

PubMed

Di Pino, Giovanni; Seidl, Tobias; Benvenuto, Antonella; Sergi, Fabrizio; Campolo, Domenico; Accoto, Dino; Maria Rossini, Paolo; Guglielmelli, Eugenio

2009-01-01

Insects exhibit remarkable navigation capabilities that current control architectures are still far from successfully mimic and reproduce. In this chapter, we present the results of a study on conceptualizing insect/machine hybrid controllers for improving autonomy of exploratory vehicles. First, the different principally possible levels of interfacing between insect and machine are examined followed by a review of current approaches towards hybridity and enabling technologies. Based on the insights of this activity, we propose a double hybrid control architecture which hinges around the concept of "insect-in-a-cockpit." It integrates both biological/artificial (insect/robot) modules and deliberative/reactive behavior. The basic assumption is that "low-level" tasks are managed by the robot, while the "insect intelligence" is exploited whenever high-level problem solving and decision making is required. Both neural and natural interfacing have been considered to achieve robustness and redundancy of exchanged information.
Response of native insect communities to invasive plants.

PubMed

Bezemer, T Martijn; Harvey, Jeffrey A; Cronin, James T

2014-01-01

Invasive plants can disrupt a range of trophic interactions in native communities. As a novel resource they can affect the performance of native insect herbivores and their natural enemies such as parasitoids and predators, and this can lead to host shifts of these herbivores and natural enemies. Through the release of volatile compounds, and by changing the chemical complexity of the habitat, invasive plants can also affect the behavior of native insects such as herbivores, parasitoids, and pollinators. Studies that compare insects on related native and invasive plants in invaded habitats show that the abundance of insect herbivores is often lower on invasive plants, but that damage levels are similar. The impact of invasive plants on the population dynamics of resident insect species has been rarely examined, but invasive plants can influence the spatial and temporal dynamics of native insect (meta)populations and communities, ultimately leading to changes at the landscape level.
Ventromedial Hypothalamus and the Generation of Aggression

PubMed Central

Hashikawa, Yoshiko; Hashikawa, Koichi; Falkner, Annegret L.; Lin, Dayu

2017-01-01

Aggression is a costly behavior, sometimes with severe consequences including death. Yet aggression is prevalent across animal species ranging from insects to humans, demonstrating its essential role in the survival of individuals and groups. The question of how the brain decides when to generate this costly behavior has intrigued neuroscientists for over a century and has led to the identification of relevant neural substrates. Various lesion and electric stimulation experiments have revealed that the hypothalamus, an ancient structure situated deep in the brain, is essential for expressing aggressive behaviors. More recently, studies using precise circuit manipulation tools have identified a small subnucleus in the medial hypothalamus, the ventrolateral part of the ventromedial hypothalamus (VMHvl), as a key structure for driving both aggression and aggression-seeking behaviors. Here, we provide an updated summary of the evidence that supports a role of the VMHvl in aggressive behaviors. We will consider our recent findings detailing the physiological response properties of populations of VMHvl cells during aggressive behaviors and provide new understanding regarding the role of the VMHvl embedded within the larger whole-brain circuit for social sensation and action. PMID:29375329
Effect of Light Availability on the Interaction between Maritime Pine and the Pine Weevil: Light Drives Insect Feeding Behavior But Also the Defensive Capabilities of the Host

PubMed Central

Suárez-Vidal, Estefanía; López-Goldar, Xosé; Sampedro, Luis; Zas, Rafael

2017-01-01

Light is a major environmental factor that may determine the interaction between plants and herbivores in several ways, including top-down effects through changes in herbivore behavior and bottom-up effects mediated by alterations of plant physiology. Here we explored the relative contribution of these two regulation processes to the outcome of the interaction of pine trees with a major forest pest, the pine weevil (Hylobius abietis). We studied to what extent light availability influence insect feeding behavior and/or the ability of pines to produce induced defenses in response to herbivory. For this purpose, 3-year old Pinus pinaster plants from three contrasting populations were subjected to 6 days of experimental herbivory by the pine weevil under two levels of light availability (complete darkness or natural sunlight) independently applied to the plant and to the insect in a fully factorial design. Light availability strongly affected the pine weevil feeding behavior. The pine weevil fed more and caused larger feeding scars in darkness than under natural sunlight. Besides, under the more intense levels of weevil damage (i.e., those registered with insects in darkness), light availability also affected the pine’s ability to respond to insect feeding by producing induced resin defenses. These results were consistent across the three studied populations despite they differed in weevil susceptibility and inducibility of defenses. Morocco was the most damaged population and the one that induced more defensive compounds. Overall, results indicate that light availability modulates the outcome of the pine–weevil interactions through both bottom-up and top-down regulation mechanisms. PMID:28912787
The monarch butterfly genome yields insights into long-distance migration

PubMed Central

Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L.; Reppert, Steven M.

2011-01-01

SUMMARY We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16, 866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals: a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. PMID:22118469
Modeling visual-based pitch, lift and speed control strategies in hoverflies

PubMed Central

Vercher, Jean-Louis

2018-01-01

To avoid crashing onto the floor, a free falling fly needs to trigger its wingbeats quickly and control the orientation of its thrust accurately and swiftly to stabilize its pitch and hence its speed. Behavioural data have suggested that the vertical optic flow produced by the fall and crossing the visual field plays a key role in this anti-crash response. Free fall behavior analyses have also suggested that flying insect may not rely on graviception to stabilize their flight. Based on these two assumptions, we have developed a model which accounts for hoverflies´ position and pitch orientation recorded in 3D with a fast stereo camera during experimental free falls. Our dynamic model shows that optic flow-based control combined with closed-loop control of the pitch suffice to stabilize the flight properly. In addition, our model sheds a new light on the visual-based feedback control of fly´s pitch, lift and thrust. Since graviceptive cues are possibly not used by flying insects, the use of a vertical reference to control the pitch is discussed, based on the results obtained on a complete dynamic model of a virtual fly falling in a textured corridor. This model would provide a useful tool for understanding more clearly how insects may or not estimate their absolute attitude. PMID:29361632
Robust Manipulations of Pest Insect Behavior Using Repellents and Practical Application for Integrated Pest Management.

PubMed

Wallingford, Anna K; Cha, Dong H; Linn, Charles E; Wolfin, Michael S; Loeb, Gregory M

2017-10-01

In agricultural settings, examples of effective control strategies using repellent chemicals in integrated pest management (IPM) are relatively scarce compared to those using attractants. This may be partly due to a poor understanding of how repellents affect insect behavior once they are deployed. Here we attempt to identify potential hallmarks of repellent stimuli that are robust enough for practical use in the field. We explore the literature for success stories using repellents in IPM and we investigate the mechanisms of repellency for two chemical oviposition deterrents for controlling Drosophila suzukii Matsumura, a serious pest of small fruit crops. Drosophila suzukii causes injury by laying her eggs in ripening fruit and resulting larvae make fruit unmarketable. In caged choice tests, reduced oviposition was observed in red raspberry fruit treated with volatile 1-octen-3-ol and geosmin at two initial concentrations (10% and 1%) compared to untreated controls. We used video monitoring to observe fly behavior in these caged choice tests and investigate the mode of action for deterrence through the entire behavioral repertoire leading to oviposition. We observed fewer visitors and more time elapsed before flies first landed on 1-octen-3-ol-treated fruits than control fruits and concluded that this odor primarily inhibits behaviors that occur before D. suzukii comes in contact with a potential oviposition substrate (precontact). We observed some qualitative differences in precontact behavior of flies around geosmin-treated fruits; however, we concluded that this odor primarily inhibits behaviors that occur after D. suzukii comes in contact with treated fruits (postcontact). Field trials found reduced oviposition in red raspberry treated with 1-octen-3-ol and a combination of 1-octen-3-ol and geosmin, but no effect of geosmin alone. Recommendations for further study of repellents for practical use in the field are discussed. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Do Insects Have Emotions? Some Insights from Bumble Bees

PubMed Central

Baracchi, David; Lihoreau, Mathieu; Giurfa, Martin

2017-01-01

While our conceptual understanding of emotions is largely based on human subjective experiences, research in comparative cognition has shown growing interest in the existence and identification of “emotion-like” states in non-human animals. There is still ongoing debate about the nature of emotions in animals (especially invertebrates), and certainly their existence and the existence of certain expressive behaviors displaying internal emotional states raise a number of exciting and challenging questions. Interestingly, at least superficially, insects (bees and flies) seem to fulfill the basic requirements of emotional behavior. Yet, recent works go a step further by adopting terminologies and interpretational frameworks that could have been considered as crude anthropocentrism and that now seem acceptable in the scientific literature on invertebrate behavior and cognition. This change in paradigm requires, therefore, that the question of emotions in invertebrates is reconsidered from a cautious perspective and with parsimonious explanations. Here we review and discuss this controversial topic based on the recent finding that bumblebees experience positive emotions while experiencing unexpected sucrose rewards, but also incorporating a broader survey of recent literature in which similar claims have been done for other invertebrates. We maintain that caution is warranted before attributing emotion-like states to honey bees and bumble bees as some experimental caveats may undermine definitive conclusions. We suggest that interpreting many of these findings in terms of motivational drives may be less anthropocentrically biased and more cautious, at least until more careful experiments warrant the use of an emotion-related terminology. PMID:28878636
Do Insects Have Emotions? Some Insights from Bumble Bees.

PubMed

Baracchi, David; Lihoreau, Mathieu; Giurfa, Martin

2017-01-01

While our conceptual understanding of emotions is largely based on human subjective experiences, research in comparative cognition has shown growing interest in the existence and identification of "emotion-like" states in non-human animals. There is still ongoing debate about the nature of emotions in animals (especially invertebrates), and certainly their existence and the existence of certain expressive behaviors displaying internal emotional states raise a number of exciting and challenging questions. Interestingly, at least superficially, insects (bees and flies) seem to fulfill the basic requirements of emotional behavior. Yet, recent works go a step further by adopting terminologies and interpretational frameworks that could have been considered as crude anthropocentrism and that now seem acceptable in the scientific literature on invertebrate behavior and cognition. This change in paradigm requires, therefore, that the question of emotions in invertebrates is reconsidered from a cautious perspective and with parsimonious explanations. Here we review and discuss this controversial topic based on the recent finding that bumblebees experience positive emotions while experiencing unexpected sucrose rewards, but also incorporating a broader survey of recent literature in which similar claims have been done for other invertebrates. We maintain that caution is warranted before attributing emotion-like states to honey bees and bumble bees as some experimental caveats may undermine definitive conclusions. We suggest that interpreting many of these findings in terms of motivational drives may be less anthropocentrically biased and more cautious, at least until more careful experiments warrant the use of an emotion-related terminology.

Identification of a novel hemolymph peptide that modulates silkworm feeding motivation.

PubMed

Nagata, Shinji; Morooka, Nobukatsu; Asaoka, Kiyoshi; Nagasawa, Hiromichi

2011-03-04

Phytophagous insects do not constantly chew their diets; most of their time is spent in a non-feeding quiescent state even though they live on or around their diets. Following starvation, phytophagous insect larvae exhibit enhanced foraging behaviors such as nibbling and walking similar to the sequential behavior that occurs prior to each meal. Although extensive physiological studies have revealed regularly occurring feeding behaviors in phytophagous insects, little has been elucidated regarding the mechanism at the molecular level. Here, we report identification and characterization of a novel 62-amino acid peptide, designated as hemolymph major anionic peptide (HemaP), from the hemolymph of Bombyx mori larvae that induces foraging behaviors. The endogenous HemaP levels are significantly increased by diet deprivation, whereas refeeding after starvation returns them to basal levels. In larvae fed ad libitum, hemolymph HemaP levels fluctuate according to the feeding cycle, indicating that locomotor-associated feeding behaviors of B. mori larvae are initiated when HemaP levels exceed an unidentified threshold. Furthermore, administration of exogenous HemaP mimics the starvation-experienced state by affecting dopamine levels in the suboesophageal ganglion, which coordinates neck and mandible movements. These data strongly suggest that fluctuation of hemolymph HemaP levels modulates the regularly occurring feeding-motivated behavior in B. mori by triggering feeding initiation.
Identification of a Novel Hemolymph Peptide That Modulates Silkworm Feeding Motivation*

PubMed Central

Nagata, Shinji; Morooka, Nobukatsu; Asaoka, Kiyoshi; Nagasawa, Hiromichi

2011-01-01

Phytophagous insects do not constantly chew their diets; most of their time is spent in a non-feeding quiescent state even though they live on or around their diets. Following starvation, phytophagous insect larvae exhibit enhanced foraging behaviors such as nibbling and walking similar to the sequential behavior that occurs prior to each meal. Although extensive physiological studies have revealed regularly occurring feeding behaviors in phytophagous insects, little has been elucidated regarding the mechanism at the molecular level. Here, we report identification and characterization of a novel 62-amino acid peptide, designated as hemolymph major anionic peptide (HemaP), from the hemolymph of Bombyx mori larvae that induces foraging behaviors. The endogenous HemaP levels are significantly increased by diet deprivation, whereas refeeding after starvation returns them to basal levels. In larvae fed ad libitum, hemolymph HemaP levels fluctuate according to the feeding cycle, indicating that locomotor-associated feeding behaviors of B. mori larvae are initiated when HemaP levels exceed an unidentified threshold. Furthermore, administration of exogenous HemaP mimics the starvation-experienced state by affecting dopamine levels in the suboesophageal ganglion, which coordinates neck and mandible movements. These data strongly suggest that fluctuation of hemolymph HemaP levels modulates the regularly occurring feeding-motivated behavior in B. mori by triggering feeding initiation. PMID:21177851
What can forest managers learn from research on fossil insects? Linking forest ecological history, biodiversity and management

Treesearch

Nicki J. Whitehouse

2006-01-01

This paper outlines the usefulness of using fossil insects, particularly Coleoptera (beetles), preserved in waterlogged palaeoenvironmental and archaeological deposits in understanding the changing nature of forest ecosystems and their associated insect population dynamics over the last 10,000 years. Research in Europe has highlighted the complex nature of early forest...
Host selection by a phytophagous insect: the interplay between feeding, egg maturation, egg load, and oviposition

USDA-ARS?s Scientific Manuscript database

Understanding movement patterns of phytophagous insects among plants is a primary goal of insect ecology. Adult females may visit plants for the purpose of depositing eggs, feeding, or both. For some species, egg maturation may be dependent on adult feeding. As a result, rates of egg maturation m...
Spatial Navigation and the Central Complex: Sensory Acquisition, Orientation, and Motor Control

PubMed Central

Varga, Adrienn G.; Kathman, Nicholas D.; Martin, Joshua P.; Guo, Peiyuan; Ritzmann, Roy E.

2017-01-01

Cockroaches are scavengers that forage through dark, maze-like environments. Like other foraging animals, for instance rats, they must continually asses their situation to keep track of targets and negotiate barriers. While navigating a complex environment, all animals need to integrate sensory information in order to produce appropriate motor commands. The integrated sensory cues can be used to provide the animal with an environmental and contextual reference frame for the behavior. To successfully reach a goal location, navigational cues continuously derived from sensory inputs have to be utilized in the spatial guidance of motor commands. The sensory processes, contextual and spatial mechanisms, and motor outputs contributing to navigation have been heavily studied in rats. In contrast, many insect studies focused on the sensory and/or motor components of navigation, and our knowledge of the abstract representation of environmental context and spatial information in the insect brain is relatively limited. Recent reports from several laboratories have explored the role of the central complex (CX), a sensorimotor region of the insect brain, in navigational processes by recording the activity of CX neurons in freely-moving insects and in more constrained, experimenter-controlled situations. The results of these studies indicate that the CX participates in processing the temporal and spatial components of sensory cues, and utilizes these cues in creating an internal representation of orientation and context, while also directing motor control. Although these studies led to a better understanding of the CX's role in insect navigation, there are still major voids in the literature regarding the underlying mechanisms and brain regions involved in spatial navigation. The main goal of this review is to place the above listed findings in the wider context of animal navigation by providing an overview of the neural mechanisms of navigation in rats and summarizing and comparing our current knowledge on the CX's role in insect navigation to these processes. By doing so, we aimed to highlight some of the missing puzzle pieces in insect navigation and provide a different perspective for future directions. PMID:28174527
A multi-layered mechanistic modelling approach to understand how effector genes extend beyond phytoplasma to modulate plant hosts, insect vectors and the environment.

PubMed

Tomkins, Melissa; Kliot, Adi; Marée, Athanasius Fm; Hogenhout, Saskia A

2018-03-13

Members of the Candidatus genus Phytoplasma are small bacterial pathogens that hijack their plant hosts via the secretion of virulence proteins (effectors) leading to a fascinating array of plant phenotypes, such as witch's brooms (stem proliferations) and phyllody (retrograde development of flowers into vegetative tissues). Phytoplasma depend on insect vectors for transmission, and interestingly, these insect vectors were found to be (in)directly attracted to plants with these phenotypes. Therefore, phytoplasma effectors appear to reprogram plant development and defence to lure insect vectors, similarly to social engineering malware, which employs tricks to lure people to infected computers and webpages. A multi-layered mechanistic modelling approach will enable a better understanding of how phytoplasma effector-mediated modulations of plant host development and insect vector behaviour contribute to phytoplasma spread, and ultimately to predict the long reach of phytoplasma effector genes. Copyright © 2018. Published by Elsevier Ltd.
Homologization of the flight musculature of zygoptera (insecta: odonata) and neoptera (insecta).

PubMed

Büsse, Sebastian; Genet, Cécile; Hörnschemeyer, Thomas

2013-01-01

Among the winged insects (Pterygota) the Dragonflies and Damselflies (Odonata) are unique for several reasons. Behaviourally they are aerial predators that hunt and catch their prey in flight, only. Morphologically the flight apparatus of Odonata is significantly different from what is found in the remaining Pterygota. However, to understand the phylogenetic relationships of winged insects and the origin and evolution of insect flight in general, it is essential to know how the elements of the odonatan flight apparatus relate to those of the other Pterygota. Here we present a comprehensive, comparative morphological investigation of the thoracic flight musculature of damselflies (Zygoptera). Based on our new data we propose a homologization scheme for the thoracic musculature throughout Pterygota. The new homology hypotheses will allow for future comparative work and especially for phylogenetic analyses using characters of the thoracic musculature throughout all winged insects. This will contribute to understand the early evolution of pterygote insects and their basal phylogenetic relationship.
Homologization of the Flight Musculature of Zygoptera (Insecta: Odonata) and Neoptera (Insecta)

PubMed Central

Büsse, Sebastian; Genet, Cécile; Hörnschemeyer, Thomas

2013-01-01

Among the winged insects (Pterygota) the Dragonflies and Damselflies (Odonata) are unique for several reasons. Behaviourally they are aerial predators that hunt and catch their prey in flight, only. Morphologically the flight apparatus of Odonata is significantly different from what is found in the remaining Pterygota. However, to understand the phylogenetic relationships of winged insects and the origin and evolution of insect flight in general, it is essential to know how the elements of the odonatan flight apparatus relate to those of the other Pterygota. Here we present a comprehensive, comparative morphological investigation of the thoracic flight musculature of damselflies (Zygoptera). Based on our new data we propose a homologization scheme for the thoracic musculature throughout Pterygota. The new homology hypotheses will allow for future comparative work and especially for phylogenetic analyses using characters of the thoracic musculature throughout all winged insects. This will contribute to understand the early evolution of pterygote insects and their basal phylogenetic relationship. PMID:23457479
Student's experiment to fly on third Shuttle mission

NASA Technical Reports Server (NTRS)

1982-01-01

A spaceborne student experiment on insect motion during weightlessness scheduled to fly on the third flight of the space shuttle is described. The experiment will focus on the flight behavior in zero gravity of two species of flying insects with differing ratios of body mass to wing area, the velvetbean caterpillar moth and the honeybee drone. Ten insects of each species will be carried in separate canisters. The crew will remove the canisters from the storage locker and attach them to the mid-deck wall, where the insects will be observed and filmed by a data acquisition camera.
Chemical signaling and insect attraction is a conserved trait in yeasts.

PubMed

Becher, Paul G; Hagman, Arne; Verschut, Vasiliki; Chakraborty, Amrita; Rozpędowska, Elżbieta; Lebreton, Sébastien; Bengtsson, Marie; Flick, Gerhard; Witzgall, Peter; Piškur, Jure

2018-03-01

Yeast volatiles attract insects, which apparently is of mutual benefit, for both yeasts and insects. However, it is unknown whether biosynthesis of metabolites that attract insects is a basic and general trait, or if it is specific for yeasts that live in close association with insects. Our goal was to study chemical insect attractants produced by yeasts that span more than 250 million years of evolutionary history and vastly differ in their metabolism and lifestyle. We bioassayed attraction of the vinegar fly Drosophila melanogaster to odors of phylogenetically and ecologically distinct yeasts grown under controlled conditions. Baker's yeast Saccharomyces cerevisiae , the insect-associated species Candida californica , Pichia kluyveri and Metschnikowia andauensis , wine yeast Dekkera bruxellensis , milk yeast Kluyveromyces lactis , the vertebrate pathogens Candida albicans and Candida glabrata , and oleophilic Yarrowia lipolytica were screened for fly attraction in a wind tunnel. Yeast headspace was chemically analyzed, and co-occurrence of insect attractants in yeasts and flowering plants was investigated through a database search. In yeasts with known genomes, we investigated the occurrence of genes involved in the synthesis of key aroma compounds. Flies were attracted to all nine yeasts studied. The behavioral response to baker's yeast was independent of its growth stage. In addition to Drosophila , we tested the basal hexapod Folsomia candida (Collembola) in a Y-tube assay to the most ancient yeast, Y. lipolytica, which proved that early yeast signals also function on clades older than neopteran insects. Behavioral and chemical data and a search for selected genes of volatile metabolites underline that biosynthesis of chemical signals is found throughout the yeast clade and has been conserved during the evolution of yeast lifestyles. Literature and database reviews corroborate that yeast signals mediate mutualistic interactions between insects and yeasts. Moreover, volatiles emitted by yeasts are commonly found also in flowers and attract many insect species. The collective evidence suggests that the release of volatile signals by yeasts is a widespread and phylogenetically ancient trait, and that insect-yeast communication evolved prior to the emergence of flowering plants. Co-occurrence of the same attractant signals in yeast and flowers suggests that yeast-insect communication may have contributed to the evolution of insect-mediated pollination in flowers.
Application of Genomics for Understanding Plant Virus-Insect Vector Interactions and Insect Vector Control.

PubMed

Kaur, Navneet; Hasegawa, Daniel K; Ling, Kai-Shu; Wintermantel, William M

2016-10-01

The relationships between plant viruses and their vectors have evolved over the millennia, and yet, studies on viruses began <150 years ago and investigations into the virus and vector interactions even more recently. The advent of next generation sequencing, including rapid genome and transcriptome analysis, methods for evaluation of small RNAs, and the related disciplines of proteomics and metabolomics offer a significant shift in the ability to elucidate molecular mechanisms involved in virus infection and transmission by insect vectors. Genomic technologies offer an unprecedented opportunity to examine the response of insect vectors to the presence of ingested viruses through gene expression changes and altered biochemical pathways. This review focuses on the interactions between viruses and their whitefly or thrips vectors and on potential applications of genomics-driven control of the insect vectors. Recent studies have evaluated gene expression in vectors during feeding on plants infected with begomoviruses, criniviruses, and tospoviruses, which exhibit very different types of virus-vector interactions. These studies demonstrate the advantages of genomics and the potential complementary studies that rapidly advance our understanding of the biology of virus transmission by insect vectors and offer additional opportunities to design novel genetic strategies to manage insect vectors and the viruses they transmit.
Harnessing Host-Vector Microbiome for Sustainable Plant Disease Management of Phloem-Limited Bacteria

PubMed Central

Trivedi, Pankaj; Trivedi, Chanda; Grinyer, Jasmine; Anderson, Ian C.; Singh, Brajesh K.

2016-01-01

Plant health and productivity is strongly influenced by their intimate interaction with deleterious and beneficial organisms, including microbes, and insects. Of the various plant diseases, insect-vectored diseases are of particular interest, including those caused by obligate parasites affecting plant phloem such as Candidatus (Ca.) Phytoplasma species and several species of Ca. Liberibacter. Recent studies on plant–microbe and plant–insect interactions of these pathogens have demonstrated that plant–microbe–insect interactions have far reaching consequences for the functioning and evolution of the organisms involved. These interactions take place within complex pathosystems and are shaped by a myriad of biotic and abiotic factors. However, our current understanding of these processes and their implications for the establishment and spread of insect-borne diseases remains limited. This article highlights the molecular, ecological, and evolutionary aspects of interactions among insects, plants, and their associated microbial communities with a focus on insect vectored and phloem-limited pathogens belonging to Ca. Phytoplasma and Ca. Liberibacter species. We propose that innovative and interdisciplinary research aimed at linking scales from the cellular to the community level will be vital for increasing our understanding of the mechanisms underpinning plant–insect–microbe interactions. Examination of such interactions could lead us to applied solutions for sustainable disease and pest management. PMID:27746788
Indirect Plant Defense against Insect Herbivores: A Review

USDA-ARS?s Scientific Manuscript database

Plants respond to herbivore attack by launching two types of defenses: direct defense and indirect defense. Direct defense includes all plant traits that increase the resistance of host plants to attacking insect herbivores by affecting the physiology and/or behavior of the attackers. Indirect defe...
Magnetoreception in Eusocial Insects: An Update

USDA-ARS?s Scientific Manuscript database

Behavioral experiments for magnetoreception in eusocial insects in the last decade are reviewed. Ants and bees use the geomagnetic field to orient and navigate in areas around their nests and in migratory paths. Bees show sensitivity to small changes in magnetic fields in conditioning experiments a...
Wind alters landing dynamics in bumblebees.

PubMed

Chang, Jeremy J; Crall, James D; Combes, Stacey A

2016-09-15

Landing is an important but understudied behavior that flying animals must perform constantly. In still air, insects decelerate smoothly prior to landing by employing the relatively simple strategy of maintaining a constant rate of image expansion during their approach. However, it is unclear whether insects employ this strategy when faced with challenging flight environments. Here, we tested the effects of wind on bumblebees (Bombus impatiens) landing on flowers. We find that bees' approach paths to flowers shift from multidirectional in still air to unidirectional in wind, regardless of flower orientation. In addition, bees landing in a 3.5 m s -1 headwind do not decelerate smoothly, but rather maintain a high flight speed until contact, resulting in higher peak decelerations upon impact. These findings suggest that wind has a strong influence on insect landing behavior and performance, with important implications for the design of micro aerial vehicles and the ecomechanics of insect flight. © 2016. Published by The Company of Biologists Ltd.
The Genome and Methylome of a Beetle with Complex Social Behavior, Nicrophorus vespilloides (Coleoptera: Silphidae).

PubMed

Cunningham, Christopher B; Ji, Lexiang; Wiberg, R Axel W; Shelton, Jennifer; McKinney, Elizabeth C; Parker, Darren J; Meagher, Richard B; Benowitz, Kyle M; Roy-Zokan, Eileen M; Ritchie, Michael G; Brown, Susan J; Schmitz, Robert J; Moore, Allen J

2015-10-09

Testing for conserved and novel mechanisms underlying phenotypic evolution requires a diversity of genomes available for comparison spanning multiple independent lineages. For example, complex social behavior in insects has been investigated primarily with eusocial lineages, nearly all of which are Hymenoptera. If conserved genomic influences on sociality do exist, we need data from a wider range of taxa that also vary in their levels of sociality. Here, we present the assembled and annotated genome of the subsocial beetle Nicrophorus vespilloides, a species long used to investigate evolutionary questions of complex social behavior. We used this genome to address two questions. First, do aspects of life history, such as using a carcass to breed, predict overlap in gene models more strongly than phylogeny? We found that the overlap in gene models was similar between N. vespilloides and all other insect groups regardless of life history. Second, like other insects with highly developed social behavior but unlike other beetles, does N. vespilloides have DNA methylation? We found strong evidence for an active DNA methylation system. The distribution of methylation was similar to other insects with exons having the most methylated CpGs. Methylation status appears highly conserved; 85% of the methylated genes in N. vespilloides are also methylated in the hymentopteran Nasonia vitripennis. The addition of this genome adds a coleopteran resource to answer questions about the evolution and mechanistic basis of sociality and to address questions about the potential role of methylation in social behavior. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Evolution of a complex behavior: the origin and initial diversification of foliar galling by Permian insects

NASA Astrophysics Data System (ADS)

Schachat, Sandra R.; Labandeira, Conrad C.

2015-04-01

A central notion of the early evolution of insect galling is that this unique behavior was uncommon to rare before the diversification of angiosperms 135 to 125 m.yr. ago. However, evidence accumulated during recent years shows that foliar galls were diverse and locally abundant as early as the Permian Period, 299 to 252 m.yr. ago. In particular, a diversity of leaf galling during the Early Permian has recently been documented by the plant-damage record of foliar galls and, now, our interpretation of the body-fossil record of culprit insect gallers. Small size is a prerequisite for gallers. Wing-length measurements of Permian insects indicate that several small-bodied hemipteroid lineages originated early during the Permian, some descendant lineages of which gall the leaves of seed plants to the present day. The earliest foliar gallers likely were Protopsyllidiidae (Hemiptera) and Lophioneuridae (Thripida). Much of the Early Permian was a xeric interval, and modern galls are most common in dry, extra-tropical habitats such as scrubland and deserts. Plant-damage, insect body fossils, and the paleoclimate record collectively support the ecological expansion of foliar galling during the Early Permian and its continued expansion through the Late Permian.
Temporal Statistics of Natural Image Sequences Generated by Movements with Insect Flight Characteristics

PubMed Central

Schwegmann, Alexander; Lindemann, Jens Peter; Egelhaaf, Martin

2014-01-01

Many flying insects, such as flies, wasps and bees, pursue a saccadic flight and gaze strategy. This behavioral strategy is thought to separate the translational and rotational components of self-motion and, thereby, to reduce the computational efforts to extract information about the environment from the retinal image flow. Because of the distinguishing dynamic features of this active flight and gaze strategy of insects, the present study analyzes systematically the spatiotemporal statistics of image sequences generated during saccades and intersaccadic intervals in cluttered natural environments. We show that, in general, rotational movements with saccade-like dynamics elicit fluctuations and overall changes in brightness, contrast and spatial frequency of up to two orders of magnitude larger than translational movements at velocities that are characteristic of insects. Distinct changes in image parameters during translations are only caused by nearby objects. Image analysis based on larger patches in the visual field reveals smaller fluctuations in brightness and spatial frequency composition compared to small patches. The temporal structure and extent of these changes in image parameters define the temporal constraints imposed on signal processing performed by the insect visual system under behavioral conditions in natural environments. PMID:25340761
Impacts of Insect Herbivores on Plant Populations.

PubMed

Myers, Judith H; Sarfraz, Rana M

2017-01-31

Apparent feeding damage by insects on plants is often slight. Thus, the influences of insect herbivores on plant populations are likely minor. The role of insects on host-plant populations can be elucidated via several methods: stage-structured life tables of plant populations manipulated by herbivore exclusion and seed-addition experiments, tests of the enemy release hypothesis, studies of the effects of accidentally and intentionally introduced insect herbivores, and observations of the impacts of insect species that show outbreak population dynamics. These approaches demonstrate that some, but not all, insect herbivores influence plant population densities. At times, insect-feeding damage kills plants, but more often, it reduces plant size, growth, and seed production. Plant populations for which seed germination is site limited will not respond at the population level to reduced seed production. Insect herbivores can influence rare plant species and need to be considered in conservation programs. Alterations due to climate change in the distributions of insect herbivores indicate the possibility of new influences on host plants. Long-term studies are required to show if density-related insect behavior stabilizes plant populations or if environmental variation drives most temporal fluctuations in plant densities. Finally, insects can influence plant populations and communities through changing the diversity of nonhost species, modifying nutrient fluxes, and rejuvenating over mature forests.
Allosteric modulation by benzodiazepines of GABA-gated chloride channels of an identified insect motor neurone.

PubMed

Buckingham, Steven D; Higashino, Yoshiaki; Sattelle, David B

2009-11-01

The actions of benzodiazepines were studied on the responses to GABA of the fast coxal depressor (D(f)) motor neurone of the cockroach, Periplaneta americana. Ro5-4864, diazepam and clonazepam were investigated. Responses to GABA receptors were enhanced by both Ro5-4864 and diazepam, whereas clonazepam, a potent-positive allosteric modulator of human GABA(A) receptors, was ineffective on the native insect GABA receptors of the D(f) motor neurone. Thus, clear pharmacological differences exist between insect and mammalian native GABA-gated chloride channels with respect to the actions of benzodiazepines. The results enhance our understanding of invertebrate GABA-gated chloride channels which have recently proved important in (a) comparative studies aimed at identifying human allosteric drug-binding sites and (b) understanding the actions of compounds used to control ectoparasites and insect crop pests.

Flapping wing aerodynamics: from insects to vertebrates.

PubMed

Chin, Diana D; Lentink, David

2016-04-01

More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight. © 2016. Published by The Company of Biologists Ltd.
Insect allergy.

PubMed

Tracy, James M

2011-01-01

Anaphylaxis is a life-threatening allergic condition. The 3 most common triggers for anaphylaxis are food, medications, and insects. All of these triggers are the sources of considerable morbidity and mortality, but of the 3, only insect allergy is treatable through means other than trigger avoidance. Because ≥ 40 deaths per year are attributed to insect stings, it is critical that healthcare providers and the public understand the proper diagnosis as well as the long-term treatment of this potentially life-threatening allergy. Unlike food and medication allergy, which are managed primarily by allergen avoidance, Hymenoptera allergy is managed prospectively using venom immunotherapy; this results in a protective level of up to 98%. Insects of the order Hymenoptera include bees, wasps, hornets, yellowjackets, and ants. They are responsible for the majority of the fatal and near-fatal sting events. Understanding the biology and habitat of the various Hymenoptera species is helpful in recommending insect-avoidance strategies. The diagnosis of insect allergy relies on a history of a systemic allergic reaction with appropriate testing for venom-specific immunoglobulin E. If the history of a systemic reaction to an insect sting and the presence of venom specific immunoglobulin E is confirmed, venom immunotherapy is indicated. The proper and primary means of treating acute anaphylaxis is immediate epinephrine-and studies suggest that it is underutilized in the acute setting. However, it is venom immunotherapy, a disease-modifying therapy, that provides the affected individual with the most effective protection against future sting reactions. Long-term management of insect allergy and anaphylaxis includes appropriate referral to an allergist familiar with insect allergy and, if indicated, venom immunotherapy. © 2011 Mount Sinai School of Medicine.
AC-DC electropenetrography: a new diagnostic technology for study of feeding behavior of piercing-sucking insects

USDA-ARS?s Scientific Manuscript database

Studying feeding, plant damage, and transmission of plant pathogens by hemipteran insect pests is challenging. Hemipteran piercing-sucking mouthparts, the stylets, are probed into opaque plant tissues precluding direct observation. This challenge was overcome by the invention of electropenetrography...
Bug City: Aquatic Insects [Videotape].

ERIC Educational Resources Information Center

1998

"Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…
The pear thrips problem

Treesearch

Bruce L. Parker

1991-01-01

As entomologists, we sometimes like to think of an insect pest problem as simply a problem with an insect and its host. Our jobs would be much easier if that were the case, but of course, it is never that simple. There are many other factors besides the insect, and each one must be fully considered to understand the problem and develop effective management solutions....
Acoustic communication in insect disease vectors

PubMed Central

Vigoder, Felipe de Mello; Ritchie, Michael Gordon; Gibson, Gabriella; Peixoto, Alexandre Afranio

2013-01-01

Acoustic signalling has been extensively studied in insect species, which has led to a better understanding of sexual communication, sexual selection and modes of speciation. The significance of acoustic signals for a blood-sucking insect was first reported in the XIX century by Christopher Johnston, studying the hearing organs of mosquitoes, but has received relatively little attention in other disease vectors until recently. Acoustic signals are often associated with mating behaviour and sexual selection and changes in signalling can lead to rapid evolutionary divergence and may ultimately contribute to the process of speciation. Songs can also have implications for the success of novel methods of disease control such as determining the mating competitiveness of modified insects used for mass-release control programs. Species-specific sound “signatures” may help identify incipient species within species complexes that may be of epidemiological significance, e.g. of higher vectorial capacity, thereby enabling the application of more focussed control measures to optimise the reduction of pathogen transmission. Although the study of acoustic communication in insect vectors has been relatively limited, this review of research demonstrates their value as models for understanding both the functional and evolutionary significance of acoustic communication in insects. PMID:24473800
Modes of Action, Resistance and Toxicity of Insecticides Targeting Nicotinic Acetylcholine Receptors.

PubMed

Ihara, Makoto; Buckingham, Steven D; Matsuda, Kazuhiko; Sattelle, David B

2017-01-01

Nicotinic acetylcholine receptors (nAChRs) of insects play a key role in fast excitatory neurotransmission. Several classes of insecticides target insect nAChRs, which are composed of subunit members of a family of multiple subunit encoding genes. Alternative splicing and RNA A-to-I editing can add further to receptor diversity. Native and recombinant receptors have been explored as sites of insecticide action using radioligands, electrophysiology and site-directed mutagenesis. We have reviewed the properties of native and recombinant insect nAChRs, the challenges of functional recombinant insect nAChR expression, nAChR interactions with ligands acting at orthosteric and allosteric sites and in particular their interactions with insecticides. Actions on insect nAChRs of cartap, neonicotinoids, spinosyns, sulfoxamines, butenolides and mesoionic insecticides are reviewed and current knowledge of their modes of action are addressed. Mutations that add to our understanding of insecticide action and those leading to resistance are discussed. Co-crystallisation of neonicotinoids with the acetylcholine binding protein (AChBP), a surrogate for the nAChR ligand binding domain, has proved instructive. Toxicity issues relating to insecticides targeting nAChRs are also considered. An overview of insecticide classes targeting insect nAChRs has enhanced our understanding of these important receptors and their insecticide binding sites. However, the subunit composition of native nAChRs remains poorly understood and functional expression still presents difficulties. These topics together with improved understanding of the precise sites of insecticide actions on insect nAChRs will be the subject of future research. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Nitric oxide contributes to high-salt perception in a blood-sucking insect model.

PubMed

Cano, Agustina; Pontes, Gina; Sfara, Valeria; Anfossi, Diego; Barrozo, Romina B

2017-11-14

In all organisms, salts produce either appetitive or aversive responses depending on the concentration. While low-salt concentration in food elicits positive responses to ingest, high-salt triggers aversion. Still the mechanisms involved in this dual behavior have just started to be uncovered in some organisms. In Rhodnius prolixus, using pharmacological and behavioral assays, we demonstrated that upon high-salt detection in food a nitric oxide (NO) dependent cascade is activated. This activation involves a soluble guanylate cyclase (sGC) and the production of cyclic guanosine monophosphate (cGMP). Thus, appetitive responses to low-salt diets turn to aversion whenever this cascade is activated. Conversely, insects feed over aversive high-salt solutions when it is blocked by reducing NO levels or by affecting the sGC activity. The activation of NO/sGC/cGMP cascade commands the avoidance feeding behavior in R. prolixus. Investigations in other insect species should examine the possibility that high-salt aversion is mediated by NO/sSG/cGMP signaling.
Spatial fidelity of workers predicts collective response to disturbance in a social insect.

PubMed

Crall, James D; Gravish, Nick; Mountcastle, Andrew M; Kocher, Sarah D; Oppenheimer, Robert L; Pierce, Naomi E; Combes, Stacey A

2018-04-03

Individuals in social insect colonies cooperate to perform collective work. While colonies often respond to changing environmental conditions by flexibly reallocating workers to different tasks, the factors determining which workers switch and why are not well understood. Here, we use an automated tracking system to continuously monitor nest behavior and foraging activity of uniquely identified workers from entire bumble bee (Bombus impatiens) colonies foraging in a natural outdoor environment. We show that most foraging is performed by a small number of workers and that the intensity and distribution of foraging is actively regulated at the colony level in response to forager removal. By analyzing worker nest behavior before and after forager removal, we show that spatial fidelity of workers within the nest generates uneven interaction with relevant localized information sources, and predicts which workers initiate foraging after disturbance. Our results highlight the importance of spatial fidelity for structuring information flow and regulating collective behavior in social insect colonies.
Early evolution and ecology of camouflage in insects

PubMed Central

Pérez-de la Fuente, Ricardo; Delclòs, Xavier; Peñalver, Enrique; Speranza, Mariela; Wierzchos, Jacek; Ascaso, Carmen; Engel, Michael S.

2012-01-01

Taxa within diverse lineages select and transport exogenous materials for the purposes of camouflage. This adaptive behavior also occurs in insects, most famously in green lacewing larvae who nestle the trash among setigerous cuticular processes, known as trash-carrying, rendering them nearly undetectable to predators and prey, as well as forming a defensive shield. We report an exceptional discovery of a green lacewing larva in Early Cretaceous amber from Spain with specialized cuticular processes forming a dorsal basket that carry a dense trash packet. The trash packet is composed of trichomes of gleicheniacean ferns, which highlight the presence of wildfires in this early forest ecosystem. This discovery provides direct evidence of an early acquisition of a sophisticated behavioral suite in stasis for over 110 million years and an ancient plant–insect interaction. PMID:23236135
Early evolution and ecology of camouflage in insects.

PubMed

Pérez-de la Fuente, Ricardo; Delclòs, Xavier; Peñalver, Enrique; Speranza, Mariela; Wierzchos, Jacek; Ascaso, Carmen; Engel, Michael S

2012-12-26

Taxa within diverse lineages select and transport exogenous materials for the purposes of camouflage. This adaptive behavior also occurs in insects, most famously in green lacewing larvae who nestle the trash among setigerous cuticular processes, known as trash-carrying, rendering them nearly undetectable to predators and prey, as well as forming a defensive shield. We report an exceptional discovery of a green lacewing larva in Early Cretaceous amber from Spain with specialized cuticular processes forming a dorsal basket that carry a dense trash packet. The trash packet is composed of trichomes of gleicheniacean ferns, which highlight the presence of wildfires in this early forest ecosystem. This discovery provides direct evidence of an early acquisition of a sophisticated behavioral suite in stasis for over 110 million years and an ancient plant-insect interaction.
Discovering the flight autostabilizer of fruit flies by inducing aerial stumbles

PubMed Central

Ristroph, Leif; Bergou, Attila J.; Ristroph, Gunnar; Coumes, Katherine; Berman, Gordon J.; Guckenheimer, John; Wang, Z. Jane; Cohen, Itai

2010-01-01

Just as the Wright brothers implemented controls to achieve stable airplane flight, flying insects have evolved behavioral strategies that ensure recovery from flight disturbances. Pioneering studies performed on tethered and dissected insects demonstrate that the sensory, neurological, and musculoskeletal systems play important roles in flight control. Such studies, however, cannot produce an integrative model of insect flight stability because they do not incorporate the interaction of these systems with free-flight aerodynamics. We directly investigate control and stability through the application of torque impulses to freely flying fruit flies (Drosophila melanogaster) and measurement of their behavioral response. High-speed video and a new motion tracking method capture the aerial “stumble,” and we discover that flies respond to gentle disturbances by accurately returning to their original orientation. These insects take advantage of a stabilizing aerodynamic influence and active torque generation to recover their heading to within 2° in < 60 ms. To explain this recovery behavior, we form a feedback control model that includes the fly’s ability to sense body rotations, process this information, and actuate the wing motions that generate corrective aerodynamic torque. Thus, like early man-made aircraft and modern fighter jets, the fruit fly employs an automatic stabilization scheme that reacts to short time-scale disturbances. PMID:20194789
Discovering the flight autostabilizer of fruit flies by inducing aerial stumbles.

PubMed

Ristroph, Leif; Bergou, Attila J; Ristroph, Gunnar; Coumes, Katherine; Berman, Gordon J; Guckenheimer, John; Wang, Z Jane; Cohen, Itai

2010-03-16

Just as the Wright brothers implemented controls to achieve stable airplane flight, flying insects have evolved behavioral strategies that ensure recovery from flight disturbances. Pioneering studies performed on tethered and dissected insects demonstrate that the sensory, neurological, and musculoskeletal systems play important roles in flight control. Such studies, however, cannot produce an integrative model of insect flight stability because they do not incorporate the interaction of these systems with free-flight aerodynamics. We directly investigate control and stability through the application of torque impulses to freely flying fruit flies (Drosophila melanogaster) and measurement of their behavioral response. High-speed video and a new motion tracking method capture the aerial "stumble," and we discover that flies respond to gentle disturbances by accurately returning to their original orientation. These insects take advantage of a stabilizing aerodynamic influence and active torque generation to recover their heading to within 2 degrees in < 60 ms. To explain this recovery behavior, we form a feedback control model that includes the fly's ability to sense body rotations, process this information, and actuate the wing motions that generate corrective aerodynamic torque. Thus, like early man-made aircraft and modern fighter jets, the fruit fly employs an automatic stabilization scheme that reacts to short time-scale disturbances.
High-throughput sequencing of fecal DNA to identify insects consumed by wild Weddell's saddleback tamarins (Saguinus weddelli, Cebidae, Primates) in Bolivia.

PubMed

Mallott, E K; Malhi, R S; Garber, P A

2015-03-01

The genus Saguinus represents a successful radiation of over 20 species of small-bodied New World monkeys. Studies of the tamarin diet indicate that insects and small vertebrates account for ∼16-45% of total feeding and foraging time, and represent an important source of lipids, protein, and metabolizable energy. Although tamarins are reported to commonly consume large-bodied insects such as grasshoppers and walking sticks (Orthoptera), little is known concerning the degree to which smaller or less easily identifiable arthropod prey comprises an important component of their diet. To better understand tamarin arthropod feeding behavior, fecal samples from 20 wild Bolivian saddleback tamarins (members of five groups) were collected over a 3 week period in June 2012, and analyzed for the presence of arthropod DNA. DNA was extracted using a Qiagen stool extraction kit, and universal insect primers were created and used to amplify a ∼280 bp section of the COI mitochondrial gene. Amplicons were sequenced on the Roche 454 sequencing platform using high-throughput sequencing techniques. An analysis of these samples indicated the presence of 43 taxa of arthropods including 10 orders, 15 families, and 12 identified genera. Many of these taxa had not been previously identified in the tamarin diet. These results highlight molecular analysis of fecal DNA as an important research tool for identifying anthropod feeding patterns in primates, and reveal broad diversity in the taxa, foraging microhabitats, and size of arthropods consumed by tamarin monkeys. © 2014 Wiley Periodicals, Inc.
Molecular mechanisms influencing efficiency of RNA interference in insects.

PubMed

Cooper, Anastasia M W; Silver, Kristopher; Jianzhen, Zhang; Park, Yoonseong; Zhu, Kun Yan

2018-06-21

RNA interference (RNAi) is an endogenous, sequence-specific gene silencing mechanism elicited by small RNA molecules. RNAi is a powerful reverse genetic tool, and is currently being utilized for managing insects and viruses. Widespread implementation of RNAi-based pest management strategies is currently hindered by inefficient and highly variable results when different insect species, strains, developmental stages, tissues, and genes are targeted. Mechanistic studies have shown that double-stranded ribonucleases (dsRNases), endosomal entrapment, deficient function of the core machinery, and inadequate immune stimulation contribute to limited RNAi efficiency. However, a comprehensive understanding of the molecular mechanisms limiting RNAi efficiency remains elusive. The recent advances in dsRNA stability in physiological tissues, dsRNA internalization into cells, the composition and function of the core RNAi machinery, as well as small-interfering RNA/double-stranded RNA amplification and spreading mechanisms are reviewed to establish a global understanding of the obstacles impeding wider understanding of RNAi mechanisms in insects. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Bug City: House and Backyard Insects [Videotape].

ERIC Educational Resources Information Center

1998

"Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography,…
Sampling stored product insect pests: a comparison of four statistical sampling models for probability of pest detection

USDA-ARS?s Scientific Manuscript database

Statistically robust sampling strategies form an integral component of grain storage and handling activities throughout the world. Developing sampling strategies to target biological pests such as insects in stored grain is inherently difficult due to species biology and behavioral characteristics. ...
Shifts in Buchnera aphidicola density in soybean aphids (Aphis glycines) feeding on virus-infected soybean

USDA-ARS?s Scientific Manuscript database

Bacterial symbioses are prevalent across insect taxa, and are considered key to several specialized feeding behaviors and to insect diversification at large. Aphids undergo an obligate symbiosis with Buchnera aphidicola, which provides essential amino acids to its host contributing directly to host ...
Characterization of Direct Current-Electrical Penetration Graph Waveforms and Correlation With the Probing Behavior of Matsumuratettix hiroglyphicus (Hemiptera: Cicadellidae), the Insect Vector of Sugarcane White Leaf Phytoplasma.

PubMed

Roddee, J; Kobori, Y; Yorozuya, H; Hanboonsong, Y

2017-06-01

The leafhopper Matsumuratettix hiroglyphicus (Matsumura) (Hemiptera: Cicadellidae) is an important vector of phytoplasma causing white leaf disease in sugarcane. Thus, the aim of our study was to understand and describe the stylet-probing activities of this vector while feeding on sugarcane plants, by using direct current (DC) electrical penetration graph (EPG) monitoring. The EPG signals were classified into six distinct waveforms, according to amplitude, frequency, voltage level, and electrical origin of the observed traces during stylet penetration into the host plant tissues (probing). These six EPG waveforms of probing behavior comprise no stylet penetration (NP); stylet pathway through epidermis, mesophyll, and parenchymal cells (waveform A); contact at the bundle sheath layer (waveform B); salivation into phloem sieve elements (waveform C); phloem sap ingestion (waveform D); and short ingestion time of xylem sap (waveform E). The above waveform patterns were correlated with histological data of salivary sheath termini in plant tissue generated from insect stylet tips. The key findings of this study were that M. hiroglyphicus ingests the phloem sap at a relatively higher rate and for longer duration from any other cell type, suggesting that M. hiroglyphicus is mainly a phloem-feeder. Quantitative comparison of probing behavior revealed that females typically probe more frequently and longer in the phloem than males. Thus, females may acquire and inoculate greater amounts of phytoplasma than males, enhancing the efficiency of phytoplasma transmission and potentially exacerbating disease spreading. Overall, our study provides basic information on the probing behavior and transmission mechanism of M. hiroglyphicus. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Strategies for Enhanced Crop Resistance to Insect Pests.

PubMed

Douglas, Angela E

2018-04-29

Insect pests are responsible for substantial crop losses worldwide through direct damage and transmission of plant diseases, and novel approaches that complement or replace broad-spectrum chemical insecticides will facilitate the sustainable intensification of food production in the coming decades. Multiple strategies for improved crop resistance to insect pests, especially strategies relating to plant secondary metabolism and immunity and microbiome science, are becoming available. Recent advances in metabolic engineering of plant secondary chemistry offer the promise of specific toxicity or deterrence to insect pests; improved understanding of plant immunity against insects provides routes to optimize plant defenses against insects; and the microbiomes of insect pests can be exploited, either as a target or as a vehicle for delivery of insecticidal agents. Implementation of these advances will be facilitated by ongoing advances in plant breeding and genetic technologies.

Roles of Octopamine and Dopamine Neurons for Mediating Appetitive and Aversive Signals in Pavlovian Conditioning in Crickets

PubMed Central

Mizunami, Makoto; Matsumoto, Yukihisa

2017-01-01

Revealing neural systems that mediate appetite and aversive signals in associative learning is critical for understanding the brain mechanisms controlling adaptive behavior in animals. In mammals, it has been shown that some classes of dopamine neurons in the midbrain mediate prediction error signals that govern the learning process, whereas other classes of dopamine neurons control execution of learned actions. In this review, based on the results of our studies on Pavlovian conditioning in the cricket Gryllus bimaculatus and by referring to the findings in honey bees and fruit-flies, we argue that comparable aminergic systems exist in the insect brain. We found that administrations of octopamine (the invertebrate counterpart of noradrenaline) and dopamine receptor antagonists impair conditioning to associate an olfactory or visual conditioned stimulus (CS) with water or sodium chloride solution (appetitive or aversive unconditioned stimulus, US), respectively, suggesting that specific octopamine and dopamine neurons mediate appetitive and aversive signals, respectively, in conditioning in crickets. These findings differ from findings in fruit-flies. In fruit-flies, appetitive and aversive signals are mediated by different dopamine neuron subsets, suggesting diversity in neurotransmitters mediating appetitive signals in insects. We also found evidences of “blocking” and “auto-blocking” phenomena, which suggested that the prediction error, the discrepancy between actual US and predicted US, governs the conditioning in crickets and that octopamine neurons mediate prediction error signals for appetitive US. Our studies also showed that activations of octopamine and dopamine neurons are needed for the execution of an appetitive conditioned response (CR) and an aversive CR, respectively, and we, thus, proposed that these neurons mediate US prediction signals that drive appetitive and aversive CRs. Our findings suggest that the basic principles of functioning of aminergic systems in associative learning, i.e., to transmit prediction error signals for conditioning and to convey US prediction signals for execution of CR, are conserved among insects and mammals, on account of the fact that the organization of the insect brain is much simpler than that of the mammalian brain. Further investigation of aminergic systems that govern associative learning in insects should lead to a better understanding of commonalities and diversities of computational rules underlying associative learning in animals. PMID:29311961
Roles of Octopamine and Dopamine Neurons for Mediating Appetitive and Aversive Signals in Pavlovian Conditioning in Crickets.

PubMed

Mizunami, Makoto; Matsumoto, Yukihisa

2017-01-01

Revealing neural systems that mediate appetite and aversive signals in associative learning is critical for understanding the brain mechanisms controlling adaptive behavior in animals. In mammals, it has been shown that some classes of dopamine neurons in the midbrain mediate prediction error signals that govern the learning process, whereas other classes of dopamine neurons control execution of learned actions. In this review, based on the results of our studies on Pavlovian conditioning in the cricket Gryllus bimaculatus and by referring to the findings in honey bees and fruit-flies, we argue that comparable aminergic systems exist in the insect brain. We found that administrations of octopamine (the invertebrate counterpart of noradrenaline) and dopamine receptor antagonists impair conditioning to associate an olfactory or visual conditioned stimulus (CS) with water or sodium chloride solution (appetitive or aversive unconditioned stimulus, US), respectively, suggesting that specific octopamine and dopamine neurons mediate appetitive and aversive signals, respectively, in conditioning in crickets. These findings differ from findings in fruit-flies. In fruit-flies, appetitive and aversive signals are mediated by different dopamine neuron subsets, suggesting diversity in neurotransmitters mediating appetitive signals in insects. We also found evidences of "blocking" and "auto-blocking" phenomena, which suggested that the prediction error, the discrepancy between actual US and predicted US, governs the conditioning in crickets and that octopamine neurons mediate prediction error signals for appetitive US. Our studies also showed that activations of octopamine and dopamine neurons are needed for the execution of an appetitive conditioned response (CR) and an aversive CR, respectively, and we, thus, proposed that these neurons mediate US prediction signals that drive appetitive and aversive CRs. Our findings suggest that the basic principles of functioning of aminergic systems in associative learning, i.e., to transmit prediction error signals for conditioning and to convey US prediction signals for execution of CR, are conserved among insects and mammals, on account of the fact that the organization of the insect brain is much simpler than that of the mammalian brain. Further investigation of aminergic systems that govern associative learning in insects should lead to a better understanding of commonalities and diversities of computational rules underlying associative learning in animals.
Evolution of Parasitism in Insect-transmitted Plant Nematodes

PubMed Central

Giblin-Davis, R. M.; Davies, K. A.; Morris, K.; Thomas, W. K.

2003-01-01

Nematode-insect associations have evolved many times in the phylum Nematoda, but these lineages involve plant parasitism only in the Secernentean orders Aphelenchida and Tylenchida. In the Aphelenchida (Aphelenchoidoidea), Bursaphelenchus xylophilus (Pine wood nematode), B. cocophilus (Red ring or Coconut palm nematode) (Parasitaphelenchidae), and the many potential host-specific species of Schistonchus (fig nematodes) (Aphelenchoididae) nematode-insect interactions probably evolved independently from dauer-forming, mycophagous ancestors that were phoretically transmitted to breeding sites of their insect hosts in plants. Mycophagy probably gave rise to facultative or obligate plant-parasitism because of opportunities due to insect host switches or peculiarities in host behavior. In the Tylenchida, there is one significant radiation of insect-associated plant parasites involving Fergusobia nematodes (Fergusobiinae: Neotylenchidae) and Fergusonina (Fergusoninidae) flies as mutualists that gall myrtaceous plant buds or leaves. These dicyclic nematodes have different phases that are parasitic in either the insect or the plant hosts. The evolutionary origin of this association is unclear. PMID:19265987
Effect of risk information exposure on consumers' responses to foods with insect contamination.

PubMed

Kimura, Atsushi; Magariyama, Yukio; Miyanoshita, Akihiro; Imamura, Taro; Shichiri, Kumiko; Masuda, Tomohiro; Wada, Yuji

2014-02-01

This study explores the impact that scientific information about insect contamination of food has on consumer perceptions. Participants (n = 320, Japanese consumers) were randomly assigned to 1 of 8 information-type conditions: (1) information about insect type, (2) information about contamination processes, (3) information about the safety of contaminated food, (4, 5, 6) combinations of 2 of (1), (2), and (3) above, (7) all information, and (8) no-information, and asked to rate their valuation, behavioral intention, and attitude toward food with insect contamination. Results demonstrated that some combinations of scientific information that include the safety of the contaminated food are effective to reduce consumers' compulsive rejection of insect contamination in food, whereas the single presentation of information about insect type increases consumers' explicit rejection of both the contaminated product and the manufacturer. These findings have implications for the coordination of risk communication strategies. © 2014 Institute of Food Technologists®
Evolution of complex higher brain centers and behaviors: behavioral correlates of mushroom body elaboration in insects.

PubMed

Farris, Sarah M

2013-01-01

Large, complex higher brain centers have evolved many times independently within the vertebrates, but the selective pressures driving these acquisitions have been difficult to pinpoint. It is well established that sensory brain centers become larger and more structurally complex to accommodate processing of a particularly important sensory modality. When higher brain centers such as the cerebral cortex become greatly expanded in a particular lineage, it is likely to support the coordination and execution of more complex behaviors, such as those that require flexibility, learning, and social interaction, in response to selective pressures that made these new behaviors advantageous. Vertebrate studies have established a link between complex behaviors, particularly those associated with sociality, and evolutionary expansions of telencephalic higher brain centers. Enlarged higher brain centers have convergently evolved in groups such as the insects, in which multimodal integration and learning and memory centers called the mushroom bodies have become greatly elaborated in at least four independent lineages. Is it possible that similar selective pressures acting on equivalent behavioral outputs drove the evolution of large higher brain centers in all bilaterians? Sociality has greatly impacted brain evolution in vertebrates such as primates, but it has not been a major driver of higher brain center enlargement in insects. However, feeding behaviors requiring flexibility and learning are associated with large higher brain centers in both phyla. Selection for the ability to support behavioral flexibility appears to be a common thread underlying the evolution of large higher brain centers, but the precise nature of these computations and behaviors may vary. © 2013 S. Karger AG, Basel.
Of Butterflies and Beetles: First Graders' Ways of Seeing and Talking about Insect Life Cycles.

ERIC Educational Resources Information Center

Shepardson, Daniel P.

1997-01-01

Explores children's understandings of insect life cycles through pre- and postinstructional interviews, analysis of children's journal entries, and talk that occurred throughout the instructional unit. Contains 38 references. (DDR)
Flash Bulletin: Fireflies

ERIC Educational Resources Information Center

Brown, Debbie

1984-01-01

Explains the flashes of light emitted by fireflies as competition, species-specific code, species identification and mating behavior and ecology. Suggests activities to conduct to study the insects and their behavior. (ERB)
DNA methylation in insects: on the brink of the epigenomic era.

PubMed

Glastad, K M; Hunt, Brendan G; Yi, S V; Goodisman, M A D

2011-10-01

DNA methylation plays an important role in gene regulation in animals. However, the evolution and function of DNA methylation has only recently emerged as the subject of widespread study in insects. In this review we profile the known distribution of DNA methylation systems across insect taxa and synthesize functional inferences from studies of DNA methylation in insects and vertebrates. Unlike vertebrate genomes, which tend to be globally methylated, DNA methylation is primarily targeted to genes in insects. Nevertheless, mounting evidence suggests that a specialized role exists for genic methylation in the regulation of transcription, and possibly mRNA splicing, in both insects and mammals. Investigations in several insect taxa further reveal that DNA methylation is preferentially targeted to ubiquitously expressed genes and may play a key role in the regulation of phenotypic plasticity. We suggest that insects are particularly amenable to advancing our understanding of the biological functions of DNA methylation, because insects are evolutionarily diverse, display several lineage-specific losses of DNA methylation and possess tractable patterns of DNA methylation in moderately sized genomes. © 2011 The Authors. Insect Molecular Biology © 2011 The Royal Entomological Society.
Plant and animal rhabdovirus host range: a bug's view.

PubMed

Hogenhout, Saskia A; Redinbaugh, Margaret G; Ammar, El-Desouky

2003-06-01

Rhabdoviruses affect human health, terrestrial and aquatic livestock and crops. Most rhabdoviruses are transmitted by insects to their vertebrate or plant hosts. For insect transmission to occur, rhabdoviruses must negotiate barriers to acquisition, replication, movement, escape and inoculation. A better understanding of the molecular interactions of rhabdoviruses with insects will clarify the complexities of rhabdovirus infection processes and epidemiology. A unique opportunity for studying how insects become hosts and vectors of rhabdoviruses is provided by five maize-infecting rhabdoviruses that are differentially transmitted by one or more related species of two divergent homopteran families.
The effects of disturbance threat on leaf-cutting ant colonies: a laboratory study.

PubMed

Norman, V C; Pamminger, T; Hughes, W O H

2017-01-01

The flexibility of organisms to respond plastically to their environment is fundamental to their fitness and evolutionary success. Social insects provide some of the most impressive examples of plasticity, with individuals exhibiting behavioral and sometimes morphological adaptations for their specific roles in the colony, such as large soldiers for nest defense. However, with the exception of the honey bee model organism, there has been little investigation of the nature and effects of environmental stimuli thought to instigate alternative phenotypes in social insects. Here, we investigate the effect of repeated threat disturbance over a prolonged (17 month) period on both behavioral and morphological phenotypes, using phenotypically plastic leaf-cutting ants ( Atta colombica ) as a model system. We found a rapid impact of threat disturbance on the behavioral phenotype of individuals within threat-disturbed colonies becoming more aggressive, threat responsive, and phototactic within as little as 2 weeks. We found no effect of threat disturbance on morphological phenotypes, potentially, because constraints such as resource limitation outweighed the benefit for colonies of producing larger individuals. The results suggest that plasticity in behavioral phenotypes can enable insect societies to respond to threats even when constraints prevent alteration of morphological phenotypes.
The Six-Legged Subject: A Survey of Secondary Science Teachers’ Incorporation of Insects into U.S. Life Science Instruction

PubMed Central

Ingram, Erin

2018-01-01

To improve students’ understanding and appreciation of insects, entomology education efforts have supported insect incorporation in formal education settings. While several studies have explored student ideas about insects and the incorporation of insects in elementary and middle school classrooms, the topic of how and why insects are incorporated in secondary science classrooms remains relatively unexplored. Using survey research methods, this study addresses the gap in the literature by (1) describing in-service secondary science teachers’ incorporation of insects in science classrooms; (2) identifying factors that support or deter insect incorporation and (3) identifying teachers’ preferred resources to support future entomology education efforts. Findings indicate that our sample of U.S. secondary science teachers commonly incorporate various insects in their classrooms, but that incorporation is infrequent throughout the academic year. Insect-related lesson plans are commonly used and often self-created to meet teachers’ need for standards-aligned curriculum materials. Obstacles to insect incorporation include a perceived lack of alignment of insect education materials to state or national science standards and a lack of time and professional training to teach about insects. Recommendations are provided for entomology and science education organizations to support teachers in overcoming these obstacles. PMID:29538297
The Six-Legged Subject: A Survey of Secondary Science Teachers' Incorporation of Insects into U.S. Life Science Instruction.

PubMed

Ingram, Erin; Golick, Douglas

2018-03-14

To improve students' understanding and appreciation of insects, entomology education efforts have supported insect incorporation in formal education settings. While several studies have explored student ideas about insects and the incorporation of insects in elementary and middle school classrooms, the topic of how and why insects are incorporated in secondary science classrooms remains relatively unexplored. Using survey research methods, this study addresses the gap in the literature by (1) describing in-service secondary science teachers' incorporation of insects in science classrooms; (2) identifying factors that support or deter insect incorporation and (3) identifying teachers' preferred resources to support future entomology education efforts. Findings indicate that our sample of U.S. secondary science teachers commonly incorporate various insects in their classrooms, but that incorporation is infrequent throughout the academic year. Insect-related lesson plans are commonly used and often self-created to meet teachers' need for standards-aligned curriculum materials. Obstacles to insect incorporation include a perceived lack of alignment of insect education materials to state or national science standards and a lack of time and professional training to teach about insects. Recommendations are provided for entomology and science education organizations to support teachers in overcoming these obstacles.
Canopy and knowledge gaps when invasive alien insects remove foundation species.

PubMed

Marler, Thomas E; Lawrence, John H

2013-01-01

The armored scale Aulacaspis yasumatsui invaded the northern range of the cycad Cycas micronesica in 2003, and epidemic tree mortality ensued due to a lack of natural enemies of the insect. We quantified cycad demographic responses to the invasion, but the ecological responses to the selective removal of this foundation species have not been addressed. We use this case to highlight information gaps in our understanding of how alien invasive phytophagous insects force cascading adverse ecosystem changes. The mechanistic role of unique canopy gaps, oceanic island examples and threatened foundation species with distinctive traits are three issues that deserve research efforts in a quest to understand this facet of ecosystem change occurring across multiple settings globally.
Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

NASA Astrophysics Data System (ADS)

Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

2017-04-01

Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion.
The Earliest Evidence of Holometabolan Insect Pupation in Conifer Wood

PubMed Central

Tapanila, Leif; Roberts, Eric M.

2012-01-01

Background The pre-Jurassic record of terrestrial wood borings is poorly resolved, despite body fossil evidence of insect diversification among xylophilic clades starting in the late Paleozoic. Detailed analysis of borings in petrified wood provides direct evidence of wood utilization by invertebrate animals, which typically comprises feeding behaviors. Methodology/Principal Findings We describe a U-shaped boring in petrified wood from the Late Triassic Chinle Formation of southern Utah that demonstrates a strong linkage between insect ontogeny and conifer wood resources. Xylokrypta durossi new ichnogenus and ichnospecies is a large excavation in wood that is backfilled with partially digested xylem, creating a secluded chamber. The tracemaker exited the chamber by way of a small vertical shaft. This sequence of behaviors is most consistent with the entrance of a larva followed by pupal quiescence and adult emergence — hallmarks of holometabolous insect ontogeny. Among the known body fossil record of Triassic insects, cupedid beetles (Coleoptera: Archostemata) are deemed the most plausible tracemakers of Xylokrypta, based on their body size and modern xylobiotic lifestyle. Conclusions/Significance This oldest record of pupation in fossil wood provides an alternative interpretation to borings once regarded as evidence for Triassic bees. Instead Xylokrypta suggests that early archostematan beetles were leaders in exploiting wood substrates well before modern clades of xylophages arose in the late Mesozoic. PMID:22355387
Evolution of a complex behavior: the origin and initial diversification of foliar galling by Permian insects.

PubMed

Schachat, Sandra R; Labandeira, Conrad C

2015-04-01

A central notion of the early evolution of insect galling is that this unique behavior was uncommon to rare before the diversification of angiosperms 135 to 125 m.yr. ago. However, evidence accumulated during recent years shows that foliar galls were diverse and locally abundant as early as the Permian Period, 299 to 252 m.yr. ago. In particular, a diversity of leaf galling during the Early Permian has recently been documented by the plant-damage record of foliar galls and, now, our interpretation of the body-fossil record of culprit insect gallers. Small size is a prerequisite for gallers. Wing-length measurements of Permian insects indicate that several small-bodied hemipteroid lineages originated early during the Permian, some descendant lineages of which gall the leaves of seed plants to the present day. The earliest foliar gallers likely were Protopsyllidiidae (Hemiptera) and Lophioneuridae (Thripida). Much of the Early Permian was a xeric interval, and modern galls are most common in dry, extra-tropical habitats such as scrubland and deserts. Plant-damage, insect body fossils, and the paleoclimate record collectively support the ecological expansion of foliar galling during the Early Permian and its continued expansion through the Late Permian.
Boomeranging in structural defense

PubMed Central

Marler, Thomas E.

2012-01-01

Plant defensive behaviors that resist arthropod herbivory include trichome-mediated defenses, and variation in plant trichome morphology and abundance provides examples of the mechanistic complexities of insect-plant interactions. Trichomes were removed from Cycas revoluta cataphylls on the island of Guam to reveal Aulacaspis yasumatsui scale infestation, and predation of the newly exposed insects by pre-existing Rhyzobius lophanthae beetles commenced within one day. The quotient of predated/total scale insects was 0.5 by day 4 and stabilized at that found on adjacent glabrous leaves in about one week. The trichome phenotype covering the C. revoluta cataphyll complex offers the invasive A. yasumatsui armored scale effectual enemy-free space in this system. This pest and predator share no known evolutionary history with C. revoluta, therefore, the adaptive significance of this plant behavior in natural habitat is not yet known. PMID:22990448
The neurobiological basis of orientation in insects: insights from the silkmoth mating dance.

PubMed

Namiki, Shigehiro; Kanzaki, Ryohei

2016-06-01

Counterturning is a common movement pattern during orientation behavior in insects. Once male moths sense sex pheromones and then lose the input, they demonstrate zigzag movements, alternating between left and right turns, to increase the probability to contact with the pheromone plume. We summarize the anatomy and function of the neural circuit involved in pheromone orientation in the silkmoth. A neural circuit, the lateral accessory lobe (LAL), serves a role as the circuit module for zigzag movements and controls this operation using a flip-flop neural switch. Circuit design of the LAL is well conserved across species. We hypothesize that this zigzag module is utilized in a wide range of insect behavior. We introduce two examples of the potential use: orientation flight and the waggle dance in bees. Copyright © 2016 Elsevier Inc. All rights reserved.
Sexual dimorphism of bed bug (Cimex lectularis) attraction and aggregation responses to cuticular extracts from nymph exuviae

USDA-ARS?s Scientific Manuscript database

A large variety of releaser pheromones are used by insects to attract or disperse conspecifics, while group cohesion is often influenced by primer pheromones that induce behavioral or physiological changes. Differentiating the roles of such pheromones in insect taxa displaying intermediate levels of...
Insect compassion, evidence of altruism, reciprocity, and midwifery behavior in aphids

USDA-ARS?s Scientific Manuscript database

Altruism is characterized by an act provided by a donor to a recipient that is considered detrimental to the donor yet benefits the recipient. Evidence of altruism is abundant in nature. In insects, altruism is manifest by ant and bee colonies where sterile workers provide labor, care of young, co...

40 CFR 158.2000 - Biochemical pesticides definition and applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... history; and (iii) Has a non-toxic mode of action to the target pest(s). (2) A Pheromone is a compound... compounds, modifies the behavior of other individuals of the same species. (i) An Arthropod Pheromone is a... to: (1) Semiochemicals (insect pheromones and kairomones), (2) Natural plant and insect regulators...
40 CFR 158.2000 - Biochemical pesticides definition and applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... history; and (iii) Has a non-toxic mode of action to the target pest(s). (2) A Pheromone is a compound... compounds, modifies the behavior of other individuals of the same species. (i) An Arthropod Pheromone is a... to: (1) Semiochemicals (insect pheromones and kairomones), (2) Natural plant and insect regulators...
40 CFR 158.2000 - Biochemical pesticides definition and applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... history; and (iii) Has a non-toxic mode of action to the target pest(s). (2) A Pheromone is a compound... compounds, modifies the behavior of other individuals of the same species. (i) An Arthropod Pheromone is a... to: (1) Semiochemicals (insect pheromones and kairomones), (2) Natural plant and insect regulators...
Tracing the evolutionary origins of insect renal function.

PubMed

Halberg, Kenneth A; Terhzaz, Selim; Cabrero, Pablo; Davies, Shireen A; Dow, Julian A T

2015-04-21

Knowledge on neuropeptide receptor systems is integral to understanding animal physiology. Yet, obtaining general insight into neuropeptide signalling in a clade as biodiverse as the insects is problematic. Here we apply fluorescent analogues of three key insect neuropeptides to map renal tissue architecture across systematically chosen representatives of the major insect Orders, to provide an unprecedented overview of insect renal function and control. In endopterygote insects, such as Drosophila, two distinct transporting cell types receive separate neuropeptide signals, whereas in the ancestral exopterygotes, a single, general cell type mediates all signals. Intriguingly, the largest insect Order Coleoptera (beetles) has evolved a unique approach, in which only a small fraction of cells are targets for neuropeptide action. In addition to demonstrating a universal utility of this technology, our results reveal not only a generality of signalling by the evolutionarily ancient neuropeptide families but also a clear functional separation of the types of cells that mediate the signal.
The Total Termite.

ERIC Educational Resources Information Center

Prestwich, Glenn D.

1982-01-01

Provides information on collecting and maintaining termites and for using these insects in behavioral studies (trail following, recognition, food choice, reproductive behavior, and behavior in a magnetic field) and termite control experiments (preventive construction techniques, termite repellents, using soil or wood pretreatment, and the bait…
Toward a better understanding of the mechanisms of symbiosis: a comprehensive proteome map of a nascent insect symbiont.

PubMed

Renoz, François; Champagne, Antoine; Degand, Hervé; Faber, Anne-Marie; Morsomme, Pierre; Foray, Vincent; Hance, Thierry

2017-01-01

Symbiotic bacteria are common in insects and can affect various aspects of their hosts' biology. Although the effects of insect symbionts have been clarified for various insect symbiosis models, due to the difficulty of cultivating them in vitro , there is still limited knowledge available on the molecular features that drive symbiosis. Serratia symbiotica is one of the most common symbionts found in aphids. The recent findings of free-living strains that are considered as nascent partners of aphids provide the opportunity to examine the molecular mechanisms that a symbiont can deploy at the early stages of the symbiosis (i.e., symbiotic factors). In this work, a proteomic approach was used to establish a comprehensive proteome map of the free-living S. symbiotica strain CWBI-2.3 T . Most of the 720 proteins identified are related to housekeeping or primary metabolism. Of these, 76 were identified as candidate proteins possibly promoting host colonization. Our results provide strong evidence that S. symbiotica CWBI-2.3 T is well-armed for invading insect host tissues, and suggest that certain molecular features usually harbored by pathogenic bacteria are no longer present. This comprehensive proteome map provides a series of candidate genes for further studies to understand the molecular cross-talk between insects and symbiotic bacteria.
Neuroarchitecture and neuroanatomy of the Drosophila central complex: A GAL4-based dissection of protocerebral bridge neurons and circuits.

PubMed

Wolff, Tanya; Iyer, Nirmala A; Rubin, Gerald M

2015-05-01

Insects exhibit an elaborate repertoire of behaviors in response to environmental stimuli. The central complex plays a key role in combining various modalities of sensory information with an insect's internal state and past experience to select appropriate responses. Progress has been made in understanding the broad spectrum of outputs from the central complex neuropils and circuits involved in numerous behaviors. Many resident neurons have also been identified. However, the specific roles of these intricate structures and the functional connections between them remain largely obscure. Significant gains rely on obtaining a comprehensive catalog of the neurons and associated GAL4 lines that arborize within these brain regions, and on mapping neuronal pathways connecting these structures. To this end, small populations of neurons in the Drosophila melanogaster central complex were stochastically labeled using the multicolor flip-out technique and a catalog was created of the neurons, their morphologies, trajectories, relative arrangements, and corresponding GAL4 lines. This report focuses on one structure of the central complex, the protocerebral bridge, and identifies just 17 morphologically distinct cell types that arborize in this structure. This work also provides new insights into the anatomical structure of the four components of the central complex and its accessory neuropils. Most strikingly, we found that the protocerebral bridge contains 18 glomeruli, not 16, as previously believed. Revised wiring diagrams that take into account this updated architectural design are presented. This updated map of the Drosophila central complex will facilitate a deeper behavioral and physiological dissection of this sophisticated set of structures. © 2014 Wiley Periodicals, Inc.
Molecular signatures of plastic phenotypes in two eusocial insect species with simple societies.

PubMed

Patalano, Solenn; Vlasova, Anna; Wyatt, Chris; Ewels, Philip; Camara, Francisco; Ferreira, Pedro G; Asher, Claire L; Jurkowski, Tomasz P; Segonds-Pichon, Anne; Bachman, Martin; González-Navarrete, Irene; Minoche, André E; Krueger, Felix; Lowy, Ernesto; Marcet-Houben, Marina; Rodriguez-Ales, Jose Luis; Nascimento, Fabio S; Balasubramanian, Shankar; Gabaldon, Toni; Tarver, James E; Andrews, Simon; Himmelbauer, Heinz; Hughes, William O H; Guigó, Roderic; Reik, Wolf; Sumner, Seirian

2015-11-10

Phenotypic plasticity is important in adaptation and shapes the evolution of organisms. However, we understand little about what aspects of the genome are important in facilitating plasticity. Eusocial insect societies produce plastic phenotypes from the same genome, as reproductives (queens) and nonreproductives (workers). The greatest plasticity is found in the simple eusocial insect societies in which individuals retain the ability to switch between reproductive and nonreproductive phenotypes as adults. We lack comprehensive data on the molecular basis of plastic phenotypes. Here, we sequenced genomes, microRNAs (miRNAs), and multiple transcriptomes and methylomes from individual brains in a wasp (Polistes canadensis) and an ant (Dinoponera quadriceps) that live in simple eusocial societies. In both species, we found few differences between phenotypes at the transcriptional level, with little functional specialization, and no evidence that phenotype-specific gene expression is driven by DNA methylation or miRNAs. Instead, phenotypic differentiation was defined more subtly by nonrandom transcriptional network organization, with roles in these networks for both conserved and taxon-restricted genes. The general lack of highly methylated regions or methylome patterning in both species may be an important mechanism for achieving plasticity among phenotypes during adulthood. These findings define previously unidentified hypotheses on the genomic processes that facilitate plasticity and suggest that the molecular hallmarks of social behavior are likely to differ with the level of social complexity.
Molecular signatures of plastic phenotypes in two eusocial insect species with simple societies

PubMed Central

Patalano, Solenn; Vlasova, Anna; Wyatt, Chris; Ewels, Philip; Camara, Francisco; Ferreira, Pedro G.; Asher, Claire L.; Jurkowski, Tomasz P.; Segonds-Pichon, Anne; Bachman, Martin; González-Navarrete, Irene; Minoche, André E.; Krueger, Felix; Lowy, Ernesto; Marcet-Houben, Marina; Rodriguez-Ales, Jose Luis; Nascimento, Fabio S.; Balasubramanian, Shankar; Gabaldon, Toni; Tarver, James E.; Andrews, Simon; Himmelbauer, Heinz; Hughes, William O. H.; Guigó, Roderic; Reik, Wolf; Sumner, Seirian

2015-01-01

Phenotypic plasticity is important in adaptation and shapes the evolution of organisms. However, we understand little about what aspects of the genome are important in facilitating plasticity. Eusocial insect societies produce plastic phenotypes from the same genome, as reproductives (queens) and nonreproductives (workers). The greatest plasticity is found in the simple eusocial insect societies in which individuals retain the ability to switch between reproductive and nonreproductive phenotypes as adults. We lack comprehensive data on the molecular basis of plastic phenotypes. Here, we sequenced genomes, microRNAs (miRNAs), and multiple transcriptomes and methylomes from individual brains in a wasp (Polistes canadensis) and an ant (Dinoponera quadriceps) that live in simple eusocial societies. In both species, we found few differences between phenotypes at the transcriptional level, with little functional specialization, and no evidence that phenotype-specific gene expression is driven by DNA methylation or miRNAs. Instead, phenotypic differentiation was defined more subtly by nonrandom transcriptional network organization, with roles in these networks for both conserved and taxon-restricted genes. The general lack of highly methylated regions or methylome patterning in both species may be an important mechanism for achieving plasticity among phenotypes during adulthood. These findings define previously unidentified hypotheses on the genomic processes that facilitate plasticity and suggest that the molecular hallmarks of social behavior are likely to differ with the level of social complexity. PMID:26483466
Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae).

PubMed

Cirino, Lauren A; Miller, Christine W

2017-01-17

Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata . This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak) over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon) decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this study is far from comprehensive, it provides tantalizing patterns that suggest many directions for future research.
Electroantennographic Bioassay as a Screening Tool for Host Plant Volatiles

PubMed Central

Beck, John J.; Light, Douglas M.; Gee, Wai S.

2012-01-01

Plant volatiles play an important role in plant-insect interactions. Herbivorous insects use plant volatiles, known as kairomones, to locate their host plant.1,2 When a host plant is an important agronomic commodity feeding damage by insect pests can inflict serious economic losses to growers. Accordingly, kairomones can be used as attractants to lure or confuse these insects and, thus, offer an environmentally friendly alternative to pesticides for insect control.3 Unfortunately, plants can emit a vast number volatiles with varying compositions and ratios of emissions dependent upon the phenology of the commodity or the time of day. This makes identification of biologically active components or blends of volatile components an arduous process. To help identify the bioactive components of host plant volatile emissions we employ the laboratory-based screening bioassay electroantennography (EAG). EAG is an effective tool to evaluate and record electrophysiologically the olfactory responses of an insect via their antennal receptors. The EAG screening process can help reduce the number of volatiles tested to identify promising bioactive components. However, EAG bioassays only provide information about activation of receptors. It does not provide information about the type of insect behavior the compound elicits; which could be as an attractant, repellent or other type of behavioral response. Volatiles eliciting a significant response by EAG, relative to an appropriate positive control, are typically taken on to further testing of behavioral responses of the insect pest. The experimental design presented will detail the methodology employed to screen almond-based host plant volatiles4,5 by measurement of the electrophysiological antennal responses of an adult insect pest navel orangeworm (Amyelois transitella) to single components and simple blends of components via EAG bioassay. The method utilizes two excised antennae placed across a "fork" electrode holder. The protocol demonstrated here presents a rapid, high-throughput standardized method for screening volatiles. Each volatile is at a set, constant amount as to standardize the stimulus level and thus allow antennal responses to be indicative of the relative chemoreceptivity. The negative control helps eliminate the electrophysiological response to both residual solvent and mechanical force of the puff. The positive control (in this instance acetophenone) is a single compound that has elicited a consistent response from male and female navel orangeworm (NOW) moth. An additional semiochemical standard that provides consistent response and is used for bioassay studies with the male NOW moth is (Z,Z)-11,13-hexdecadienal, an aldehyde component from the female-produced sex pheromone.6-8 PMID:22588282
The Odorant Receptor Co-Receptor from the Bed Bug, Cimex lectularius L

PubMed Central

Hansen, Immo A.; Rodriguez, Stacy D.; Drake, Lisa L.; Price, David P.; Blakely, Brittny N.; Hammond, John I.; Tsujimoto, Hitoshi; Monroy, Erika Y.; Maio, William A.; Romero, Alvaro

2014-01-01

Recently, the bed bug, Cimex lectularius L. has re-emerged as a serious and growing problem in many parts of the world. Presence of resistant bed bugs and the difficulty to eliminate them has renewed interest in alternative control tactics. Similar to other haematophagous arthropods, bed bugs rely on their olfactory system to detect semiochemicals in the environment. Previous studies have morphologically characterized olfactory organs of bed bugs’ antenna and have physiologically evaluated the responses of olfactory receptor neurons (ORNs) to host-derived chemicals. To date, odorant binding proteins (OBPs) and odorant receptors (ORs) associated with these olfaction processes have not been studied in bed bugs. Chemoreception in insects requires formation of heteromeric complexes of ORs and a universal OR coreceptor (Orco). Orco is the constant chain of every odorant receptor in insects and is critical for insect olfaction but does not directly bind to odorants. Orco agonists and antagonists have been suggested as high-value targets for the development of novel insect repellents. In this study, we have performed RNAseq of bed bug sensory organs and identified several odorant receptors as well as Orco. We characterized Orco expression and investigated the effect of chemicals targeting Orco on bed bug behavior and reproduction. We have identified partial cDNAs of six C. lectularius OBPs and 16 ORs. Full length bed bug Orco was cloned and sequenced. Orco is widely expressed in different parts of the bed bug including OR neurons and spermatozoa. Treatment of bed bugs with the agonist VUAA1 changed bed bug pheromone-induced aggregation behavior and inactivated spermatozoa. We have described and characterized for the first time OBPs, ORs and Orco in bed bugs. Given the importance of these molecules in chemoreception of this insect they are interesting targets for the development of novel insect behavior modifiers. PMID:25411789
The odorant receptor co-receptor from the bed bug, Cimex lectularius L.

PubMed

Hansen, Immo A; Rodriguez, Stacy D; Drake, Lisa L; Price, David P; Blakely, Brittny N; Hammond, John I; Tsujimoto, Hitoshi; Monroy, Erika Y; Maio, William A; Romero, Alvaro

2014-01-01

Recently, the bed bug, Cimex lectularius L. has re-emerged as a serious and growing problem in many parts of the world. Presence of resistant bed bugs and the difficulty to eliminate them has renewed interest in alternative control tactics. Similar to other haematophagous arthropods, bed bugs rely on their olfactory system to detect semiochemicals in the environment. Previous studies have morphologically characterized olfactory organs of bed bugs' antenna and have physiologically evaluated the responses of olfactory receptor neurons (ORNs) to host-derived chemicals. To date, odorant binding proteins (OBPs) and odorant receptors (ORs) associated with these olfaction processes have not been studied in bed bugs. Chemoreception in insects requires formation of heteromeric complexes of ORs and a universal OR coreceptor (Orco). Orco is the constant chain of every odorant receptor in insects and is critical for insect olfaction but does not directly bind to odorants. Orco agonists and antagonists have been suggested as high-value targets for the development of novel insect repellents. In this study, we have performed RNAseq of bed bug sensory organs and identified several odorant receptors as well as Orco. We characterized Orco expression and investigated the effect of chemicals targeting Orco on bed bug behavior and reproduction. We have identified partial cDNAs of six C. lectularius OBPs and 16 ORs. Full length bed bug Orco was cloned and sequenced. Orco is widely expressed in different parts of the bed bug including OR neurons and spermatozoa. Treatment of bed bugs with the agonist VUAA1 changed bed bug pheromone-induced aggregation behavior and inactivated spermatozoa. We have described and characterized for the first time OBPs, ORs and Orco in bed bugs. Given the importance of these molecules in chemoreception of this insect they are interesting targets for the development of novel insect behavior modifiers.
Abnormally high digestive enzyme activity and gene expression explain the contemporary evolution of a Diabrotica biotype able to feed on soybeans

PubMed Central

Curzi, Matías J; Zavala, Jorge A; Spencer, Joseph L; Seufferheld, Manfredo J

2012-01-01

Western corn rootworm (Diabrotica virgifera) (WCR) depends on the continuous availability of corn. Broad adoption of annual crop rotation between corn (Zea mays) and nonhost soybean (Glycine max) exploited WCR biology to provide excellent WCR control, but this practice dramatically reduced landscape heterogeneity in East-central Illinois and imposed intense selection pressure. This selection resulted in behavioral changes and “rotation-resistant” (RR) WCR adults. Although soybeans are well defended against Coleopteran insects by cysteine protease inhibitors, RR-WCR feed on soybean foliage and remain long enough to deposit eggs that will hatch the following spring and larvae will feed on roots of planted corn. Other than documenting changes in insect mobility and egg laying behavior, 15 years of research have failed to identify any diagnostic differences between wild-type (WT)- and RR-WCR or a mechanism that allows for prolonged RR-WCR feeding and survival in soybean fields. We documented differences in behavior, physiology, digestive protease activity (threefold to fourfold increases), and protease gene expression in the gut of RR-WCR adults. Our data suggest that higher constitutive activity levels of cathepsin L are part of the mechanism that enables populations of WCR to circumvent soybean defenses, and thus, crop rotation. These new insights into the mechanism of WCR tolerance of soybean herbivory transcend the issue of RR-WCR diagnostics and management to link changes in insect gut proteolytic activity and behavior with landscape heterogeneity. The RR-WCR illustrates how agro-ecological factors can affect the evolution of insects in human-altered ecosystems. PMID:22957201
Comparative Feeding and Development of Pseudoplusia includens (Lepidoptera Noctuidae) on Kudzu and Soybean Foliage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kidd, K.A.; Orr, D.B.

2000-04-10

Kudzu is a close relative of soybean and is a widely distributed exotic weed in the southern U.S. The biology of the soybean looper was studied to better understand the foraging behavior of this species on kudzu. Insects feeding on kudzu had higher mortality, longer development and lower pupal weights than those fed on soybean. Foliage consumption did not differ between treatments and nutritional quality between soybean and kudzu did not differ. In an oviposition test, females readily used kudzu if it was the only species available, but when soybean was provided more eggs were deposited on soybean.
Active listening for spatial orientation in a complex auditory scene.

PubMed

Moss, Cynthia F; Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

2006-04-01

To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.
Active Listening for Spatial Orientation in a Complex Auditory Scene

PubMed Central

Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

2006-01-01

To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal–motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10–20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate “terminal buzz” decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar “strobe groups,” clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal–motor control that directly impacts the signals used for perception. PMID:16509770
Oviposition of aquatic insects in a tropical high altitude stream.

PubMed

Rios-Touma, Blanca; Encalada, A C; Prat, N

2012-12-01

The persistence of aquatic insect populations in streams depends on the recruitment of larval populations from egg masses deposited by adults, especially after disturbance. However, recruitment of aquatic populations by oviposition is a process that remains unstudied in streams and rivers. The objectives of our study were to document flying and oviposition patterns of aquatic insects in a high altitude tropical stream during both dry and wet seasons. In particular we studied 1) richness and abundance of adult forms of aquatic insects flying and ovipositing; 2) number of eggs (oviposition pattern), egg mass identity, and morphology; and 3) substrate preferences by ovipositing females. We found 2,383 aquatic insects corresponding to 28 families, with dipterans representing 89% of total individuals collected. Adult insects had lower richness (28 taxa) than larval diversity (up to 52 taxa) and distinct community composition. Richness and relative abundance of most taxa (adults) were not significantly different between seasons, behaviors, diel period, or all three. During both sampling periods we found females with eggs in a total of 15 different families (13 in the dry season and 14 in the wet season). There were no significant differences in the proportion of females with eggs between seasons, diel periods, or different behaviors (flying versus ovipositing traps) of the different female taxa. Few types of egg masses were found in rocks at the stream during both seasons, and most egg masses found corresponded to families Baetidae and Chironomidae. Finally, we provide the first description of eggs masses (size, shape, color, and number of eggs per female) of gravid females (10 taxa) and those found in the stream substrate (six taxa) of Andean macroinvertebrates. This is the first study reporting oviposition, adult diversity, and oviposition patterns of aquatic insects in the Andean region.
Reducing the maladaptive attractiveness of solar panels to polarotactic insects.

PubMed

Horváth, Gábor; Blahó, Miklós; Egri, Adám; Kriska, György; Seres, István; Robertson, Bruce

2010-12-01

Human-made objects (e.g., buildings with glass surfaces) can reflect horizontally polarized light so strongly that they appear to aquatic insects to be bodies of water. Insects that lay eggs in water are especially attracted to such structures because these insects use horizontal polarization of light off bodies of water to find egg-laying sites. Thus, these sources of polarized light can become ecological traps associated with reproductive failure and mortality in organisms that are attracted to them and by extension with rapid population declines or collapse. Solar panels are a new source of polarized light pollution. Using imaging polarimetry, we measured the reflection-polarization characteristics of different solar panels and in multiple-choice experiments in the field we tested their attractiveness to mayflies, caddis flies, dolichopodids, and tabanids. At the Brewster angle, solar panels polarized reflected light almost completely (degree of polarization d ≈ 100%) and substantially exceeded typical polarization values for water (d ≈ 30-70%). Mayflies (Ephemeroptera), stoneflies (Trichoptera), dolichopodid dipterans, and tabanid flies (Tabanidae) were the most attracted to solar panels and exhibited oviposition behavior above solar panels more often than above surfaces with lower degrees of polarization (including water), but in general they avoided solar cells with nonpolarizing white borders and white grates. The highly and horizontally polarizing surfaces that had nonpolarizing, white cell borders were 10- to 26-fold less attractive to insects than the same panels without white partitions. Although solar panels can act as ecological traps, fragmenting their solar-active area does lessen their attractiveness to polarotactic insects. The design of solar panels and collectors and their placement relative to aquatic habitats will likely affect populations of aquatic insects that use polarized light as a behavioral cue. © 2010 Society for Conservation Biology.
Insect-induced effects on plants and possible effectors used by galling and leaf-mining insects to manipulate their host-plant.

PubMed

Giron, David; Huguet, Elisabeth; Stone, Graham N; Body, Mélanie

2016-01-01

Gall-inducing insects are iconic examples in the manipulation and reprogramming of plant development, inducing spectacular morphological and physiological changes of host-plant tissues within which the insect feeds and grows. Despite decades of research, effectors involved in gall induction and basic mechanisms of gall formation remain unknown. Recent research suggests that some aspects of the plant manipulation shown by gall-inducers may be shared with other insect herbivorous life histories. Here, we illustrate similarities and contrasts by reviewing current knowledge of metabolic and morphological effects induced on plants by gall-inducing and leaf-mining insects, and ask whether leaf-miners can also be considered to be plant reprogrammers. We review key plant functions targeted by various plant reprogrammers, including plant-manipulating insects and nematodes, and functionally characterize insect herbivore-derived effectors to provide a broader understanding of possible mechanisms used in host-plant manipulation. Consequences of plant reprogramming in terms of ecology, coevolution and diversification of plant-manipulating insects are also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

RNAi Technology for Insect Management and Protection of Beneficial Insects from Diseases: Lessons, Challenges and Risk Assessments.

PubMed

Zotti, M J; Smagghe, G

2015-06-01

The time has passed for us to wonder whether RNA interference (RNAi) effectively controls pest insects or protects beneficial insects from diseases. The RNAi era in insect science began with studies of gene function and genetics that paved the way for the development of novel and highly specific approaches for the management of pest insects and, more recently, for the treatment and prevention of diseases in beneficial insects. The slight differences in components of RNAi pathways are sufficient to provide a high degree of variation in responsiveness among insects. The current framework to assess the negative effects of genetically modified (GM) plants on human health is adequate for RNAi-based GM plants. Because of the mode of action of RNAi and the lack of genomic data for most exposed non-target organisms, it becomes difficult to determine the environmental risks posed by RNAi-based technologies and the benefits provided for the protection of crops. A better understanding of the mechanisms that determine the variability in the sensitivity of insects would accelerate the worldwide release of commercial RNAi-based approaches.
An insect-like mushroom body in a crustacean brain

PubMed Central

Wolff, Gabriella Hannah; Thoen, Hanne Halkinrud; Marshall, Justin; Sayre, Marcel E

2017-01-01

Mushroom bodies are the iconic learning and memory centers of insects. No previously described crustacean possesses a mushroom body as defined by strict morphological criteria although crustacean centers called hemiellipsoid bodies, which serve functions in sensory integration, have been viewed as evolutionarily convergent with mushroom bodies. Here, using key identifiers to characterize neural arrangements, we demonstrate insect-like mushroom bodies in stomatopod crustaceans (mantis shrimps). More than any other crustacean taxon, mantis shrimps display sophisticated behaviors relating to predation, spatial memory, and visual recognition comparable to those of insects. However, neuroanatomy-based cladistics suggesting close phylogenetic proximity of insects and stomatopod crustaceans conflicts with genomic evidence showing hexapods closely related to simple crustaceans called remipedes. We discuss whether corresponding anatomical phenotypes described here reflect the cerebral morphology of a common ancestor of Pancrustacea or an extraordinary example of convergent evolution. PMID:28949916
Learning in Insect Pollinators and Herbivores.

PubMed

Jones, Patricia L; Agrawal, Anurag A

2017-01-31

The relationship between plants and insects is influenced by insects' behavioral decisions during foraging and oviposition. In mutualistic pollinators and antagonistic herbivores, past experience (learning) affects such decisions, which ultimately can impact plant fitness. The higher levels of dietary generalism in pollinators than in herbivores may be an explanation for the differences in learning seen between these two groups. Generalist pollinators experience a high level of environmental variation, which we suggest favors associative learning. Larval herbivores employ habituation and sensitization-strategies useful in their less variable environments. Exceptions to these patterns based on habitats, mobility, and life history provide critical tests of current theory. Relevant plant traits should be under selection to be easily learned and remembered in pollinators and difficult to learn in herbivores. Insect learning thereby has the potential to have an important, yet largely unexplored, role in plant-insect coevolution.
Can antibodies against flies alter malaria transmission in birds by changing vector behavior?

PubMed

Ghosh, Suma; Waite, Jessica L; Clayton, Dale H; Adler, Frederick R

2014-10-07

Transmission of insect-borne diseases is shaped by the interactions among parasites, vectors, and hosts. Any factor that alters movement of infected vectors from infected to uninfeced hosts will in turn alter pathogen spread. In this paper, we study one such pathogen-vector-host system, avian malaria in pigeons transmitted by fly ectoparasites, where both two-way and three-way interactions play a key role in shaping disease spread. Bird immune defenses against flies can decrease malaria prevalence by reducing fly residence time on infected birds or increase disease prevalence by enhancing fly movement and thus infection transmission. We develop a mathematical model that illustrates how these changes in vector behavior influence pathogen transmission and show that malaria prevalence is maximized at an intermediate level of defense avoidance by the flies. Understanding how host immune defenses indirectly alter disease transmission by influencing vector behavior has implications for reducing the transmission of human malaria and other vectored pathogens. Published by Elsevier Ltd.
Shotgun proteomic analysis of Bombyx mori brain: emphasis on regulation of behavior and development of the nervous system.

PubMed

Wang, Guo-Bao; Zheng, Qin; Shen, Yun-Wang; Wu, Xiao-Feng

2016-02-01

The insect brain plays crucial roles in the regulation of growth and development and in all types of behavior. We used sodium dodecyl sulfate polyacrylamide gel electrophoresis and high-performance liquid chromatography - electron spray ionization tandem mass spectrometry (ESI-MS/MS) shotgun to identify the proteome of the silkworm brain, to investigate its protein composition and to understand their biological functions. A total of 2210 proteins with molecular weights in the range of 5.64-1539.82 kDa and isoelectric points in the range of 3.78-12.55 were identified. These proteins were annotated according to Gene Ontology Annotation into the categories of molecular function, biological process and cellular component. We characterized two categories of proteins: one includes behavior-related proteins involved in the regulation of behaviors, such as locomotion, reproduction and learning; the other consists of proteins related to the development or function of the nervous system. The identified proteins were classified into 283 different pathways according to KEGG analysis, including the PI3K-Akt signaling pathway which plays a crucial role in mediating survival signals in a wide range of neuronal cell types. This extensive protein profile provides a basis for further understanding of the physiological functions in the silkworm brain. © 2014 Institute of Zoology, Chinese Academy of Sciences.
Evolutionary genetics of insect innate immunity.

PubMed

Viljakainen, Lumi

2015-11-01

Patterns of evolution in immune defense genes help to understand the evolutionary dynamics between hosts and pathogens. Multiple insect genomes have been sequenced, with many of them having annotated immune genes, which paves the way for a comparative genomic analysis of insect immunity. In this review, I summarize the current state of comparative and evolutionary genomics of insect innate immune defense. The focus is on the conserved and divergent components of immunity with an emphasis on gene family evolution and evolution at the sequence level; both population genetics and molecular evolution frameworks are considered. © The Author 2015. Published by Oxford University Press.
A case of flying insects visiting an anatomy and embalming laboratory in Medellín, Colombia.

PubMed

Amat, Eduardo; Serna-Giraldo, Claudia; Antia-Montoya, German

2016-10-01

From July to September of 2012, the fauna of flying insects visiting the anatomy and embalming laboratory of the Tecnológico de Antioquia, Faculty of Forensic Sciences, located in the city of Medellin, Colombia, were recorded. The first checklist in the literature of incidental flying insects occurring in this type of locale is provided, and a brief discussion is given of their behavioral habits related to this uncommon case. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Pigment-Dispersing Factor Signaling and Circadian Rhythms in Insect Locomotor Activity

PubMed Central

Shafer, Orie T.; Yao, Zepeng

2014-01-01

Though expressed in relatively few neurons in insect nervous systems, pigment-dispersing factor (PDF) plays many roles in the control of behavior and physiology. PDF’s role in circadian timekeeping is its best-understood function and the focus of this review. Here we recount the isolation and characterization of insect PDFs, review the evidence that PDF acts as a circadian clock output factor, and discuss emerging models of how PDF functions within circadian clock neuron network of Drosophila, the species in which this peptide’s circadian roles are best understood. PMID:25386391
Adipokinetic hormone receptor gene identification and its role in triacylglycerol mobilization and sexual behavior in the oriental fruit fly (Bactrocera dorsalis).

PubMed

Hou, Qiu-Li; Chen, Er-Hu; Jiang, Hong-Bo; Wei, Dan-Dan; Gui, Shun-Hua; Wang, Jin-Jun; Smagghe, Guy

2017-11-01

Energy homeostasis requires continuous compensation for fluctuations in energy expenditure and availability of food resources. In insects, energy mobilization is under control of the adipokinetic hormone (AKH) where it is regulating the nutritional status by supporting the mobilization of lipids. In this study, we characterized the gene coding for the AKH receptor (AKHR) and investigated its function in the oriental fruit fly (Bactrocera dorsalis) that is economically one of the most important pest insects of tropical and subtropical fruit. Bacdo-AKHR is a typical G protein-coupled receptor (GPCR) and phylogenetic analysis confirmed that Bacdo-AKHR is closely related to insect AKHRs from other species. When expressed in Chinese hamster ovary (CHO) cells, Bacdo-AKHR exhibited a high sensitivity and selectivity for AKH peptide (EC 50 = 19.3 nM). Using qPCR, the developmental stage and tissue-specific expression profiles demonstrated that Bacdo-AKHR was highly expressed in both the larval and adult stages, and also specifically in the fat body and midgut of the adult with no difference in sex. To investigate the role of AKHR in B. dorsalis, RNAi assays were performed with dsRNA against Bacdo-AKHR in adult flies of both sexes and under starvation and feeding condition. As major results, the knockdown of this gene resulted in triacylglycerol (TAG) accumulation. With RNAi-males, we observed a severe decrease in their sexual courtship activity when starved, but there was a partial rescue in copulation when refed. Also in RNAi-males, the tethered-flight duration declined compared with the control group when starved, which is confirming the dependency on energy metabolism. In RNAi-females, the sexual behavior was not affected, but their fecundity was decreased. Our findings indicate an interesting role of AKHR in the sexual behavior of males specifically. The effects are associated with TAG accumulation, and we also reported that the conserved role of AKH-mediated system in B. dorsalis is nutritional state-dependent. Hence, we provided further understanding on the multiple functions of AKH/AKHR in B. dorsalis. Copyright © 2017 Elsevier Ltd. All rights reserved.
Insect pest management decisions in food processing facilities

USDA-ARS?s Scientific Manuscript database

Pest management decision making in food processing facilities such as flour mills, rice mills, human and pet food manufacturing facilities, distribution centers and warehouses, and retail stores is a challenging undertaking. Insect pest management programs require an understanding of the food facili...
A reaction-diffusion model of the Darien Gap Sterile Insect Release Method

NASA Astrophysics Data System (ADS)

Alford, John G.

2015-05-01

The Sterile Insect Release Method (SIRM) is used as a biological control for invasive insect species. SIRM involves introducing large quantities of sterilized male insects into a wild population of invading insects. A fertile/sterile mating produces offspring that are not viable and the wild insect population will eventually be eradicated. A U.S. government program maintains a permanent sterile fly barrier zone in the Darien Gap between Panama and Columbia to control the screwworm fly (Cochliomyia Hominivorax), an insect that feeds off of living tissue in mammals and has devastating effects on livestock. This barrier zone is maintained by regular releases of massive quantities of sterilized male screwworm flies from aircraft. We analyze a reaction-diffusion model of the Darien Gap barrier zone. Simulations of the model equations yield two types of spatially inhomogeneous steady-state solutions representing a sterile fly barrier that does not prevent invasion and a barrier that does prevent invasion. We investigate steady-state solutions using both phase plane methods and monotone iteration methods and describe how barrier width and the sterile fly release rate affects steady-state behavior.
Effect of seeding on the capture of six stored product beetle species: The relative species matters

USDA-ARS?s Scientific Manuscript database

n trapping programs prior capture of individuals of the same or different species may influence subsequent attractiveness of the trap. To evaluate this process with stored-product insects, the effect of the presence of dead or alive adults on the behavioral responses of six stored product insect spe...
Chaos-order transition in foraging behavior of ants.

PubMed

Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

2014-06-10

The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants' physical abilities, and ants' knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal.
8. The development and evolution of division of labor and foraging specialization in a social insect (Apis mellifera L.).

PubMed

Page, Robert E; Scheiner, Ricarda; Erber, Joachim; Amdam, Gro V

2006-01-01

How does complex social behavior evolve? What are the developmental building blocks of division of labor and specialization, the hallmarks of insect societies? Studies have revealed the developmental origins in the evolution of division of labor and specialization in foraging worker honeybees, the hallmarks of complex insect societies. Selective breeding for a single social trait, the amount of surplus pollen stored in the nest (pollen hoarding) revealed a phenotypic architecture of correlated traits at multiple levels of biological organization in facultatively sterile female worker honeybees. Verification of this phenotypic architecture in "wild-type" bees provided strong support for a "pollen foraging syndrome" that involves increased senso-motor responses, motor activity, associative learning, reproductive status, and rates of behavioral development, as well as foraging behavior. This set of traits guided further research into reproductive regulatory systems that were co-opted by natural selection during the evolution of social behavior. Division of labor, characterized by changes in the tasks performed by bees, as they age, is controlled by hormones linked to ovary development. Foraging specialization on nectar and pollen results also from different reproductive states of bees where nectar foragers engage in pre-reproductive behavior, foraging for nectar for self-maintenance, while pollen foragers perform foraging tasks associated with reproduction and maternal care, collecting protein.
Chaos–order transition in foraging behavior of ants

PubMed Central

Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

2014-01-01

The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants’ physical abilities, and ants’ knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal. PMID:24912159
Streambed Mobility and Dispersal of Aquatic Insect Larvae: Results from a Laboratory Study.

NASA Astrophysics Data System (ADS)

Kenworthy, S. T.

2002-12-01

Three series of flume experiments were conducted to quantify relationships between entrainment of surface layer gravels and displacement of benthic insect larvae. One series (B) utilized a sediment mixture with a median size 6.9 mm, maximum size 45 mm, and 10% < 2mm. Two other series examined the effects of locally coarsening the bed surface (Bc) and increasing the < 2mm fraction to 20% (S). Aquatic insect larvae were collected in the field and placed in an upstream segment of the flume bed. Flow rate, flume slope, and sediment transport rate were varied systematically among experiments. Displaced larvae were collected in a net at the end of the flume. The distribution of larvae remaining in the bed was obtained by sorting larvae from the sediment in 25 channel segments. Flow rate and mean boundary shear stress varied among runs by factors of 1.2 and 2.4 respectively. Proportional entrainment of >11mm surface grains ranged from <0.05 to >0.90. Displacement of insect larvae increased in a regular and consistent manner with increasing flow strength and surface sediment entrainment. Significant displacement occurred for some types of larvae (Ephemerellid mayflies) over a relatively low range of shear stress and bed surface entrainment. Other larvae (Atherix sp.) were displaced only at the highest levels of bed surface entrainment. Displacement was lower from coarsened bed surfaces in series Bc, and higher from sandier sediments in series S experiments. The differential effects of bed surface entrainment upon various types of larvae are consistent with anatomical and behavioral differences that influence exposure to near-bed flow and bedload transport. These results suggest that spatial patterns of sediment mobilization are important for understanding patterns of dispersal and disturbance of streambed communities.
Nutritional attributes of ash (Fraxinus spp.) outer bark and phloem and their relationships to resistance against the emerald ash borer.

PubMed

Hill, Amy L; Whitehill, Justin G A; Opiyo, Stephen O; Phelan, P Larry; Bonello, Pierluigi

2012-12-01

The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an alien, invasive wood-boring insect that is responsible for killing millions of ash trees since its discovery in North America in 2002. All North American ash species (Fraxinus spp.) that EAB has encountered have shown various degrees of susceptibility, while Manchurian ash (Fraxinus mandshurica Ruprecht), which shares a co-evolutionary history with this insect, is resistant. Recent studies have looked into constitutive resistance mechanisms in Manchurian ash, concentrating on the secondary phloem, which is the feeding substrate for the insect. In addition to specialized metabolism and defense-related components, primary metabolites and nutritional summaries can also be important to understand the feeding behavior of insect herbivores. Here, we have compared the nutritional characteristics (water content, total protein, free amino acids, total soluble sugars and starch, percent carbon and nitrogen, and macro- and micronutrients) of outer bark and phloem from black, green, white and Manchurian ash to determine their relevance to resistance or susceptibility to EAB. Water content and concentrations of Al, Ba, Cu, Fe, K, Li, tryptophan and an unknown compound were found to separate black and Manchurian ash from green and white ash in a principal component analysis (PCA), confirming their phylogenetic placements into two distinct clades. The traits that distinguished Manchurian ash from black ash in the PCA were water content and concentrations of total soluble sugars, histidine, lysine, methionine, ornithine, proline, sarcosine, tyramine, tyrosol, Al, Fe, K, Na, V and an unknown compound. However, only proline, tyramine and tyrosol were significantly different, and higher, in Manchurian ash than in black ash.
Neuromechanism study of insect-machine interface: flight control by neural electrical stimulation.

PubMed

Zhao, Huixia; Zheng, Nenggan; Ribi, Willi A; Zheng, Huoqing; Xue, Lei; Gong, Fan; Zheng, Xiaoxiang; Hu, Fuliang

2014-01-01

The insect-machine interface (IMI) is a novel approach developed for man-made air vehicles, which directly controls insect flight by either neuromuscular or neural stimulation. In our previous study of IMI, we induced flight initiation and cessation reproducibly in restrained honeybees (Apis mellifera L.) via electrical stimulation of the bilateral optic lobes. To explore the neuromechanism underlying IMI, we applied electrical stimulation to seven subregions of the honeybee brain with the aid of a new method for localizing brain regions. Results showed that the success rate for initiating honeybee flight decreased in the order: α-lobe (or β-lobe), ellipsoid body, lobula, medulla and antennal lobe. Based on a comparison with other neurobiological studies in honeybees, we propose that there is a cluster of descending neurons in the honeybee brain that transmits neural excitation from stimulated brain areas to the thoracic ganglia, leading to flight behavior. This neural circuit may involve the higher-order integration center, the primary visual processing center and the suboesophageal ganglion, which is also associated with a possible learning and memory pathway. By pharmacologically manipulating the electrically stimulated honeybee brain, we have shown that octopamine, rather than dopamine, serotonin and acetylcholine, plays a part in the circuit underlying electrically elicited honeybee flight. Our study presents a new brain stimulation protocol for the honeybee-machine interface and has solved one of the questions with regard to understanding which functional divisions of the insect brain participate in flight control. It will support further studies to uncover the involved neurons inside specific brain areas and to test the hypothesized involvement of a visual learning and memory pathway in IMI flight control.
Bioinspired optical sensors for unmanned aerial systems

NASA Astrophysics Data System (ADS)

Chahl, Javaan; Rosser, Kent; Mizutani, Akiko

2011-04-01

Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.
Aggregative group behavior in insect parasitic nematode disperal

USDA-ARS?s Scientific Manuscript database

Movement behavior is critical to determination of spatial ecology and success of foraging in predators and parasites. In this study movement behavior of entomopathogenic nematodes was explored. Movement patterns in sand were investigated when nematodes were applied to a specific locus or when the ne...

Evolved differences in larval social behavior mediated by novel pheromones

USDA-ARS?s Scientific Manuscript database

Pheromones, chemical signals that convey social information, mediate many insect social behaviors in both adult and immature stages. Multiple pheromones and neural pathways that underlie adult social behavior have been described in the genetic model organism, Drosophila melanogaster, but there is no...
Synchronous, Alternating, and Phase-Locked Stridulation by a Tropical Katydid

NASA Astrophysics Data System (ADS)

Sismondo, Enrico

1990-07-01

In the field the chirps of neighboring Mecopoda sp. (Orthoptera, Tettigoniidae, and Mecopodinae) males are normally synchronized, but between more distant individuals the chirps are either synchronous or regularly alternating. The phase response to single-stimulus chirps depends on both the phase and the intensity of the stimulus. Iteration of the Poincare map of the phase response predicts a variety of phase-locked synchronization regimes, including period-doubling bifurcations, in close agreement with experimental observations. The versatile acoustic behavior of Mecopoda encompasses most of the phenomena found in other synchronizing insects and thus provides a general model of insect synchronization behavior.
Edible insects - defining knowledge gaps in biological and ethical considerations of entomophagy.

PubMed

Pali-Schöll, Isabella; Binder, Regina; Moens, Yves; Polesny, Friedrich; Monsó, Susana

2018-04-25

While seeking novel food sources to feed the increasing population of the globe, several alternatives have been discussed, including algae, fungi or in vitro meat. The increasingly propagated usage of farmed insects for human nutrition raises issues regarding food safety, consumer information and animal protection. In line with law, insects like any other animals must not be reared or manipulated in a way that inflicts unnecessary pain, distress or harm on them. Currently, there is a great need for research in the area of insect welfare, especially regarding species-specific needs, health, farming systems and humane methods of killing. Recent results from neurophysiological, neuroanatomical and behavioral sciences prompt caution when denying consciousness and therefore the likelihood of presence of pain and suffering or something closely related to it to insects. From an animal protection point of view, these issues should be satisfyingly solved before propagating and establishing intensive husbandry systems for insects as a new type of mini-livestock factory farming.
The evolution of dorsal-ventral patterning mechanisms in insects.

PubMed

Lynch, Jeremy A; Roth, Siegfried

2011-01-15

The gene regulatory network (GRN) underpinning dorsal-ventral (DV) patterning of the Drosophila embryo is among the most thoroughly understood GRNs, making it an ideal system for comparative studies seeking to understand the evolution of development. With the emergence of widely applicable techniques for testing gene function, species with sequenced genomes, and multiple tractable species with diverse developmental modes, a phylogenetically broad and molecularly deep understanding of the evolution of DV axis formation in insects is feasible. Here, we review recent progress made in this field, compare our emerging molecular understanding to classical embryological experiments, and suggest future directions of inquiry.
Thermosensory perception regulates speed of movement in response to temperature changes in Drosophila melanogaster.

PubMed

Soto-Padilla, Andrea; Ruijsink, Rick; Sibon, Ody C M; van Rijn, Hedderik; Billeter, Jean-Christophe

2018-04-12

Temperature influences physiology and behavior of all organisms. For ectotherms, which lack central temperature regulation, temperature adaptation requires sheltering from or moving to a heat source. As temperature constrains the rate of metabolic reactions, it can directly affect ectotherm physiology and thus behavioral performance. This direct effect is particularly relevant for insects whose small body readily equilibrates with ambient temperature. In fact, models of enzyme kinetics applied to insect behavior predict performance at different temperatures, suggesting that thermal physiology governs behavior. However, insects also possess thermosensory neurons critical for locating preferred temperatures, showing cognitive control. This suggests that temperature-related behavior can emerge directly from a physiological effect, indirectly as consequence of thermosensory processing, or through both. To separate the roles of thermal physiology and cognitive control, we developed an arena that allows fast temperature changes in time and space, and in which animals' movements are automatically quantified. We exposed wild-type and thermosensory receptor mutants Drosophila melanogaster to a dynamic temperature environment and tracked their movements. The locomotor speed of wild-type flies closely matched models of enzyme kinetics, but the behavior of thermosensory mutants did not. Mutations in thermosensory receptor dTrpA1 ( Transient receptor potential ) expressed in the brain resulted in a complete lack of response to temperature changes, while mutation in peripheral thermosensory receptor Gr28b(D) resulted in diminished response. We conclude that flies react to temperature through cognitive control, informed by interactions between various thermosensory neurons, whose behavioral output resembles that of enzyme kinetics. © 2018. Published by The Company of Biologists Ltd.
The Comet assay in insects--Status, prospects and benefits for science.

PubMed

Augustyniak, Maria; Gladysz, Marcin; Dziewięcka, Marta

2016-01-01

The Comet assay has been recently adapted to investigate DNA damage in insects. The first reports of its use in Drosophila melanogaster appeared in 2002. Since then, the interest in the application of the Comet assay to studies of insects has been rapidly increasing. Many authors see substantial potential in the use of the Comet assay in D. melanogaster for medical toxicology studies. This application could allow the testing of drugs and result in an understanding of the mechanisms of action of toxins, which could significantly influence the limited research that has been performed on vertebrates. The possible perspectives and benefits for science are considered in this review. In the last decade, the use of the Comet assay has been described in insects other than D. melanogaster. Specifically, methods to prepare a cell suspension from insect tissues, which is a difficult task, were analyzed and compared in detail. Furthermore, attention was paid to any differences and modifications in the research protocols, such as the buffer composition and electrophoresis conditions. Various scientific fields in addition to toxicological and ecotoxicological research were considered. We expect the Comet assay to be used in environmental risk assessments and to improve our understanding of many important phenomena of insect life, such as metamorphosis, molting, diapause and quiescence. The use of this method to study species that are of key importance to humans, such as pests and beneficial insects, appears to be highly probable and very promising. The use of the Comet assay for DNA stability testing in insects will most likely rapidly increase in the future. Copyright © 2015 Elsevier B.V. All rights reserved.
Chemical and genetic defenses against disease in insect societies.

PubMed

Stow, Adam; Beattie, Andrew

2008-10-01

The colonies of ants, bees, wasps and termites, the social insects, consist of large numbers of closely related individuals; circumstances ideal for contagious diseases. Antimicrobial assays of these animals have demonstrated a wide variety of chemical defenses against both bacteria and fungi that can be broadly classified as either external antiseptic compounds or internal immune molecules. Reducing the disease risks inherent in colonies of social insects is also achieved by behaviors, such as multiple mating or dispersal, that lower genetic relatedness both within- and among colonies. The interactions between social insects and their pathogens are complex, as illustrated by some ants that require antimicrobial and behavioral defenses against highly specialized fungi, such as those in the genus Cordyceps that attack larvae and adults and species in the genus Escovopsis that attack their food supplies. Studies of these defenses, especially in ants, have revealed remarkably sophisticated immune systems, including peptides induced by, and specific to, individual bacterial strains. The latter may be the result of the recruitment by the ants of antibiotic-producing bacteria but the extent of such three-way interactions remains unknown. There is strong experimental evidence that the evolution of sociality required dramatic increases in antimicrobial defenses and that microbes have been powerful selective agents. The antimicrobial chemicals and the insect-killing fungi may be useful in medicine and agriculture, respectively.
Innate immune system still works at diapause, a physiological state of dormancy in insects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, Akihiro; Miyado, Kenji, E-mail: kmiyado@nch.go.jp; Takezawa, Youki

Highlights: {yields} Two major types of cells are present in the body fluid isolated from the thoracic region of a diapausing pupa. {yields} Phagocytosis and encapsulation by these cells were observed when latex beads as foreign targets were microinjected into a pupa. {yields} Such behavior by these cells was still observed even when pupae were continuously chilled at 4 {sup o}C. {yields} Innate cellular reactions can work in diapausing insects in a dormant state. -- Abstract: Diapause is most often observed in insects and is a physiologically dormant state different from other types of dormancy, such as hibernation. It allowsmore » insects to survive in harsh environments or extend longevity. In general, larval, pupal, or adult non-diapausing insects possess an innate immune system preventing the invasion of microorganisms into their bodies; however, it is unclear whether this system works under the dormant condition of diapause. We here report the occurrence of innate cellular reactions during diapause using pupae of a giant silkmoth, Samia cynthia pryeri. Scanning electron microscopic analysis demonstrated the presence of two major types of cells in the body fluid isolated from the thoracic region of a pupa. Phagocytosis and encapsulation, characteristics of innate cellular reactions, by these cells were observed when latex beads as foreign targets were microinjected into the internal portion of a pupa. Such behavior by these cells was still observed even when pupae were continuously chilled at 4 {sup o}C. Our results indicate that innate cellular reactions can work in diapausing insects in a dormant state.« less
Lipophilic metabolite profiling of maize and sorghum seeds and seedlings, and their pest spotted stem borer larvae: a standardized GC-MS based approach.

PubMed

Kumar, Sandeep; Dhillon, Mukesh K

2015-03-01

In order to better understand the biochemical interactions and to identify new biomarkers for plant resistance against insects, we proposed a suitable lipophilic profiling method for insects and their host plants. The critical components of GC-MS based analysis are: sample amount, extraction, derivatization, temperature gradient, run time, and identification of peaks. For lipophilic metabolite profiling of maize and sorghum, and their insect pest, spotted stem borer larvae, we recommend 100 mg sample weight for seeds and insect samples (whole insect body), and 200 mg for seedlings. Maize and sorghum seeds required less time for fat extraction in comparison to their seedlings and the pest fed on these seedlings. GC-MS was standardized for better separation and intensity of peaks using different temperature gradients in the range of 180-300 C. A total of 48 lipophilic compounds encompassing various classes based on their functional groups such as fatty acids, fatty alcohols, hydrocarbons, sterols and terpenoids, vitamin derivative, etc. were separated in the seedlings (30), seeds (14), and the pest (26) in the retention time range of 3.22 to 29.41 min. This method could be useful to study nutritional aspects of different field crops in relation to various stresses apart from the analysis of lipophilic compounds for better understanding of insect-plant interactions.
Flying insect detection and classification with inexpensive sensors.

PubMed

Chen, Yanping; Why, Adena; Batista, Gustavo; Mafra-Neto, Agenor; Keogh, Eamonn

2014-10-15

An inexpensive, noninvasive system that could accurately classify flying insects would have important implications for entomological research, and allow for the development of many useful applications in vector and pest control for both medical and agricultural entomology. Given this, the last sixty years have seen many research efforts devoted to this task. To date, however, none of this research has had a lasting impact. In this work, we show that pseudo-acoustic optical sensors can produce superior data; that additional features, both intrinsic and extrinsic to the insect's flight behavior, can be exploited to improve insect classification; that a Bayesian classification approach allows to efficiently learn classification models that are very robust to over-fitting, and a general classification framework allows to easily incorporate arbitrary number of features. We demonstrate the findings with large-scale experiments that dwarf all previous works combined, as measured by the number of insects and the number of species considered.
Radar Observation of Insects - Mosquitoes

NASA Technical Reports Server (NTRS)

Frost, E.; Downing, J.

1979-01-01

Tests were conducted at several sites over the coastal lowlands of New Jersey and over a region of high plains and low mountains in Oklahoma. In one area, a salt marsh in New Jersey, extensive ground tests were combined with laboratory data on expected insect backscatter to arrive at an extremely convincing model of the insect origin of most Dot Angels. A great deal of insight was studied from radar on the buildup and dispersal of insect swarms, since radar can follow where other means of trapping and observation cannot. Data on large-scale behavior as a function of wind and topography are presented. Displayed techniques which show individual or small swarm motion within some larger cloud or mass, or which can show the overall motion over great distances were developed. The influence of wind and terrain on insect motion and dispersal is determined from radar data.
Bacteria Mediate Oviposition by the Black Soldier Fly, Hermetia illucens (L.), (Diptera: Stratiomyidae)

PubMed Central

Zheng, Longyu; Crippen, Tawni L.; Holmes, Leslie; Singh, Baneshwar; Pimsler, Meaghan L.; Benbow, M. Eric; Tarone, Aaron M.; Dowd, Scot; Yu, Ziniu; Vanlaerhoven, Sherah L.; Wood, Thomas K.; Tomberlin, Jeffery K.

2013-01-01

There can be substantial negative consequences for insects colonizing a resource in the presence of competitors. We hypothesized that bacteria, associated with an oviposition resource and the insect eggs deposited on that resource, serve as a mechanism regulating subsequent insect attraction, colonization, and potentially succession of insect species. We isolated and identified bacterial species associated with insects associated with vertebrate carrion and used these bacteria to measure their influence on the oviposition preference of adult black soldier flies which utilizes animal carcasses and is an important species in waste management and forensics. We also ascertained that utilizing a mixture of bacteria, rather than a single species, differentially influenced behavioral responses of the flies, as did bacterial concentration and the species of fly from which the bacteria originated. These studies provide insight into interkingdom interactions commonly occurring during decomposition, but not commonly studied. PMID:23995019
Bacteria mediate oviposition by the black soldier fly, Hermetia illucens (L.), (Diptera: Stratiomyidae).

PubMed

Zheng, Longyu; Crippen, Tawni L; Holmes, Leslie; Singh, Baneshwar; Pimsler, Meaghan L; Benbow, M Eric; Tarone, Aaron M; Dowd, Scot; Yu, Ziniu; Vanlaerhoven, Sherah L; Wood, Thomas K; Tomberlin, Jeffery K

2013-01-01

There can be substantial negative consequences for insects colonizing a resource in the presence of competitors. We hypothesized that bacteria, associated with an oviposition resource and the insect eggs deposited on that resource, serve as a mechanism regulating subsequent insect attraction, colonization, and potentially succession of insect species. We isolated and identified bacterial species associated with insects associated with vertebrate carrion and used these bacteria to measure their influence on the oviposition preference of adult black soldier flies which utilizes animal carcasses and is an important species in waste management and forensics. We also ascertained that utilizing a mixture of bacteria, rather than a single species, differentially influenced behavioral responses of the flies, as did bacterial concentration and the species of fly from which the bacteria originated. These studies provide insight into interkingdom interactions commonly occurring during decomposition, but not commonly studied.
Novel Insights into Insect-Microbe Interactions—Role of Epigenomics and Small RNAs

PubMed Central

Kim, Dohyup; Thairu, Margaret W.; Hansen, Allison K.

2016-01-01

It has become increasingly clear that microbes form close associations with the vast majority of animal species, especially insects. In fact, an array of diverse microbes is known to form shared metabolic pathways with their insect hosts. A growing area of research in insect-microbe interactions, notably for hemipteran insects and their mutualistic symbionts, is to elucidate the regulation of this inter-domain metabolism. This review examines two new emerging mechanisms of gene regulation and their importance in host-microbe interactions. Specifically, we highlight how the incipient areas of research on regulatory “dark matter” such as epigenomics and small RNAs, can play a pivotal role in the evolution of both insect and microbe gene regulation. We then propose specific models of how these dynamic forms of gene regulation can influence insect-symbiont-plant interactions. Future studies in this area of research will give us a systematic understanding of how these symbiotic microbes and animals reciprocally respond to and regulate their shared metabolic processes. PMID:27540386
Remote sensing of forest insect disturbances: Current state and future directions

NASA Astrophysics Data System (ADS)

Senf, Cornelius; Seidl, Rupert; Hostert, Patrick

2017-08-01

Insect disturbance are important agents of change in forest ecosystems around the globe, yet their spatial and temporal distribution and dynamics are not well understood. Remote sensing has gained much attention in mapping and understanding insect outbreak dynamics. Consequently, we here review the current literature on the remote sensing of insect disturbances. We suggest to group studies into three insect types: bark beetles, broadleaved defoliators, and coniferous defoliators. By so doing, we systematically compare the sensors and methods used for mapping insect disturbances within and across insect types. Results suggest that there are substantial differences between methods used for mapping bark beetles and defoliators, and between methods used for mapping broadleaved and coniferous defoliators. Following from this, we highlight approaches that are particularly suited for each insect type. Finally, we conclude by highlighting future research directions for remote sensing of insect disturbances. In particular, we suggest to: 1) Separate insect disturbances from other agents; 2) Extend the spatial and temporal domain of analysis; 3) Make use of dense time series; 4) Operationalize near-real time monitoring of insect disturbances; 5) Identify insect disturbances in the context of coupled human-natural systems; and 6) Improve reference data for assessing insect disturbances. Since the remote sensing of insect disturbances has gained much interest beyond the remote sensing community recently, the future developments identified here will help integrating remote sensing products into operational forest management. Furthermore, an improved spatiotemporal quantification of insect disturbances will support an inclusion of these processes into regional to global ecosystem models.
Remote sensing of forest insect disturbances: Current state and future directions.

PubMed

Senf, Cornelius; Seidl, Rupert; Hostert, Patrick

2017-08-01

Insect disturbance are important agents of change in forest ecosystems around the globe, yet their spatial and temporal distribution and dynamics are not well understood. Remote sensing has gained much attention in mapping and understanding insect outbreak dynamics. Consequently, we here review the current literature on the remote sensing of insect disturbances. We suggest to group studies into three insect types: bark beetles, broadleaved defoliators, and coniferous defoliators. By so doing, we systematically compare the sensors and methods used for mapping insect disturbances within and across insect types. Results suggest that there are substantial differences between methods used for mapping bark beetles and defoliators, and between methods used for mapping broadleaved and coniferous defoliators. Following from this, we highlight approaches that are particularly suited for each insect type. Finally, we conclude by highlighting future research directions for remote sensing of insect disturbances. In particular, we suggest to: 1) Separate insect disturbances from other agents; 2) Extend the spatial and temporal domain of analysis; 3) Make use of dense time series; 4) Operationalize near-real time monitoring of insect disturbances; 5) Identify insect disturbances in the context of coupled human-natural systems; and 6) Improve reference data for assessing insect disturbances. Since the remote sensing of insect disturbances has gained much interest beyond the remote sensing community recently, the future developments identified here will help integrating remote sensing products into operational forest management. Furthermore, an improved spatiotemporal quantification of insect disturbances will support an inclusion of these processes into regional to global ecosystem models.
RNA Interference in Insect Vectors for Plant Viruses.

PubMed

Kanakala, Surapathrudu; Ghanim, Murad

2016-12-12

Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. The last decade has witnessed a dramatic increase in the functional analysis of insect genes, especially those whose silencing results in mortality or interference with pathogen transmission. The identification of such candidates poses a major challenge for increasing the role of RNAi in pest control. Another challenge is to understand the RNAi machinery in insect cells and whether components that were identified in other organisms are also present in insect. This review will focus on summarizing success cases in which RNAi was used for silencing genes in insect vector for plant pathogens, and will be particularly helpful for vector biologists.
RNA Interference in Insect Vectors for Plant Viruses

PubMed Central

Kanakala, Surapathrudu; Ghanim, Murad

2016-01-01

Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. The last decade has witnessed a dramatic increase in the functional analysis of insect genes, especially those whose silencing results in mortality or interference with pathogen transmission. The identification of such candidates poses a major challenge for increasing the role of RNAi in pest control. Another challenge is to understand the RNAi machinery in insect cells and whether components that were identified in other organisms are also present in insect. This review will focus on summarizing success cases in which RNAi was used for silencing genes in insect vector for plant pathogens, and will be particularly helpful for vector biologists. PMID:27973446
Dyeing Insects for Behavioral Assays: the Mating Behavior of Anesthetized Drosophila

PubMed Central

Verspoor, Rudi L.; Heys, Chloe; Price, Thomas A. R.

2015-01-01

Mating experiments using Drosophila have contributed greatly to the understanding of sexual selection and behavior. Experiments often require simple, easy and cheap methods to distinguish between individuals in a trial. A standard technique for this is CO2 anaesthesia and then labelling or wing clipping each fly. However, this is invasive and has been shown to affect behavior. Other techniques have used coloration to identify flies. This article presents a simple and non-invasive method for labelling Drosophila that allows them to be individually identified within experiments, using food coloring. This method is used in trials where two males compete to mate with a female. Dyeing allowed quick and easy identification. There was, however, some difference in the strength of the coloration across the three species tested. Data is presented showing the dye has a lower impact on mating behavior than CO2 in Drosophila melanogaster. The impact of CO2 anaesthesia is shown to depend on the species of Drosophila, with D. pseudoobscura and D. subobscura showing no impact, whereas D. melanogaster males had reduced mating success. The dye method presented is applicable to a wide range of experimental designs. PMID:25938821
Experimental tests of light-pollution impacts on nocturnal insect courtship and dispersal.

PubMed

Firebaugh, Ariel; Haynes, Kyle J

2016-12-01

Though a number of effects of artificial light pollution on behavior and physiology have been described, there is little understanding of their consequences for the growth and distribution of populations. Here, we document impacts of light pollution on aspects of firefly population ecology and underlying mating behaviors. Many firefly species have a unique communication system whereby bioluminescent flashes are used in courtship displays to find and attract mates. We performed a series of manipulative field experiments in which we quantified the effects of adding artificial nighttime lighting on abundances and total flashing activity of fireflies, courtship behaviors and mating between tethered females and free-flying males, and dispersal distances of marked individuals. We show that light pollution reduces flashing activities in a dark-active firefly species (Photuris versicolor) by 69.69 % and courtship behavior and mating success in a twilight-active species (Photinus pyralis). Though courtship behavior and mating success of Photinus pyralis was reduced by light pollution, we found no effects of light pollution on male dispersal in this species. Our findings suggest that light pollution is likely to adversely impact firefly populations, and contribute to wider discussions about the ecological consequences of sensory pollution.

The RFamide receptor DMSR-1 regulates stress-induced sleep in C. elegans.

PubMed

Iannacone, Michael J; Beets, Isabel; Lopes, Lindsey E; Churgin, Matthew A; Fang-Yen, Christopher; Nelson, Matthew D; Schoofs, Liliane; Raizen, David M

2017-01-17

In response to environments that cause cellular stress, animals engage in sleep behavior that facilitates recovery from the stress. In Caenorhabditis elegans , stress-induced sleep(SIS) is regulated by cytokine activation of the ALA neuron, which releases FLP-13 neuropeptides characterized by an amidated arginine-phenylalanine (RFamide) C-terminus motif. By performing an unbiased genetic screen for mutants that impair the somnogenic effects of FLP-13 neuropeptides, we identified the gene dmsr-1 , which encodes a G-protein coupled receptor similar to an insect RFamide receptor. DMSR-1 is activated by FLP-13 peptides in cell culture, is required for SIS in vivo , is expressed non-synaptically in several wake-promoting neurons, and likely couples to a Gi/o heterotrimeric G-protein. Our data expand our understanding of how a single neuroendocrine cell coordinates an organism-wide behavioral response, and suggest that similar signaling principles may function in other organisms to regulate sleep during sickness.
The buzz on caffeine in invertebrates: effects on behavior and molecular mechanisms

PubMed Central

Mustard, Julie A.

2014-01-01

A number of recent studies from as diverse fields as plant-pollinator interactions, analyses of caffeine as an environmental pollutant, and the ability of caffeine to provide protection against neurodegenerative diseases have generated interest in understanding the actions of caffeine in invertebrates. This review summarizes what is currently known about the effects of caffeine on behavior and its molecular mechanisms in invertebrates. Caffeine appears to have similar effects on locomotion and sleep in both invertebrates and mammals. Furthermore, as in mammals, caffeine appears to have complex effects on learning and memory. However, the underlying mechanisms for these effects may differ between invertebrates and vertebrates. While caffeine’s ability to cause release of intracellular calcium stores via ryanodine receptors and its actions as a phosphodiesterase inhibitor have been clearly established in invertebrates, its ability to interact with invertebrate adenosine receptors remains an important open question. Initial studies in insects and mollusks suggest an interaction between caffeine and the dopamine signaling pathway; more work needs to be done to understand the mechanisms by which caffeine influences signaling via biogenic amines. As of yet, little is known about whether other actions of caffeine in vertebrates, such as its effects on GABAA and glycine receptors, are conserved. Furthermore, the pharmacokinetics of caffeine remains to be elucidated. Overall behavioral responses to caffeine appear to be conserved amongst organisms; however, we are just beginning to understand the mechanisms underlying its effects across animal phyla. PMID:24162934
The buzz on caffeine in invertebrates: effects on behavior and molecular mechanisms.

PubMed

Mustard, Julie A

2014-04-01

A number of recent studies from as diverse fields as plant-pollinator interactions, analyses of caffeine as an environmental pollutant, and the ability of caffeine to provide protection against neurodegenerative diseases have generated interest in understanding the actions of caffeine in invertebrates. This review summarizes what is currently known about the effects of caffeine on behavior and its molecular mechanisms in invertebrates. Caffeine appears to have similar effects on locomotion and sleep in both invertebrates and mammals. Furthermore, as in mammals, caffeine appears to have complex effects on learning and memory. However, the underlying mechanisms for these effects may differ between invertebrates and vertebrates. While caffeine's ability to cause release of intracellular calcium stores via ryanodine receptors and its actions as a phosphodiesterase inhibitor have been clearly established in invertebrates, its ability to interact with invertebrate adenosine receptors remains an important open question. Initial studies in insects and mollusks suggest an interaction between caffeine and the dopamine signaling pathway; more work needs to be done to understand the mechanisms by which caffeine influences signaling via biogenic amines. As of yet, little is known about whether other actions of caffeine in vertebrates, such as its effects on GABAA and glycine receptors, are conserved. Furthermore, the pharmacokinetics of caffeine remains to be elucidated. Overall behavioral responses to caffeine appear to be conserved amongst organisms; however, we are just beginning to understand the mechanisms underlying its effects across animal phyla.
An endoparasitoid Cretaceous fly and the evolution of parasitoidism.

PubMed

Zhang, Qingqing; Zhang, Junfeng; Feng, Yitao; Zhang, Haichun; Wang, Bo

2016-02-01

Parasitoidism is a key innovation in insect evolution, and parasitoid insects, nowadays, play a significant role in structuring ecological communities. Despite their diversity and ecological impact, little is known about the early evolution and ecology of parasitoid insects, especially parasitoid true flies (Diptera). Here, we describe a bizarre fly, Zhenia xiai gen. et sp. nov., from Late Cretaceous Burmese amber (about 99 million years old) that represents the latest occurrence of the family Eremochaetidae. Z. xiai is an endoparasitoid insect as evidenced by a highly developed, hypodermic-like ovipositor formed by abdominal tergites VIII + IX that was used for injecting eggs into hosts and enlarged tridactylous claws supposedly for clasping hosts. Our results suggest that eremochaetids are among the earliest definite records of parasitoid insects. Our findings reveal an unexpected morphological specialization of flies and broaden our understanding of the evolution and diversity of ancient parasitoid insects.
An endoparasitoid Cretaceous fly and the evolution of parasitoidism

NASA Astrophysics Data System (ADS)

Zhang, Qingqing; Zhang, Junfeng; Feng, Yitao; Zhang, Haichun; Wang, Bo

2016-02-01

Parasitoidism is a key innovation in insect evolution, and parasitoid insects, nowadays, play a significant role in structuring ecological communities. Despite their diversity and ecological impact, little is known about the early evolution and ecology of parasitoid insects, especially parasitoid true flies (Diptera). Here, we describe a bizarre fly, Zhenia xiai gen. et sp. nov., from Late Cretaceous Burmese amber (about 99 million years old) that represents the latest occurrence of the family Eremochaetidae. Z. xiai is an endoparasitoid insect as evidenced by a highly developed, hypodermic-like ovipositor formed by abdominal tergites VIII + IX that was used for injecting eggs into hosts and enlarged tridactylous claws supposedly for clasping hosts. Our results suggest that eremochaetids are among the earliest definite records of parasitoid insects. Our findings reveal an unexpected morphological specialization of flies and broaden our understanding of the evolution and diversity of ancient parasitoid insects.
Estimating bacterial diversity in Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) via next generation sequencing

USDA-ARS?s Scientific Manuscript database

The last two decades have produced a better understanding of insect-microbial associations and yielded some important opportunities for insect control. However, most of our knowledge comes from model systems. Thrips (Thysanoptera: Thripidae) have been understudied despite their global importance as ...
Spatial dispersal of Douglas-fir beetle populations in Colorado and Wyoming

Treesearch

John R. Withrow; John E. Lundquist; Jose F. Negron

2013-01-01

Bark beetles (Coleoptera: Curculionidae: Scolytinae) are mortality agents to multiple tree species throughout North America. Understanding spatiotemporal dynamics of these insects can assist management, prediction of outbreaks, and development of "real time" assessments of forest susceptibility incorporating insect population data. Here, dispersal of Douglas-...
A framework for standardizing flight characteristics for separating biology from meteorology in long-range insect transport

Treesearch

Gary L. Achtemeier

1998-01-01

Once airborne during long-range transport, to what extent is the final destination determined by the biota? It is well known that a biological mechanism initiates flight and another biological mechanism terminates flight. Therefore, efforts to answer the above question should be focused on en route insect behavior. A strategy is proposed to isolate biology...
Interactions Among Plants, Insects, and Microbes: Elucidation of Inter-Organismal Chemical Communications in Agricultural Ecology.

PubMed

Beck, John J; Alborn, Hans; Block, Anna; Christensen, Shawn A; Hunter, Charles T; Rering, Caitlin C; Seidl-Adams, Irmgard; Stuhl, Charles; Torto, Baldwyn; Tumlinson, James H

2018-06-12

The last two decades have witnessed a sustained increase in the study of plant-emitted volatiles and their role in plant-insect, plant-microbe and plant-plant interactions. While each of these binary systems involves complex chemical and biochemical processes between two organisms, the progression of increasing complexity of a ternary system (i.e., plant-insect-microbe), and the study of a ternary system requires non-trivial planning. This planning can include: an experimental design that factors in potential overarching ecological interactions regarding the binary or ternary system; correctly identifying and understanding unexpected observations that may occur during the experiment; and, thorough interpretation of the resultant data. This challenge of planning, performing and interpreting a plant's defensive response to multiple biotic stressors will be even greater when abiotic stressors (i.e., temperature or water) are factored into the system. To fully understand the system, we need to not only continue to investigate and understand the volatile profiles, but also include and understand the biochemistry of the plant's response to these stressors. In this paper, we provide examples and discuss interaction considerations with respect to how readers and future authors of the Journal of Agricultural and Food Chemistry can contribute their expertise toward the extraction and interpretation of chemical information exchanged between agricultural commodities and their associated pests. This holistic, multidisciplinary and thoughtful approach to interactions of plants, insects, and microbes, and the resultant response of the plants, can lead to a better understanding of agricultural ecology, in turn leading to practical and viable solutions to agricultural problems.
First record of lobed trace fossils in Brazil's Upper Cretaceous paleosols: Rhizoliths or evidence of insects and their social behavior?

NASA Astrophysics Data System (ADS)

Luciano do Nascimento, Diego; Batezelli, Alessandro; Bernardes Ladeira, Francisco Sérgio

2017-11-01

This is the first report of trace fossils potentially associated with insect social behavior in sandy and well-drained paleosols of the Upper Cretaceous continental sequence of Brazil. The trace fossils consist of dozens of lobed and vertical structures cemented by CaCO3 and preserved mainly in full relief in paleosols of the Marilia Formation (Bauru Basin) in the state of Minas Gerais. The described ichnofossils are predominantly vertical, up to 2 m long, and are composed of horizontal lobed structures connected by vertical tunnel-like structures that intersect in the center and at the edges. The lobed structures range from 3 to 15 cm long and 2-6 cm thick. Two different hypotheses are analyzed to explain the origin of the trace fossils; the less probable one is that the structures are laminar calcretes associated with rhizoliths and rhizoconcretions. The hypothesis involving social insects was considered because the trace fossils described herein partially resemble a modern ant nest and the ichnofossil Daimoniobarax. The micromorphological analysis of the lobed and tunnel-like structures indicates modifications of the walls, such as the presence of inorganic fluidized linings, dark linings and oriented grains, supporting the hypothesis that they are chambers and shafts. The architecture and size of the reported nests suggest the possibility that social insect colonies existed during the Maastrichtian and are direct evidence of the social behavior and reproductive strategies of the Cretaceous pedofauna.
Signatures of DNA Methylation across Insects Suggest Reduced DNA Methylation Levels in Holometabola

PubMed Central

Provataris, Panagiotis; Meusemann, Karen; Niehuis, Oliver; Grath, Sonja; Misof, Bernhard

2018-01-01

Abstract It has been experimentally shown that DNA methylation is involved in the regulation of gene expression and the silencing of transposable element activity in eukaryotes. The variable levels of DNA methylation among different insect species indicate an evolutionarily flexible role of DNA methylation in insects, which due to a lack of comparative data is not yet well-substantiated. Here, we use computational methods to trace signatures of DNA methylation across insects by analyzing transcriptomic and genomic sequence data from all currently recognized insect orders. We conclude that: 1) a functional methylation system relying exclusively on DNA methyltransferase 1 is widespread across insects. 2) DNA methylation has potentially been lost or extremely reduced in species belonging to springtails (Collembola), flies and relatives (Diptera), and twisted-winged parasites (Strepsiptera). 3) Holometabolous insects display signs of reduced DNA methylation levels in protein-coding sequences compared with hemimetabolous insects. 4) Evolutionarily conserved insect genes associated with housekeeping functions tend to display signs of heavier DNA methylation in comparison to the genomic/transcriptomic background. With this comparative study, we provide the much needed basis for experimental and detailed comparative analyses required to gain a deeper understanding on the evolution and function of DNA methylation in insects. PMID:29697817
Nonspiking local interneurons in insect leg motor control. I. Common layout and species-specific response properties of femur-tibia joint control pathways in stick insect and locust.

PubMed

Büschges, A; Wolf, H

1995-05-01

1. Locusts (Locusta migratoria) and stick insects (Carausius morosus) exhibit different strategies for predator avoidance. Locusts rely primarily on walking and jumping to evade predators, whereas stick insects become cataleptic, catalepsy forming a major component of the twig mimesis exhibited by this species. The neuronal networks that control postural leg movements in locusts and stick insects are tuned differently to their specific behavioral tasks. An important prerequisite for the production of catalepsy in the stick insect is the marked velocity dependency of the control network, which appears to be generated at the level of nonspiking local interneurons. We examined interneuronal pathways in the network controlling the femur-tibia joint of the locust middle leg and compared its properties with those described for the stick insect middle leg. It was our aim to identify possible neural correlates of the species-specific behavior with regard to postural leg motor control. 2. We obtained evidence that the neuronal networks that control the femur-tibia joints in the two species consist of morphologically and physiologically similar--and thus probably homologous--interneurons. Qualitatively, these interneurons receive the same input from the femoral chordotonal organ receptors and they drive the same pools of leg motoneurons in both species. 3. Pathways that contribute to the control of the femur-tibia joint include interneurons that support both "resisting" and "assisting" responses with respect to the motoneuron activity that is actually elicited during reflex movements. Signal processing via parallel, antagonistic pathways therefore appears to be a common principle in insect leg motor control. 4. Differences between the two insect species were found with regard to the processing of velocity information provided by the femoral chordotonal organ. Interneuronal pathways are sensitive to stimulus velocity in both species. However, in the locust there is no marked velocity dependency of the interneuronal responses, whereas in the same interneurons of the stick insect it is pronounced. This characteristic was maintained at the level of the motoneurons controlling the femur-tibia joint. Pathways for postural leg motor control in the locust thus lack an important prerequisite for the generation of catalepsy, that is, a marked velocity dependency.
Dm5-HT2B: Pharmacological Characterization of the Fifth Serotonin Receptor Subtype of Drosophila melanogaster.

PubMed

Blenau, Wolfgang; Daniel, Stöppler; Balfanz, Sabine; Thamm, Markus; Baumann, Arnd

2017-01-01

Serotonin (5-hydroxytryptamine, 5-HT) is an important regulator of physiological and behavioral processes in both protostomes (e.g., insects) and deuterostomes (e.g., mammals). In insects, serotonin has been found to modulate the heart rate and to control secretory processes, development, circadian rhythms, aggressive behavior, as well as to contribute to learning and memory. Serotonin exerts its activity by binding to and activating specific membrane receptors. The clear majority of these receptors belong to the superfamily of G-protein-coupled receptors. In Drosophila melanogaster , a total of five genes have been identified coding for 5-HT receptors. From this family of proteins, four have been pharmacologically examined in greater detail, so far. While Dm5-HT 1A , Dm5-HT 1B , and Dm5-HT 7 couple to cAMP signaling cascades, the Dm5-HT 2A receptor leads to Ca 2+ signaling in an inositol-1,4,5-trisphosphate-dependent manner. Based on sequence similarity to homologous genes in other insects, a fifth D. melanogaster gene was uncovered coding for a Dm5-HT 2B receptor. Knowledge about this receptor's pharmacological properties is very limited. This is quite surprising because Dm5-HT 2B has been attributed to distinct physiological functions based on genetic interference with its gene expression. Mutations were described reducing the response of the larval heart to 5-HT, and specific knockdown of Dm5-HT 2B mRNA in hemocytes resulted in a higher susceptibility of the flies to bacterial infection. To gain deeper understanding of Dm5-HT 2B 's pharmacology, we evaluated the receptor's response to a series of established 5-HT receptor agonists and antagonists in a functional cell-based assay. Metoclopramide and mianserin were identified as two potent antagonists that may allow pharmacological interference with Dm5-HT 2B signaling in vitro and in vivo .
Dm5-HT2B: Pharmacological Characterization of the Fifth Serotonin Receptor Subtype of Drosophila melanogaster

PubMed Central

Blenau, Wolfgang; Daniel, Stöppler; Balfanz, Sabine; Thamm, Markus; Baumann, Arnd

2017-01-01

Serotonin (5-hydroxytryptamine, 5-HT) is an important regulator of physiological and behavioral processes in both protostomes (e.g., insects) and deuterostomes (e.g., mammals). In insects, serotonin has been found to modulate the heart rate and to control secretory processes, development, circadian rhythms, aggressive behavior, as well as to contribute to learning and memory. Serotonin exerts its activity by binding to and activating specific membrane receptors. The clear majority of these receptors belong to the superfamily of G-protein-coupled receptors. In Drosophila melanogaster, a total of five genes have been identified coding for 5-HT receptors. From this family of proteins, four have been pharmacologically examined in greater detail, so far. While Dm5-HT1A, Dm5-HT1B, and Dm5-HT7 couple to cAMP signaling cascades, the Dm5-HT2A receptor leads to Ca2+ signaling in an inositol-1,4,5-trisphosphate-dependent manner. Based on sequence similarity to homologous genes in other insects, a fifth D. melanogaster gene was uncovered coding for a Dm5-HT2B receptor. Knowledge about this receptor’s pharmacological properties is very limited. This is quite surprising because Dm5-HT2B has been attributed to distinct physiological functions based on genetic interference with its gene expression. Mutations were described reducing the response of the larval heart to 5-HT, and specific knockdown of Dm5-HT2B mRNA in hemocytes resulted in a higher susceptibility of the flies to bacterial infection. To gain deeper understanding of Dm5-HT2B’s pharmacology, we evaluated the receptor’s response to a series of established 5-HT receptor agonists and antagonists in a functional cell-based assay. Metoclopramide and mianserin were identified as two potent antagonists that may allow pharmacological interference with Dm5-HT2B signaling in vitro and in vivo. PMID:28553207
Nutritional contributions of insects to primate diets: implications for primate evolution.

PubMed

Rothman, Jessica M; Raubenheimer, David; Bryer, Margaret A H; Takahashi, Maressa; Gilbert, Christopher C

2014-06-01

Insects and other invertebrates form a portion of many living and extinct primate diets. We review the nutritional profiles of insects in comparison with other dietary items, and discuss insect nutrients in relation to the nutritional needs of living primates. We find that insects are incorporated into some primate diets as staple foods whereby they are the majority of food intake. They can also be incorporated as complements to other foods in the diet, providing protein in a diet otherwise dominated by gums and/or fruits, or be incorporated as supplements to likely provide an essential nutrient that is not available in the typical diet. During times when they are very abundant, such as in insect outbreaks, insects can serve as replacements to the usual foods eaten by primates. Nutritionally, insects are high in protein and fat compared with typical dietary items like fruit and vegetation. However, insects are small in size and for larger primates (>1 kg) it is usually nutritionally profitable only to consume insects when they are available in large quantities. In small quantities, they may serve to provide important vitamins and fatty acids typically unavailable in primate diets. In a brief analysis, we found that soft-bodied insects are higher in fat though similar in chitin and protein than hard-bodied insects. In the fossil record, primates can be defined as soft- or hard-bodied insect feeders based on dental morphology. The differences in the nutritional composition of insects may have implications for understanding early primate evolution and ecology. Copyright © 2014 Elsevier Ltd. All rights reserved.
Siberian forest insects: ready for export

Treesearch

Yuri N. Baranchikov

1998-01-01

Existing publications on Palaearctic insect invaders to North America forests are devoted exclusively to Europe-U.S. comparisons. This is understandable from both geographical and historical points of view. But as the history of mankind continues, new economical relations are established which, unfortunately, make new possibilities for the introductions of pests. The...
Bug Talk: A Learning Module on Insect Communication

ERIC Educational Resources Information Center

Bergman, Daniel J.

2008-01-01

The study of insects (entomology) can be used to stimulate students' interest in science and nature. It can develop students' understanding of fundamental science concepts, awareness of interdisciplinary connections, and mastery of science process skills. This teaching module provides opportunities for middle school students (Grades 5-8) to learn…
Pond and Stream Safari: A Guide to the Ecology of Aquatic Invertebrates.

ERIC Educational Resources Information Center

Edelstein, Karen

This packet includes a leader's guide, a quick reference guide to aquatic invertebrates, a checklist of common aquatic invertebrates, and activity sheets. The leader's guide includes four sections on background information and seven activities. Background sections include: Understanding Aquatic Insects; Growing Up: Aquatic Insect Forms; Adapting…
Population dynamics of stored maize insect pests in warehouses in two districts of Ghana

USDA-ARS?s Scientific Manuscript database

Understanding what insect species are present and their temporal and spatial patterns of distribution is important for developing a successful integrated pest management strategy for food storage in warehouses. Maize in many countries in Africa is stored in bags in warehouses, but little monitoring ...
Lives within lives: hidden fungal biodiversity within insects, mammals, mites, and plants

USDA-ARS?s Scientific Manuscript database

Nothing is sterile. Insects, mammals, mites, and plants, all hide a vast fungal biodiversity whose role is for the most part unknown. From the work of Lynn Margulies, Miriam Rothschild and Johanna Westerdijk, we have gained a better understanding of how microbial associations pervade living systems ...

Improving mycoinsecticides for insect biological control.

PubMed

Ortiz-Urquiza, Almudena; Luo, Zhibing; Keyhani, Nemat O

2015-02-01

The desire for decreased reliance on chemical pesticides continues to fuel interest in alternative means for pest control including the use of naturally occurring microbial insect pathogens. Insects, as vectors of disease causing agents or as agricultural pests, are responsible for millions of deaths and significant economic losses worldwide, placing stresses on productivity (GDP) and human health and welfare. In addition, alterations in climate change are likely to affect insect ranges, expanding their access to previously constrained geographic areas, a potentially worrisome outcome. Metarhizium anisopliae and Beauveria bassiana, two cosmopolitan fungal pathogens of insects found in almost all ecosystems, are the most commonly applied mycoinsecticides for a variety of insect control purposes. The availability of the complete genomes for both organisms coupled to robust technologies for their transformation has led to several advances in engineering these fungi for greater efficacy and/or utility in pest control applications. Here, we will provide an overview of the fungal-insect and fungal-plant interactions that occur and highlight recent advances in the genetic engineering of these fungi. The latter work has resulted in the development of strains displaying (1) increased resistance to abiotic stress, (2) increased cuticular targeting and degradation, (3) increased virulence via expression of insecticidal protein/peptide toxins, (4) the ability to block transmission of disease causing agents, and (5) the ability to target specific insect hosts, decrease host fecundity, and/or alter insect behaviors.
Microbial Brokers of Insect-Plant Interactions Revisited

PubMed Central

Douglas, Angela E

2013-01-01

Recent advances in sequencing methods have transformed the field of microbial ecology, making it possible to determine the composition and functional capabilities of uncultured microorganisms. These technologies have been instrumental in the recognition that resident microorganisms can have profound effects on the phenotype and fitness of their animal hosts by modulating the animal signaling networks that regulate growth, development, behavior, etc. Against this backdrop, this review assesses the impact of microorganisms on insect-plant interactions, in the context of the hypothesis that microorganisms are biochemical brokers of plant utilization by insects. There is now overwhelming evidence for a microbial role in insect utilization of certain plant diets with an extremely low or unbalanced nutrient content. Specifically, microorganisms enable insect utilization of plant sap by synthesizing essential amino acids. They also can broker insect utilization of plant products of extremely high lignocellulose content, by enzymatic breakdown of complex plant polysaccharides, nitrogen fixation, and sterol synthesis. However, the experimental evidence for microbial-mediated detoxification of plant allelochemicals is limited. The significance of microorganisms as brokers of plant utilization by insects is predicted to vary, possibly widely, as a result of potentially complex interactions between the composition of the microbiota and the diet and insect developmental age or genotype. For every insect species feeding on plant material, the role of resident microbiota as biochemical brokers of plant utilization is a testable hypothesis. PMID:23793897
Neuroarchitecture and neuroanatomy of the Drosophila central complex: A GAL4-based dissection of protocerebral bridge neurons and circuits

PubMed Central

Wolff, Tanya; Iyer, Nirmala A; Rubin, Gerald M

2015-01-01

Insects exhibit an elaborate repertoire of behaviors in response to environmental stimuli. The central complex plays a key role in combining various modalities of sensory information with an insect's internal state and past experience to select appropriate responses. Progress has been made in understanding the broad spectrum of outputs from the central complex neuropils and circuits involved in numerous behaviors. Many resident neurons have also been identified. However, the specific roles of these intricate structures and the functional connections between them remain largely obscure. Significant gains rely on obtaining a comprehensive catalog of the neurons and associated GAL4 lines that arborize within these brain regions, and on mapping neuronal pathways connecting these structures. To this end, small populations of neurons in the Drosophila melanogaster central complex were stochastically labeled using the multicolor flip-out technique and a catalog was created of the neurons, their morphologies, trajectories, relative arrangements, and corresponding GAL4 lines. This report focuses on one structure of the central complex, the protocerebral bridge, and identifies just 17 morphologically distinct cell types that arborize in this structure. This work also provides new insights into the anatomical structure of the four components of the central complex and its accessory neuropils. Most strikingly, we found that the protocerebral bridge contains 18 glomeruli, not 16, as previously believed. Revised wiring diagrams that take into account this updated architectural design are presented. This updated map of the Drosophila central complex will facilitate a deeper behavioral and physiological dissection of this sophisticated set of structures. J. Comp. Neurol. 523:997–1037, 2015. © 2014 Wiley Periodicals, Inc. PMID:25380328
Host-location behavior of the tea green leafhopper Empoasca vitis Göthe (Hemiptera: Cicadellidae): olfactory and visual effects on their orientation.

PubMed

Zhang, X; Pengsakul, T; Tukayo, M; Yu, L; Fang, W; Luo, D

2017-09-25

The tea green leafhopper, Empoasca vitis Göthe, is one of the most serious pests in tea growing areas. This study investigated the roles played by olfaction and vision in host orientation behavior. The compound eye of E. vitis was found to be a photopic eye; few olfactory sensilla were found on the antennae, while abundant gustatory sensilla were recorded on the mouthparts. Three opsin genes (EV_LWop, EV_UVop, EV_Bop) were isolated and found to be mainly expressed in the compound eye compared with other parts of the body. Immunolocalization indicated that the opsins mainly located in the different regions of rhabdom. The transcription levels of EV_LWop, EV_Bop and EV_UVop were reduced by 77.3, 70.0 and 40.0%, respectively, by RNA interference induced by being fed a special RNA-rich diet for 6 days. The rate of tropism to host color was effectively impaired by 67.6 and 29.5% in the dsEV_LWop and dsEV_Bop treatment groups, but there was no significant change in the dsEV_UVop group. The determination of the cause of the tropism indicated that odors from the host over long distances were unable to attract E. vitis and were only detected when the insects were close to the host. The developed compound eye of E. vitis plays a leading role in host location, and the long-wavelength opsin significantly affects the tropism to host color; the lack of olfactory sensilla results in long-distance odors not being able to be detected until the insect is near to the host-plant. The understanding of these behavioral mechanisms, especially the importance of opsin genes is expected to be useful for pest management.
Manipulation of host behavior by parasitic insects and insect parasites.

PubMed

Libersat, Frederic; Delago, Antonia; Gal, Ram

2009-01-01

Parasites often alter the behavior of their hosts in ways that are ultimately beneficial to the parasite or its offspring. Although the alteration of host behavior by parasites is a widespread phenomenon, the underlying neuronal mechanisms are only beginning to be understood. Here, we focus on recent advances in the study of behavioral manipulation via modulation of the host central nervous system. We elaborate on a few case studies, in which recently published data provide explanations for the neuronal basis of parasite-induced alteration of host behavior. Among these, we describe how a worm may influence the nervous system of its cricket host and manipulate the cricket into committing suicide by jumping into water. We then focus on Ampulex compressa, which uses an Alien-like strategy for the sake of its offspring. Unlike most venomous hunters, this wasp injects venom directly into specific cerebral regions of its cockroach prey. As a result of the sting, the cockroach remains alive but immobile, but not paralyzed, and serves to nourish the developing wasp larva.
Mind Control: How Parasites Manipulate Cognitive Functions in Their Insect Hosts

PubMed Central

Libersat, Frederic; Kaiser, Maayan; Emanuel, Stav

2018-01-01

Neuro-parasitology is an emerging branch of science that deals with parasites that can control the nervous system of the host. It offers the possibility of discovering how one species (the parasite) modifies a particular neural network, and thus particular behaviors, of another species (the host). Such parasite–host interactions, developed over millions of years of evolution, provide unique tools by which one can determine how neuromodulation up-or-down regulates specific behaviors. In some of the most fascinating manipulations, the parasite taps into the host brain neuronal circuities to manipulate hosts cognitive functions. To name just a few examples, some worms induce crickets and other terrestrial insects to commit suicide in water, enabling the exit of the parasite into an aquatic environment favorable to its reproduction. In another example of behavioral manipulation, ants that consumed the secretions of a caterpillar containing dopamine are less likely to move away from the caterpillar and more likely to be aggressive. This benefits the caterpillar for without its ant bodyguards, it is more likely to be predated upon or attacked by parasitic insects that would lay eggs inside its body. Another example is the parasitic wasp, which induces a guarding behavior in its ladybug host in collaboration with a viral mutualist. To exert long-term behavioral manipulation of the host, parasite must secrete compounds that act through secondary messengers and/or directly on genes often modifying gene expression to produce long-lasting effects. PMID:29765342
Mind Control: How Parasites Manipulate Cognitive Functions in Their Insect Hosts.

PubMed

Libersat, Frederic; Kaiser, Maayan; Emanuel, Stav

2018-01-01

Neuro-parasitology is an emerging branch of science that deals with parasites that can control the nervous system of the host. It offers the possibility of discovering how one species (the parasite) modifies a particular neural network, and thus particular behaviors, of another species (the host). Such parasite-host interactions, developed over millions of years of evolution, provide unique tools by which one can determine how neuromodulation up-or-down regulates specific behaviors. In some of the most fascinating manipulations, the parasite taps into the host brain neuronal circuities to manipulate hosts cognitive functions. To name just a few examples, some worms induce crickets and other terrestrial insects to commit suicide in water, enabling the exit of the parasite into an aquatic environment favorable to its reproduction. In another example of behavioral manipulation, ants that consumed the secretions of a caterpillar containing dopamine are less likely to move away from the caterpillar and more likely to be aggressive. This benefits the caterpillar for without its ant bodyguards, it is more likely to be predated upon or attacked by parasitic insects that would lay eggs inside its body. Another example is the parasitic wasp, which induces a guarding behavior in its ladybug host in collaboration with a viral mutualist. To exert long-term behavioral manipulation of the host, parasite must secrete compounds that act through secondary messengers and/or directly on genes often modifying gene expression to produce long-lasting effects.
Proteomics Improves the New Understanding of Honeybee Biology.

PubMed

Hora, Zewdu Ararso; Altaye, Solomon Zewdu; Wubie, Abebe Jemberie; Li, Jianke

2018-04-11

The honeybee is one of the most valuable insect pollinators, playing a key role in pollinating wild vegetation and agricultural crops, with significant contribution to the world's food production. Although honeybees have long been studied as model for social evolution, honeybee biology at the molecular level remained poorly understood until the year 2006. With the availability of the honeybee genome sequence and technological advancements in protein separation, mass spectrometry, and bioinformatics, aspects of honeybee biology such as developmental biology, physiology, behavior, neurobiology, and immunology have been explored to new depths at molecular and biochemical levels. This Review comprehensively summarizes the recent progress in honeybee biology using proteomics to study developmental physiology, task transition, and physiological changes in some of the organs, tissues, and cells based on achievements from the authors' laboratory in this field. The research advances of honeybee proteomics provide new insights for understanding of honeybee biology and future research directions.
Pollination by brood-site deception.

PubMed

Urru, Isabella; Stensmyr, Marcus C; Hansson, Bill S

2011-09-01

Pollination is often regarded as a mutualistic relationship between flowering plants and insects. In such a relationship, both partners gain a fitness benefit as a result of their interaction. The flower gets pollinated and the insect typically gets a food-related reward. However, flower-insect communication is not always a mutualistic system, as some flowers emit deceitful signals. Insects are thus fooled by irresistible stimuli and pollination is accomplished. Such deception requires very fine tuning, as insects in their typically short life span, try to find mating/feeding breeding sites as efficiently as possible, and following deceitful signals thus is both costly and time-consuming. Deceptive flowers have thus evolved the ability to emit signals that trigger obligate innate or learned responses in the targeted insects. The behavior, and thus the signals, exploited are typically involved in reproduction, from attracting pheromones to brood/food-site cues. Chemical mimicry is one of the main modalities through which flowers trick their pollen vectors, as olfaction plays a pivotal role in insect-insect and insect-plant interactions. Here we focus on floral odors that specifically mimic an oviposition substrate, i.e., brood-site mimicry. The phenomenon is wide spread across unrelated plant lineages of Angiosperm, Splachnaceae and Phallaceae. Targeted insects are mainly beetles and flies, and flowers accordingly often emit, to the human nose, highly powerful and fetid smells that are conversely extremely attractive to the duped insects. Brood-site deceptive plants often display highly elaborate flowers and have evolved a trap-release mechanism. Chemical cues often act in unison with other sensory cues to refine the imitation. Copyright © 2011 Elsevier Ltd. All rights reserved.
Volatile science? Metabolic engineering of terpenoids in plants.

PubMed

Aharoni, Asaph; Jongsma, Maarten A; Bouwmeester, Harro J

2005-12-01

Terpenoids are important for plant survival and also possess biological properties that are beneficial to humans. Here, we describe the state of the art in terpenoid metabolic engineering, showing that significant progress has been made over the past few years. Subcellular targeting of enzymes has demonstrated that terpenoid precursors in subcellular compartments are not as strictly separated as previously thought and that multistep pathway engineering is feasible, even across cell compartments. These engineered plants show that insect behavior is influenced by terpenoids. In the future, we expect rapid progress in the engineering of terpenoid production in plants. In addition to commercial applications, such transgenic plants should increase our understanding of the biological relevance of these volatile secondary metabolites.
A neotropical migrant bird's dilemma: where to stop for a good meal

USGS Publications Warehouse

Fontaine, Joseph J.; van Riper, Charles

2009-01-01

To learn how migrating birds determine where to stop and find food, scientists from the U.S. Geological Survey, Northern Arizona University, and The University of Arizona studied the behavior of 28 species of neotropical migrant songbirds - warblers, flycatchers, tanagers, and vireos - along the lower Colorado River from 2001 to 2004. They found that, like interstate travelers greeted by restaurant billboards, songbirds flying over Cibola National Wildlife Refuge, Arizona, relied on the flowering of honey mesquite (Prosopis glandulosa) to detect the availability of insects that they prey on. Understanding where and why migrant birds stop will help land managers better protect key habitats used by these tiny travelers.
Silencing of Chemosensory Protein Gene NlugCSP8 by RNAi Induces Declining Behavioral Responses of Nilaparvata lugens

PubMed Central

Waris, Muhammad I.; Younas, Aneela; ul Qamar, Muhammad T.; Hao, Liu; Ameen, Asif; Ali, Saqib; Abdelnabby, Hazem Elewa; Zeng, Fang-Fang; Wang, Man-Qun

2018-01-01

Chemosensory proteins (CSPs) play imperative functions in chemical and biochemical signaling of insects, as they distinguish and transfer ecological chemical indications to a sensory system in order to initiate behavioral responses. The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), has emerged as the most destructive pest, causing serious damage to rice in extensive areas throughout Asia. Biotic characteristics like monophagy, dual wing forms, and annual long-distance migration imply a critical role of chemoreception in N. lugens. In this study, we cloned the full-length CSP8 gene from N. lugens. Protein sequence analysis indicated that NlugCSP8 shared high sequence resemblance with the CSPs of other insect family members and had the typical four-cysteine signature. Analysis of gene expression indicated that NlugCSP8 mRNA was specifically expressed in the wings of mated 3-day brachypterous females with a 175-fold difference compare to unmated 3-day brachypterous females. The NlugCSP8 mRNA was also highly expressed in the abdomen of unmated 5-day brachypterous males and correlated to the age, gender, adult wing form, and mating status. A competitive ligand-binding assay demonstrated that ligands with long chain carbon atoms, nerolidol, hexanal, and trans-2-hexenal were able to bind to NlugCSP8 in declining order of affinity. By using bioinformatics techniques, three-dimensional protein structure modeling and molecular docking, the binding sites of NlugCSP8 to the volatiles which had high binding affinity were predicted. In addition, behavioral experiments using the compounds displaying the high binding affinity for the NlugCSP8, revealed four compounds able to elicit significant behavioral responses from N. lugens. The in vivo functions of NlugCSP8 were further confirmed through the testing of RNAi and post-RNAi behavioral experiments. The results revealed that reduction in NlugCSP8 transcript abundance caused a decrease in behavioral response to representative attractants. An enhanced understanding of the NlugCSP8 is expected to contribute in the improvement of more effective and eco-friendly control strategies of BPH. PMID:29706901
Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae)

PubMed Central

Cirino, Lauren A.; Miller, Christine W.

2017-01-01

Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata. This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak) over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon) decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this study is far from comprehensive, it provides tantalizing patterns that suggest many directions for future research. PMID:28106715
A Tyrosine-Hydroxylase Characterization of Dopaminergic Neurons in the Honey Bee Brain

PubMed Central

Tedjakumala, Stevanus R.; Rouquette, Jacques; Boizeau, Marie-Laure; Mesce, Karen A.; Hotier, Lucie; Massou, Isabelle; Giurfa, Martin

2017-01-01

Dopamine (DA) plays a fundamental role in insect behavior as it acts both as a general modulator of behavior and as a value system in associative learning where it mediates the reinforcing properties of unconditioned stimuli (US). Here we aimed at characterizing the dopaminergic neurons in the central nervous system of the honey bee, an insect that serves as an established model for the study of learning and memory. We used tyrosine hydroxylase (TH) immunoreactivity (ir) to ensure that the neurons detected synthesize DA endogenously. We found three main dopaminergic clusters, C1–C3, which had been previously described; the C1 cluster is located in a small region adjacent to the esophagus (ES) and the antennal lobe (AL); the C2 cluster is situated above the C1 cluster, between the AL and the vertical lobe (VL) of the mushroom body (MB); the C3 cluster is located below the calyces (CA) of the MB. In addition, we found a novel dopaminergic cluster, C4, located above the dorsomedial border of the lobula, which innervates the visual neuropils of the bee brain. Additional smaller processes and clusters were found and are described. The profuse dopaminergic innervation of the entire bee brain and the specific connectivity of DA neurons, with visual, olfactory and gustatory circuits, provide a foundation for a deeper understanding of how these sensory modules are modulated by DA, and the DA-dependent value-based associations that occur during associative learning. PMID:28740466
Vision drives accurate approach behavior during prey capture in laboratory mice

PubMed Central

Hoy, Jennifer L.; Yavorska, Iryna; Wehr, Michael; Niell, Cristopher M.

2016-01-01

Summary The ability to genetically identify and manipulate neural circuits in the mouse is rapidly advancing our understanding of visual processing in the mammalian brain [1,2]. However, studies investigating the circuitry that underlies complex ethologically-relevant visual behaviors in the mouse have been primarily restricted to fear responses [3–5]. Here, we show that a laboratory strain of mouse (Mus musculus, C57BL/6J) robustly pursues, captures and consumes live insect prey, and that vision is necessary for mice to perform the accurate orienting and approach behaviors leading to capture. Specifically, we differentially perturbed visual or auditory input in mice and determined that visual input is required for accurate approach, allowing maintenance of bearing to within 11 degrees of the target on average during pursuit. While mice were able to capture prey without vision, the accuracy of their approaches and capture rate dramatically declined. To better explore the contribution of vision to this behavior, we developed a simple assay that isolated visual cues and simplified analysis of the visually guided approach. Together, our results demonstrate that laboratory mice are capable of exhibiting dynamic and accurate visually-guided approach behaviors, and provide a means to estimate the visual features that drive behavior within an ethological context. PMID:27773567
What insects can tell us about the origins of consciousness

PubMed Central

Barron, Andrew B.; Klein, Colin

2016-01-01

How, why, and when consciousness evolved remain hotly debated topics. Addressing these issues requires considering the distribution of consciousness across the animal phylogenetic tree. Here we propose that at least one invertebrate clade, the insects, has a capacity for the most basic aspect of consciousness: subjective experience. In vertebrates the capacity for subjective experience is supported by integrated structures in the midbrain that create a neural simulation of the state of the mobile animal in space. This integrated and egocentric representation of the world from the animal’s perspective is sufficient for subjective experience. Structures in the insect brain perform analogous functions. Therefore, we argue the insect brain also supports a capacity for subjective experience. In both vertebrates and insects this form of behavioral control system evolved as an efficient solution to basic problems of sensory reafference and true navigation. The brain structures that support subjective experience in vertebrates and insects are very different from each other, but in both cases they are basal to each clade. Hence we propose the origins of subjective experience can be traced to the Cambrian. PMID:27091981
Tracking the elusive history of diversification in plant-herbivorous insect-parasitoid food webs: insights from figs and fig wasps.

PubMed

Kjellberg, Finn; Proffit, Magali

2016-02-01

The food webs consisting of plants, herbivorous insects and their insect parasitoids are a major component of terrestrial biodiversity. They play a central role in the functioning of all terrestrial ecosystems, and the number of species involved is mind-blowing (Nyman et al. 2015). Nevertheless, our understanding of the evolutionary and ecological determinants of their diversity is still in its infancy. In this issue of Molecular Ecology, Sutton et al. (2016) open a window into the comparative analysis of spatial genetic structuring in a set of comparable multitrophic models, involving highly species-specific interactions: figs and fig wasps. This is the first study to compare genetic structure using population genetics tools in a fig-pollinating wasp (Pleistodontes imperialis sp1) and its main parasitoid (Sycoscapter sp.A). The fig-pollinating wasp has a discontinuous spatial distribution that correlates with genetic differentiation, while the parasitoid bridges the discontinuity by parasitizing other pollinator species on the same host fig tree and presents basically no spatial genetic structure. The full implications of these results for our general understanding of plant-herbivorous insect-insect parasitoids diversification become apparent when envisioned within the framework of recent advances in fig and fig wasp biology. © 2016 John Wiley & Sons Ltd.
Advanced technologies for genetically manipulating the silkworm Bombyx mori, a model Lepidopteran insect

PubMed Central

Xu, Hanfu; O'Brochta, David A.

2015-01-01

Genetic technologies based on transposon-mediated transgenesis along with several recently developed genome-editing technologies have become the preferred methods of choice for genetically manipulating many organisms. The silkworm, Bombyx mori, is a Lepidopteran insect of great economic importance because of its use in silk production and because it is a valuable model insect that has greatly enhanced our understanding of the biology of insects, including many agricultural pests. In the past 10 years, great advances have been achieved in the development of genetic technologies in B. mori, including transposon-based technologies that rely on piggyBac-mediated transgenesis and genome-editing technologies that rely on protein- or RNA-guided modification of chromosomes. The successful development and application of these technologies has not only facilitated a better understanding of B. mori and its use as a silk production system, but also provided valuable experiences that have contributed to the development of similar technologies in non-model insects. This review summarizes the technologies currently available for use in B. mori, their application to the study of gene function and their use in genetically modifying B. mori for biotechnology applications. The challenges, solutions and future prospects associated with the development and application of genetic technologies in B. mori are also discussed. PMID:26108630
On-plant selection and genetic analysis of European corn borer (Lepidoptera: Crambidae) behavioral traits: plant abandonment versus plant establishment

USDA-ARS?s Scientific Manuscript database

Although some studies have investigated how insect behavior could influence resistance evolution to transgenic plants, none have determined if behavioral traits respond to selection pressure and how they may be inherited. We investigated plant establishment and plant abandonment traits for the Euro...
Towards Biological Control of Kudzu Through an Improved Understanding of Insect-Kudzu Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orr, D.; Barber, G.; DeBarr, G.

2001-08-03

The authors evaluated various approaches to the biological control of kudzu and exotic weed that infests the SRS. A large number of native pollinators were found to be attracted to kudzu. The viability of seed was found to be low, between 2% and 11%. This is the result of native Hemiptera. The results suggest that seed feeding insects should not be targeted for importation. Both kudzu and soybeans had the same level of abundance and diversity of herbivore insects and the same levels of defoliation. No vine or root damaging species were found. Efforts should be targeted to the lattermore » insects to control kudzu.« less

Pyrokinin β-neuropeptide affects necrophoretic behavior in fire ants (S. invicta), and expression of β-NP in a mycoinsecticide increases its virulence.

PubMed

Fan, Yanhua; Pereira, Roberto M; Kilic, Engin; Casella, George; Keyhani, Nemat O

2012-01-01

Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β-neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT(50), but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed.
Pyrokinin β-Neuropeptide Affects Necrophoretic Behavior in Fire Ants (S. invicta), and Expression of β-NP in a Mycoinsecticide Increases Its Virulence

PubMed Central

Fan, Yanhua; Pereira, Roberto M.; Kilic, Engin; Casella, George; Keyhani, Nemat O.

2012-01-01

Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β -neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT50, but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed. PMID:22238569
Fossil record of stem groups employed in evaluating the chronogram of insects (Arthropoda: Hexapoda)

PubMed Central

Wang, Yan-hui; Engel, Michael S.; Rafael, José A.; Wu, Hao-yang; Rédei, Dávid; Xie, Qiang; Wang, Gang; Liu, Xiao-guang; Bu, Wen-jun

2016-01-01

Insecta s. str. (=Ectognatha), comprise the largest and most diversified group of living organisms, accounting for roughly half of the biodiversity on Earth. Understanding insect relationships and the specific time intervals for their episodes of radiation and extinction are critical to any comprehensive perspective on evolutionary events. Although some deeper nodes have been resolved congruently, the complete evolution of insects has remained obscure due to the lack of direct fossil evidence. Besides, various evolutionary phases of insects and the corresponding driving forces of diversification remain to be recognized. In this study, a comprehensive sample of all insect orders was used to reconstruct their phylogenetic relationships and estimate deep divergences. The phylogenetic relationships of insect orders were congruently recovered by Bayesian inference and maximum likelihood analyses. A complete timescale of divergences based on an uncorrelated log-normal relaxed clock model was established among all lineages of winged insects. The inferred timescale for various nodes are congruent with major historical events including the increase of atmospheric oxygen in the Late Silurian and earliest Devonian, the radiation of vascular plants in the Devonian, and with the available fossil record of the stem groups to various insect lineages in the Devonian and Carboniferous. PMID:27958352
Bacillus thuringiensis: A story of a successful bioinsecticide

PubMed Central

Bravo, Alejandra; Likitvivatanavong, Supaporn; Gill, Sarjeet S.; Soberón, Mario

2013-01-01

Bacillus thuringiensis (Bt) bacteria are insect pathogens that rely on insecticidal pore forming proteins known as Cry and Cyt toxins to kill their insect larval hosts. At least four different non-structurally related families of proteins form the Cry toxin group of toxins. The expression of certain Cry toxins in transgenic crops has contributed to an efficient control of insect pests resulting in a significant reduction in chemical insecticide use. The mode of action of the three domain Cry toxin family involves sequential interaction of these toxins with several insect midgut proteins facilitating the formation of a pre-pore oligomer structure and subsequent membrane insertion that leads to the killing of midgut insect cells by osmotic shock. In this manuscript we review recent progress in understanding the mode of action of this family of proteins in lepidopteran, dipteran and coleopteran insects. Interestingly, similar Cry-binding proteins have been identified in the three insect orders, as cadherin, aminopeptidase-N and alkaline phosphatase suggesting a conserved mode of action. Also, recent data on insect responses to Cry toxin attack is discussed. Finally, we review the different Bt based products, including transgenic crops, that are currently used in agriculture. PMID:21376122
Determining putative vectors of the Bogia Coconut Syndrome phytoplasma using loop-mediated isothermal amplification of single-insect feeding media

PubMed Central

Lu, Hengyu; Wilson, Bree A. L.; Ash, Gavin J.; Woruba, Sharon B.; Fletcher, Murray J.; You, Minsheng; Yang, Guang; Gurr, Geoff M.

2016-01-01

Phytoplasmas are insect vectored mollicutes responsible for disease in many economically important crops. Determining which insect species are vectors of a given phytoplasma is important for managing disease but is methodologically challenging because disease-free plants need to be exposed to large numbers of insects, often over many months. A relatively new method to detect likely transmission involves molecular testing for phytoplasma DNA in sucrose solution that insects have fed upon. In this study we combined this feeding medium method with a loop-mediated isothermal amplification (LAMP) assay to study 627 insect specimens of 11 Hemiptera taxa sampled from sites in Papua New Guinea affected by Bogia coconut syndrome (BCS). The LAMP assay detected phytoplasma DNA from the feeding solution and head tissue of insects from six taxa belonging to four families: Derbidae, Lophopidae, Flatidae and Ricaniidae. Two other taxa yielded positives only from the heads and the remainder tested negative. These results demonstrate the utility of combining single-insect feeding medium tests with LAMP assays to identify putative vectors that can be the subject of transmission tests and to better understand phytoplasma pathosystems. PMID:27786249
More than 75 percent decline over 27 years in total flying insect biomass in protected areas

PubMed Central

Sorg, Martin; Jongejans, Eelke; Siepel, Henk; Hofland, Nick; Schwan, Heinz; Stenmans, Werner; Müller, Andreas; Sumser, Hubert; Hörren, Thomas; Goulson, Dave; de Kroon, Hans

2017-01-01

Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape. PMID:29045418
Toxicological effects of pyrethroids on non-target aquatic insects.

PubMed

Antwi, Frank B; Reddy, Gadi V P

2015-11-01

The toxicological effects of pyrethroids on non-target aquatic insects are mediated by several modes of entry of pyrethroids into aquatic ecosystems, as well as the toxicological characteristics of particular pyrethroids under field conditions. Toxicokinetics, movement across the integument of aquatic insects, and the toxicodynamics of pyrethroids are discussed, and their physiological, symptomatic and ecological effects evaluated. The relationship between pyrethroid toxicity and insecticide uptake is not fully defined. Based on laboratory and field data, it is likely that the susceptibility of aquatic insects (vector and non-vector) is related to biochemical and physiological constraints associated with life in aquatic ecosystems. Understanding factors that influence aquatic insects susceptibility to pyrethroids is critical for the effective and safe use of these compounds in areas adjacent to aquatic environments. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
Freshwater ecosystems and aquatic insects: a paradox in biological invasions.

PubMed

Fenoglio, Stefano; Bonada, Núria; Guareschi, Simone; López-Rodríguez, Manuel J; Millán, Andrés; Tierno de Figueroa, J Manuel

2016-04-01

Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur. © 2016 The Author(s).
Behavioral and Neurophysiological Study of Olfactory Perception and Learning in Honeybees

PubMed Central

Sandoz, Jean Christophe

2011-01-01

The honeybee Apis mellifera has been a central insect model in the study of olfactory perception and learning for more than a century, starting with pioneer work by Karl von Frisch. Research on olfaction in honeybees has greatly benefited from the advent of a range of behavioral and neurophysiological paradigms in the Lab. Here I review major findings about how the honeybee brain detects, processes, and learns odors, based on behavioral, neuroanatomical, and neurophysiological approaches. I first address the behavioral study of olfactory learning, from experiments on free-flying workers visiting artificial flowers to laboratory-based conditioning protocols on restrained individuals. I explain how the study of olfactory learning has allowed understanding the discrimination and generalization ability of the honeybee olfactory system, its capacity to grant special properties to olfactory mixtures as well as to retain individual component information. Next, based on the impressive amount of anatomical and immunochemical studies of the bee brain, I detail our knowledge of olfactory pathways. I then show how functional recordings of odor-evoked activity in the brain allow following the transformation of the olfactory message from the periphery until higher-order central structures. Data from extra- and intracellular electrophysiological approaches as well as from the most recent optical imaging developments are described. Lastly, I discuss results addressing how odor representation changes as a result of experience. This impressive ensemble of behavioral, neuroanatomical, and neurophysiological data available in the bee make it an attractive model for future research aiming to understand olfactory perception and learning in an integrative fashion. PMID:22163215
Effects of hermetic storage on adult Sitophilus oryzae L. (Coleoptera: Curculionidae) acoustic activity patterns and mortality

USDA-ARS?s Scientific Manuscript database

Hermetic storage is of interest to farmers and warehouse managers as a method to control insect pests in small storage facilities. To develop improved understanding of effects of hermetic storage on insect pest activity and mortality over time, oxygen levels, acoustic signals, and observations of vi...
Analyzing the movement of an invasive weevil (Polydrusus sericeus) using stable Isotopes

Treesearch

Joanne Lund; Paula Marquardt; William Jr. Mattson

2010-01-01

To better understand the response of insect populations to increasing CO2 and O3, we used ratios of stable carbon isotopes (d 13C) to trace the movement of an invasive insect in mixed tree communities grown under different air quality conditions. Polydrusus sericeus is a non-native...
Transcriptional analysis of susceptible and resistant European corn borer strains and their response to Cry1F protoxin

USDA-ARS?s Scientific Manuscript database

The development of insect resistance to pesticides and biological toxins expressed by genetically modified crop plants is a serious threat to sustainable agricultural production. One of the central goals of insect resistance management (IRM) is to understand the evolution and adaptation of pest inse...
Impacts of insect biological control on soil N transformations in Tamarix-invaded ecosystems in the Great Basin, USA

USDA-ARS?s Scientific Manuscript database

Understanding the impacts of insect biological control of Tamarix spp. on soil nitrogen (N) transformations is important because changes to N supply could alter plant community succession. We investigated short-term and longer-term impacts of herbivory by the northern tamarisk beetle (Diorhabda cari...
Impacts of insect biological control on soil N transformations in Tamarix-invaded ecosystems in the Great Basin

USDA-ARS?s Scientific Manuscript database

Understanding the impacts of insect biological control of Tamarix spp. on soil nitrogen (N) transformations is important because changes to N supply could alter plant community succession. We investigated short-term and longer-term impacts of herbivory by the northern tamarisk beetle (Diorhabda cari...
Phenotypic Plasticity of Cuticular Hydrocarbon Profiles in Insects.

PubMed

Otte, Tobias; Hilker, Monika; Geiselhardt, Sven

2018-03-01

The insect integument is covered by cuticular hydrocarbons (CHCs) which provide protection against environmental stresses, but are also used for communication. Here we review current knowledge on environmental and insect-internal factors which shape phenotypic plasticity of solitary living insects, especially herbivorous ones. We address the dynamics of changes which may occur within minutes, but may also last weeks, depending on the species and conditions. Two different modes of changes are suggested, i.e. stepwise and gradual. A switch between two distinct environments (e.g. host plant switch by phytophagous insects) results in stepwise formation of two distinct adaptive phenotypes, while a gradual environmental change (e.g. temperature gradients) induces a gradual change of numerous adaptive CHC phenotypes. We further discuss the ecological and evolutionary consequences of phenotypic plasticity of insect CHC profiles by addressing the question at which conditions is CHC phenotypic plasticity beneficial. The high plasticity of CHC profiles might be a trade-off for insects using CHCs for communication. We discuss how insects cope with the challenge to produce and "understand" a highly plastic, environmentally dependent CHC pattern that conveys reliable and comprehensible information. Finally, we outline how phenotypic plasticity of CHC profiles may promote speciation in insects that rely on CHCs for mate recognition.
RNA interference: Applications and advances in insect toxicology and insect pest management.

PubMed

Kim, Young Ho; Soumaila Issa, Moustapha; Cooper, Anastasia M W; Zhu, Kun Yan

2015-05-01

Since its discovery, RNA interference (RNAi) has revolutionized functional genomic studies due to its sequence-specific nature of post-transcriptional gene silencing. In this paper, we provide a comprehensive review of the recent literature and summarize the current knowledge and advances in the applications of RNAi technologies in the field of insect toxicology and insect pest management. Many recent studies have focused on identification and validation of the genes encoding insecticide target proteins, such as acetylcholinesterases, ion channels, Bacillus thuringiensis receptors, and other receptors in the nervous system. RNAi technologies have also been widely applied to reveal the role of genes encoding cytochrome P450 monooxygenases, carboxylesterases, and glutathione S-transferases in insecticide detoxification and resistance. More recently, studies have focused on understanding the mechanism of insecticide-mediated up-regulation of detoxification genes in insects. As RNAi has already shown great potentials for insect pest management, many recent studies have also focused on host-induced gene silencing, in which several RNAi-based transgenic plants have been developed and tested as proof of concept for insect pest management. These studies indicate that RNAi is a valuable tool to address various fundamental questions in insect toxicology and may soon become an effective strategy for insect pest management. Copyright © 2015 Elsevier Inc. All rights reserved.
Using insects to drive mobile robots - hybrid robots bridge the gap between biological and artificial systems.

PubMed

Ando, Noriyasu; Kanzaki, Ryohei

2017-09-01

The use of mobile robots is an effective method of validating sensory-motor models of animals in a real environment. The well-identified insect sensory-motor systems have been the major targets for modeling. Furthermore, mobile robots implemented with such insect models attract engineers who aim to avail advantages from organisms. However, directly comparing the robots with real insects is still difficult, even if we successfully model the biological systems, because of the physical differences between them. We developed a hybrid robot to bridge the gap. This hybrid robot is an insect-controlled robot, in which a tethered male silkmoth (Bombyx mori) drives the robot in order to localize an odor source. This robot has the following three advantages: 1) from a biomimetic perspective, the robot enables us to evaluate the potential performance of future insect-mimetic robots; 2) from a biological perspective, the robot enables us to manipulate the closed-loop of an onboard insect for further understanding of its sensory-motor system; and 3) the robot enables comparison with insect models as a reference biological system. In this paper, we review the recent works regarding insect-controlled robots and discuss the significance for both engineering and biology. Copyright © 2017 Elsevier Ltd. All rights reserved.
Ionotropic Receptor-dependent moist and dry cells control hygrosensation in Drosophila.

PubMed

Knecht, Zachary A; Silbering, Ana F; Cruz, Joyner; Yang, Ludi; Croset, Vincent; Benton, Richard; Garrity, Paul A

2017-06-16

Insects use hygrosensation (humidity sensing) to avoid desiccation and, in vectors such as mosquitoes, to locate vertebrate hosts. Sensory neurons activated by either dry or moist air ('dry cells' and 'moist cells') have been described in many insects, but their behavioral roles and the molecular basis of their hygrosensitivity remain unclear. We recently reported that Drosophila hygrosensation relies on three Ionotropic Receptors (IRs) required for dry cell function: IR25a, IR93a and IR40a (Knecht et al., 2016). Here, we discover Drosophila moist cells and show that they require IR25a and IR93a together with IR68a, a conserved, but orphan IR. Both IR68a- and IR40a-dependent pathways drive hygrosensory behavior: each is important for dry-seeking by hydrated flies and together they underlie moist-seeking by dehydrated flies. These studies reveal that humidity sensing in Drosophila , and likely other insects, involves the combined activity of two molecularly related but neuronally distinct hygrosensing systems.
A host beetle pheromone regulates development and behavior in the nematode Pristionchus pacificus.

PubMed

Cinkornpumin, Jessica K; Wisidagama, Dona R; Rapoport, Veronika; Go, James L; Dieterich, Christoph; Wang, Xiaoyue; Sommer, Ralf J; Hong, Ray L

2014-10-15

Nematodes and insects are the two most speciose animal phyla and nematode-insect associations encompass widespread biological interactions. To dissect the chemical signals and the genes mediating this association, we investigated the effect of an oriental beetle sex pheromone on the development and behavior of the nematode Pristionchus pacificus. We found that while the beetle pheromone is attractive to P. pacificus adults, the pheromone arrests embryo development, paralyzes J2 larva, and inhibits exit of dauer larvae. To uncover the mechanism that regulates insect pheromone sensitivity, a newly identified mutant, Ppa-obi-1, is used to reveal the molecular links between altered attraction towards the beetle pheromone, as well as hypersensitivity to its paralyzing effects. Ppa-obi-1 encodes lipid-binding domains and reaches its highest expression in various cell types, including the amphid neuron sheath and excretory cells. Our data suggest that the beetle host pheromone may be a species-specific volatile synomone that co-evolved with necromeny.
Feeding and defecation behavior of Triatoma rubida (Uhler, 1894) (Hemiptera: Reduviidae) under laboratory conditions, and its potential role as a vector of Chagas disease in Arizona, USA.

PubMed

Reisenman, Carolina E; Gregory, Teresa; Guerenstein, Pablo G; Hildebrand, John G

2011-10-01

Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defecation behaviors of the prevalent species in southern Arizona, Triatoma rubida. We found that whereas defecation during feeding was frequent in females (93%), it was very rare in immature stages (3%), and absent in males. Furthermore, more than half of the immature insects that exhibited multiple feeding bouts (62%) defecated during interruptions of feeding, i.e., while likely on or near the host. These results indicate that T. rubida potentially could transmit T. cruzi to humans.

Exploring the Role of Habitat on the Wettability of Cicada Wings.

PubMed

Oh, Junho; Dana, Catherine E; Hong, Sungmin; Román, Jessica K; Jo, Kyoo Dong; Hong, Je Won; Nguyen, Jonah; Cropek, Donald M; Alleyne, Marianne; Miljkovic, Nenad

2017-08-16

Evolutionary pressure has pushed many extant species to develop micro/nanostructures that can significantly affect wettability and enable functionalities such as droplet jumping, self-cleaning, antifogging, antimicrobial, and antireflectivity. In particular, significant effort is underway to understand the insect wing surface structure to establish rational design tools for the development of novel engineered materials. Most studies, however, have focused on superhydrophobic wings obtained from a single insect species, in particular, the Psaltoda claripennis cicada. Here, we investigate the relationship between the spatially dependent wing wettability, topology, and droplet jumping behavior of multiple cicada species and their habitat, lifecycle, and interspecies relatedness. We focus on cicada wings of four different species: Neotibicen pruinosus, N. tibicen, Megatibicen dorsatus, and Magicicada septendecim and take a comparative approach. Using spatially resolved microgoniometry, scanning electron microscopy, atomic force microscopy, and high speed optical microscopy, we show that within cicada species, the wettability of wings is spatially homogeneous across wing cells. All four species were shown to have truncated conical pillars with widely varying length scales ranging from 50 to 400 nm in height. Comparison of the wettability revealed three cicada species with wings that are superhydrophobic (>150°) with low contact angle hysteresis (<5°), resulting in stable droplet jumping behavior. The fourth, more distantly related species (Ma. septendecim) showed only moderate hydrophobic behavior, eliminating some of the beneficial surface functional aspects for this cicada. Correlation between cicada habitat and wing wettability yielded little connection as wetter, swampy environments do not necessarily equate to higher measured wing hydrophobicity. The results, however, do point to species relatedness and reproductive strategy as a closer proxy for predicting wettability and surface structure and resultant enhanced wing surface functionality. This work not only elucidates the differences between inter- and intraspecies cicada wing topology, wettability, and water shedding behavior but also enables the development of rational design tools for the manufacture of artificial surfaces for energy and water applications.
Forest habitat conservation in Africa using commercially important insects.

PubMed

Raina, Suresh Kumar; Kioko, Esther; Zethner, Ole; Wren, Susie

2011-01-01

African forests, which host some of the world's richest biodiversity, are rapidly diminishing. The loss of flora and fauna includes economically and socially important insects. Honey bees and silk moths, grouped under commercial insects, are the source for insect-based enterprises that provide income to forest-edge communities to manage the ecosystem. However, to date, research output does not adequately quantify the impact of such enterprises on buffering forest ecosystems and communities from climate change effects. Although diseases/pests of honey bees and silk moths in Africa have risen to epidemic levels, there is a dearth of practical research that can be utilized in developing effective control mechanisms that support the proliferation of these commercial insects as pollinators of agricultural and forest ecosystems. This review highlights the critical role of commercial insects within the environmental complexity of African forest ecosystems, in modern agroindustry, and with respect to its potential contribution to poverty alleviation and pollination services. It identifies significant research gaps that exist in understanding how insects can be utilized as ecosystem health indicators and nurtured as integral tools for important socioeconomic and industrial gains.
Cross-ecosystem impacts of stream pollution reduce resource and contaminant flux to riparian food webs

USGS Publications Warehouse

Kraus, Johanna M.; Schmidt, Travis S.; Walters, David; Wanty, Richard B.; Zuellig, Robert E.; Wolf, Ruth E.

2014-01-01

The effects of aquatic contaminants are propagated across ecosystem boundaries by aquatic insects that export resources and contaminants to terrestrial food webs; however, the mechanisms driving these effects are poorly understood. We examined how emergence, contaminant concentration, and total contaminant flux by adult aquatic insects changed over a gradient of bioavailable metals in streams and how these changes affected riparian web-building spiders. Insect emergence decreased 97% over the metal gradient, whereas metal concentrations in adult insects changed relatively little. As a result, total metal exported by insects (flux) was lowest at the most contaminated streams, declining 96% among sites. Spiders were affected by the decrease in prey biomass, but not by metal exposure or metal flux to land in aquatic prey. Aquatic insects are increasingly thought to increase exposure of terrestrial consumers to aquatic contaminants, but stream metals reduce contaminant flux to riparian consumers by strongly impacting the resource linkage. Our results demonstrate the importance of understanding the contaminant-specific effects of aquatic pollutants on adult insect emergence and contaminant accumulation in adults to predict impacts on terrestrial food webs.
Made for Each Other: Ascomycete Yeasts and Insects.

PubMed

Blackwell, Meredith

2017-06-01

Fungi and insects live together in the same habitats, and many species of both groups rely on each other for success. Insects, the most successful animals on Earth, cannot produce sterols, essential vitamins, and many enzymes; fungi, often yeast-like in growth form, make up for these deficits. Fungi, however, require constantly replenished substrates because they consume the previous ones, and insects, sometimes lured by volatile fungal compounds, carry fungi directly to a similar, but fresh, habitat. Yeasts associated with insects include Ascomycota (Saccharomycotina, Pezizomycotina) and a few Basidiomycota. Beetles, homopterans, and flies are important associates of fungi, and in turn the insects carry yeasts in pits, specialized external pouches, and modified gut pockets. Some yeasts undergo sexual reproduction within the insect gut, where the genetic diversity of the population is increased, while others, well suited to their stable environment, may never mate. The range of interactions extends from dispersal of yeasts on the surface of insects (e.g., cactus- Drosophila -yeast and ephemeral flower communities, ambrosia beetles, yeasts with holdfasts) to extremely specialized associations of organisms that can no longer exist independently, as in the case of yeast-like symbionts of planthoppers. In a few cases yeast-like fungus-insect associations threaten butterflies and other species with extinction. Technical advances improve discovery and identification of the fungi but also inform our understanding of the evolution of yeast-insect symbioses, although there is much more to learn.
Phenotypic responses to microbial volatiles render a mold fungus more susceptible to insect damage.

PubMed

Caballero Ortiz, Silvia; Trienens, Monika; Pfohl, Katharina; Karlovsky, Petr; Holighaus, Gerrit; Rohlfs, Marko

2018-04-01

In decomposer systems, fungi show diverse phenotypic responses to volatile organic compounds of microbial origin (volatiles). The mechanisms underlying such responses and their consequences for the performance and ecological success of fungi in a multitrophic community context have rarely been tested explicitly. We used a laboratory-based approach in which we investigated a tripartite yeast-mold-insect model decomposer system to understand the possible influence of yeast-borne volatiles on the ability of a chemically defended mold fungus to resist insect damage. The volatile-exposed mold phenotype (1) did not exhibit protein kinase A-dependent morphological differentiation, (2) was more susceptible to insect foraging activity, and (3) had reduced insecticidal properties. Additionally, the volatile-exposed phenotype was strongly impaired in secondary metabolite formation and unable to activate "chemical defense" genes upon insect damage. These results suggest that volatiles can be ecologically important factors that affect the chemical-based combative abilities of fungi against insect antagonists and, consequently, the structure and dynamics of decomposer communities.
Resource concentration hypothesis: effect of host plant patch size on density of herbivorous insects.

PubMed

Grez, A A; González, R H

1995-09-01

The resource concentration hypothesis (Root 1973) predicts that specialist herbivorous insects should be more abundant in large patches of host plants, because the insects are more likely to find and stay longer in those patches. Between August 1989 and January 1990 we experimentally tested Root's hypothesis by analyzing the numerical response of four species of herbivorous insects associated with patches of 4, 16, 64 and 225 cabbage plants, Brassica oleracea var. capitata. In addition, we studied the colonization of patches by adults of Plutella xylostella (L.) (Lepidoptera: Plutellidae), and the migration of their larvae in patches of different sizes. No herbivorous insect densities differed significantly with patch size. Adults of P. xylostella colonized all kind of patches equally. Larvae did not migrate between patches, and their disappearance rate did not differ between patches. The resource concentration hypothesis is organism-dependent, being a function of the adult and juvenile herbivore dispersal behavior in relation to the spatial scale of patchiness.
United States Department of Agriculture-Agricultural Research Service: advances in the molecular genetic analysis of insects and their application to pest management.

PubMed

Handler, Alfred M; Beeman, Richard W

2003-01-01

USDA-ARS scientists have made important contributions to the molecular genetic analysis of agriculturally important insects, and have been in the forefront of using this information for the development of new pest management strategies. Advances have been made in the identification and analysis of genetic systems involved in insect development, reproduction and behavior which enable the identification of new targets for control, as well as the development of highly specific insecticidal products. Other studies have been on the leading edge of developing gene transfer technology to better elucidate these biological processes though functional genomics and to develop new transgenic strains for biological control. Important contributions have also been made to the development and use of molecular markers and methodologies to identify and track insect populations. The use of molecular genetic technology and strategies will become increasingly important to pest management as genomic sequencing information becomes available from important pest insects, their targets and other associated organisms.
Intrinsic worker mortality depends on behavioral caste and the queens' presence in a social insect

NASA Astrophysics Data System (ADS)

Kohlmeier, Philip; Negroni, Matteo Antoine; Kever, Marion; Emmling, Stefanie; Stypa, Heike; Feldmeyer, Barbara; Foitzik, Susanne

2017-04-01

According to the classic life history theory, selection for longevity depends on age-dependant extrinsic mortality and fecundity. In social insects, the common life history trade-off between fecundity and longevity appears to be reversed, as the most fecund individual, the queen, often exceeds workers in lifespan several fold. But does fecundity directly affect intrinsic mortality also in social insect workers? And what is the effect of task on worker mortality? Here, we studied how social environment and behavioral caste affect intrinsic mortality of ant workers. We compared worker survival between queenless and queenright Temnothorax longispinosus nests and demonstrate that workers survive longer under the queens' absence. Temnothorax ant workers fight over reproduction when the queen is absent and dominant workers lay eggs. Worker fertility might therefore increase lifespan, possibly due to a positive physiological link between fecundity and longevity, or better care for fertile workers. In social insects, division of labor among workers is age-dependant with young workers caring for the brood and old ones going out to forage. We therefore expected nurses to survive longer than foragers, which is what we found. Surprisingly, inactive inside workers showed a lower survival than nurses but comparable to that of foragers. The reduced longevity of inactive workers could be due to them being older than the nurses, or due to a positive effect of activity on lifespan. Overall, our study points to behavioral caste-dependent intrinsic mortality rates and a positive association between fertility and longevity not only in queens but also in ant workers.
Flight performance of bumble bee as a possible pollinator in space agriculture under partial gravity

NASA Astrophysics Data System (ADS)

Yamashita, Masamichi; Hashimoto, Hirofumi; Mitsuhata, Masahiro; Sasaki, Masami; Space Agriculture Task Force, J.

Space agriculture is an advanced life support concept for habitation on extraterrestrial bodies based on biological and ecological function. Flowering plant species are core member of space agriculture to produce food and revitalize air and water. Selection of crop plant species is made on the basis of nutritional requirements to maintain healthy life of space crew. Species selected for space agriculture have several mode of reproduction. For some of plant species, insect pollination is effective to increase yield and quality of food. In terrestrial agriculture, bee is widely introduced to pollinate flower. For pollinator insect on Mars, working environment is different from Earth. Magnitude of gravity is 0.38G on Mars surface. In order to confirm feasibility of insect pollination for space agriculture, capability of flying pollinator insect under such exotic condition should be examined. Even bee does not possess evident gravity sensory system, gravity dominates flying performance and behavior. During flight or hovering, lifting force produced by wing beat sustains body weight, which is the product of body mass and gravitational acceleration. Flying behavior of bumble bee, Bombus ignitus, was documented under partial or micro-gravity produced by parabolic flight of jet plane. Flying behavior at absence of gravity differed from that under normal gravity. Ability of bee to fly under partial gravity was examined at the level of Mars, Moon and the less, to determine the threshold level of gravity for bee flying maneuver. Adaptation process of bee flying under different gravity level was evaluated as well by successive documentation of parabolic flight experiment.
Motion as a source of environmental information: a fresh view on biological motion computation by insect brains

PubMed Central

Egelhaaf, Martin; Kern, Roland; Lindemann, Jens Peter

2014-01-01

Despite their miniature brains insects, such as flies, bees and wasps, are able to navigate by highly erobatic flight maneuvers in cluttered environments. They rely on spatial information that is contained in the retinal motion patterns induced on the eyes while moving around (“optic flow”) to accomplish their extraordinary performance. Thereby, they employ an active flight and gaze strategy that separates rapid saccade-like turns from translatory flight phases where the gaze direction is kept largely constant. This behavioral strategy facilitates the processing of environmental information, because information about the distance of the animal to objects in the environment is only contained in the optic flow generated by translatory motion. However, motion detectors as are widespread in biological systems do not represent veridically the velocity of the optic flow vectors, but also reflect textural information about the environment. This characteristic has often been regarded as a limitation of a biological motion detection mechanism. In contrast, we conclude from analyses challenging insect movement detectors with image flow as generated during translatory locomotion through cluttered natural environments that this mechanism represents the contours of nearby objects. Contrast borders are a main carrier of functionally relevant object information in artificial and natural sceneries. The motion detection system thus segregates in a computationally parsimonious way the environment into behaviorally relevant nearby objects and—in many behavioral contexts—less relevant distant structures. Hence, by making use of an active flight and gaze strategy, insects are capable of performing extraordinarily well even with a computationally simple motion detection mechanism. PMID:25389392
Motion as a source of environmental information: a fresh view on biological motion computation by insect brains.

PubMed

Egelhaaf, Martin; Kern, Roland; Lindemann, Jens Peter

2014-01-01

Despite their miniature brains insects, such as flies, bees and wasps, are able to navigate by highly erobatic flight maneuvers in cluttered environments. They rely on spatial information that is contained in the retinal motion patterns induced on the eyes while moving around ("optic flow") to accomplish their extraordinary performance. Thereby, they employ an active flight and gaze strategy that separates rapid saccade-like turns from translatory flight phases where the gaze direction is kept largely constant. This behavioral strategy facilitates the processing of environmental information, because information about the distance of the animal to objects in the environment is only contained in the optic flow generated by translatory motion. However, motion detectors as are widespread in biological systems do not represent veridically the velocity of the optic flow vectors, but also reflect textural information about the environment. This characteristic has often been regarded as a limitation of a biological motion detection mechanism. In contrast, we conclude from analyses challenging insect movement detectors with image flow as generated during translatory locomotion through cluttered natural environments that this mechanism represents the contours of nearby objects. Contrast borders are a main carrier of functionally relevant object information in artificial and natural sceneries. The motion detection system thus segregates in a computationally parsimonious way the environment into behaviorally relevant nearby objects and-in many behavioral contexts-less relevant distant structures. Hence, by making use of an active flight and gaze strategy, insects are capable of performing extraordinarily well even with a computationally simple motion detection mechanism.
How plant neighborhood composition influences herbivory: Testing four mechanisms of associational resistance and susceptibility

PubMed Central

2017-01-01

Neighboring plants can decrease or increase each other’s likelihood of damage from herbivores through associational resistance or susceptibility, respectively. Associational effects (AE) can transpire through changes in herbivore or plant traits that affect herbivore movement, densities, and feeding behaviors to ultimately affect plant damage. While much work has focused on understanding the mechanisms that underlie associational effects, we know little about how these mechanisms are influenced by neighborhood composition, i.e., plant density or relative frequency which is necessary to make predictions about when AE should occur in nature. Using a series of field and greenhouse experiments, I examined how plant density and relative frequency affected plant damage to Solanum carolinense and four mechanisms that underlie AE; (i) accumulation of insect herbivores and arthropod predators, (ii) microclimate conditions, (iii) plant resistance, and (iv) specialist herbivore preference. I found a positive relationship between S. carolinense damage and the relative frequency of a non-focal neighbor (Solidago altissima) and all four AE mechanisms were influenced by one or multiple neighborhood components. Frequency-dependence in S. carolinense damage is most likely due to greater generalist herbivore load on S. carolinense (through spillover from S. altissima) with microclimate variables, herbivore preference, predation pressures, and plant resistance having relatively weaker effects. Associational effects may have long-term consequences for these two plant species during plant succession and understanding context-dependent herbivory has insect pest management implication for other plant species in agriculture and forestry. PMID:28486538
Visual control of navigation in insects and its relevance for robotics.

PubMed

Srinivasan, Mandyam V

2011-08-01

Flying insects display remarkable agility, despite their diminutive eyes and brains. This review describes our growing understanding of how these creatures use visual information to stabilize flight, avoid collisions with objects, regulate flight speed, detect and intercept other flying insects such as mates or prey, navigate to a distant food source, and orchestrate flawless landings. It also outlines the ways in which these insights are now being used to develop novel, biologically inspired strategies for the guidance of autonomous, airborne vehicles. Copyright © 2011 Elsevier Ltd. All rights reserved.
Studies on African Trypanosomiasis and Leishmaniasis. Volume 2.

DTIC Science & Technology

1984-07-01

8217 flies with heavy infections in their anterior midguts transmit parasites when they feed is not known, but the biting behavior of such insects is not the...of cutaneous leishmaniasis by contaminated mouthparts of the 4 hamsters developed a culture-positive nose lesion of both biting and nonbiting insects ...the cibarium, an experiment predicated on the hypothesis that such infections interfer with cibarial blood meal-sensing receptors , thereby changing
Responses of aquatic insects to Cu and Zn in stream microcosms: understanding differences between single species tests and field responses.

PubMed

Clements, William H; Cadmus, Pete; Brinkman, Stephen F

2013-07-02

Field surveys of metal-contaminated streams suggest that some aquatic insects, particularly mayflies (Ephemeroptera) and stoneflies (Plecoptera), are highly sensitive to metals. However, results of single species toxicity tests indicate these organisms are quite tolerant, with LC50 values often several orders of magnitude greater than those obtained using standard test organisms (e.g., cladocerans and fathead minnows). Reconciling these differences is a critical research need, particularly since water quality criteria for metals are based primarily on results of single species toxicity tests. In this research we provide evidence based on community-level microcosm experiments to support the hypothesis that some aquatic insects are highly sensitive to metals. We present results of three experiments that quantified effects of Cu and Zn, alone and in combination, on stream insect communities. EC50 values, defined as the metal concentration that reduced abundance of aquatic insects by 50%, were several orders of magnitude lower than previously published values obtained from single species tests. We hypothesize that the short duration of laboratory toxicity tests and the failure to evaluate effects of metals on sensitive early life stages are the primary factors responsible for unrealistically high LC50 values in the literature. We also observed that Cu alone was significantly more toxic to aquatic insects than the combination of Cu and Zn, despite the fact that exposure concentrations represented theoretically similar toxicity levels. Our results suggest that water quality criteria for Zn were protective of most aquatic insects, whereas Cu was highly toxic to some species at concentrations near water quality criteria. Because of the functional significance of aquatic insects in stream ecosystems and their well-established importance as indicators of water quality, reconciling differences between field and laboratory responses and understanding the mechanisms responsible for variation in sensitivity among metals and metal mixtures is of critical importance.
Divergent mating patterns and a unique mode of external sperm transfer in Zoraptera: an enigmatic group of pterygote insects

NASA Astrophysics Data System (ADS)

Dallai, R.; Gottardo, M.; Mercati, D.; Machida, R.; Mashimo, Y.; Matsumura, Y.; Beutel, R. G.

2013-06-01

A remarkable external sperm transfer is described for the first time in a species of a group of winged insects (Pterygota), the enigmatic Zoraptera. Mating and sperm transfer of two species of the order were examined in detail, documented, and compared with each other and with patterns described for other species belonging to the order. The behavior differs strikingly in Zorotypus impolitus and Zorotypus magnicaudelli. A copula is performed by males and females of the latter, as it is also the case in other zorapteran species and generally in pterygote insects. In striking contrast to this, males of Z. impolitus do not copulate but deposit small (100 μm in diameter) spermatophores externally on the abdomen of the female. Each spermatophore contains only one giant spermatozoon (3 mm long and 3 μm wide), a unique feature in the entire Hexapoda. External sperm transfer in Pterygota is a highly unusual case of evolutionary reversal. The very small relict group Zoraptera displays a uniform general morphology but exhibits very different reproductive structures and patterns of mating behavior. This may be an extreme form of a more general situation in insects, with a specific form of selection resulting in an accelerated rate of evolution in the reproductive system.
Genomic Features of the Damselfly Calopteryx splendens Representing a Sister Clade to Most Insect Orders

PubMed Central

Ioannidis, Panagiotis; Simao, Felipe A.; Waterhouse, Robert M.; Manni, Mosè; Seppey, Mathieu; Robertson, Hugh M.; Misof, Bernhard; Niehuis, Oliver

2017-01-01

Insects comprise the most diverse and successful animal group with over one million described species that are found in almost every terrestrial and limnic habitat, with many being used as important models in genetics, ecology, and evolutionary research. Genome sequencing projects have greatly expanded the sampling of species from many insect orders, but genomic resources for species of certain insect lineages have remained relatively limited to date. To address this paucity, we sequenced the genome of the banded demoiselle, Calopteryx splendens, a damselfly (Odonata: Zygoptera) belonging to Palaeoptera, the clade containing the first winged insects. The 1.6 Gbp C. splendens draft genome assembly is one of the largest insect genomes sequenced to date and encodes a predicted set of 22,523 protein-coding genes. Comparative genomic analyses with other sequenced insects identified a relatively small repertoire of C. splendens detoxification genes, which could explain its previously noted sensitivity to habitat pollution. Intriguingly, this repertoire includes a cytochrome P450 gene not previously described in any insect genome. The C. splendens immune gene repertoire appears relatively complete and features several genes encoding novel multi-domain peptidoglycan recognition proteins. Analysis of chemosensory genes revealed the presence of both gustatory and ionotropic receptors, as well as the insect odorant receptor coreceptor gene (OrCo) and at least four partner odorant receptors (ORs). This represents the oldest known instance of a complete OrCo/OR system in insects, and provides the molecular underpinning for odonate olfaction. The C. splendens genome improves the sampling of insect lineages that diverged before the radiation of Holometabola and offers new opportunities for molecular-level evolutionary, ecological, and behavioral studies. PMID:28137743
SPATIAL AGGREGATION IN A FOREST FLOOR INSECT DEPENDS ON SEASONAL CONGREGATION AND SCATTERING EFFECTS OF PREDATORS

EPA Science Inventory

Spatial aggregations arising from gregarious behavior are common in nature and have important implications for population dynamics, community stability, and conservation. However, the translation of aggregation behaviors into emergent properties of populations and communities de...
A Simple Flight Mill for the Study of Tethered Flight in Insects.

PubMed

Attisano, Alfredo; Murphy, James T; Vickers, Andrew; Moore, Patricia J

2015-12-10

Flight in insects can be long-range migratory flights, intermediate-range dispersal flights, or short-range host-seeking flights. Previous studies have shown that flight mills are valuable tools for the experimental study of insect flight behavior, allowing researchers to examine how factors such as age, host plants, or population source can influence an insects' propensity to disperse. Flight mills allow researchers to measure components of flight such as speed and distance flown. Lack of detailed information about how to build such a device can make their construction appear to be prohibitively complex. We present a simple and relatively inexpensive flight mill for the study of tethered flight in insects. Experimental insects can be tethered with non-toxic adhesives and revolve around an axis by means of a very low friction magnetic bearing. The mill is designed for the study of flight in controlled conditions as it can be used inside an incubator or environmental chamber. The strongest points are the very simple electronic circuitry, the design that allows sixteen insects to fly simultaneously allowing the collection and analysis of a large number of samples in a short time and the potential to use the device in a very limited workspace. This design is extremely flexible, and we have adjusted the mill to accommodate different species of insects of various sizes.
Air pollutants degrade floral scents and increase insect foraging times

NASA Astrophysics Data System (ADS)

Fuentes, Jose D.; Chamecki, Marcelo; Roulston, T.'ai; Chen, Bicheng; Pratt, Kenneth R.

2016-09-01

Flowers emit mixtures of scents that mediate plant-insect interactions such as attracting insect pollinators. Because of their volatile nature, however, floral scents readily react with ozone, nitrate radical, and hydroxyl radical. The result of such reactions is the degradation and the chemical modification of scent plumes downwind of floral sources. Large Eddy Simulations (LES) are developed to investigate dispersion and chemical degradation and modification of floral scents due to reactions with ozone, hydroxyl radical, and nitrate radical within the atmospheric surface layer. Impacts on foraging insects are investigated by utilizing a random walk model to simulate insect search behavior. Results indicate that even moderate air pollutant levels (e.g., ozone mixing ratios greater than 60 parts per billion on a per volume basis, ppbv) substantially degrade floral volatiles and alter the chemical composition of released floral scents. As a result, insect success rates of locating plumes of floral scents were reduced and foraging times increased in polluted air masses due to considerable degradation and changes in the composition of floral scents. Results also indicate that plant-pollinator interactions could be sensitive to changes in floral scent composition, especially if insects are unable to adapt to the modified scentscape. The increase in foraging time could have severe cascading and pernicious impacts on the fitness of foraging insects by reducing the time devoted to other necessary tasks.

Indirect plant defense against insect herbivores: a review.

PubMed

Aljbory, Zainab; Chen, Ming-Shun

2018-02-01

Plants respond to herbivore attack by launching 2 types of defenses: direct defense and indirect defense. Direct defense includes all plant traits that increase the resistance of host plants to insect herbivores by affecting the physiology and/or behavior of the attackers. Indirect defense includes all traits that by themselves do not have significant direct impact on the attacking herbivores, but can attract natural enemies of the herbivores and thus reduce plant loss. When plants recognize herbivore-associated elicitors, they produce and release a blend of volatiles that can attract predators, parasites, and other natural enemies. Known herbivore-associated elicitors include fatty acid-amino acid conjugates, sulfur-containing fatty acids, fragments of cell walls, peptides, esters, and enzymes. Identified plant volatiles include terpenes, nitrogenous compounds, and indoles. In addition, constitive traits including extrafloral nectars, food bodies, and domatia can be further induced to higher levels and attract natural enemies as well as provide food and shelter to carnivores. A better understanding of indirect plant defense at global and componential levels via advanced high throughput technologies may lead to utilization of indirect defense in suppression of herbivore damage to plants. © 2016 Institute of Zoology, Chinese Academy of Sciences.
Toward understanding the mechanics of hovering in insects, hummingbirds and bats

NASA Astrophysics Data System (ADS)

Vejdani, Hamid; Boerma, David; Swartz, Sharon; Breuer, Kenneth

2016-11-01

We present results on the dynamical characteristics of two different mechanisms of hovering, corresponding to the behavior of hummingbirds and bats. Using a Lagrangian formulation, we have developed a dynamical model of a body (trunk) and two rectangular wings. The trunk has 3 degrees of freedom (x, z and pitch angle) and each wing has 3 modes of actuation: flapping, pronation/supination, and wingspan extension/flexion (only present for bats). Wings can be effectively massless (hummingbird and insect wings) or relatively massive (important in the case of bats). The aerodynamic drag and lift forces are calculated using a quasi-steady blade-element model. The regions of state space in which hovering is possible are computed by over an exhaustive range of parameters. The effect of wing mass is to shrink the phase space available for viable hovering and, in general, to require higher wingbeat frequency. Moreover, by exploring hovering energy requirements, we find that the pronation angle of the wings also plays a critical role. For bats, who have relatively heavy wings, we show wing extension and flexion is critical in order to maintain a plausible hovering posture with reasonable power requirements. Comparisons with biological data show good agreement with our model predictions.
A computational model of conditioning inspired by Drosophila olfactory system.

PubMed

Faghihi, Faramarz; Moustafa, Ahmed A; Heinrich, Ralf; Wörgötter, Florentin

2017-03-01

Recent studies have demonstrated that Drosophila melanogaster (briefly Drosophila) can successfully perform higher cognitive processes including second order olfactory conditioning. Understanding the neural mechanism of this behavior can help neuroscientists to unravel the principles of information processing in complex neural systems (e.g. the human brain) and to create efficient and robust robotic systems. In this work, we have developed a biologically-inspired spiking neural network which is able to execute both first and second order conditioning. Experimental studies demonstrated that volume signaling (e.g. by the gaseous transmitter nitric oxide) contributes to memory formation in vertebrates and invertebrates including insects. Based on the existing knowledge of odor encoding in Drosophila, the role of retrograde signaling in memory function, and the integration of synaptic and non-synaptic neural signaling, a neural system is implemented as Simulated fly. Simulated fly navigates in a two-dimensional environment in which it receives odors and electric shocks as sensory stimuli. The model suggests some experimental research on retrograde signaling to investigate neural mechanisms of conditioning in insects and other animals. Moreover, it illustrates a simple strategy to implement higher cognitive capabilities in machines including robots. Copyright © 2016 Elsevier Ltd. All rights reserved.
Orchid sexual deceit provokes ejaculation.

PubMed

Gaskett, A C; Winnick, C G; Herberstein, M E

2008-06-01

Sexually deceptive orchids lure pollinators by mimicking female insects. Male insects fooled into gripping or copulating with orchids unwittingly transfer the pollinia. The effect of deception on pollinators has been considered negligible, but we show that pollinators may suffer considerable costs. Insects pollinating Australian tongue orchids (Cryptostylis species) frequently ejaculate and waste copious sperm. The costs of sperm wastage could select for pollinator avoidance of orchids, thereby driving and maintaining sexual deception via antagonistic coevolution or an arms race between pollinator learning and escalating orchid mimicry. However, we also show that orchid species provoking such extreme pollinator behavior have the highest pollination success. How can deception persist, given the costs to pollinators? Sexually-deceptive-orchid pollinators are almost exclusively solitary and haplodiploid species. Therefore, female insects deprived of matings by orchid deception could still produce male offspring, which may even enhance orchid pollination.
Mixed xylem and phloem sap ingestion in sheath-feeders as normal dietary behavior: Evidence from the leafhopper Scaphoideus titanus.

PubMed

Chuche, Julien; Sauvion, Nicolas; Thiéry, Denis

2017-10-01

In phytophagous piercing-sucking insects, salivary sheath-feeding species are often described as xylem- or phloem-sap feeding specialists. Because these two food sources have very different characteristics, two feeding tactics are often associated with this supposed specialization. Studying the feeding behavior of insects provides substantial information on their biology, ecology, and evolution. Furthermore, study of feeding behavior is of primary importance to elucidate the transmission ability of insects that act as vectors of plant pathogens. In this study, we compared the durations of ingestion performed in xylem versus phloem by a leafhopper species, Scaphoideus titanus Ball, 1932. This was done by characterizing and statistically analyzing electrical signals recorded using the electropenetrography technique, derived from the feeding behaviors of males and females. We identified three groups of S. titanus based on their feeding behavior: 1) a group that reached the phloem quickly and probed for a longer time in phloem tissue than the other groups, 2) a group that reached the xylem quickly and probed for a longer time in xylem tissue than the other groups, and 3) a group where individuals did not ingest much sap. In addition, the numbers and durations of waveforms representing ingestion of xylem and phloem saps differed significantly depending on the sex of the leafhopper, indicating that the two sexes exhibit different feeding behaviors. Males had longer phloem ingestion events than did females, which indicates that males are greater phloem feeders than females. These differences are discussed, specifically in relation to hypotheses about evolution of sap feeding and phytoplasma transmission from plant to plant. Copyright © 2017 Elsevier Ltd. All rights reserved.
Artificial diet sandwiches reveal sub-social behavior in the coffee berry borer Hypothenemus hampei (Coleoptera: Scolytinae)

USDA-ARS?s Scientific Manuscript database

A diet sandwich, consisting of coffee berry borer artificial diet within two glass panes, has been developed to elucidate the behavior of the coffee berry borer, an insect that in nature spends most of its life cycle inside the coffee berry. Various types of behavior have been observed for the first...
Detectors for polarized skylight in insects: a survey of ommatidial specializations in the dorsal rim area of the compound eye.

PubMed

Labhart, T; Meyer, E P

1999-12-15

Apart from the sun, the polarization pattern of the sky offers insects a reference for visual compass orientation. Using behavioral experiments, it has been shown in a few insect species (field crickets, honey bees, desert ants, and house flies) that the detection of the oscillation plane of polarized skylight is mediated exclusively by a group of specialized ommatidia situated at the dorsal rim of the compound eye (dorsal rim area). The dorsal rim ommatidia of these species share a number physiological properties that make them especially suitable for polarization vision: each ommatidium contains two sets of homochromatic, strongly polarization-sensitive photoreceptors with orthogonally-arranged analyzer orientations. The physiological specialization of the dorsal rim area goes along with characteristic changes in ommatidial structure, providing actual anatomical hallmarks of polarized skylight detection, that are readily detectable in histological sections of compound eyes. The presence of anatomically specialized dorsal rim ommatidia in many other insect species belonging to a wide range of different orders indicates that polarized skylight detection is a common visual function in insects. However, fine-structural disparities in the design of dorsal rim ommatidia of different insect groups indicate that polarization vision arose polyphyletically in the insects. Copyright 1999 Wiley-Liss, Inc.
Analysis of spatial density dependence in gypsy moth mortality

Treesearch

Andrew Liebhold; Joseph S. Elkinton

1991-01-01

The gypsy moth is perhaps the most widely studied forest insect in the world and much of this research has focused on various aspects of population dynamics. But despite this voluminous amount of research we still lack a good understanding of which, if any, natural enemy species regulate gypsy moth populations. The classical approach to analyzing insect population...
Opposite Actions of Dopamine on Aversive and Appetitive Memories in the Crab

ERIC Educational Resources Information Center

Klappenbach, Martin; Maldonado, Hector; Locatelli, Fernando; Kaczer, Laura

2012-01-01

The understanding of how the reinforcement is represented in the central nervous system during memory formation is a current issue in neurobiology. Several studies in insects provide evidence of the instructive role of biogenic amines during the learning and memory process. In insects it was widely accepted that dopamine (DA) mediates aversive…
In-field volatile collection and analysis method utilizing a portable GC-MS: in situ headspace analysis of intact and damaged yellow starthistle flower heads

USDA-ARS?s Scientific Manuscript database

Introduction: Understanding the complex chemical signaling of plants and insects is an important component of chemical ecology. Accordingly, the collection of chemical cues from plants in their normal environment is integral to elucidation of multifaceted plant-insect communications. Often times rem...
Detoxifying symbiosis: microbe-mediated detoxification of phytotoxins and pesticides in insects.

PubMed

Itoh, Hideomi; Tago, Kanako; Hayatsu, Masahito; Kikuchi, Yoshitomo

2018-04-12

Covering: up to 2018Insects live in a world full of toxic compounds such as plant toxins and manmade pesticides. To overcome the effects of these toxins, herbivorous insects have evolved diverse, elaborate mechanisms of resistance, such as toxin avoidance, target-site alteration, and detoxification. These resistance mechanisms are thought to be encoded by the insects' own genomes, and in many cases, this holds true. However, recent omics analyses, in conjunction with classic culture-dependent analyses, have revealed that a number of insects possess specific gut microorganisms, some of which significantly contribute to resistance against phytotoxins and pesticides by degrading such chemical compounds. Here, we review recent advances in our understanding on the symbiont-mediated degradation of natural and artificial toxins, with a special emphasis on their underlying genetic basis, focus on the importance of environmental microbiota as a resource of toxin-degrading microorganisms, and discuss the ecological and evolutionary significance of these symbiotic associations.
The need for higher-order averaging in the stability analysis of hovering, flapping-wing flight.

PubMed

Taha, Haithem E; Tahmasian, Sevak; Woolsey, Craig A; Nayfeh, Ali H; Hajj, Muhammad R

2015-01-05

Because of the relatively high flapping frequency associated with hovering insects and flapping wing micro-air vehicles (FWMAVs), dynamic stability analysis typically involves direct averaging of the time-periodic dynamics over a flapping cycle. However, direct application of the averaging theorem may lead to false conclusions about the dynamics and stability of hovering insects and FWMAVs. Higher-order averaging techniques may be needed to understand the dynamics of flapping wing flight and to analyze its stability. We use second-order averaging to analyze the hovering dynamics of five insects in response to high-amplitude, high-frequency, periodic wing motion. We discuss the applicability of direct averaging versus second-order averaging for these insects.
Factors affecting the sticking of insects on modified aircraft wings

NASA Technical Reports Server (NTRS)

Yi, O.; Chitsaz-Z, M. R.; Eiss, N. S.; Wightman, J. P.

1987-01-01

Past studies have shown that the surface energy of a polymer coating has an important effect on the sticking of insects to the surface. However, mechanical properties of polymer coatings such as elasticity may also be important. A further study is suggested using polymer coatings of known surface energy and modulus so that a better understanding of the mechanism of the sticking of insects to surfaces can be achieved. As the first step for the study, surface analysis and road tests were performed using elastomers having different energies and different moduli. The number of insects sticking to each elastomer was counted and compared from sample to sample and with a control (aluminum). An average height moment was also calculated and comparisons made between samples.
[Genetic mechanism and evolutionary significance of the origin of parthenogenetic insects].

PubMed

Wang, Cheng-Ye

2011-12-01

There is a high proportion of parthenogenesis in insecta, and the parthenogenetic potential of insects is an important but often ignored threaten factor for the agricultural and forestry production. The maintenance of parthenogenetic species is a puzzling issue in evolutionary biology. In recent years, although the cellular mechanisms during parthenogenesis in some species have been well studied, the underlying genetic mechanisms that cause the switch from sexual reproduction to parthenogenesis have not been defined. While, understanding the genetic mechanism and evolutionary significance of the origin of parthenogenetic insects is crucial for preventing the pests in agricultural and forestry production. Here we summarized recent studies aimed at identifying the underlying genetic mechanism of parthenogenesis in insects, and briefly discussed its potential application in this filed.
The Leafhoppers: Anatomy, Physiology and Behavior of Feeding and Its Sensory Mediation

USDA-ARS?s Scientific Manuscript database

The present book contains chapters summarizing all major aspects of the biology of leafhoppers (family Cicadellidae), among the most numerous and important insect pests in the world. Major chapter topics discussed include internal and external morphology, physiology, behavior, reproduction, taxonom...
Effects of immunostimulation on social behavior, chemical communication and genome-wide gene expression in honey bee workers (Apis mellifera)

PubMed Central

2012-01-01

Background Social insects, such as honey bees, use molecular, physiological and behavioral responses to combat pathogens and parasites. The honey bee genome contains all of the canonical insect immune response pathways, and several studies have demonstrated that pathogens can activate expression of immune effectors. Honey bees also use behavioral responses, termed social immunity, to collectively defend their hives from pathogens and parasites. These responses include hygienic behavior (where workers remove diseased brood) and allo-grooming (where workers remove ectoparasites from nestmates). We have previously demonstrated that immunostimulation causes changes in the cuticular hydrocarbon profiles of workers, which results in altered worker-worker social interactions. Thus, cuticular hydrocarbons may enable workers to identify sick nestmates, and adjust their behavior in response. Here, we test the specificity of behavioral, chemical and genomic responses to immunostimulation by challenging workers with a panel of different immune stimulants (saline, Sephadex beads and Gram-negative bacteria E. coli). Results While only bacteria-injected bees elicited altered behavioral responses from healthy nestmates compared to controls, all treatments resulted in significant changes in cuticular hydrocarbon profiles. Immunostimulation caused significant changes in expression of hundreds of genes, the majority of which have not been identified as members of the canonical immune response pathways. Furthermore, several new candidate genes that may play a role in cuticular hydrocarbon biosynthesis were identified. Effects of immune challenge expression of several genes involved in immune response, cuticular hydrocarbon biosynthesis, and the Notch signaling pathway were confirmed using quantitative real-time PCR. Finally, we identified common genes regulated by pathogen challenge in honey bees and other insects. Conclusions These results demonstrate that honey bee genomic responses to immunostimulation are substantially broader than the previously identified canonical immune response pathways, and may mediate the behavioral changes associated with social immunity by orchestrating changes in chemical signaling. These studies lay the groundwork for future research into the genomic responses of honey bees to native honey bee parasites and pathogens. PMID:23072398
Effects of immunostimulation on social behavior, chemical communication and genome-wide gene expression in honey bee workers (Apis mellifera).

PubMed

Richard, Freddie-Jeanne; Holt, Holly L; Grozinger, Christina M

2012-10-16

Social insects, such as honey bees, use molecular, physiological and behavioral responses to combat pathogens and parasites. The honey bee genome contains all of the canonical insect immune response pathways, and several studies have demonstrated that pathogens can activate expression of immune effectors. Honey bees also use behavioral responses, termed social immunity, to collectively defend their hives from pathogens and parasites. These responses include hygienic behavior (where workers remove diseased brood) and allo-grooming (where workers remove ectoparasites from nestmates). We have previously demonstrated that immunostimulation causes changes in the cuticular hydrocarbon profiles of workers, which results in altered worker-worker social interactions. Thus, cuticular hydrocarbons may enable workers to identify sick nestmates, and adjust their behavior in response. Here, we test the specificity of behavioral, chemical and genomic responses to immunostimulation by challenging workers with a panel of different immune stimulants (saline, Sephadex beads and Gram-negative bacteria E. coli). While only bacteria-injected bees elicited altered behavioral responses from healthy nestmates compared to controls, all treatments resulted in significant changes in cuticular hydrocarbon profiles. Immunostimulation caused significant changes in expression of hundreds of genes, the majority of which have not been identified as members of the canonical immune response pathways. Furthermore, several new candidate genes that may play a role in cuticular hydrocarbon biosynthesis were identified. Effects of immune challenge expression of several genes involved in immune response, cuticular hydrocarbon biosynthesis, and the Notch signaling pathway were confirmed using quantitative real-time PCR. Finally, we identified common genes regulated by pathogen challenge in honey bees and other insects. These results demonstrate that honey bee genomic responses to immunostimulation are substantially broader than the previously identified canonical immune response pathways, and may mediate the behavioral changes associated with social immunity by orchestrating changes in chemical signaling. These studies lay the groundwork for future research into the genomic responses of honey bees to native honey bee parasites and pathogens.
Root-feeding insects and their interactions with organisms in the rhizosphere.

PubMed

Johnson, Scott N; Rasmann, Sergio

2015-01-07

Root-feeding insects are an increasingly studied group of herbivores whose impacts on plant productivity and ecosystem processes are widely recognized. Their belowground habitat has hitherto hindered our understanding of how they interact with other organisms that share the rhizosphere. A surge in research in this area has now shed light on these interactions. We review key interactions between root-feeding insects and other rhizospheric organisms, including beneficial plant microbes (mycorrhizal fungi, nitrogen-fixing bacteria), antagonists/pathogens of root herbivores (arthropod predators, entomopathogenic nematodes/fungi, and bacterial pathogens), competitors, symbiotic microbes, and detritivores. Patterns for these interactions are emerging. The negative impacts of mycorrhizal fungi on root herbivores, for instance, raise the intriguing prospect that these fungi could be used for pest management. Moreover, a better understanding of symbiotic microbes in root herbivores, especially those underpinning digestion, could prove useful in industries such as biofuel production.
Towards an integrated understanding of gut microbiota using insects as model systems.

PubMed

Pernice, Mathieu; Simpson, Stephen J; Ponton, Fleur

2014-10-01

Metazoans form symbioses with microorganisms that synthesize essential nutritional compounds and increase their efficiency to digest and absorb nutrients. Despite the growing awareness that microbes within the gut play key roles in metabolism, health and development of metazoans, symbiotic relationships within the gut are far from fully understood. Insects, which generally harbor a lower microbial diversity than vertebrates, have recently emerged as potential model systems to study these interactions. In this review, we give a brief overview of the characteristics of the gut microbiota in insects in terms of low diversity but high variability at intra- and interspecific levels and we investigate some of the ecological and methodological factors that might explain such variability. We then emphasize how studies integrating an array of techniques and disciplines have the potential to provide new understanding of the biology of this micro eco-system. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.
Computer-assisted 3D kinematic analysis of all leg joints in walking insects.

PubMed

Bender, John A; Simpson, Elaine M; Ritzmann, Roy E

2010-10-26

High-speed video can provide fine-scaled analysis of animal behavior. However, extracting behavioral data from video sequences is a time-consuming, tedious, subjective task. These issues are exacerbated where accurate behavioral descriptions require analysis of multiple points in three dimensions. We describe a new computer program written to assist a user in simultaneously extracting three-dimensional kinematics of multiple points on each of an insect's six legs. Digital video of a walking cockroach was collected in grayscale at 500 fps from two synchronized, calibrated cameras. We improved the legs' visibility by painting white dots on the joints, similar to techniques used for digitizing human motion. Compared to manual digitization of 26 points on the legs over a single, 8-second bout of walking (or 106,496 individual 3D points), our software achieved approximately 90% of the accuracy with 10% of the labor. Our experimental design reduced the complexity of the tracking problem by tethering the insect and allowing it to walk in place on a lightly oiled glass surface, but in principle, the algorithms implemented are extensible to free walking. Our software is free and open-source, written in the free language Python and including a graphical user interface for configuration and control. We encourage collaborative enhancements to make this tool both better and widely utilized.

Vertical T-maze Choice Assay for Arthropod Response to Odorants

PubMed Central

Stelinski, Lukasz; Tiwari, Siddharth

2013-01-01

Given the economic importance of insects and arachnids as pests of agricultural crops, urban environments or as vectors of plant and human diseases, various technologies are being developed as control tools. A subset of these tools focuses on modifying the behavior of arthropods by attraction or repulsion. Therefore, arthropods are often the focus of behavioral investigations. Various tools have been developed to measure arthropod behavior, including wind tunnels, flight mills, servospheres, and various types of olfactometers. The purpose of these tools is to measure insect or arachnid response to visual or more often olfactory cues. The vertical T-maze oflactometer described here measures choices performed by insects in response to attractants or repellents. It is a high throughput assay device that takes advantage of the positive phototaxis (attraction to light) and negative geotaxis (tendency to walk or fly upward) exhibited by many arthropods. The olfactometer consists of a 30 cm glass tube that is divided in half with a Teflon strip forming a T-maze. Each half serves as an arm of the olfactometer enabling the test subjects to make a choice between two potential odor fields in assays involving attractants. In assays involving repellents, lack of normal response to known attractants can also be measured as a third variable. PMID:23439130
Transformation of leaf litter by insect herbivory in the Subarctic: Consequences for soil biogeochemistry under global change

NASA Astrophysics Data System (ADS)

Kristensen, J. A.; Metcalfe, D. B.; Rousk, J.

2017-12-01

Climate warming may increase insect herbivore ranges and outbreak intensities in arctic ecosystems. Thorough understanding of the implications of these changes for ecosystem processes is essential to make accurate predictions of surface-atmosphere carbon (C) feedbacks. Yet, we lack a comprehensive understanding of the impacts of herbivore outbreaks on soil microbial underpinnings of C and nitrogen (N) fluxes. Here, we investigate the growth responses of heterotrophic soil decomposers and C and N mineralisation to simulated defoliator outbreaks in Subarctic birch forests. In microcosms, topsoil was incubated with leaf litter, insect frass, mineral N and combinations of the three; all was added in equal amounts of N. A higher fraction of added C and N was mineralised during outbreaks (frass addition) relative to non-outbreak years (litter addition). However, under high mineral N-availability in the soil of the kind likely under longer periods of enhanced insect herbivory (litter+mineral N), the mineralised fraction of added C decreased while the mineralised fraction of N increased substantially, which suggest a shift towards more N-mining of the organic substrates. This shift was accompanied by higher fungal dominance, and may facilitate soil C-accumulation assuming constant quality of C-inputs. Thus, long-term increases of insect herbivory, of the kind observed in some areas and projected by some models, may facilitate higher ecosystem C-sink capacity in this Subarctic ecosystem.
Anaphylaxis and insect allergy.

PubMed

Demain, Jeffrey G; Minaei, Ashley A; Tracy, James M

2010-08-01

Anaphylaxis is an acute-onset and potentially life-threatening allergic reaction that can be caused by numerous allergic triggers including stinging insects. This review focuses on recent advances, natural history, risk factors and therapeutic considerations. Recent work suggests that concerns over insect allergy diagnosis continue to exist. This is especially true with individuals who have a convincing history of a serious life-threatening anaphylactic event, but lack the necessary diagnostic criteria of venom-specific IgE by skin test or in-vitro diagnostic methods to confirm the diagnosis. The role of occult mastocytosis or increased basophile reactivity may play a role in this subset population. Additionally, epinephrine continues to be underutilized as the primary acute intervention for an anaphylactic reaction in the emergent setting. The incidence of anaphylaxis continues to rise across all demographic groups, especially those less than 20 years of age. Fortunately, the fatalities related to anaphylaxis appear to have decreased over the past decades. Our understanding of various triggers, associated risk factors, as well as an improved understanding and utilization of biological markers such as serum tryptase have improved. Our ability to treat insect anaphylaxis by venom immunotherapy is highly effective. Unfortunately, anaphylaxis continues to be underappreciated and undertreated especially in regard to insect sting anaphylaxis. This includes the appropriate use of injectable epinephrine as the primary acute management tool. These findings suggest that continued education of the general population, primary care healthcare providers and emergency departments is required.
Traditional consumption of and rearing edible insects in Africa, Asia and Europe.

PubMed

Raheem, Dele; Carrascosa, Conrado; Oluwole, Oluwatoyin Bolanle; Nieuwland, Maaike; Saraiva, Ariana; Millán, Rafael; Raposo, António

2018-02-15

The traditional consumption of edible insects is common in one third of the world's population, mostly in Latin America, Africa and Asia. There are over one thousand identified species of insects eaten in some stage of their life cycle; and they play important roles in ensuring food security. The most common way to collect insects are from the wild, which is seasonal with limited availability and has an increasing demand resulting in a disruption to the ecosystem. There is a growing interest shown in rearing insects for commercial purposes, and an industrial scale production will be required to ensure steady supplies. Industrial production will need to take into account the living environment of insects, the nutritional composition of their feed and the overall efficiency of the production system. We provide a short overview on the consumption of and rearing insects in Africa, Asia and Europe. For Africa, a snapshot is given for Nigeria, Ghana, Central African Republic, Kenya and Uganda, while the following countries are reported for Asia: China, Japan, Lao People's Democratic Republic, Thailand and Vietnam. In addition, a list of insect species with the highest potential for food and feed in the European Union is provided with some reference to The Netherlands and Finland. The review concludes that there is need to better understand the rearing and farming procedures that will yield high quality edible insects in Africa, Asia and Europe.
Size effects on insect hovering aerodynamics: an integrated computational study.

PubMed

Liu, H; Aono, H

2009-03-01

Hovering is a miracle of insects that is observed for all sizes of flying insects. Sizing effect in insect hovering on flapping-wing aerodynamics is of interest to both the micro-air-vehicle (MAV) community and also of importance to comparative morphologists. In this study, we present an integrated computational study of such size effects on insect hovering aerodynamics, which is performed using a biology-inspired dynamic flight simulator that integrates the modelling of realistic wing-body morphology, the modelling of flapping-wing and body kinematics and an in-house Navier-Stokes solver. Results of four typical insect hovering flights including a hawkmoth, a honeybee, a fruit fly and a thrips, over a wide range of Reynolds numbers from O(10(4)) to O(10(1)) are presented, which demonstrate the feasibility of the present integrated computational methods in quantitatively modelling and evaluating the unsteady aerodynamics in insect flapping flight. Our results based on realistically modelling of insect hovering therefore offer an integrated understanding of the near-field vortex dynamics, the far-field wake and downwash structures, and their correlation with the force production in terms of sizing and Reynolds number as well as wing kinematics. Our results not only give an integrated interpretation on the similarity and discrepancy of the near- and far-field vortex structures in insect hovering but also demonstrate that our methods can be an effective tool in the MAVs design.
Interaction of entomopathogenic fungi with the host immune system.

PubMed

Qu, Shuang; Wang, Sibao

2018-06-01

Entomopathogenic fungi can invade wide range of insect hosts in the natural world and have been used as environmentally friendly alternatives to chemical insecticides for pest control. Studies of host-pathogen interactions provide valuable insights into the coevolutionay arms race between fungal pathogens and their hosts. Entomopathogenic fungi have evolved a series of sophisticated strategies to counter insect immune defenses. In response to fungal infection, insect hosts rely on behavior avoidance, physical barrier and innate immune defenses in the fight against invading pathogens. The insect cuticle acts as the first physical barrier against pathogens. It is an inhospitable physiological environment that contains chemicals (e.g., antimicrobial peptides and reactive oxygen species), which inhibit fungal growth. In addition, innate immune responses, including cellular immunity and humoral immunity, play critical roles in preventing fungal infection. In this review, we outline the current state of our knowledge of insect defenses to fungal infection and discuss the strategies by which entomopathogenic fungi counter the host immune system. Increased knowledge regarding the molecular interactions between entomopathogenic fungi and the insect host could provide new strategies for pest management. Copyright © 2018 Elsevier Ltd. All rights reserved.
Insect Analogue to the Lotus Leaf: A Planthopper Wing Membrane Incorporating a Low-Adhesion, Nonwetting, Superhydrophobic, Bactericidal, and Biocompatible Surface.

PubMed

Watson, Gregory S; Green, David W; Cribb, Bronwen W; Brown, Christopher L; Meritt, Christopher R; Tobin, Mark J; Vongsvivut, Jitraporn; Sun, Mingxia; Liang, Ai-Ping; Watson, Jolanta A

2017-07-19

Nature has produced many intriguing and spectacular surfaces at the micro- and nanoscales. These small surface decorations act for a singular or, in most cases, a range of functions. The minute landscape found on the lotus leaf is one such example, displaying antiwetting behavior and low adhesion with foreign particulate matter. Indeed the lotus leaf has often been considered the "benchmark" for such properties. One could expect that there are animal counterparts of this self-drying and self-cleaning surface system. In this study, we show that the planthopper insect wing (Desudaba danae) exhibits a remarkable architectural similarity to the lotus leaf surface. Not only does the wing demonstrate a topographical likeness, but some surface properties are also expressed, such as nonwetting behavior and low adhering forces with contaminants. In addition, the insect-wing cuticle exhibits an antibacterial property in which Gram-negative bacteria (Porphyromonas gingivalis) are killed over many consecutive waves of attacks over 7 days. In contrast, eukaryote cell associations, upon contact with the insect membrane, lead to a formation of integrated cell sheets (e.g., among human stem cells (SHED-MSC) and human dermal fibroblasts (HDF)). The multifunctional features of the insect membrane provide a potential natural template for man-made applications in which specific control of liquid, solid, and biological contacts is desired and required. Moreover, the planthopper wing cuticle provides a "new" natural surface with which numerous interfacial properties can be explored for a range of comparative studies with both natural and man-made materials.
Attention-like processes in insects

PubMed Central

2016-01-01

Attention is fundamentally important for sensory systems to focus on behaviourally relevant stimuli. It has therefore been an important field of study in human psychology and neuroscience. Primates, however, are not the only animals that might benefit from attention-like processes. Other animals, including insects, also have to use their senses and select one among many stimuli to forage, avoid predators and find mates. They have evolved different mechanisms to reduce the information processed by their brains to focus on only relevant stimuli. What are the mechanisms used by insects to selectively attend to visual and auditory stimuli? Do these attention-like mechanisms achieve the same functions as they do in primates? To investigate these questions, I use an established framework for investigating attention in non-human animals that proposes four fundamental components of attention: salience filters, competitive selection, top-down sensitivity control and working memory. I discuss evidence for each of these component processes in insects and compare the characteristics of these processes in insects to what we know from primates. Finally, I highlight important outstanding questions about insect attention that need to be addressed for us to understand the differences and similarities between vertebrate and insect attention. PMID:27852803
Attention-like processes in insects.

PubMed

Nityananda, Vivek

2016-11-16

Attention is fundamentally important for sensory systems to focus on behaviourally relevant stimuli. It has therefore been an important field of study in human psychology and neuroscience. Primates, however, are not the only animals that might benefit from attention-like processes. Other animals, including insects, also have to use their senses and select one among many stimuli to forage, avoid predators and find mates. They have evolved different mechanisms to reduce the information processed by their brains to focus on only relevant stimuli. What are the mechanisms used by insects to selectively attend to visual and auditory stimuli? Do these attention-like mechanisms achieve the same functions as they do in primates? To investigate these questions, I use an established framework for investigating attention in non-human animals that proposes four fundamental components of attention: salience filters, competitive selection, top-down sensitivity control and working memory. I discuss evidence for each of these component processes in insects and compare the characteristics of these processes in insects to what we know from primates. Finally, I highlight important outstanding questions about insect attention that need to be addressed for us to understand the differences and similarities between vertebrate and insect attention. © 2016 The Author(s).
Tomographic Reconstruction of Neopterous Carboniferous Insect Nymphs

PubMed Central

Garwood, Russell; Ross, Andrew; Sotty, Daniel; Chabard, Dominique; Charbonnier, Sylvain; Sutton, Mark; Withers, Philip J.

2012-01-01

Two new polyneopteran insect nymphs from the Montceau-les-Mines Lagerstätte of France are presented. Both are preserved in three dimensions, and are imaged with the aid of X-ray micro-tomography, allowing their morphology to be recovered in unprecedented detail. One–Anebos phrixos gen. et sp. nov.–is of uncertain affinities, and preserves portions of the antennae and eyes, coupled with a heavily spined habitus. The other is a roachoid with long antennae and chewing mouthparts very similar in form to the most generalized mandibulate mouthparts of extant orthopteroid insects. Computer reconstructions reveal limbs in both specimens, allowing identification of the segments and annulation in the tarsus, while poorly developed thoracic wing pads suggest both are young instars. This work describes the morphologically best-known Palaeozoic insect nymphs, allowing a better understanding of the juveniles’ palaeobiology and palaeoecology. We also consider the validity of evidence from Palaeozoic juvenile insects in wing origin theories. The study of juvenile Palaeozoic insects is currently a neglected field, yet these fossils provide direct evidence on the evolution of insect development. It is hoped this study will stimulate a renewed interest in such work. PMID:23049858
Effects of Microgravity and Hypergravity on Invertebrate Development

NASA Technical Reports Server (NTRS)

Miquel, J.

1985-01-01

Data suggest that abnormal gravity loads do not increase the rate of mutations in lower animals. Insects such as Drosophila melanogaster and Tribolium confusum have been able to reproduce aboard unmanned and manned space satellites, though no precise quantitative data have been obtained on mating competence and various aspects of development. Research with Drosophila flown on Cosmos spacecraft suggests that flight behavior is seriously disturbed in insects exposed to microgravity, which is reflected in increased oxygen utilization and concomitant life shortening. The decrease in longevity was less striking when the flies were enclosed in space, which suggests that they could adapt to the altered gravitational environment when maturation of flight behavior took place in microgravity. The reviewed data suggest that further research on the development of invertebrates in space is in order for clarification of the metabolic and behavioral effects of microgravity and of the development and function of the orientation and gravity sensing mechanisms of lower animals.
Phase Coexistence in Insect Swarms

NASA Astrophysics Data System (ADS)

Sinhuber, Michael; Ouellette, Nicholas T.

2017-10-01

Animal aggregations are visually striking, and as such are popular examples of collective behavior in the natural world. Quantitatively demonstrating the collective nature of such groups, however, remains surprisingly difficult. Inspired by thermodynamics, we applied topological data analysis to laboratory insect swarms and found evidence for emergent, material-like states. We show that the swarms consist of a core "condensed" phase surrounded by a dilute "vapor" phase. These two phases coexist in equilibrium, and maintain their distinct macroscopic properties even though individual insects pass freely between them. We further define a pressure and chemical potential to describe these phases, extending theories of active matter to aggregations of macroscopic animals and laying the groundwork for a thermodynamic description of collective animal groups.
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
Flying Insect Detection and Classification with Inexpensive Sensors

PubMed Central

Chen, Yanping; Why, Adena; Batista, Gustavo; Mafra-Neto, Agenor; Keogh, Eamonn

2014-01-01

An inexpensive, noninvasive system that could accurately classify flying insects would have important implications for entomological research, and allow for the development of many useful applications in vector and pest control for both medical and agricultural entomology. Given this, the last sixty years have seen many research efforts devoted to this task. To date, however, none of this research has had a lasting impact. In this work, we show that pseudo-acoustic optical sensors can produce superior data; that additional features, both intrinsic and extrinsic to the insect’s flight behavior, can be exploited to improve insect classification; that a Bayesian classification approach allows to efficiently learn classification models that are very robust to over-fitting, and a general classification framework allows to easily incorporate arbitrary number of features. We demonstrate the findings with large-scale experiments that dwarf all previous works combined, as measured by the number of insects and the number of species considered. PMID:25350921
Oligocene Termite Nests with In Situ Fungus Gardens from the Rukwa Rift Basin, Tanzania, Support a Paleogene African Origin for Insect Agriculture

PubMed Central

Roberts, Eric M.; Todd, Christopher N.; Aanen, Duur K.; Nobre, Tânia; Hilbert-Wolf, Hannah L.; O’Connor, Patrick M.; Tapanila, Leif; Mtelela, Cassy; Stevens, Nancy J.

2016-01-01

Based on molecular dating, the origin of insect agriculture is hypothesized to have taken place independently in three clades of fungus-farming insects: the termites, ants or ambrosia beetles during the Paleogene (66–24 Ma). Yet, definitive fossil evidence of fungus-growing behavior has been elusive, with no unequivocal records prior to the late Miocene (7–10 Ma). Here we report fossil evidence of insect agriculture in the form of fossil fungus gardens, preserved within 25 Ma termite nests from southwestern Tanzania. Using these well-dated fossil fungus gardens, we have recalibrated molecular divergence estimates for the origins of termite agriculture to around 31 Ma, lending support to hypotheses suggesting an African Paleogene origin for termite-fungus symbiosis; perhaps coinciding with rift initiation and changes in the African landscape. PMID:27333288
Decadal-Scale Reduction in Forest Net Ecosystem Production Following Insect Defoliation Contrasts with Short-Term Impacts of Prescribed Fires

Treesearch

Kenneth L. Clark; Heidi J. Renninger; Nicholas Skowronski; Michael Gallagher; Karina V.R. Schäfer

2018-01-01

Understanding processes underlying forest carbon dynamics is essential for accurately predicting the outcomes of non-stand-replacing disturbance in intermediate-age forests. We quantified net ecosystem production (NEP), aboveground net primary production (ANPP), and the dynamics of major carbon (C) pools before and during the decade following invasive insect...
Physics-Based Design of Micro Air Vehicles

DTIC Science & Technology

2012-04-01

7 Figure 5. Comparison of an insect wing and a manufactured wing for a flapping MAV. .............. 8...topologies for a flapping-wing compliant actuation mechanism. Hatched areas are clamped. Cases 1-3 have fixed supports; cases 4 and 5 have variable...world by flying insects , birds, and mammals. However, an inadequate understanding of the complex, nonlinear, and multidisciplinary physics that
Insect-Based Vision for Autonomous Vehicles: A Feasibility Study

NASA Technical Reports Server (NTRS)

Srinivasan, Mandyam V.

1999-01-01

The aims of the project were to use a high-speed digital video camera to pursue two questions: i) To explore the influence of temporal imaging constraints on the performance of vision systems for autonomous mobile robots; To study the fine structure of insect flight trajectories with in order to better understand the characteristics of flight control, orientation and navigation.
Observed and anticipated impacts of drought on forest insects and diseases in the United States

Treesearch

Thomas E. Kolb; Chris Fettig; Matthew P. Ayres; Barbara J. Bentz; Jeffrey A. Hicke; Robert Mathiasen; Jane E. Stewart; Aaron S. Weed

2016-01-01

Future anthropogenic-induced changes to the earthâs climate will likely include increases in temperature and changes in precipitation that will increase the frequency and severity of droughts. Insects and fungal diseases are important disturbances in forests, yet understanding of the role of drought in outbreaks of these agents is limited. Current knowledge...
Insect-Based Vision for Autonomous Vehicles: A Feasibility Study

NASA Technical Reports Server (NTRS)

Srinivasan, Mandyam V.

1999-01-01

The aims of the project were to use a high-speed digital video camera to pursue two questions: (1) To explore the influence of temporal imaging constraints on the performance of vision systems for autonomous mobile robots; (2) To study the fine structure of insect flight trajectories in order to better understand the characteristics of flight control, orientation and navigation.

Deconstructing Superorganisms and Societies to Address Big Questions in Biology.

PubMed

Kennedy, Patrick; Baron, Gemma; Qiu, Bitao; Freitak, Dalial; Helanterä, Heikki; Hunt, Edmund R; Manfredini, Fabio; O'Shea-Wheller, Thomas; Patalano, Solenn; Pull, Christopher D; Sasaki, Takao; Taylor, Daisy; Wyatt, Christopher D R; Sumner, Seirian

2017-11-01

Social insect societies are long-standing models for understanding social behaviour and evolution. Unlike other advanced biological societies (such as the multicellular body), the component parts of social insect societies can be easily deconstructed and manipulated. Recent methodological and theoretical innovations have exploited this trait to address an expanded range of biological questions. We illustrate the broadening range of biological insight coming from social insect biology with four examples. These new frontiers promote open-minded, interdisciplinary exploration of one of the richest and most complex of biological phenomena: sociality. Copyright © 2017 Elsevier Ltd. All rights reserved.
Infection Density Dynamics of the Citrus Greening Bacterium “Candidatus Liberibacter asiaticus” in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants

PubMed Central

Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi

2015-01-01

Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, “Candidatus Liberibacter asiaticus,” and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of “Ca. Liberibacter asiaticus” in field populations of D. citri with experiments using field-collected insects to address how “Ca. Liberibacter asiaticus” infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from “Ca. Liberibacter asiaticus”-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were “Ca. Liberibacter asiaticus” positive. The infections were systemic across head-thorax and abdomen, ranging from 103 to 107 bacteria per insect. In spring, the infection densities were low in March, at ∼103 bacteria per insect, increasing up to 106 to 107 bacteria per insect in April and May, and decreasing to 105 to 106 bacteria per insect in late May, whereas the infection densities were constantly ∼106 to 107 bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with “Ca. Liberibacter asiaticus” infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected “Ca. Liberibacter asiaticus”-infected insects suggested that (i) “Ca. Liberibacter asiaticus”-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼106 bacteria per insect) of “Ca. Liberibacter asiaticus” density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits “Ca. Liberibacter asiaticus” to citrus plants in a stochastic manner. These findings provide valuable insights into understanding, predicting, and controlling this notorious citrus pathogen. PMID:25819961
[Double-ambient CO2 concentration affects the growth, development and sucking behavior of non-target brown plant hopper Nilaparvata lugens fed on transgenic Bt rice.

PubMed

Lu, Yong Qing; Dai, Yang; Yu, Xiu Ying; Yu, Fu-Lan; Jiang, Shou Lin; Zhou, Zong Yuan; Chen, Fa Jun

2018-02-01

In recent years, the two issues of climate change including elevated CO 2 etc., and resistance of transgenic Bt crops against non-target insect pests have received widespread attention. Elevated CO 2 can affect the herbivorous insects. To date, there is no consensus about the effect of elevated CO 2 on the suck-feeding insect pests (non-target insect pests of transgenic Bt crops). Its effects on the suck-feeding behavior have rarely been reported. In this study, CO 2 levels were set up in artificial climate chamber to examined the effects of ambient (400 μL·L -1 ) and double-ambient (800 μL·L -1 ) CO 2 levels on the suck-feeding behavior, growth, development, and reproduction of the non-target insect pest of transgenic Bt rice, brown planthopper, Nilaparvata lugens. The results showed that CO 2 level significantly affected the egg and nymph duration, longevity and body mass of adults, and feeding behavior of the 4th and 5th instar nymphs, while had no effect on the fecundity of N. lugens. The duration of eggs and nymphs, and the longevity of female adults were significantly shortened by 4.0%, 4.2% and 6.6% respectively, the proportion of the macropterous adults was significantly increased by 11.6%, and the body mass of newly hatched female adults was significantly decreased by 2.2% by elevated CO 2 . In addition, elevated CO 2 significantly enhanced the stylet puncturing efficiency of the 4th and 5th instar nymphs of N. lugens. The duration ofphloem ingestion of the N4b waveform was significantly prolonged by 60.0% and 50.1%, and the frequency significantly was increased by 230.0% and 155.9% for the 4th and 5th instar nymphs of N. lugens by elevated CO 2 , respectively. It was concluded that double-ambient CO 2 could promote the growth and development of N. lugens through enhancing its suck-feeding, shorten the generation life-span and increase the macropertous adults' proportion of N. lugens. Thus, it could result in the occurrence of non-target rice planthopper N. lugens and make the transgenic Bt crops face with harm risk due to migration and diffusion of N. lugens under elevated CO 2 .
Context dependency and generality of fever in insects.

PubMed

Stahlschmidt, Z R; Adamo, S A

2013-07-01

Fever can reduce mortality in infected animals. Yet, despite its fitness-enhancing qualities, fever often varies among animals. We used several approaches to examine this variation in insects. Texas field crickets (Gryllus texensis) exhibited a modest fever (1 °C increase in preferred body temperature, T pref) after injection of prostaglandin, which putatively mediates fever in both vertebrates and invertebrates, but they did not exhibit fever during chronic exposure to heat-killed bacteria. Further, chronic food limitation and mating status did not affect T pref or the expression of behavioural fever, suggesting limited context dependency of fever in G. texensis. Our meta-analysis of behavioural fever studies indicated that behavioural fever occurs in many insects, but it is not ubiquitous. Thus, both empirical and meta-analytical results suggest that the fever response in insects 'is widespread, although certainly not inevitable' (Moore 2002). We highlight the need for future work focusing on standardizing an experimental protocol to measure behavioural fever, understanding the specific mechanism(s) underlying fever in insects, and examining whether ecological or physiological costs often outweigh the benefits of fever and can explain the sporadic nature of fever in insects.
Context dependency and generality of fever in insects

NASA Astrophysics Data System (ADS)

Stahlschmidt, Z. R.; Adamo, S. A.

2013-07-01

Fever can reduce mortality in infected animals. Yet, despite its fitness-enhancing qualities, fever often varies among animals. We used several approaches to examine this variation in insects. Texas field crickets ( Gryllus texensis) exhibited a modest fever (1 °C increase in preferred body temperature, T pref) after injection of prostaglandin, which putatively mediates fever in both vertebrates and invertebrates, but they did not exhibit fever during chronic exposure to heat-killed bacteria. Further, chronic food limitation and mating status did not affect T pref or the expression of behavioural fever, suggesting limited context dependency of fever in G. texensis. Our meta-analysis of behavioural fever studies indicated that behavioural fever occurs in many insects, but it is not ubiquitous. Thus, both empirical and meta-analytical results suggest that the fever response in insects `is widespread, although certainly not inevitable' (Moore 2002). We highlight the need for future work focusing on standardizing an experimental protocol to measure behavioural fever, understanding the specific mechanism(s) underlying fever in insects, and examining whether ecological or physiological costs often outweigh the benefits of fever and can explain the sporadic nature of fever in insects.
Phylogenetic distribution and evolutionary dynamics of the sex determination genes doublesex and transformer in insects.

PubMed

Geuverink, E; Beukeboom, L W

2014-01-01

Sex determination in insects is characterized by a gene cascade that is conserved at the bottom but contains diverse primary signals at the top. The bottom master switch gene doublesex is found in all insects. Its upstream regulator transformer is present in the orders Hymenoptera, Coleoptera and Diptera, but has thus far not been found in Lepidoptera and in the basal lineages of Diptera. transformer is presumed to be ancestral to the holometabolous insects based on its shared domains and conserved features of autoregulation and sex-specific splicing. We interpret that its absence in basal lineages of Diptera and its order-specific conserved domains indicate multiple independent losses or recruitments into the sex determination cascade. Duplications of transformer are found in derived families within the Hymenoptera, characterized by their complementary sex determination mechanism. As duplications are not found in any other insect order, they appear linked to the haplodiploid reproduction of the Hymenoptera. Further phylogenetic analyses combined with functional studies are needed to understand the evolutionary history of the transformer gene among insects. © 2013 S. Karger AG, Basel.
Epigenetic Mechanisms Regulate Innate Immunity against Uropathogenic and Commensal-Like Escherichia coli in the Surrogate Insect Model Galleria mellonella.

PubMed

Heitmueller, Miriam; Billion, André; Dobrindt, Ulrich; Vilcinskas, Andreas; Mukherjee, Krishnendu

2017-10-01

Innate-immunity-related genes in humans are activated during urinary tract infections (UTIs) caused by pathogenic strains of Escherichia coli but are suppressed by commensals. Epigenetic mechanisms play a pivotal role in the regulation of gene expression in response to environmental stimuli. To determine whether epigenetic mechanisms can explain the different behaviors of pathogenic and commensal bacteria, we infected larvae of the greater wax moth, Galleria mellonella , a widely used model insect host, with a uropathogenic E. coli (UPEC) strain that causes symptomatic UTIs in humans or a commensal-like strain that causes asymptomatic bacteriuria (ABU). Infection with the UPEC strain (CFT073) was more lethal to larvae than infection with the attenuated ABU strain (83972) due to the recognition of each strain by different Toll-like receptors, ultimately leading to differential DNA/RNA methylation and histone acetylation. We used next-generation sequencing and reverse transcription (RT)-PCR to correlate epigenetic changes with the induction of innate-immunity-related genes. Transcriptomic analysis of G. mellonella larvae infected with E. coli strains CFT073 and 83972 revealed strain-specific variations in the class and expression levels of genes encoding antimicrobial peptides, cytokines, and enzymes controlling DNA methylation and histone acetylation. Our results provide evidence for the differential epigenetic regulation of transcriptional reprogramming by UPEC and ABU strains of E. coli in G. mellonella larvae, which may be relevant to understanding the different behaviors of these bacterial strains in the human urinary tract. Copyright © 2017 American Society for Microbiology.
The RFamide receptor DMSR-1 regulates stress-induced sleep in C. elegans

PubMed Central

Iannacone, Michael J; Beets, Isabel; Lopes, Lindsey E; Churgin, Matthew A; Fang-Yen, Christopher; Nelson, Matthew D; Schoofs, Liliane; Raizen, David M

2017-01-01

In response to environments that cause cellular stress, animals engage in sleep behavior that facilitates recovery from the stress. In Caenorhabditis elegans, stress-induced sleep(SIS) is regulated by cytokine activation of the ALA neuron, which releases FLP-13 neuropeptides characterized by an amidated arginine-phenylalanine (RFamide) C-terminus motif. By performing an unbiased genetic screen for mutants that impair the somnogenic effects of FLP-13 neuropeptides, we identified the gene dmsr-1, which encodes a G-protein coupled receptor similar to an insect RFamide receptor. DMSR-1 is activated by FLP-13 peptides in cell culture, is required for SIS in vivo, is expressed non-synaptically in several wake-promoting neurons, and likely couples to a Gi/o heterotrimeric G-protein. Our data expand our understanding of how a single neuroendocrine cell coordinates an organism-wide behavioral response, and suggest that similar signaling principles may function in other organisms to regulate sleep during sickness. DOI: http://dx.doi.org/10.7554/eLife.19837.001 PMID:28094002
Targeted gene delivery in the cricket brain, using in vivo electroporation.

PubMed

Matsumoto, Chihiro Sato; Shidara, Hisashi; Matsuda, Koji; Nakamura, Taro; Mito, Taro; Matsumoto, Yukihisa; Oka, Kotaro; Ogawa, Hiroto

2013-12-01

The cricket (Gryllus bimaculatus) is a hemimetabolous insect that is emerging as a model organism for the study of neural and molecular mechanisms of behavioral traits. However, research strategies have been limited by a lack of genetic manipulation techniques that target the nervous system of the cricket. The development of a new method for efficient gene delivery into cricket brains, using in vivo electroporation, is described here. Plasmid DNA, which contained an enhanced green fluorescent protein (eGFP) gene, under the control of a G. bimaculatus actin (Gb'-act) promoter, was injected into adult cricket brains. Injection was followed by electroporation at a sufficient voltage. Expression of eGFP was observed within the brain tissue. Localized gene expression, targeted to specific regions of the brain, was also achieved using a combination of local DNA injection and fine arrangement of the electroporation electrodes. Further studies using this technique will lead to a better understanding of the neural and molecular mechanisms that underlie cricket behaviors. Copyright © 2013 Elsevier Ltd. All rights reserved.
Lethal and Sublethal Effects of Mineral Oil on Potato Pests.

PubMed

Galimberti, Andrew; Alyokhin, Andrei

2018-05-28

Mineral oil is a product used to reduce Potato Virus Y transmission in potato fields. However, there is little information available about other effects that oil may have on insect pests of potato. To better understand how mineral oil affects potato pests, we performed a series of experiments testing the effects of oil on mortality, behavior, and development of potato aphids, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae), green peach aphids, Myzus persicae (Sulzer) (Hemiptera: Aphididae), and Colorado potato beetles, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). All three species showed negative behavioral responses to oil-treated potato foliage. Oil treatment also increased aphid mortality. Colorado potato beetle mortality was not affected, but developing on oil-treated potato plants resulted in prolonged development and smaller adults. Additionally, oil acted synergistically with the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae); Colorado potato beetle larvae were killed more rapidly when sprayed with both products compared with when sprayed with B. bassiana alone. Based on these results, mineral oil has the potential for expanded use in potato IPM programs.
Plant rhabdoviruses: new insights and research needs in the interplay of negative-strand RNA viruses with plant and insect hosts.

PubMed

Mann, Krin S; Dietzgen, Ralf G

2014-08-01

Rhabdoviruses are taxonomically classified in the family Rhabdoviridae, order Mononegavirales. As a group, rhabdoviruses can infect plants, invertebrates and vertebrates. Plant cyto- and nucleorhabdoviruses infect a wide variety of species across both monocot and dicot families, including agriculturally important crops such as lettuce, wheat, barley, rice, maize, potato and tomato. Plant rhabdoviruses are transmitted by and replicate in hemipteran insects such as aphids (Aphididae), leafhoppers (Cicadellidae), or planthoppers (Delphacidae). These specific interactions between plants, viruses and insects offer new insights into host adaptation and molecular virus evolution. This review explores recent advances as well as knowledge gaps in understanding of replication, RNA silencing suppression and movement of plant rhabdoviruses with respect to both plant and insect hosts.
Chemical environment manipulation for pest insects control

NASA Astrophysics Data System (ADS)

Greenblatt, J. A.; Lewis, W. J.

1983-01-01

The chemical environment of pest species may be considered a habitat susceptible to management Management may be by means of manipulation of the environment of the pest for population suppression or for enhancement of natural enemies Examples of each are reviewed here Chemical stimuli influencing the behavior of phytophagous insects include host plant originated stimuli and pheromones The latter, especially sex pheromones, have proved most successful as tools for manipulation of pest population dynamics Factors influencing search behavior of natural enemies include habitat characteristics such as crop, associated plants and plant assemblages, host plant characteristics, influence of associated organisms, and characteristics of the searching entomophage Recent studies have shown potential for simultaneous management of a pest species and enhancement of natural enemies using pest pheromones
Intrinsic Fluctuations and Driven Response of Insect Swarms

NASA Astrophysics Data System (ADS)

Ni, Rui; Puckett, James G.; Dufresne, Eric R.; Ouellette, Nicholas T.

2015-09-01

Animals of all sizes form groups, as acting together can convey advantages over acting alone; thus, collective animal behavior has been identified as a promising template for designing engineered systems. However, models and observations have focused predominantly on characterizing the overall group morphology, and often focus on highly ordered groups such as bird flocks. We instead study a disorganized aggregation (an insect mating swarm), and compare its natural fluctuations with the group-level response to an external stimulus. We quantify the swarm's frequency-dependent linear response and its spectrum of intrinsic fluctuations, and show that the ratio of these two quantities has a simple scaling with frequency. Our results provide a new way of comparing models of collective behavior with experimental data.
Water loss in insects: an environmental change perspective.

PubMed

Chown, Steven L; Sørensen, Jesper G; Terblanche, John S

2011-08-01

In the context of global environmental change much of the focus has been on changing temperatures. However, patterns of rainfall and water availability have also been changing and are expected to continue doing so. In consequence, understanding the responses of insects to water availability is important, especially because it has a pronounced influence on insect activity, distribution patterns, and species richness. Here we therefore provide a critical review of key questions that either are being or need to be addressed in this field. First, an overview of insect behavioural responses to changing humidity conditions and the mechanisms underlying sensing of humidity variation is provided. The primary sensors in insects belong to the temperature receptor protein superfamily of cation channels. Temperature-activated transient receptor potential ion channels, or thermoTRPs, respond to a diverse range of stimuli and may be a primary integrator of sensory information, such as environmental temperature and moisture. Next we touch briefly on the components of water loss, drawing attention to a new, universal model of the water costs of gas exchange and its implications for responses to a warming, and in places drying, world. We also provide an overview of new understanding of the role of the sub-elytral chamber for water conservation, and developments in understanding of the role of cuticular hydrocarbons in preventing water loss. Because of an increasing focus on the molecular basis of responses to dehydration stress we touch briefly on this area, drawing attention to the role of sugars, heat shock proteins, aquaporins, and LEA proteins. Next we consider phenotypic plasticity or acclimation responses in insect water balance after initial exposures to altered humidity, temperature or nutrition. Although beneficial acclimation has been demonstrated in several instances, this is not always the case. Laboratory studies show that responses to selection for enhanced ability to survive water stress do evolve and that genetic variation for traits underlying such responses does exist in many species. However, in others, especially tropical, typically narrowly distributed species, this appears not to be the case. Using the above information we then demonstrate that habitat alteration, climate change, biological invasions, pollution and overexploitation are likely to be having considerable effects on insect populations mediated through physiological responses (or the lack thereof) to water stress, and that these effects may often be non-intuitive. Copyright © 2011 Elsevier Ltd. All rights reserved.
Analysis of electrical penetration graph data: what to do with artificially terminated events?

USDA-ARS?s Scientific Manuscript database

Observing the durations of hemipteran feeding behaviors via Electrical Penetration Graph (EPG) results in situations where the duration of the last behavior is not ended by the insect under observation, but by the experimenter. These are artificially terminated events. In data analysis, one must ch...
Behavioral and chemical mechanisms of plant-mediated deterrence and attraction among frugivorous insects

USDA-ARS?s Scientific Manuscript database

A number of studies have now reported increased levels of non Bt-targeted secondary pests in Bt crops. Although pesticide reduction plays a role, interactions between the secondary pests and the targeted primary pest may also be important. Feeding preference—attractiveness (selection behavior, acce...
Effects of atmospheric pressure trends on calling, mate-seeking, and phototaxis of Diaphorina citri (Hemiptera: Liviidae)

USDA-ARS?s Scientific Manuscript database

Insects and other animals sometimes modify behavior in response to changes in atmospheric pressure, an environmental cue that can provide warning of potentially injurious windy and rainy weather. To determine if Diaphorina citri (Hemiptera: Liviidae) calling, mate-seeking, and phototaxis behaviors w...
Hypoxia and hypercarbia in endophagous insects: Larval position in the plant gas exchange network is key.

PubMed

Pincebourde, Sylvain; Casas, Jérôme

2016-01-01

Gas composition is an important component of any micro-environment. Insects, as the vast majority of living organisms, depend on O2 and CO2 concentrations in the air they breathe. Low O2 (hypoxia), and high CO2 (hypercarbia) levels can have a dramatic effect. For phytophagous insects that live within plant tissues (endophagous lifestyle), gas is exchanged between ambient air and the atmosphere within the insect habitat. The insect larva contributes to the modification of this environment by expiring CO2. Yet, knowledge on the gas exchange network in endophagous insects remains sparse. Our study identified mechanisms that modulate gas composition in the habitat of endophagous insects. Our aim was to show that the mere position of the insect larva within plant tissues could be used as a proxy for estimating risk of occurrence of hypoxia and hypercarbia, despite the widely diverse life history traits of these organisms. We developed a conceptual framework for a gas diffusion network determining gas composition in endophagous insect habitats. We applied this framework to mines, galls and insect tunnels (borers) by integrating the numerous obstacles along O2 and CO2 pathways. The nature and the direction of gas transfers depended on the physical structure of the insect habitat, the photosynthesis activity as well as stomatal behavior in plant tissues. We identified the insect larva position within the gas diffusion network as a predictor of risk exposure to hypoxia and hypercarbia. We ranked endophagous insect habitats in terms of risk of exposure to hypoxia and/or hypercarbia, from the more to the less risky as cambium mines>borer tunnels≫galls>bark mines>mines in aquatic plants>upper and lower surface mines. Furthermore, we showed that the photosynthetically active tissues likely assimilate larval CO2 produced. In addition, temperature of the microhabitat and atmospheric CO2 alter gas composition in the insect habitat. We predict that (i) hypoxia indirectly favors the evolution of cold-tolerant gallers, which do not perform well at high temperatures, and (ii) normoxia (ambient O2 level) in mines allows miners to develop at high temperatures. Little is known, however, about physiological and morphological adaptations to hypoxia and hypercarbia in endophagous insects. Endophagy strongly constrains the diffusion processes with cascading consequences on the evolutionary ecology of endophagous insects. Copyright © 2015 Elsevier Ltd. All rights reserved.
Insektenpheromone

NASA Astrophysics Data System (ADS)

Bestmann, H. J.; Vostrowsky, O.

1982-10-01

Pheromones — semiochemicals used by insects for intraspecific chemical communication — can be isolated and with special analytical techniques their chemical structure elucidated. With stereoselective synthesis methods, presented by the preparation of sex attractants and aggregating pheromones of moths and beetles, respectively, a synthetic access to compounds is given which can be used for behavior manipulation of insects. Aside the importance of these compounds for investigations of the sensoric process the possibility of their application in an integrated and biological pest control is discussed.
Members of the neuropeptide transcriptional network in Helicoverpa armigera and their expression in response to light stress.

PubMed

Wang, Lijun; Liu, Xinhui; Liu, Zhengxing; Wang, Xiaoping; Lei, Chaoliang; Zhu, Fen

2018-05-19

Neuropeptides and peptide hormones play central roles in the regulation of various types of insect physiology and behavior. Artificial light at night, a form of environmental stress, has recently been regarded as a source of light stress on nocturnal insects. Because related genomic information is not available, molecular biological studies on the response of neuropeptides in nocturnal insects to light stress are limited. Based on the de novo sequencing of the Helicoverpa armigera head transcriptome, we obtained 124,960 unigenes. Of these, the number of unigenes annotated as neuropeptides and peptide hormones, neurotransmitter precursor processing enzymes, and neurotransmitter receptors were 34, 17, and 58, respectively. Under light stress, there were sex-specific differences in gene expression measured by qRT-PCR. The IMFamide, leucokinin and sNPF genes were differentially expressed at the mRNA level in males but not in females in response to light stress. The results provide new insights on the diversity of the neuropeptide transcriptional network of H. armigera. In addition, some neuropeptides exhibited sex-specific differential expression in response to light stress. Taken collectively, these results not only expand the catalog of known insect neuropeptides but also provide a framework for future functional studies on the physiological roles they play in the light stress response behavior of nocturnal moths. Copyright © 2017. Published by Elsevier B.V.

Tools for detecting insect semiochemicals: a review.

PubMed

Brezolin, Alexandra Nava; Martinazzo, Janine; Muenchen, Daniela Kunkel; de Cezaro, Alana Marie; Rigo, Aline Andressa; Steffens, Clarice; Steffens, Juliana; Blassioli-Moraes, Maria Carolina; Borges, Miguel

2018-07-01

Semiochemicals are chemical compounds that are released by many species as a means of intra- and interspecific communication. Insects have extremely advanced olfactory systems; indeed, they rely on smell when performing many of their main behaviors, such as oviposition, breeding, prey location, and defense. This characteristic of insects implies that semiochemicals could be used for various applications, including in agriculture, where they could be employed along with other tools to control pest insects. The aim of this review is to present the main techniques used and the state of the art in the detection of semiochemicals, focusing on pheromones. In addition to the traditional methods of identifying semiochemicals, such as gas chromatography coupled to a high-resolution detection mode (e.g., flame ionization (FID), electron capture (ECD), photoionization (PID), or mass spectrometry (MS)), other tools are addressed in this review, including sensors and biosensors. While these new technologies may be used under laboratory conditions to improve or complement technologies that are already being used, they are mainly intended for use as new agricultural tools for detecting and controlling pest insects in the field.
Ant-plant mutualism: a dietary by-product of a tropical ant's macronutrient requirements.

PubMed

Arcila Hernández, Lina M; Sanders, Jon G; Miller, Gabriel A; Ravenscraft, Alison; Frederickson, Megan E

2017-12-01

Many arboreal ants depend on myrmecophytic plants for both food and shelter; in return, these ants defend their host plants against herbivores, which are often insects. Ant-plant and other mutualisms do not necessarily involve the exchange of costly rewards or services; they may instead result from by-product benefits, or positive outcomes that do not entail a cost for one or both partners. Here, we examined whether the plant-ant Allomerus octoarticulatus pays a short-term cost to defend their host plants against herbivores, or whether plant defense is a by-product benefit of ant foraging for insect prey. Because the food offered by ant-plants is usually nitrogen-poor, arboreal ants may balance their diets by consuming insect prey or associating with microbial symbionts to acquire nitrogen, potentially shifting the costs and benefits of plant defense for the ant partner. To determine the effect of ant diet on an ant-plant mutualism, we compared the behavior, morphology, fitness, stable isotope signatures, and gaster microbiomes of A. octoarticulatus ants nesting in Cordia nodosa trees maintained for nearly a year with or without insect herbivores. At the end of the experiment, ants from herbivore exclosures preferred protein-rich baits more than ants in the control (i.e., herbivores present) treatment. Furthermore, workers in the control treatment were heavier than in the herbivore-exclusion treatment, and worker mass predicted reproductive output, suggesting that foraging for insect prey directly increased ant colony fitness. The gaster microbiome of ants was not significantly affected by the herbivore exclusion treatment. We conclude that the defensive behavior of some phytoecious ants is a by-product of their need for external protein sources; thus, the consumption of insect herbivores by ants benefits both the ant colony and the host plant. © 2017 by the Ecological Society of America.
Seasonal bat activity related to insect emergence at three temperate lakes.

PubMed

Salvarina, Ioanna; Gravier, Dorian; Rothhaupt, Karl-Otto

2018-04-01

Knowledge of aquatic food resources entering terrestrial systems is important for food web studies and conservation planning. Bats, among other terrestrial consumers, often profit from aquatic insect emergence and their activity might be closely related to such events. However, there is a lack of studies which monitor bat activity simultaneously with aquatic insect emergence, especially from lakes. Thus, our aim was to understand the relationship between insect emergence and bat activity, and investigate whether there is a general spatial or seasonal pattern at lakeshores. We assessed whole-night bat activity using acoustic monitoring and caught emerging and aerial flying insects at three different lakes through three seasons. We predicted that insect availability and seasonality explain the variation in bat activity, independent of the lake size and characteristics. Spatial (between lakes) differences of bat activity were stronger than temporal (seasonal) differences. Bat activity did not always correlate to insect emergence, probably because other factors, such as habitat characteristics, or bats' energy requirements, play an important role as well. Aerial flying insects explained bat activity better than the emerged aquatic insects in the lake with lowest insect emergence. Bats were active throughout the night with some activity peaks, and the pattern of their activity also differed among lakes and seasons. Lakes are important habitats for bats, as they support diverse bat communities and activity throughout the night and the year when bats are active. Our study highlights that there are spatial and temporal differences in bat activity and its hourly nocturnal pattern, that should be considered when investigating aquatic-terrestrial interactions or designing conservation and monitoring plans.
Viruses of insects reared for food and feed.

PubMed

Maciel-Vergara, Gabriela; Ros, Vera I D

2017-07-01

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics. Copyright © 2017 Elsevier Inc. All rights reserved.
Faunistic Study of the Aquatic Arthropods in a Tourism Area in Northern Iran.

PubMed

Shaeghi, Mansoureh; Dehghan, Hossein; Pakdad, Kamran; Nikpour, Fatemeh; Absavaran, Azad; Sofizadeh, Aioub; Akhavan, Amir Ahmad; Vatandoost, Hassan; Aghai-Afshar, Abbass

2017-06-01

Aquatic insects are very abundant and divers groups of insects that are associated with an aquatic or semiaquatic environment in one or more of their life stages. These insects have been, in some cases, well studied because they are vectors of several diseases. This is the first comprehensive faunistic study of aquatic insects from Babol County. The results may provide basic data for further taxonomic and ecological studies of aquatic insects as biological control agent or classification of water quality for the country. The specimens were collected using different methods including: D-frame net collector, standard mosquito dipper (350ml), Sweep-Netting and plastic pipette. Sampling carried out in different part of breading places in several times. During this study a total of 196 aquatic specimens were collected from different habitats and were morphologically identified including 18 families classified in 6 orders: Diptera, Trichoptera, Ephemeroptera, Plecoptera, Hemiptera and Odonata. Babol and Amol district in Mazandaran Province are located in humid climate regions with suitable ecological factors of humidity, moderate temperature and the variety of plant species. There are different species of aquatic insects in different habitats. The results will provide information for biodeveristy, species richness, their role for biological control as well as calcification of rivers based on abundance of aquatic insects. Therefore the understanding of ecological specifications of aquatic insects could provide a clue for further Arthropod-borne disease control. Additionally aquatic insect could be used for classification of water bodies.
Faunistic Study of the Aquatic Arthropods in a Tourism Area in Northern Iran

PubMed Central

Shaeghi, Mansoureh; Dehghan, Hossein; Pakdad, Kamran; Nikpour, Fatemeh; Absavaran, Azad; Sofizadeh, Aioub; Akhavan, Amir Ahmad; Vatandoost, Hassan; Aghai-Afshar, Abbass

2017-01-01

Background: Aquatic insects are very abundant and divers groups of insects that are associated with an aquatic or semiaquatic environment in one or more of their life stages. These insects have been, in some cases, well studied because they are vectors of several diseases. This is the first comprehensive faunistic study of aquatic insects from Babol County. The results may provide basic data for further taxonomic and ecological studies of aquatic insects as biological control agent or classification of water quality for the country. Methods: The specimens were collected using different methods including: D-frame net collector, standard mosquito dipper (350ml), Sweep-Netting and plastic pipette. Sampling carried out in different part of breading places in several times. Results: During this study a total of 196 aquatic specimens were collected from different habitats and were morphologically identified including 18 families classified in 6 orders: Diptera, Trichoptera, Ephemeroptera, Plecoptera, Hemiptera and Odonata. Babol and Amol district in Mazandaran Province are located in humid climate regions with suitable ecological factors of humidity, moderate temperature and the variety of plant species. There are different species of aquatic insects in different habitats. Conclusion: The results will provide information for biodeveristy, species richness, their role for biological control as well as calcification of rivers based on abundance of aquatic insects. Therefore the understanding of ecological specifications of aquatic insects could provide a clue for further Arthropod-borne disease control. Additionally aquatic insect could be used for classification of water bodies PMID:29062853
Evolutionary Ecology of Multitrophic Interactions between Plants, Insect Herbivores and Entomopathogens.

PubMed

Shikano, Ikkei

2017-06-01

Plants play an important role in the interactions between insect herbivores and their pathogens. Since the seminal review by Cory and Hoover (2006) on plant-mediated effects on insect-pathogen interactions, considerable progress has been made in understanding the complexity of these tritrophic interactions. Increasing interest in the areas of nutritional and ecological immunology over the last decade have revealed that plant primary and secondary metabolites can influence the outcomes of insect-pathogen interactions by altering insect immune functioning and physical barriers to pathogen entry. Some insects use plant secondary chemicals and nutrients to prevent infections (prophylactic medication) and medicate to limit the severity of infections (therapeutic medication). Recent findings suggest that there may be selectable plant traits that enhance entomopathogen efficacy, suggesting that entomopathogens could potentially impose selection pressure on plant traits that improve both pathogen and plant fitness. Moreover, plants in nature are inhabited by diverse communities of microbes, in addition to entomopathogens, some of which can trigger immune responses in insect herbivores. Plants are also shared by numerous other herbivorous arthropods with different modes of feeding that can trigger different defensive responses in plants. Some insect symbionts and gut microbes can degrade ingested defensive phytochemicals and be orally secreted onto wounded plant tissue during herbivory to alter plant defenses. Since non-entomopathogenic microbes and other arthropods are likely to influence the outcomes of plant-insect-entomopathogen interactions, I discuss a need to consider these multitrophic interactions within the greater web of species interactions.
Convergent bacterial microbiotas in the fungal agricultural systems of insects.

PubMed

Aylward, Frank O; Suen, Garret; Biedermann, Peter H W; Adams, Aaron S; Scott, Jarrod J; Malfatti, Stephanie A; Glavina del Rio, Tijana; Tringe, Susannah G; Poulsen, Michael; Raffa, Kenneth F; Klepzig, Kier D; Currie, Cameron R

2014-11-18

The ability to cultivate food is an innovation that has produced some of the most successful ecological strategies on the planet. Although most well recognized in humans, where agriculture represents a defining feature of civilization, species of ants, beetles, and termites have also independently evolved symbioses with fungi that they cultivate for food. Despite occurring across divergent insect and fungal lineages, the fungivorous niches of these insects are remarkably similar, indicating convergent evolution toward this successful ecological strategy. Here, we characterize the microbiota of ants, beetles, and termites engaged in nutritional symbioses with fungi to define the bacterial groups associated with these prominent herbivores and forest pests. Using culture-independent techniques and the in silico reconstruction of 37 composite genomes of dominant community members, we demonstrate that different insect-fungal symbioses that collectively shape ecosystems worldwide have highly similar bacterial microbiotas comprised primarily of the genera Enterobacter, Rahnella, and Pseudomonas. Although these symbioses span three orders of insects and two phyla of fungi, we show that they are associated with bacteria sharing high whole-genome nucleotide identity. Due to the fine-scale correspondence of the bacterial microbiotas of insects engaged in fungal symbioses, our findings indicate that this represents an example of convergence of entire host-microbe complexes. The cultivation of fungi for food is a behavior that has evolved independently in ants, beetles, and termites and has enabled many species of these insects to become ecologically important and widely distributed herbivores and forest pests. Although the primary fungal cultivars of these insects have been studied for decades, comparatively little is known of their bacterial microbiota. In this study, we show that diverse fungus-growing insects are associated with a common bacterial community composed of the same dominant members. Furthermore, by demonstrating that many of these bacteria have high whole-genome similarity across distantly related insect hosts that reside thousands of miles apart, we show that these bacteria are an important and underappreciated feature of diverse fungus-growing insects. Because of the similarities in the agricultural lifestyles of these insects, this is an example of convergence between both the life histories of the host insects and their symbiotic microbiota. Copyright © 2014 Aylward et al.
Molecular Genetics of Beauveria bassiana Infection of Insects.

PubMed

Ortiz-Urquiza, A; Keyhani, N O

2016-01-01

Research on the insect pathogenic filamentous fungus, Beauveria bassiana has witnessed significant growth in recent years from mainly physiological studies related to its insect biological control potential, to addressing fundamental questions regarding the underlying molecular mechanisms of fungal development and virulence. This has been in part due to a confluence of robust genetic tools and genomic resources for the fungus, and recognition of expanded ecological interactions with which the fungus engages. Beauveria bassiana is a broad host range insect pathogen that has the ability to form intimate symbiotic relationships with plants. Indeed, there is an increasing realization that the latter may be the predominant environmental interaction in which the fungus participates, and that insect parasitism may be an opportunist lifestyle evolved due to the carbon- and nitrogen-rich resources present in insect bodies. Here, we will review progress on the molecular genetics of B. bassiana, which has largely been directed toward identifying genetic pathways involved in stress response and virulence assumed to have practical applications in improving the insect control potential of the fungus. Important strides have also been made in understanding aspects of B. bassiana development. Finally, although increasingly apparent in a number of studies, there is a need for progressing beyond phenotypic mutant characterization to sufficiently investigate the molecular mechanisms underlying B. bassiana's unique and diverse lifestyles as saprophyte, insect pathogen, and plant mutualist. Copyright © 2016 Elsevier Inc. All rights reserved.
Sensory Coordination of Insect Flight

DTIC Science & Technology

2010-10-22

sources in the fruit fly, Drosophila melanogaster. 3) Wing-haltere coordination in the soldier fly, Hermetia illucens. 4) Landing behavior in the housefly ...modular behaviors (e.g. a territorial chase between houseflies is composed of a take-off followed by many sharp turns). In pursuing this goal, we have...coordination in the soldier fly, Hermetia illucens. 4) Landing behavior in the housefly , Musca domestica. We have also recently established an
Analysis of gene expression in the midgut of Bombyx mori during the larval molting stage.

PubMed

Yang, Bing; Huang, Wuren; Zhang, Jie; Xu, Qiuyun; Zhu, Shoulin; Zhang, Qiaoli; Beerntsen, Brenda T; Song, Hongsheng; Ling, Erjun

2016-11-03

Insects can be models for understanding human intestinal infection and pathology. Molting, a special period during which the old insect cuticle is shed and a new one is produced, is crucial for insect development. Holometabolous insects may experience several larva-to-larva moltings to become larger, a pupal molt and adult eclosion to become adults. During the larval molts, they stop feeding and become quiescent. Although the molting larvae become quiescent, it is not known if changes in microbiome, physiology, development and immunity of midguts occur. Transcriptome analysis indicated that functions such as metabolism, digestion, and transport may become reduced due to the downregulated expression of many associated genes. During the molting stage, midguts harbor less microflora and DNA synthesis decreases. Both ecdysone and juvenile hormone in the larval midgut likely degrade after entering the larva-to-larva molting stage. However, at 12 h after ecdysis, the feeding larvae of 5th instars that were injected with 20-hydroxyecdysone entered a molting-like stage, during which changes in midgut morphology, DNA synthesis, gene expression, and microflora exhibited the same patterns as observed in the actual molting state. This study is important for understanding insect midgut physiology, development and immunity during a special development stage when no food is ingested. Although the molting larva becomes immobile and quiescent, we demonstrate that numerous changes occur in midgut morphology, physiology, metabolism and microbiome during this period.
Radiocesium Transfer in Forest Insect Communities after the Fukushima Dai-ichi Nuclear Power Plant Accident.

PubMed

Ishii, Yumiko; Hayashi, Seiji; Takamura, Noriko

2017-01-01

To understand radiocesium transfer in the forest insect food web, we investigated the activity concentrations of radiocesium in forest insects in the Fukushima and Ibaraki Prefectures approximately 1.5-2.5 years after the Fukushima Dai-ichi Nuclear Power Plant. We analyzed 34 species of insects sampled from 4 orders and 4 feeding functional groups (herbivore, carnivore, omnivore, and detritivore) from three sites in each prefecture. 137Cs activity concentrations were lowest in herbivorous species and were especially high in detritivorous and omnivorous species that feed on forest litter and fungi. Radiocesium activity concentrations in any given species reflected the degree of contamination of that species' primary food sources since radiocesium activity concentrations were found to be the lowest in leaves and grass and the highest in litter, bark, and fungi. This study confirmed that litter and other highly contaminated forest components such as fungi, decaying wood, bryophytes, and lichens serve as sources of 137Cs transfer into the forest insect community.
The Effect of Host-Plant Phylogenetic Isolation on Species Richness, Composition and Specialization of Insect Herbivores: A Comparison between Native and Exotic Hosts

PubMed Central

Grandez-Rios, Julio Miguel; Lima Bergamini, Leonardo; Santos de Araújo, Walter; Villalobos, Fabricio; Almeida-Neto, Mário

2015-01-01

Understanding the drivers of plant-insect interactions is still a key issue in terrestrial ecology. Here, we used 30 well-defined plant-herbivore assemblages to assess the effects of host plant phylogenetic isolation and origin (native vs. exotic) on the species richness, composition and specialization of the insect herbivore fauna on co-occurring plant species. We also tested for differences in such effects between assemblages composed exclusively of exophagous and endophagous herbivores. We found a consistent negative effect of the phylogenetic isolation of host plants on the richness, similarity and specialization of their insect herbivore faunas. Notably, except for Jaccard dissimilarity, the effect of phylogenetic isolation on the insect herbivore faunas did not vary between native and exotic plants. Our findings show that the phylogenetic isolation of host plants is a key factor that influences the richness, composition and specialization of their local herbivore faunas, regardless of the host plant origin. PMID:26379159
Radiocesium Transfer in Forest Insect Communities after the Fukushima Dai-ichi Nuclear Power Plant Accident

PubMed Central

Hayashi, Seiji; Takamura, Noriko

2017-01-01

To understand radiocesium transfer in the forest insect food web, we investigated the activity concentrations of radiocesium in forest insects in the Fukushima and Ibaraki Prefectures approximately 1.5–2.5 years after the Fukushima Dai-ichi Nuclear Power Plant. We analyzed 34 species of insects sampled from 4 orders and 4 feeding functional groups (herbivore, carnivore, omnivore, and detritivore) from three sites in each prefecture. 137Cs activity concentrations were lowest in herbivorous species and were especially high in detritivorous and omnivorous species that feed on forest litter and fungi. Radiocesium activity concentrations in any given species reflected the degree of contamination of that species’ primary food sources since radiocesium activity concentrations were found to be the lowest in leaves and grass and the highest in litter, bark, and fungi. This study confirmed that litter and other highly contaminated forest components such as fungi, decaying wood, bryophytes, and lichens serve as sources of 137Cs transfer into the forest insect community. PMID:28125745
Molecular modeling of the elastomeric properties of repeating units and building blocks of resilin, a disordered elastic protein.

PubMed

Khandaker, Md Shahriar K; Dudek, Daniel M; Beers, Eric P; Dillard, David A; Bevan, David R

2016-08-01

The mechanisms responsible for the properties of disordered elastomeric proteins are not well known. To better understand the relationship between elastomeric behavior and amino acid sequence, we investigated resilin, a disordered rubber-like protein, found in specialized regions of the cuticle of insects. Resilin of Drosophila melanogaster contains Gly-rich repetitive motifs comprised of the amino acids, PSSSYGAPGGGNGGR, which confer elastic properties to resilin. The repetitive motifs of insect resilin can be divided into smaller partially conserved building blocks: PSS, SYGAP, GGGN and GGR. Using molecular dynamics (MD) simulations, we studied the relative roles of SYGAP, and its less common variants SYSAP and TYGAP, on the elastomeric properties of resilin. Results showed that SYGAP adopts a bent structure that is one-half to one-third the end-to-end length of the other motifs having an equal number of amino acids but containing SYSAP or TYGAP substituted for SYGAP. The bent structure of SYGAP forms due to conformational freedom of glycine, and hydrogen bonding within the motif apparently plays a role in maintaining this conformation. These structural features of SYGAP result in higher extensibility compared to other motifs, which may contribute to elastic properties at the macroscopic level. Overall, the results are consistent with a role for the SYGAP building block in the elastomeric properties of these disordered proteins. What we learned from simulating the repetitive motifs of resilin may be applicable to the biology and mechanics of other elastomeric biomaterials, and may provide us the deeper understanding of their unique properties. Copyright © 2016 Elsevier Ltd. All rights reserved.
How do honeybees use their magnetic compass? Can they see the North?

PubMed

Válková, T; Vácha, M

2012-08-01

While seeking food sources and routes back to their hive, bees make use of their advanced nervous and sensory capacities, which underlie a diverse behavioral repertoire. One of several honeybee senses that is both exceptional and intriguing is magnetoreception - the ability to perceive the omnipresent magnetic field (MF) of the Earth. The mechanism by which animals sense MFs has remained fascinating as well as elusive because of the intricacies involved, which makes it one of the grand challenges for neural and sensory biology. However, investigations in recent years have brought substantial progress to our understanding of how such magneto-receptor(s) may work. Some terrestrial animals (birds) are reported to be equipped even with a dual perception system: one based on diminutive magnetic particles - in line with the original model which has also always been hypothesized for bees - and the other one, as the more recent model describes, based on a sensitivity of some photochemical reactions to MF (radical-pair or chemical mechanism). The latter model postulates a close link to vision and supposes that the animals can see the position of the geomagnetic North as a visible pattern superimposed on the picture of the environment. In recent years, a growing body of evidence has shown that radical-pair magnetoreception might also be used by insects. It is realistic to expect that such evidence will inspire a re-examination and extension or confirmation of established views on the honeybee magnetic-compass mechanism. However, the problem of bee magnetoreception will not be solved at the moment that a receptor is discovered. On the contrary, the meaning of magnetoreception in insect life and its involvement in the orchestration of other senses is yet to be fully understood. The crucial question to be addressed in the near future is whether the compass abilities of the honeybee could suffer from radio frequency (RF) smog accompanying modern civilization and whether the fitness of this dominant pollinator might be affected by RF fields. The goal of this review is to provide an overview of the path that the behavioral research on honeybee magnetoreception has taken and to discuss it in the context of contemporary data obtained on other insects.
Pre- and post-hatch trophic egg production in the subsocial burrower bug, Canthophorus niveimarginatus (Heteroptera: Cydnidae)

NASA Astrophysics Data System (ADS)

Filippi, Lisa; Baba, Narumi; Inadomi, Koichi; Yanagi, Takao; Hironaka, Mantaro; Nomakuchi, Shintaro

2009-02-01

In recent years, three terrestrial bugs, Adomerus triguttulus and Sehirus cinctus (Cydnidae) and the closely related Parastrachia japonensis (Parastrachiidae), have been the focus of several fascinating studies because of the remarkable, extensive parental care they were found to display. This care includes egg and nymph guarding, production of trophic eggs, unfertilized, low cost eggs that are used as food by newly hatched nymphs, and progressive provisioning of the host seed. In this study, we have investigated yet a third related Asian cydnid, Canthophorus niveimarginatus, with regard to the possible occurrence of some or all of these complex traits in order to assess how widespread these maternal investment patterns are in this group of insects and to better understand the implications of their manifestations from an evolutionary context. Manipulative experiments were carried out in the lab to determine whether females provision nests. Observational and egg removal studies were carried out to determine whether trophic eggs are produced, and, if they are, their possible impact on nymphal success. The findings revealed that C. niveimarginatus does, in fact, progressively provision young, and this species also displays all of the other behaviors associated with extended parental care in subsocial insects. Moreover, unlike the other two related species, which place trophic eggs on the surface of the original egg mass, C. niveimarginatus produces both pre- and post-hatch trophic eggs. Nymphs deprived of access to post-hatch trophic eggs had significantly lower body weight and survival rate than those that fed on them. To our knowledge, this is the first time the production of both pre- and post-hatch trophic eggs has been demonstrated in insects outside the Hymenoptera. In this paper, we qualitatively and quantitatively demonstrate the provisioning behavior and patterns of trophic egg production in C. niveimarginatus. When and how trophic eggs are produced and delivered to young should have important correlations with the ecological and life history constraints under which a species has evolved. Thus, we also discuss the possible ecological and life history factors that favor the evolution of post-hatch trophic eggs.
Joint torques in a freely walking insect reveal distinct functions of leg joints in propulsion and posture control

PubMed Central

2016-01-01

Determining the mechanical output of limb joints is critical for understanding the control of complex motor behaviours such as walking. In the case of insect walking, the neural infrastructure for single-joint control is well described. However, a detailed description of the motor output in form of time-varying joint torques is lacking. Here, we determine joint torques in the stick insect to identify leg joint function in the control of body height and propulsion. Torques were determined by measuring whole-body kinematics and ground reaction forces in freely walking animals. We demonstrate that despite strong differences in morphology and posture, stick insects show a functional division of joints similar to other insect model systems. Propulsion was generated by strong depression torques about the coxa–trochanter joint, not by retraction or flexion/extension torques. Torques about the respective thorax–coxa and femur–tibia joints were often directed opposite to fore–aft forces and joint movements. This suggests a posture-dependent mechanism that counteracts collapse of the leg under body load and directs the resultant force vector such that strong depression torques can control both body height and propulsion. Our findings parallel propulsive mechanisms described in other walking, jumping and flying insects, and challenge current control models of insect walking. PMID:26791608
Lipophorin Drives Lipid Incorporation and Metabolism in Insect Trypanosomatids.

PubMed

Ximenes, Aline dos Anjos; Silva-Cardoso, Lívia; De Cicco, Nuccia Nicole T; Pereira, Miria G; Lourenço, Daniela C; Fampa, Patricia; Folly, Evelize; Cunha-e-Silva, Narcisa L; Silva-Neto, Mario A C; Atella, Georgia C

2015-07-01

Insect trypanosomatids are inhabitants of the insect digestive tract. These parasites can be either monoxenous or dixenous. Plant trypanosomatids are known as insect trypanosomatids once they and are transmitted by phytophagous insects. Such parasites can be found in latex, phloem, fruits and seeds of many plant families. Infections caused by these pathogens are a major cause of serious economic losses. Studies by independent groups have demonstrated the metabolic flow of lipids from the vertebrate host to trypanosomatids. This mechanism is usually present when parasites possess an incomplete de novo lipid biosynthesis pathway. Here, we show that both insect trypanosomatids Phytomonas françai and Leptomonas wallacei incorporate (3)H-palmitic acid and inorganic phosphate. These molecules are used for lipid biosynthesis. Moreover, we have isolated the main hemolymphatic lipoprotein, Lipophorin (Lp) from Oncopeltus fasciatus, the natural insect vector of such parasites. Both parasites were able to incorporate Lp to be utilized both as a lipid and protein source for their metabolism. Also, we have observed the presence of Lp binding sites in the membrane of a parasite. In conclusion, we believe that the elucidation of trypanosomatid metabolic pathways will lead to a better understanding of parasite-host interactions and the identification of novel potential chemotherapy targets. Copyright © 2015 Elsevier GmbH. All rights reserved.
Characterization of Insect Resistance Loci in the USDA Soybean Germplasm Collection Using Genome-Wide Association Studies

PubMed Central

Chang, Hao-Xun; Hartman, Glen L.

2017-01-01

Management of insects that cause economic damage to yields of soybean mainly rely on insecticide applications. Sources of resistance in soybean plant introductions (PIs) to different insect pests have been reported, and some of these sources, like for the soybean aphid (SBA), have been used to develop resistant soybean cultivars. With the availability of SoySNP50K and the statistical power of genome-wide association studies, we integrated phenotypic data for beet armyworm, Mexican bean beetle (MBB), potato leafhopper (PLH), SBA, soybean looper (SBL), velvetbean caterpillar (VBC), and chewing damage caused by unspecified insects for a comprehensive understanding of insect resistance in the United States Department of Agriculture Soybean Germplasm Collection. We identified significant single nucleotide (SNP) polymorphic markers for MBB, PLH, SBL, and VBC, and we highlighted several leucine-rich repeat-containing genes and myeloblastosis transcription factors within the high linkage disequilibrium region surrounding significant SNP markers. Specifically for soybean resistance to PLH, we found the PLH locus is close but distinct to a locus for soybean pubescence density on chromosome 12. The results provide genetic support that pubescence density may not directly link to PLH resistance. This study offers a novel insight of soybean resistance to four insect pests and reviews resistance mapping studies for major soybean insects. PMID:28555141

Some links on this page may take you to non-federal websites. Their policies may differ from this site.