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Sample records for acoustic parasitoid emblemasoma

  1. Phonotactic flight of the parasitoid fly Emblemasoma auditrix (Diptera: Sarcophagidae).

    PubMed

    Tron, Nanina; Lakes-Harlan, Reinhard

    2017-01-01

    The parasitoid fly Emblemasoma auditrix locates its hosts using acoustic cues from sound producing males of the cicada Okanagana rimosa. Here, we experimentally analysed the flight path of the phonotaxis from a landmark to the target, a hidden loudspeaker in the field. During flight, the fly showed only small lateral deviations. The vertical flight direction angles were initially negative (directed downwards relative to starting position), grew positive (directed upwards) in the second half of the flight, and finally flattened (directed horizontally or slightly upwards), typically resulting in a landing above the loudspeaker. This phonotactic flight pattern was largely independent from sound pressure level or target distance, but depended on the elevation of the sound source. The flight velocity was partially influenced by sound pressure level and distance, but also by elevation. The more elevated the target, the lower was the speed. The accuracy of flight increased with elevation of the target as well as the landing precision. The minimal vertical angle difference eliciting differences in behaviour was 10°. By changing the elevation of the acoustic target after take-off, we showed that the fly is able to orientate acoustically while flying.

  2. Eavesdropping to Find Mates: The Function of Male Hearing for a Cicada-Hunting Parasitoid Fly, Emblemasoma erro (Diptera: Sarcophagidae).

    PubMed

    Stucky, Brian J

    2016-01-01

    Females of several species of dipteran parasitoids use long-range hearing to locate hosts for their offspring by eavesdropping on the acoustic mating calls of other insects. Males of these acoustic eavesdropping parasitoids also have physiologically functional ears, but so far, no adaptive function for male hearing has been discovered. I investigated the function of male hearing for the sarcophagid fly Emblemasoma erro Aldrich, an acoustic parasitoid of cicadas, by testing the hypothesis that both male and female E. erro use hearing to locate potential mates. I found that both male and nongravid female E. erro perform phonotaxis to the sounds of calling cicadas, that male flies engage in short-range, mate-finding behavior once they arrive at a sound source, and that encounters between females and males at a sound source can lead to copulation. Thus, cicada calling songs appear to serve as a mate-finding cue for both sexes of E. erro Emblemasoma erro's mate-finding behavior is compared to that of other sarcophagid flies, other acoustic parasitoids, and nonacoustic eavesdropping parasitoids.

  3. Eavesdropping to Find Mates: The Function of Male Hearing for a Cicada-Hunting Parasitoid Fly, Emblemasoma erro (Diptera: Sarcophagidae)

    PubMed Central

    Stucky, Brian J.

    2016-01-01

    Females of several species of dipteran parasitoids use long-range hearing to locate hosts for their offspring by eavesdropping on the acoustic mating calls of other insects. Males of these acoustic eavesdropping parasitoids also have physiologically functional ears, but so far, no adaptive function for male hearing has been discovered. I investigated the function of male hearing for the sarcophagid fly Emblemasoma erro Aldrich, an acoustic parasitoid of cicadas, by testing the hypothesis that both male and female E. erro use hearing to locate potential mates. I found that both male and nongravid female E. erro perform phonotaxis to the sounds of calling cicadas, that male flies engage in short-range, mate-finding behavior once they arrive at a sound source, and that encounters between females and males at a sound source can lead to copulation. Thus, cicada calling songs appear to serve as a mate-finding cue for both sexes of E. erro. Emblemasoma erro’s mate-finding behavior is compared to that of other sarcophagid flies, other acoustic parasitoids, and nonacoustic eavesdropping parasitoids. PMID:27382133

  4. The Auditory System of the Dipteran Parasitoid Emblemasoma auditrix (Sarcophagidae)

    PubMed Central

    Tron, Nanina; Stölting, Heiko; Kampschulte, Marian; Martels, Gunhild; Stumpner, Andreas; Lakes-Harlan, Reinhard

    2016-01-01

    Several taxa of insects evolved a tympanate ear at different body positions, whereby the ear is composed of common parts: a scolopidial sense organ, a tracheal air space, and a tympanal membrane. Here, we analyzed the anatomy and physiology of the ear at the ventral prothorax of the sarcophagid fly, Emblemasoma auditrix (Soper). We used micro-computed tomography to analyze the ear and its tracheal air space in relation to the body morphology. Both tympana are separated by a small cuticular bridge, face in the same frontal direction, and are backed by a single tracheal enlargement. This enlargement is connected to the anterior spiracles at the dorsofrontal thorax and is continuous with the tracheal network in the thorax and in the abdomen. Analyses of responses of auditory afferents and interneurons show that the ear is broadly tuned, with a sensitivity peak at 5 kHz. Single-cell recordings of auditory interneurons indicate a frequency- and intensity-dependent tuning, whereby some neurons react best to 9 kHz, the peak frequency of the host’s calling song. The results are compared to the convergently evolved ear in Tachinidae (Diptera). PMID:27538415

  5. Effect of continuous rearing on courtship acoustics of five braconid parasitoids, candidates for augmentative biological control of Anastrepha species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The courtship acoustics of five species of parasitoid wasps (Hymenoptera: Braconidae), potential candidates for augmentative biological control of Anastrepha species (Diptera: Tephritidae), were compared between recently colonized individuals and those continuously reared 70-148 generations. During...

  6. Parasitoid flies exploiting acoustic communication of insects-comparative aspects of independent functional adaptations.

    PubMed

    Lakes-Harlan, Reinhard; Lehmann, Gerlind U C

    2015-01-01

    Two taxa of parasitoid Diptera have independently evolved tympanal hearing organs to locate sound producing host insects. Here we review and compare functional adaptations in both groups of parasitoids, Ormiini and Emblemasomatini. Tympanal organs in both groups originate from a common precursor organ and are somewhat similar in morphology and physiology. In terms of functional adaptations, the hearing thresholds are largely adapted to the frequency spectra of the calling song of the hosts. The large host ranges of some parasitoids indicate that their neuronal filter for the temporal patterns of the calling songs are broader than those found in intraspecific communication. For host localization the night active Ormia ochracea and the day active E. auditrix are able to locate a sound source precisely in space. For phonotaxis flight and walking phases are used, whereby O. ochracea approaches hosts during flight while E. auditrix employs intermediate landings and re-orientation, apparently separating azimuthal and vertical angles. The consequences of the parasitoid pressure are discussed for signal evolution and intraspecific communication of the host species. This natural selection pressure might have led to different avoidance strategies in the hosts: silent males in crickets, shorter signals in tettigoniids and fluctuating population abundances in cicadas.

  7. Useless hearing in male Emblemasoma auditrix (Diptera, Sarcophagidae)--a case of intralocus sexual conflict during evolution of a complex sense organ?

    PubMed

    Lakes-Harlan, Reinhard; Devries, Thomas; Stölting, Heiko; Stumpner, Andreas

    2014-01-01

    Sensory modalities typically are important for both sexes, although sex-specific functional adaptations may occur frequently. This is true for hearing as well. Consequently, distinct behavioural functions were identified for the different insect hearing systems. Here we describe a first case, where a trait of an evolutionary novelty and a highly specialized hearing organ is adaptive in only one sex. The main function of hearing of the parasitoid fly Emblemasoma auditrix is to locate the host, males of the cicada species Okanagana rimosa, by their calling song. This task is performed by female flies, which deposit larvae into the host. We show that male E. auditrix possess a hearing sense as well. The morphology of the tympanal organ of male E. auditrix is rather similar to the female ear, which is 8% broader than the male ear. In both sexes the physiological hearing threshold is tuned to 5 kHz. Behavioural tests show that males are able to orient towards the host calling song, although phonotaxis often is incomplete. However, despite extensive observations in the field and substantial knowledge of the biology of E. auditrix, no potentially adaptive function of the male auditory sense has been identified. This unique hearing system might represent an intralocus sexual conflict, as the complex sense organ and the behavioural relevant neuronal network is adaptive for only one sex. The correlated evolution of the sense organ in both sexes might impose substantial constraints on the sensory properties of the ear. Similar constraints, although hidden, might also apply to other sensory systems in which behavioural functions differ between sexes.

  8. Carabid Beetles as Parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The parasitoid habit is uncommon in beetles; only 11 beetle families include parasitoid species. Three tribes of 76 in the Carabidae are known to have species in which larvae are pupal ectoparasitoids: Brachinini, Peleciini, and Lebiini. The first larval instar is the free-living, host-finding stage...

  9. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  10. The impact of parasitoid emergence time on host-parasitoid population dynamics.

    PubMed

    Cobbold, Christina A; Roland, Jens; Lewis, Mark A

    2009-01-01

    We investigate the effect of parasitoid phenology on host-parasitoid population cycles. Recent experimental research has shown that parasitized hosts can continue to interact with their unparasitized counterparts through competition. Parasitoid phenology, in particular the timing of emergence from the host, determines the duration of this competition. We construct a discrete-time host-parasitoid model in which within-generation dynamics associated with parasitoid timing is explicitly incorporated. We found that late-emerging parasitoids induce less severe, but more frequent, host outbreaks, independent of the choice of competition model. The competition experienced by the parasitized host reduces the parasitoids' numerical response to changes in host numbers, preventing the 'boom-bust' dynamics associated with more efficient parasitoids. We tested our findings against experimental data for the forest tent caterpillar (Malacosoma disstria Hübner) system, where a large number of consecutive years at a high host density is synonymous with severe forest damage.

  11. Host-parasitoid dynamics of a generalized Thompson model.

    PubMed

    Schreiber, Sebastian J

    2006-06-01

    A discrete-time host-parasitoid model including host-density dependence and a generalized Thompson escape function is analyzed. This model assumes that parasitoids are egg-limited but not search-limited, and is proven to exhibit five types of dynamics: host failure in which the host goes extinct in the parasitoid's presence or absence, unconditional parasitoid failure in which the parasitoid always goes extinct while the host persists, conditional parasitoid failure in the host and the parasitoid go extinct or coexist depending on the initial host-parasitoid ratio, parasitoid driven extinction in which the parasitoid invariably drives the host to extinction, and coexistence in which the host and parasitoid coexist about a global attractor. The latter two dynamics only occur when the parasitoid's maximal rate of growth exceeds the host's maximal rate of growth. Moreover, coexistence requires parasitism events to be sufficiently aggregated. Small additive noise is proven to alter the dynamical outcomes in two ways. The addition of noise to parasitoid driven extinction results in random outbreaks of the host and parasitoid with varying intensity. Additive noise converts conditional parasitoid failure to unconditional parasitoid failure. Implications for classical biological control are discussed.

  12. Egg parasitoids of Megamelus spp. (Hemiptera:Delphacidae) in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Egg parasitoids (Hymenoptera: Eulophidae, Mymaridae, and Platygastridae) of Megamelus spp. (Hemiptera: Delphacidae) in Argentina are reviewed and keyed. Newly described are Anagrus (Anagrus) empanadus Triapitsyn, sp. n. (Mymaridae, parasitoid of M. scutellaris Berg on water hyacinth, Eichhornia cras...

  13. Trophic relationships between aphids and their primary parasitoids.

    PubMed

    Khan, Imtinan A; Naeem, Muhammad; Hassan, Soaib A; Bilal, Hazrat; Ata-ul-Mohsin; Bodlah, Imran

    2012-01-01

    The present research was carried out to study the trophic relationship between aphids and their primary parasitoids in Pothwar, Pakistan during 2009-2010 in the districts of Rawalpindi, Attock, Chakwal, and Jhelum. Ten species of aphids were recorded from 17 host plants. The aphids were parasitized by 11 species of primary parasitoids. Five quantitative aphid-parasitoid food webs were constructed describing the trophic relationships between the community of aphids and their primary parasitoids.

  14. Evolution and manipulation of parasitoid egg load.

    PubMed

    Gandon, Sylvain; Varaldi, Julien; Fleury, Frédéric; Rivero, Ana

    2009-11-01

    In proovigenic parasitoids such as Leptopilina boulardi, the female emerges with a limited egg load and no further eggs are produced during its adult life. A female thus runs the risk of exhausting this limited supply of eggs before the end of her life. Given that the production of an egg is costly, what is the evolutionarily stable egg load at emergence? This question has attracted a lot of attention in the last decade. Here, we analyze a model that allows us to track both the evolution and the population dynamics of a solitary, proovigenic parasitoid. First, we show how host-parasitoid dynamics feedbacks on the evolution of parasitoid egg load. Second, we use this model to consider the situation in which the parasitoid can be infected by a virus that manipulates the oviposition behavior of the females. In particular, we model the effect of the LbFV virus in L. boulardi, a virus that is known to enhance its horizontal transmission by increasing superparasitism (i.e., the laying of eggs in a host already parasitized). Specifically, we model (1) the effect of the virus on parasitoid egg load strategies, and (2) the evolution of egg load manipulation by the virus. This analysis yields two alternative, yet not mutually exclusive, adaptive explanations for the observation that females infected by the virus harbor higher egg loads than uninfected females. Infected females could either respond plastically to the infection status, or be manipulated by the virus. Further experimental work is required to distinguish between these two hypotheses. In a broader context, we present a general theoretical framework that allows us to study the epidemiology, the evolution, the coevolution, and the evolution of manipulation of various reproductive strategies of parasitoids.

  15. Host-Parasitoid Dynamics and the Success of Biological Control When Parasitoids Are Prone to Allee Effects

    PubMed Central

    Bompard, Anaïs; Amat, Isabelle; Fauvergue, Xavier; Spataro, Thierry

    2013-01-01

    In sexual organisms, low population density can result in mating failures and subsequently yields a low population growth rate and high chance of extinction. For species that are in tight interaction, as in host-parasitoid systems, population dynamics are primarily constrained by demographic interdependences, so that mating failures may have much more intricate consequences. Our main objective is to study the demographic consequences of parasitoid mating failures at low density and its consequences on the success of biological control. For this, we developed a deterministic host-parasitoid model with a mate-finding Allee effect, allowing to tackle interactions between the Allee effect and key determinants of host-parasitoid demography such as the distribution of parasitoid attacks and host competition. Our study shows that parasitoid mating failures at low density result in an extinction threshold and increase the domain of parasitoid deterministic extinction. When proned to mate finding difficulties, parasitoids with cyclic dynamics or low searching efficiency go extinct; parasitoids with high searching efficiency may either persist or go extinct, depending on host intraspecific competition. We show that parasitoids suitable as biocontrol agents for their ability to reduce host populations are particularly likely to suffer from mate-finding Allee effects. This study highlights novel perspectives for understanding of the dynamics observed in natural host-parasitoid systems and improving the success of parasitoid introductions. PMID:24116153

  16. Competitive interactions between parasitoids provide new insight into host suppression.

    PubMed

    Xu, Hai-Yun; Yang, Nian-Wan; Wan, Fang-Hao

    2013-01-01

    Understanding the dynamics of potential inter- and intraspecific competition in parasitoid communities is crucial in the screening of efficient parasitoid species and for utilization of the best parasitoid species combinations. In this respect, the host-parasitoid systems, Bemisia tabaci and two parasitoids, Eretmocerus hayati (exotic) and Encarsia sophia (existing) were studied under laboratory conditions to investigate whether interference competition between the exotic and existing species occurs as well as the influence of potential interference competition on the suppression of the host B. tabaci. Studies on interspecific-, intraspecific- and self-interference competition in two parasitoid species were conducted under both rich and limited host resource conditions. Results showed that (1) both parasitoid species negatively affect the progeny production of the other under both rich and limited host resource conditions; (2) both parasitoid species interfered intraspecifically on conspecific parasitized hosts when the available hosts are scarce and; 3) the mortality of B. tabaci induced by parasitoids via parasitism, host-feeding or both parasitism and host-feeding together varied among treatments under different host resource conditions, but showed promise for optimizing control strategies. As a result of our current findings, we suggest a need to investigate the interactions between the two parasitoids on continuous generations.

  17. Biological control of livestock pests : Parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), are common pests on livestock, poultry, and equine facilities. Biological control of filth flies with pupal parasitoids can be used in conjunction with other control methods as part of an integrated fly management program. ...

  18. A parasitoid wasp Doryctobracon areolatus (Szepligeti)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Doryctobracon areolatus (Szépligeti, 1911), formerly Parachasma cereum (Gahan), is a parasitoid of Anastrepha spp. in the Neo- and subtropics (Ovruski et al. 2000). It was introduced into Florida and the Dominican Republic for control of the Caribbean fruit fly, Anastrepha suspensa (Loe...

  19. Interspecific competition/facilitation among insect parasitoids.

    PubMed

    Cusumano, Antonino; Peri, Ezio; Colazza, Stefano

    2016-04-01

    Competition for limited resources is a widespread ecological interaction in animals. In the case of insect parasitoids, species can compete for host resources both at the adult stage as well as at the larval stage. Interspecific competition can play a role in sizing and shaping community structures. In addition of being relevant for basic ecological studies, understanding how interspecific competition between parasitoids affects pest suppression is important for biological control. In this opinion paper we review recent advances in the field of interspecific competition among parasitoids in a biological control perspective. We first discuss adult competition, highlighting which factors are likely to play a role in the outcome of competition when adults interact either directly or indirectly. Then we focus on the interactions occurring between competing larvae that develop within the same host taking also into account the fitness consequences of competition for the larva surviving interspecific competition. We also explore the possibility of interspecific facilitation among parasitoids in those situations in which a given species may benefit from interspecific competition.

  20. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor; Hearing loss - acoustic; Tinnitus - acoustic ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  1. 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.

  2. Caterpillar hairs as an anti-parasitoid defence

    NASA Astrophysics Data System (ADS)

    Kageyama, Azusa; Sugiura, Shinji

    2016-10-01

    Caterpillar hairs are thought to act as a physical barrier against natural enemies, including parasitoids. However, very few studies have experimentally demonstrated how hairs protect caterpillars from parasitoid oviposition. To clarify the importance of caterpillar hairs as an anti-parasitoid defence, we observed the generalist endoparasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) attacking both smooth and hairy caterpillars under laboratory conditions. A female Meteorus pulchricornis uses its ovipositor to inject venom and lay a single egg inside host larvae. We placed a smooth Spodoptera litura (Lepidoptera: Noctuidae) caterpillar or a hairy Lymantria dispar japonica (Lepidoptera: Erebidae) caterpillar in front of parasitoid females. We observed that 100 % and 84 % of the parasitoids could successfully stab their ovipositors into the smooth larvae of S. litura and first instars of the hairy caterpillar L. dispar japonica, respectively. However, only 24 % of parasitoids could successfully stab their ovipositors into second-instar L. dispar japonica. A higher rate of successful stabs (94 %) by parasitoids was obtained by cutting the hairs of second instar L. dispar japonica much shorter than the parasitoid ovipositor. The results demonstrate that the long, thick hairs of second and later instars of L. dispar japonica function as a physical barrier against parasitoid oviposition.

  3. Matching host reactions to parasitoid wasp vibrations.

    PubMed Central

    Djemai, I; Casas, J; Magal, C

    2001-01-01

    The sensory ecology of predator detection by prey has been little studied for any arthropod prey predator system, in contrast to the sensory ecology of prey finding by predators. The aim of this study was to quantify the foraging signals produced by the parasitoid Sympiesis sericeicornis (Hymenoptera: Eulophidae) and the sensory ecology of enemy detection and the avoidance behaviour of the leaf-mining host, Phyllonorycter spp. (Lepidoptera: Gracillariidae). We used synthetic vibrations approximating the signals generated by ovipositor insertions to stimulate the host in its mine. Tothe authors' knowledge, this is the first manipulative study to describe a match in the frequency range between a parasitoid foraging stimulus and a host behavioural response. We discuss our findings in relation to other predator-prey systems for which a coevolution between prey sensitivity and predator signal has been described. PMID:11747557

  4. Systemic Imidacloprid Affects Intraguild Parasitoids Differently.

    PubMed

    Taylor, Sally V; Burrack, Hannah J; Roe, R Michael; Bacheler, Jack S; Sorenson, Clyde E

    2015-01-01

    Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) and Campoletis sonorensis (Cameron) (Hymenoptera, Ichneumonidae) are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011-2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches.

  5. Systemic Imidacloprid Affects Intraguild Parasitoids Differently

    PubMed Central

    Roe, R. Michael; Bacheler, Jack S.

    2015-01-01

    Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) and Campoletis sonorensis (Cameron) (Hymenoptera, Ichneumonidae) are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011–2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches. PMID:26658677

  6. Deforestation homogenizes tropical parasitoid-host networks.

    PubMed

    Laliberté, Etienne; Tylianakis, Jason M

    2010-06-01

    Human activities drive biotic homogenization (loss of regional diversity) of many taxa. However, whether species interaction networks (e.g., food webs) can also become homogenized remains largely unexplored. Using 48 quantitative parasitoid-host networks replicated through space and time across five tropical habitats, we show that deforestation greatly homogenized network structure at a regional level, such that interaction composition became more similar across rice and pasture sites compared with forested habitats. This was not simply caused by altered consumer and resource community composition, but was associated with altered consumer foraging success, such that parasitoids were more likely to locate their hosts in deforested habitats. Furthermore, deforestation indirectly homogenized networks in time through altered mean consumer and prey body size, which decreased in deforested habitats. Similar patterns were obtained with binary networks, suggesting that interaction (link) presence-absence data may be sufficient to detect network homogenization effects. Our results show that tropical agroforestry systems can support regionally diverse parasitoid-host networks, but that removal of canopy cover greatly homogenizes the structure of these networks in space, and to a lesser degree in time. Spatiotemporal homogenization of interaction networks may alter coevolutionary outcomes and reduce ecological resilience at regional scales, but may not necessarily be predictable from community changes observed within individual trophic levels.

  7. Long term dynamics of aphelinid parasitoids attacking Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aphelinid parasitoids are widely known natural enemies of Bemisia tabaci, a serious pest of agriculture globally. Here we examine pest and parasitoid interactions and dynamics in cotton from 1996–2010, during which a classical biological control program was underway. Two native species, Eremocerus e...

  8. Host Niches and Defensive Extended Phenotypes Structure Parasitoid Wasp Communities

    PubMed Central

    Bailey, Richard; Schönrogge, Karsten; Cook, James M.; Melika, George; Csóka, György; Thuróczy, Csaba; Stone, Graham N.

    2009-01-01

    Oak galls are spectacular extended phenotypes of gallwasp genes in host oak tissues and have evolved complex morphologies that serve, in part, to exclude parasitoid natural enemies. Parasitoids and their insect herbivore hosts have coevolved to produce diverse communities comprising about a third of all animal species. The factors structuring these communities, however, remain poorly understood. An emerging theme in community ecology is the need to consider the effects of host traits, shaped by both natural selection and phylogenetic history, on associated communities of natural enemies. Here we examine the impact of host traits and phylogenetic relatedness on 48 ecologically closed and species-rich communities of parasitoids attacking gall-inducing wasps on oaks. Gallwasps induce the development of spectacular and structurally complex galls whose species- and generation-specific morphologies are the extended phenotypes of gallwasp genes. All the associated natural enemies attack their concealed hosts through gall tissues, and several structural gall traits have been shown to enhance defence against parasitoid attack. Here we explore the significance of these and other host traits in predicting variation in parasitoid community structure across gallwasp species. In particular, we test the “Enemy Hypothesis,” which predicts that galls with similar morphology will exclude similar sets of parasitoids and therefore have similar parasitoid communities. Having controlled for phylogenetic patterning in host traits and communities, we found significant correlations between parasitoid community structure and several gall structural traits (toughness, hairiness, stickiness), supporting the Enemy Hypothesis. Parasitoid community structure was also consistently predicted by components of the hosts' spatiotemporal niche, particularly host oak taxonomy and gall location (e.g., leaf versus bud versus seed). The combined explanatory power of structural and spatiotemporal

  9. Vibration-mediated interactions in a host–parasitoid system

    PubMed Central

    Meyhöfer, R.; Casas, J.; Dorn, S.

    1997-01-01

    The aim of this paper was to obtain behavioral evidence of vibration mediated interactions between the apple tentiform leafminer Phyllonorycter malella (Ger.) (Lepidoptera, Gracillariidae) and its parasitoid Sympiesis sericeicornis Nees (Hymenoptera, Eulophidae). The experimental set-up allowed the simultaneous recording on video film of both the parasitoids and the hosts behavior, thus enabling us to contrast their respective responses to the leaf vibrations produced by the other party. We analysed the one step transition probabilties from one behavioral state to the following. Active larval movements had a marked influence on the parasitoid's behavior, while feeding and still had no detectable effect. We found no evidence for vibrotaxis on the part of the parasitoid. While parasitoid searching behavior on the leaf surface did not seem to alter the leafminers behavior, ovipositor insertions triggered a characteristic avoidance response. The described interactions are discussed in the context of the 'princess and monster' model developed in search and game theory.

  10. Resource acquisition, allocation, and utilization in parasitoid reproductive strategies.

    PubMed

    Jervis, Mark A; Ellers, Jacintha; Harvey, Jeffrey A

    2008-01-01

    Parasitoids display remarkable inter- and intraspecific variation in their reproductive and associated traits. Adaptive explanations have been proposed for many of the between-trait relationships. We present an overview of the current knowledge of parasitoid reproductive biology, focusing on egg production strategies in females, by placing parasitoid reproduction within physiological and ecological contexts. Thus, we relate parasitoid reproduction both to inter- and intraspecific patterns of nutrient allocation, utilization, and acquisition, and to key aspects of host ecology, specifically abundance and dispersion pattern. We review the evidence that resource trade-offs underlie several key intertrait correlations and that reproductive and feeding strategies are closely integrated at both the physiological and the behavioral levels. The idea that parasitoids can be divided into capital-breeders or income-breeders is no longer tenable; such terminology is best restricted to the females' utilization of particular nutrients.

  11. Venom Proteins from Parasitoid Wasps and Their Biological Functions

    PubMed Central

    Moreau, Sébastien J. M.; Asgari, Sassan

    2015-01-01

    Parasitoid wasps are valuable biological control agents that suppress their host populations. Factors introduced by the female wasp at parasitization play significant roles in facilitating successful development of the parasitoid larva either inside (endoparasitoid) or outside (ectoparasitoid) the host. Wasp venoms consist of a complex cocktail of proteinacious and non-proteinacious components that may offer agrichemicals as well as pharmaceutical components to improve pest management or health related disorders. Undesirably, the constituents of only a small number of wasp venoms are known. In this article, we review the latest research on venom from parasitoid wasps with an emphasis on their biological function, applications and new approaches used in venom studies. PMID:26131769

  12. Venom Proteins from Parasitoid Wasps and Their Biological Functions.

    PubMed

    Moreau, Sébastien J M; Asgari, Sassan

    2015-06-26

    Parasitoid wasps are valuable biological control agents that suppress their host populations. Factors introduced by the female wasp at parasitization play significant roles in facilitating successful development of the parasitoid larva either inside (endoparasitoid) or outside (ectoparasitoid) the host. Wasp venoms consist of a complex cocktail of proteinacious and non-proteinacious components that may offer agrichemicals as well as pharmaceutical components to improve pest management or health related disorders. Undesirably, the constituents of only a small number of wasp venoms are known. In this article, we review the latest research on venom from parasitoid wasps with an emphasis on their biological function, applications and new approaches used in venom studies.

  13. Effect of host diet and adult parasitoid diet on egg load dynamics and egg size of braconid parasitoids attacking Anastrepha ludens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The quantity and quality of host nutrients can affect fitness-related traits in hymenopteran parasitoids, including oogenesis. We predicted that increasing host quality would positively influence oogenesis-related traits in synovigenic parasitoids, and that increasing quality of adult parasitoid die...

  14. Acoustic Neuroma

    MedlinePlus

    ... search IRSA's site Unique Hits since January 2003 Acoustic Neuroma Click Here for Acoustic Neuroma Practice Guideline ... to microsurgery. One doctor's story of having an acoustic neuroma In August 1991, Dr. Thomas F. Morgan ...

  15. Effects of urbanisation on the parasitoid community of a leafminer

    NASA Astrophysics Data System (ADS)

    Fenoglio, María S.; Salvo, Adriana; Estallo, Elizabet L.

    2009-03-01

    Urbanisation may have detrimental effects on communities of parasitoids, affecting their species richness, abundance, and species dominance. Here we investigated the influence of the degree of urbanisation on parasitoid communities of Liriomyza commelinae (Frost) (Diptera: Agromyzidae), a leafminer of Commelina erecta L. (Commelinaceae), in the city of Córdoba, Argentina. To study changes in species richness, the specific composition of parasitic complexes and their degree of impact on the leafminer, 18 sampling sites from the centre to the outskirts of the city were selected and different variables indicative of urbanisation were quantified in each site. During January and February of 2005 and 2006, all mined leaves found in each plant patch were collected and the following variables were estimated: proportion of mined patches, abundance of the leafminer, total parasitoid species richness, total parasitism rates and parasitism due to the most abundant parasitoid species. The percentage of mined patches and leafminer abundance increased with urbanisation degree. Estimates of parasitoid species richness were not influenced by urbanisation degree but increased with species richness of mined plants. Changes in the specific composition of species along the urbanisation gradient were observed. Although parasitism by one of the species studied was higher in more urbanised sites of the city, the total parasitism rate of L. commelinae was not affected by urbanisation degree, species richness of mined plants or leafminer abundance. It appears that urbanisation benefits the herbivore species here studied but not through altering parasitoid activity. Changes in parasitoid community composition reflex dissimilar tolerance to environmental conditions displayed by different parasitoid species.

  16. Hymenopteran parasitoids of diamondback moth (Lepidoptera: Ypeunomutidae) in northern Thailand.

    PubMed

    Rowell, Brent; Bunsong, Nittayaporn; Satthaporn, Kosin; Phithamma, Sompian; Doungsa-Ard, Charnnarong

    2005-04-01

    Larvae of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Ypeunomutidae), cause severe economic damage to cabbage, Brassica oleracea L. variety capitata (Brassicaceae) and related vegetables in Thailand. Overuse of broad-spectrum insecticides for diamondback moth control is a serious problem and has obscured the contributions of indigenous parasitoids. Our objectives were to identify indigenous diamondback moth parasitoids in northern Thailand and to assess their potential for natural control. Six parasitoid species were reared from diamondback moth larvae and pupae collected in 1990 and in 2003-2004. These included the larval parasitoid Cotesia plutellae Kurdjumov (Braconidae), a larval-pupal parasitoid Macromalon orientale Kerrich (Ichneumonidae), and pupal parasitoids Diadromus collaris Gravenhorst (Ichneumonidae) and Brachymeria excarinata Gahan (Chalcididae). Single specimens of Isotima sp. Forster (Ichneumonidae) and Brachymeria lasus Walker (Chalcididae) also were reared from diamondback moth hosts. C. plutellae was the dominant larval parasitoid and was often reared from host larvae collected from fields sprayed regularly with insecticides; parasitism ranged from 14 to 78%. Average parasitism by M. orientale was only 0.5-6%. Parasitism of host pupae by D. collaris ranged from 9 to 31%, whereas B. excarinata pupal parasitism ranged from 9 to 25%. An integrated pest management (IPM) protocol using simple presence-absence sampling for lepidopterous larvae and the exclusive use of Bacillus thuringiensis (Bt) or neem resulted in the highest yields of undamaged cabbage compared with a control or weekly sprays of cypermethrin (local farmer practice). IPM programs focused on conservation of local diamondback moth parasitoids and on greater implementation of biological control will help alleviate growing public concerns regarding the effects of pesticides on vegetable growers and consumers.

  17. Packing of Fruit Fly Parasitoids for Augmentative Releases.

    PubMed

    Montoya, Pablo; Cancino, Jorge; Ruiz, Lía

    2012-09-20

    The successful application of Augmentative Biological Control (ABC) to control pest fruit flies (Diptera: Tephritidae) confronts two fundamental requirements: (1) the establishment of efficient mass rearing procedures for the species to be released, and (2) the development of methodologies for the packing and release of parasitoids that permit a uniform distribution and their optimal field performance under an area-wide approach. Parasitoid distributions have been performed by ground and by air with moderate results; both options face challenges that remain to be addressed. Different devices and strategies have been used for these purposes, including paper bags and the chilled adult technique, both of which are commonly used when releasing sterile flies. However, insect parasitoids have morphological and behavioral characteristics that render the application of such methodologies suboptimal. In this paper, we discuss an alternate strategy for the augmentative release of parasitoids and describe packing conditions that favor the rearing and emergence of adult parasitoids for increased field performance. We conclude that the use of ABC, including the packaging of parasitoids, requires ongoing development to ensure that this technology remains a viable and effective control technique for pest fruit flies.

  18. Packing of Fruit Fly Parasitoids for Augmentative Releases

    PubMed Central

    Montoya, Pablo; Cancino, Jorge; Ruiz, Lía

    2012-01-01

    The successful application of Augmentative Biological Control (ABC) to control pest fruit flies (Diptera: Tephritidae) confronts two fundamental requirements: (1) the establishment of efficient mass rearing procedures for the species to be released, and (2) the development of methodologies for the packing and release of parasitoids that permit a uniform distribution and their optimal field performance under an area-wide approach. Parasitoid distributions have been performed by ground and by air with moderate results; both options face challenges that remain to be addressed. Different devices and strategies have been used for these purposes, including paper bags and the chilled adult technique, both of which are commonly used when releasing sterile flies. However, insect parasitoids have morphological and behavioral characteristics that render the application of such methodologies suboptimal. In this paper, we discuss an alternate strategy for the augmentative release of parasitoids and describe packing conditions that favor the rearing and emergence of adult parasitoids for increased field performance. We conclude that the use of ABC, including the packaging of parasitoids, requires ongoing development to ensure that this technology remains a viable and effective control technique for pest fruit flies. PMID:26466634

  19. Host behaviour manipulation as an evolutionary route towards attenuation of parasitoid virulence.

    PubMed

    Maure, F; Doyon, J; Thomas, F; Brodeur, J

    2014-12-01

    By definition, insect parasitoids kill their host during their development. Data are presented showing that ladybirds not only can survive parasitism by Dinocampus coccinellae, but also can retain their capacity to reproduce following parasitoid emergence. We hypothesize that host behaviour manipulation constitutes a preadaptation leading to the attenuation of parasitoid virulence. Following larval development, the parasitoid egresses from the host and spins a cocoon between the ladybird's legs. Throughout parasitoid pupation, the manipulated host acts as a bodyguard to protect the parasitoid cocoon from predation. The parasitoid has evolved mechanisms to avoid killing the host prematurely so that its own survival is not compromised. Bodyguard manipulation may thus constitute a selective trait for the evolution of true parasitism in some host-parasitoid associations.

  20. Partial aphid resistance in lettuce negatively affects parasitoids.

    PubMed

    Lanteigne, Marie-Eve; Brodeur, Jacques; Jenni, Sylvie; Boivin, Guy

    2014-10-01

    This study investigated the effects of partial plant resistance on the lettuce aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae), a major pest of cultivated lettuce (Lactuca sativa L.), and one of its parasitoids, Aphidius ervi Haliday (Hymenoptera: Braconidae). Aphids were reared on susceptible (L. sativa variety Estival; S) or partially resistant (Lactuca serriola L. PI 491093; PR) lettuce, and next parasitized by A. ervi females. Fitness proxies were measured for both aphids and parasitoids. Developmental time to adult stage took longer for alate and apterous aphids (an average of 3.5 and 1.5 additional days, respectively) on PR than on S lettuce, and fecundity of alate aphids reared on PR lettuce was reduced by 37.8% relative to those reared on S lettuce. Size (tibia length) and weight of aphids reared on PR lettuce were lower than for aphids reared on S lettuce from the third and second instar onward, respectively. Parasitism of aphids reared on PR plants resulted in lower parasitoid offspring emergence (-49.9%), lower adult female (-30.3%) and male (-27.5%) weight, smaller adult female (-17.5%) and male (-11.9%) size, and lower female fecundity (37.8% fewer eggs) than when parasitoids developed from aphids reared on S plants. Our results demonstrate that partial aphid resistance in lettuce negatively affects both the second and third trophic levels. Host plant resistance in cultivated lettuce may therefore create an ecological sink for aphid parasitoids.

  1. Factors affecting stem borer parasitoid species diversity and parasitism in cultivated and natural habitats.

    PubMed

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Calatayud, Paul-André; Dupas, Stéphane

    2010-02-01

    The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance, and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya. Comparing habitat types, we found partial support for the "natural enemy" hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, parasitoid richness was mainly influenced by stem borer density and/or its interaction with stem borer richness, whereas parasitoid abundance was mainly affected by stem borer abundance. Parasitoid richness was higher in localities (with bimodal rainfall distribution) with increased spatial and temporal availability of host plants that harbored the borers. Across seasons, parasitoid richness was lower in both cultivated and natural habitats in the driest locality, Mtito Andei. Overall, parasitoid diversity was low in Suam and Mtito Andei, where maize cultivation was practiced on a commercial scale and intense grazing activities persist across seasons, respectively. Across localities, habitats, and seasons, stem borer parasitism was positively correlated with parasitoid richness and abundance. Furthermore, the interaction of rainfall and altitude influenced the presence and absence of parasitoids, and consequently, stem borer parasitism. Parasitism was positively and negatively correlated with temperature in cultivated and natural habitats, respectively. Overall, natural habitats seem to serve as important refugia for sustaining parasitoid diversity, which in turn can affect stem borer parasitism in the cereal cropping system.

  2. The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage

    PubMed Central

    Gagic, Vesna; Petrović-Obradović, Olivera; Fründ, Jochen; Kavallieratos, Nickolas G.; Athanassiou, Christos G.; Starý, Petr; Tomanović, Željko

    2016-01-01

    Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and host-use efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts) on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant), without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure. PMID:27309729

  3. Self-Injection of a Dipteran Parasitoid into a Spider

    NASA Astrophysics Data System (ADS)

    Overgaard Nielsen, B.; Funch, P.; Toft, S.

    A host invasion strategy hitherto unknown from other insect parasitoids was observed in the dipteran Acrocera orbicula (Fabricius) (Diptera: Acroceridae) parasitizing the wolf spider, Pardosa prativaga (L. Koch) (Araneida: Lycosidae). In laboratory experiments the free-living first instar acrocerid larvae attached themselves firmly to the spiders' integument by the mouthparts, cutting a tiny hole through the integument. No first instar larvae invaded the host. A week later the parasitoids molted, and a small, flexible, and glabrous second instar larva left each of the attached first instar exuviae and invaded the host through the attachment hole of the first instar larva. The novel host invasion pattern observed may reduce physical damage to the host in the initial phase of endoparasitism, enhancing parasitoid survival.

  4. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  5. Lobesia botrana larvae develop faster in the presence of parasitoids.

    PubMed

    Vogelweith, Fanny; Moret, Yannick; Thiery, Denis; Moreau, Jérôme

    2013-01-01

    To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-parasite dynamics.

  6. Lobesia botrana Larvae Develop Faster in the Presence of Parasitoids

    PubMed Central

    Vogelweith, Fanny; Moret, Yannick; Thiery, Denis; Moreau, Jérôme

    2013-01-01

    To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host–parasite dynamics. PMID:24015260

  7. Acoustic Seaglider

    DTIC Science & Technology

    2008-03-07

    a national naval responsibility. Acoustic sensors on mobile, autonomous platforms will enable basic research topics on temporal and spatial...problem and acoustic navigation and communications within the context of distributed autonomous persistent undersea surveillance sensor networks...Acoustic sensors on mobile, autonomous platforms will enable basic research topics on temporal and spatial coherence and the description of ambient

  8. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  9. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  10. Hymenopteran parasitoids of forensic importance: host associations, seasonality, and prevalence of parasitoids of carrion flies in Western Australia.

    PubMed

    Voss, Sasha C; Spafford, Helen; Dadour, Ian R

    2009-09-01

    A 2-yr survey of hymenopteran parasitoids associated with carrion-breeding flies was conducted to establish the parasitoid species of potential forensic significance in Western Australia. Host associations, seasonality, and rates of parasitism in the field were examined to assess the value of the identified parasitoids as forensic indicators of time since death. Four species of parasitoid emerged from dipteran specimens collected from carcasses: Tachinaephagus zealandicus Ashmead (Encryptidae), Nasonia vitripennis Walker (Pteromalidae), Spilomicrus sp. (Diapriidae), and Aphaereta sp. (Braconidae). Overall parasitism of carrion-breeding flies was 11.8%. T. zealandicus and N. vitripennis were the predominant species, accounting for 86.3 and 11.5% of parasitism observed, respectively. In contrast, Aphaereta sp. and Spilomicrus sp. were intermittently collected from carcasses throughout the study and the parasitism rates of both species were low (< or = 3.0%). Our findings provide forensically important biological and behavioral data of parasitoid-host interactions within carcass environments. The cosmopolitan parasitoids T. zealandicus and N. vitripennis have the greatest potential as indicators of time since death in forensic investigations based on their broad host ranges, rates of parasitism, and seasonal prevalence. In combination, these two species are present throughout the year and they parasitized nearly all of the dipteran species that colonize carcasses. Because both are cosmopolitan species, the data presented here are applicable to regions experiencing a similar Mediterranean climate. This work reports the first incidence of T. zealandicus and N. vitripennis parasitizing the dipteran species Calliphora albifrontalis Malloch (Calliphoridae), Calliphora dubia Macquart (Calliphoridae), and Hydrotaea rostrata Robineau-Desvoidy (Muscidae).

  11. Local and Landscape Drivers of Parasitoid Abundance, Richness, and Composition in Urban Gardens.

    PubMed

    Burks, Julia M; Philpott, Stacy M

    2017-03-08

    Urbanization negatively affects biodiversity, yet some urban habitat features can support diversity. Parasitoid wasps, an abundant and highly diverse group of arthropods, can inhabit urban areas and do well in areas with higher host abundance, floral resources, or local or landscape complexity. Parasitoids provide biological control services in many agricultural habitats, yet few studies have examined diversity and abundance of parasitoids in urban agroecosystems to understand how to promote conservation and function. We examined the local habitat and landscape drivers of parasitoid abundance, superfamily and family richness, and parasitoid composition in urban gardens in the California central coast. Local factors included garden size, ground cover type, herbaceous plant species, and number of trees and shrubs. Landscape characteristics included land cover and landscape diversity around gardens. We found that garden size, mulch cover, and urban cover within 500 m of gardens predicted increases in parasitoid abundance within gardens. The height of herbaceous vegetation and tree and shrub richness predicted increases in superfamily and family richness whereas increases in urban cover resulted in declines in parasitoid richness. Abundance of individual superfamilies and families responded to a wide array of local and landscape factors, sometimes in opposite ways. Composition of parasitoid communities responded to changes in garden size, herbaceous plant cover, and number of flowers. Thus, both local scale management and landscape planning may impact the abundance, diversity, and community composition of parasitoids in urban gardens, and may result in differences in the effectiveness of parasitoids in biological control.

  12. Multiple ant species tending lac insect Kerria yunnanensis (Hemiptera: Kerriidae) provide asymmetric protection against parasitoids.

    PubMed

    Chen, Youqing; Lu, Zhixing; Li, Qiao; Hoffmann, Benjamin D; Zhang, Wei

    2014-01-01

    This study investigated the effects of ant attendance on the parasitoid community and parasitism of lac insect Kerria yunnanensis aggregations in Yunnan province, China. We manipulated ant attendance to establish three treatments: (1) ant exclusion; (2) low ant attendance by several ant species; and (3) high ant attendance by Crematogaster macaoensis. Five parasitoid species were collected, with two species contributing 82.7 and 13.2% of total abundance respectively. Total parasitoid abundance was lowest in the February sample when K. yunnanensis was in its younger life stage, being significantly lower in the ant exclusion treatment. In April, all three treatments had significantly different parasitoid abundances, being highest in the ant exclusion treatment and the lowest in the high ant attendance treatment. When ants were present, there were strong negative relationships between total parasitoid abundance and ant abundance, with the relationships being dependent upon the ant species composition and abundance. The patterns of total parasitoid abundance were driven by the two most abundant parasitoid species. Parasitoid species richness did not differ among treatments or between sample times, however, multivariate analysis confirmed that overall parasitoid community structure differed significantly among treatments and between sample times, with the high ant attendance treatment differing most from the other two treatments. Interestingly the absence of ants did not result in increased parasitism from four of the five parasitoids. Ants in lac insect farming systems have a clear role for agricultural pest management. A full understanding of the asymmetric abilities of ants to influence parasitoid communities, and affect parasitism of hosts will require further experimental manipulation to assess the relative roles of 1) the abundance of each individual ant species on parasitoid access to hosts, 2) competition among parasitoids, and 3) the interaction between the

  13. Testing the habituation assumption underlying models of parasitoid foraging behavior

    PubMed Central

    Abram, Katrina; Colazza, Stefano; Peri, Ezio

    2017-01-01

    Background Habituation, a form of non-associative learning, has several well-defined characteristics that apply to a wide range of physiological and behavioral responses in many organisms. In classic patch time allocation models, habituation is considered to be a major mechanistic component of parasitoid behavioral strategies. However, parasitoid behavioral responses to host cues have not previously been tested for the known, specific characteristics of habituation. Methods In the laboratory, we tested whether the foraging behavior of the egg parasitoid Trissolcus basalis shows specific characteristics of habituation in response to consecutive encounters with patches of host (Nezara viridula) chemical contact cues (footprints), in particular: (i) a training interval-dependent decline in response intensity, and (ii) a training interval-dependent recovery of the response. Results As would be expected of a habituated response, wasps trained at higher frequencies decreased their behavioral response to host footprints more quickly and to a greater degree than those trained at low frequencies, and subsequently showed a more rapid, although partial, recovery of their behavioral response to host footprints. This putative habituation learning could not be blocked by cold anesthesia, ingestion of an ATPase inhibitor, or ingestion of a protein synthesis inhibitor. Discussion Our study provides support for the assumption that diminishing responses of parasitoids to chemical indicators of host presence constitutes habituation as opposed to sensory fatigue, and provides a preliminary basis for exploring the underlying mechanisms. PMID:28321365

  14. Fire ant microsporidia acquired by parasitoid flies of fire ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microsporidium Kneallhazia (formerly Thelohania) solenopsae and parasitoid flies in the genus Pseudacteon are natural enemies of the invasive fire ant, Solenopsis invicta. Pseudacteon flies oviposit into adult fire ants, where maggots that eclose from eggs migrate to the ants’ head, pupate, and...

  15. PARASITOID VENOM INDUCES METABOLIC CASCADES IN FLY HOSTS

    PubMed Central

    Mrinalini; Siebert, Aisha L.; Wright, Jeremy; Martinson, Ellen; Wheeler, David; Werren, John H.

    2016-01-01

    Parasitoid wasps inject insect hosts with a cocktail of venoms to manipulate the physiology, development, and immunity of the hosts and to promote development of the parasitoid offspring. The jewel wasp Nasonia vitripennis is a model parasitoid with at least 79 venom proteins. We conducted a high-throughput analysis of Nasonia venom effects on temporal changes of 249 metabolites in pupae of the flesh fly host (Sarcophaga bullata), over a five-day time course. Our results show that venom does not simply arrest the metabolism of the fly host. Rather, it targets specific metabolic processes while keeping hosts alive for at least five days post venom injection by the wasp. We found that venom: (a) Activates the sorbitol biosynthetic pathway while maintaining stable glucose levels, (b) Causes a shift in intermediary metabolism by switching to anaerobic metabolism and blocking the tricarboxylic acid cycle, (c) Arrests chitin biosynthesis that likely reflects developmental arrest of adult fly structures, (d) Elevates the majority of free amino acids, and (e) May be increasing phospholipid degradation. Despite sharing some metabolic effects with cold treatment, diapause, and hypoxia, the venom response is distinct from these conditions. Because Nasonia venom dramatically increases sorbitol levels without changing glucose levels, it could be a useful model for studying the regulation of the sorbitol pathway, which is relevant to diabetes research. Our findings generally support the view that parasitoid venoms are a rich source of bioactive molecules with potential biomedical applications. PMID:27867325

  16. First foreign exploration for asian parasitoids of Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The invasive spotted wing drosophila, Drosophila suzukii Matsumura (Dipt.: Drosophilidae), is a native of East Asia and is now widely established in North America and Europe, where it is a serious pest of small and stone fruit crops. The lack of effective indigenous parasitoids of D. suzukii in the ...

  17. Evidence for specificity in symbiont-conferred protection against parasitoids

    PubMed Central

    McLean, Ailsa H. C.; Godfray, H. Charles J.

    2015-01-01

    Many insects harbour facultative symbiotic bacteria, some of which have been shown to provide resistance against natural enemies. One of the best-known protective symbionts is Hamiltonella defensa, which in pea aphid (Acyrthosiphon pisum) confers resistance against attack by parasitoid wasps in the genus Aphidius (Braconidae). We asked (i) whether this symbiont also confers protection against a phylogenetically distant group of parasitoids (Aphelinidae) and (ii) whether there are consistent differences in the effects of bacteria found in pea aphid biotypes adapted to different host plants. We found that some H. defensa strains do provide protection against an aphelinid parasitoid Aphelinus abdominalis. Hamiltonella defensa from the Lotus biotype provided high resistance to A. abdominalis and moderate to low resistance to Aphidius ervi, while the reverse was seen from Medicago biotype isolates. Aphids from Ononis showed no evidence of symbiont-mediated protection against either wasp species and were relatively vulnerable to both. Our results may reflect the different selection pressures exerted by the parasitoid community on aphids feeding on different host plants, and could help explain the maintenance of genetic diversity in bacterial symbionts. PMID:26136451

  18. Preventive control of aphids in ornamental plants with complementary parasitoids.

    PubMed

    Dassonville, N; Thielemans, T; Ruisinger, M; Rosemeyer, V

    2012-01-01

    Biological control of aphids can be achieved with parasitoids. A parasitoid is a wasp able to parasitize aphids in a host-specific way. These natural enemies of aphids are used in organic or integrated pest management strategies. In order to apply the matching parasitoid against a given aphid species, the aphid has to be detected in the crop and subsequently identified. By the time the aphids are spotted by the grower and then identified by himself or a specialist, it is usually more difficult to gain control over an increasing aphid population. Viridaxis developed a new concept of aphid control, based not on the species identified but on the crop treated. There was a need for a product controlling the largest possible spectrum of aphid species susceptibly present in ornamental crops. As the first step of development, an inventory of the aphid species attacking ornamental crops was made in various regions. A unique cocktail of parasitoids species (OrnaProtect) controlling all these aphids was then developed. OrnaProtect contains six different species of natural aphid enemies, and is able to control all commonly appearing aphids attacking ornamental crops. The fact of mixing different species not only covers the entire spectrum of aphids, but also contributes to prolonged hatching. To reinforce this long lasting emergence, mummies of different ages are mixed, older mummies (stored at low temperature) emerging earlier after release than young mummies. With that prolonged hatching dynamics, a release every two weeks assures a permanent presence of fresh adult parasitoids in the crop. The ready-to-use units of OrnaProtect contain an integrated feeding point which contributes to longevity and efficiency of the parasitoids. Its application in the crop is much faster than even any chemical treatment. Here, we show the results of trials made with OrnaProtect in 2011 on several crops (Hydrangea macrophylla, Solanum jasminoides, Argyranthemum frutescens and Osteospermum

  19. Physiological correlates of sound localization in a parasitoid fly, Ormia ochracea

    NASA Astrophysics Data System (ADS)

    Oshinsky, Michael Lee

    A major focus of research in the nervous system is the investigation of neural circuits. The question of how neurons connect to form functional units has driven modern neuroscience research from its inception. From the beginning, the neural circuits of the auditory system and specifically sound localization were used as a model system for investigating neural connectivity and computation. Sound localization lends itself to this task because there is no mapping of spatial information on a receptor sheet as in vision. With only one eye, an animal would still have positional information for objects. Since the receptor sheet in the ear is frequency oriented and not spatially oriented, positional information for a sound source does not exist with only one ear. The nervous system computes the location of a sound source based on differences in the physiology of the two ears. In this study, I investigated the neural circuits for sound localization in a fly, Ormia ochracea (Diptera, Tachinidae, Ormiini), which is a parasitoid of crickets. This fly possess a unique mechanically coupled hearing organ. The two ears are contained in one air sac and a cuticular bridge, that has a flexible spring-like structure at its center, connects them. This mechanical coupling preprocesses the sound before it is detected by the nervous system and provides the fly with directional information. The subject of this study is the neural coding of the location of sound stimuli by a mechanically coupled auditory system. In chapter 1, I present the natural history of an acoustic parasitoid and I review the peripheral processing of sound by the Ormian ear. In chapter 2, I describe the anatomy and physiology of the auditory afferents. I present this physiology in the context of sound localization. In chapter 3, I describe the directional dependent physiology for the thoracic local and ascending acoustic interneurons. In chapter 4, I quantify the threshold and I detail the kinematics of the phonotactic

  20. Sunflower stem weevil and its larval parasitoids in native sunflowers: Is parasitoid abundance and diversity greater in the US Southwest?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunflower stem weevils (Cylindrocopturus adspersus) and their larval parasitoids were collected from stems of four native sunflower species (Helianthus annuus, H. nuttallii, H. pauciflorus, and H. petiolaris) from 147 sites across eight states in 2003 and 2005. Native H. annuus constituted the major...

  1. New parasitoid-predator associations: female parasitoids do not avoid competition with generalist predators when sharing invasive prey

    NASA Astrophysics Data System (ADS)

    Chailleux, Anaïs; Wajnberg, Eric; Zhou, Yuxiang; Amiens-Desneux, Edwige; Desneux, Nicolas

    2014-12-01

    Optimal habitat selection is essential for species survival in ecosystems, and interspecific competition is a key ecological mechanism for many observed species association patterns. Specialized animal species are commonly affected by resource and interference competition with generalist and/or omnivorous competitors, so avoidance behavior could be expected. We hypothesize that specialist species may exploit broad range cues from such potential resource competitors (i.e., cues possibly common to various generalist and/or omnivorous predators) to avoid costly competition regarding food or reproduction, even in new species associations. We tested this hypothesis by studying short-term interactions between a native larval parasitoid and a native generalist omnivorous predator recently sharing the same invasive host/prey, the leaf miner Tuta absoluta. We observed a strong negative effect of kleptoparasitism (food resource stealing) instead of classical intraguild predation on immature parasitoids. There was no evidence that parasitoid females avoided the omnivorous predator when searching for oviposition sites, although we studied both long- and short-range known detection mechanisms. Therefore, we conclude that broad range cue avoidance may not exist in our biological system, probably because it would lead to too much oviposition site avoidance which would not be an efficient and, thus, beneficial strategy. If confirmed in other parasitoids or specialist predators, our findings may have implications for population dynamics, especially in the current context of increasing invasive species and the resulting creation of many new species associations.

  2. Parasitism and Food Web Structure in Defoliating Lepidoptera - Parasitoid Communities on Soybean.

    PubMed

    Avalos, D S; Mangeaud, A; Valladares, G R

    2016-12-01

    Food webs are usually regarded as snapshots of community feeding interactions. Here, we describe the yearly and cumulative structure of parasitoid-caterpillar food webs on soybean in central Argentina, analyzing parasitism rates and their variability in relation to parasitoid diversity and food web vulnerability in the system. Lepidoptera larvae were collected along four seasons from soybean crops and reared in laboratory to obtain and identify adults and parasitoids. Eleven species of defoliating Lepidoptera and ten parasitoid species were recorded. Food web statistics showed rather low annual variability, with most variation coefficients in the order of 0.20 and generality showing the most stable values. Parasitism showed the highest variability, which was independent of parasitoid diversity and food web vulnerability, although parasitism rates were negatively related to parasitoid richness. Our study highlights the need to consider food web structure and variability in order to understand the functioning of ecological communities in general and in extensive agricultural ecosystems in particular.

  3. Hymenopteran parasitoids of the ant-eating spider Zodarion styliferum (Simon) (Araneae, Zodariidae)

    PubMed Central

    Korenko, Stanislav; Schmidt, Stefan; Schwarz, Martin; Gibson, Gary A.P.; Pekár, Stano

    2013-01-01

    Abstract Calymmochilus dispar Bouček & Andriescu (Hymenoptera, Eupelmidae) and Gelis apterus (Pontoppidan) (Hymenoptera, Ichneumonidae) are newly recorded as parasitoids of the ant-eating spider Zodarion styliferum (Simon) (Araneae, Zodariidae). The larvae of both parasitoid species fed on juvenile spiders. The final instar larva and pupa of Calymmochilus dispar and the male of Gelis apterus are described for the first time. Both species represent new distribution records for Portugal. The biology and host associations of the parasitoids are discussed. PMID:23653512

  4. African parasitoid fig wasp diversification is a function of Ficus species ranges.

    PubMed

    McLeish, Michael J; van Noort, Simon; Tolley, Krystal A

    2010-10-01

    Host specificity is a fundamental property implicit in obligate insect-plant associations. Rigid life history constraints exhibited by parasitoid fig wasps are believed to select for specialization directed at fig trees and this is supported by evidence of phenotypic adaptation to figs and partial co-speciation with the fig wasps they attack. Conversely, the ability to colonize such novel communities occurs under relaxed specificity, a behavior typified by more generalist groups such as parasitoids. The specificity directed towards Ficus species by Sycoryctinae parasitoid fig wasps is important in order to understand how this form of specialization influences their diversification and interactions with other fig wasp guilds. We use genetic distance analyses and reconstruct ancestral patterns of Ficus trait association with two genera of Sycoryctinae parasitoid fig wasps to identify evolutionary conservatism in Ficus species utilization. Ancestral state reconstructions of (i) affiliate Ficus subsection and (ii) syconia diameters of natal Ficus species indicate contrasting Ficus species ranges between Arachonia and Sycoryctes parasitoid genera. This work demonstrates that parasitoid speciation is not tightly constrained to Ficus speciation and rather a function of Ficus range limitations. Ficus evolution, ecology, and functional compatibility between parasitoid and Ficus traits appear to constrain parasitoid Ficus utilization. These results suggest that contrasting ecological settings and potential number of hosts available impose different ramifications for the evolution of parasitoid host specificity and so to the species interactions within the communities to which they belong.

  5. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  6. Notes on the ovipositional behavior of Trichogramma fuentesi (Hymenoptera:Trichogrammatidae), an egg parasitoid of Cactoblastis cactorum (Lepidoptera:Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichogramma fuentesi Torre (Hymenoptera: Trichogrammatidae) is an arrhenotokous egg parasitoid of Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae). The parasitoid was identified attacking C. cactorum eggs at several north Florida locations in 2010 (Paraiso et al. 2011). Low incidence of this...

  7. Host instar susceptibility and selection and interspecific competition of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococccidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana, three introduced parasitoids of Paracoccus marginatus were investigated for host stage susceptibility and sex ratio, host stage suitability, and interspecific competition. All three parasitoid species were able to develop and emer...

  8. An insect parasitoid carrying an ochratoxin producing fungus

    NASA Astrophysics Data System (ADS)

    Vega, Fernando E.; Posada, Francisco; Gianfagna, Thomas J.; Chaves, Fabio C.; Peterson, Stephen W.

    2006-06-01

    The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.

  9. An insect parasitoid carrying an ochratoxin producing fungus.

    PubMed

    Vega, Fernando E; Posada, Francisco; Gianfagna, Thomas J; Chaves, Fabio C; Peterson, Stephen W

    2006-06-01

    The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.

  10. Describing a multitrophic plant-herbivore-parasitoid system at four spatial scales

    NASA Astrophysics Data System (ADS)

    Cuautle, M.; Parra-Tabla, V.

    2014-02-01

    Herbivore-parasitoid interactions must be studied using a multitrophic and multispecies approach. The strength and direction of multiple effects through trophic levels may change across spatial scales. In this work, we use the herbaceous plant Ruellia nudiflora, its moth herbivore Tripudia quadrifera, and several parasitoid morphospecies that feed on the herbivore to answer the following questions: Do herbivore and parasitoid attack levels vary depending on the spatial scale considered? With which plant characteristics are the parasitoid and the herbivore associated? Do parasitoid morphospecies vary in the magnitude of their positive indirect effect on plant reproduction? We evaluated three approximations of herbivore and parasitoid abundance (raw numbers, ratios, and attack rates) at four spatial scales: regional (three different regions which differ in terms of abiotic and biotic characteristics); population (i.e. four populations within each region); patch (four 1 m2 plots in each population); and plant level (using a number of plant characteristics). Finally, we determined whether parasitoids have a positive indirect effect on plant reproductive success (seed number). Herbivore and parasitoid numbers differed at three of the spatial scales considered. However, herbivore/fruit ratio and attack rates did not differ at the population level. Parasitoid/host ratio and attack rates did not differ at any scale, although there was a tendency of a higher attack in one region. At the plant level, herbivore and parasitoid abundances were related to different plant traits, varying the importance and the direction (positive or negative) of those traits. In addition, only one parasitoid species (Bracon sp.) had a positive effect on plant fitness saving up to 20% of the seeds in a fruit. These results underline the importance of knowing the scales that are relevant to organisms at different trophic levels and distinguish between the specific effects of species.

  11. Laterally Transferred Gene Recruited as a Venom in Parasitoid Wasps.

    PubMed

    Martinson, Ellen O; Martinson, Vincent G; Edwards, Rachel; Mrinalini; Werren, John H

    2016-04-01

    Parasitoid wasps use venom to manipulate the immunity and metabolism of their host insects in a variety of ways to provide resources for their offspring. Yet, how genes are recruited and evolve to perform venom functions remain open questions. A recently recognized source of eukaryotic genome innovation is lateral gene transfer (LGT). Glycoside hydrolase family 19 (GH19) chitinases are widespread in bacteria, microsporidia, and plants where they are used in nutrient acquisition or defense, but have previously not been known in metazoans. In this study, a GH19 chitinase LGT is described from the unicellular microsporidia/Rozella clade into parasitoid wasps of the superfamily Chalcidoidea, where it has become recruited as a venom protein. The GH19 chitinase is present in 15 species of chalcidoid wasps representing four families, and phylogenetic analysis indicates that it was laterally transferred near or before the origin of Chalcidoidea (∼95 Ma). The GH19 chitinase gene is highly expressed in the venom gland of at least seven species, indicating a role in the complex host manipulations performed by parasitoid wasp venom. RNAi knockdown in the model parasitoid Nasonia vitripennis reveals that-following envenomation-the GH19 chitinase induces fly hosts to upregulate genes involved in an immune response to fungi. A second, independent LGT of GH19 chitinase from microsporidia into mosquitoes was also found, also supported by phylogenetic reconstructions. Besides these two LGT events, GH19 chitinase is not found in any other sequenced animal genome, or in any fungi outside the microsporidia/Rozella clade.

  12. Plant-mediated resource partitioning by coexisting parasitoids.

    PubMed

    Xi, Xinqiang; Yang, Yangheshan; Yang, Yonghua; Segoli, Michal; Sun, Shucun

    2017-03-29

    Although it has been frequently suggested that resource partitioning of species coexisting at the same trophic level can be mediated by interactions with species at non-adjacent trophic levels, empirical evidence supporting this claim is scarce. Here we demonstrate that plants may mediate resource partitioning for two parasitoids that share the same herbivorous host. The tephritid fly Tephritis femoralis is the primary pre-dispersal seed predator of two Asteraceae species, Saussurea nigrescens and Anaphalis flavescens, both of which dominate the plant community in the alpine meadows of the Tibetan Plateau. Field surveys and molecular barcoding analyses showed that the identity of the fly's main predator depended on the plant in which the fly developed. Tephritid flies that developed in S. nigrescens were preyed upon mainly by the parasitoid wasp Pteromalus albipennis, while the parasitoid Mesopolobus sp. was the main predator of flies that developed in A. flavescens. Microcosm experiments revealed that P. albipennis could not exploit the host flies within the capitula of A. flavescens due to food limitation (capitula are too small), while Mesopolobus sp. could not exploit the host flies within the capitula of S. nigrescens due to its inability to reach the host with its ovipositor (capitula are too large). Such bottom-up control of plant species traits may facilitate the coexistence of parasitoid wasps sharing a common host in this system. We suggest that interactions between non-adjacent trophic levels may potentially promote species coexistence and diversity in biological communities. This article is protected by copyright. All rights reserved.

  13. The tympanal hearing organ of the parasitoid fly Ormia ochracea (Diptera, Tachinidae, Ormiini).

    PubMed

    Robert, D; Read, M P; Hoy, R R

    1994-01-01

    Tympanate hearing has evolved in at least 6 different orders of insects, but had not been reported until recently in the Diptera. This study presents a newly discovered tympanal hearing organ, in the parasitoid tachinid fly, Ormia ochracea. The hearing organ is described in terms of external and internal morphology, cellular organization of the sensory organ and preliminary neuroanatomy of the primary auditory afferents. The ear is located on the frontal face of the prothorax, directly behind the head capsule. Conspicuously visible are a pair of thin cuticular membranes specialized for audition, the prosternal tympanal membranes. Directly attached to these membranes, within the enlarged prosternal chamber, are a pair of auditory sensory organs, the bulbae acusticae. These sensory organs are unique among all auditory organs known so far because both are contained within an unpartitioned acoustic chamber. The prosternal chamber is connected to the outside by a pair of tracheae. The cellular anatomy of the fly's scolopophorous organ was investigated by light and electron microscopy. The bulba acustica is a typical chordotonal organ and it contains approximately 70 receptor cells. It is similar to other insect sensory organs associated with tympanal ears. The similarity of the cellular organization and tympanal morphology of the ormiine ear to the ears of other tympanate insects suggests that there are potent constraints in the design features of tympanal hearing organs, which must function to detect high frequency auditory signals over long distances. Each sensory organ is innervated by a branch of the frontal nerve of the fused thoracic ganglia. The primary auditory afferents project to each of the pro-, meso-, and metathoracic neuropils. The fly's hearing organ is sexually dimorphic, whereby the tympanal membranes are larger in females and the spiracles larger in males. The dimorphism presumably reflects differences in the acoustic behavior in the two sexes.

  14. Relative importance of predators and parasitoids for cereal aphid control.

    PubMed Central

    Schmidt, Martin H; Lauer, Andreas; Purtauf, Tobias; Thies, Carsten; Schaefer, Matthias; Tscharntke, Teja

    2003-01-01

    Field experiments with manipulations of natural enemies of plant-feeding insects may show how a diverse enemy group ensures an important ecosystem function such as naturally occurring biological pest control. We studied cereal aphid populations in winter wheat under experimentally reduced densities of: (i) ground-dwelling generalist predators (mostly spiders, carabid and staphylinid beetles); (ii) flying predators (coccinellid beetles, syrphid flies, gall midges, etc.) and parasitoids (aphidiid wasps), and a combination of (i) and (ii), compared with open controls. Aphid populations were 18% higher at reduced densities of ground-dwelling predators, 70% higher when flying predators and parasitoids were removed, and 172% higher on the removal of both enemy groups. Parasitoid wasps probably had the strongest effect, as flying predators occurred only in negligible densities. The great importance of parasitism is a new finding for aphid control in cereal fields. In conclusion, a more detailed knowledge of the mechanisms of natural pest control would help to develop environmentally sound crop management with reduced pesticide applications. PMID:14561303

  15. Whitefly parasitoids: distribution, life history, bionomics, and utilization.

    PubMed

    Liu, Tong-Xian; Stansly, Philip A; Gerling, Dan

    2015-01-07

    Whiteflies are small hemipterans numbering more than 1,550 described species, of which about 50 are agricultural pests. Adults are free-living, whereas late first to fourth instars are sessile on the plant. All known species of whitefly parasitoids belong to Hymenoptera; two genera, Encarsia and Eretmocerus, occur worldwide, and others are mostly specific to different continents. All parasitoid eggs are laid in-or in Eretmocerus, under-the host. They develop within whitefly nymphs and emerge from the fourth instar, and in Cales, from either the third or fourth instar. Parasitized hosts are recognized by conspecifics, but super- and hyperparasitism occur. Dispersal flights are influenced by gender and mating status, but no long-range attraction to whitefly presence on leaves is known. Studies on En. formosa have laid the foundation for behavioral studies and biological control in general. We review past and ongoing studies of whitefly parasitoids worldwide, updating available information on species diversity, biology, behavior, tritrophic interactions, and utilization in pest management.

  16. The larval parasitoid Microplitis croceipes oviposits in conspecific adults

    NASA Astrophysics Data System (ADS)

    Takasu, Keiji; Hoang Le, K.

    2007-03-01

    Microplitis croceipes (Hymenoptera: Braconidae) is a larval parasitoid of Helicoverpa/Heliothis spp. In the course of mass rearing of M. croceipes, we found that females oviposited in the conspecific adults in rearing cages. When 20 pairs of inexperienced females and males or of experienced females and males were reared in a cage, the males lived for 14-15 days and the females for 18-20 days on average. At their death, 37-42% of the males and 50-57% of the females contained conspecific eggs or first instar larvae in their abdominal cavity. When two of inexperienced females met on a host-infested leaf of soybean, they attempted to sting each other. Of the attacked females, 30% contained a conspecific egg laid in their abdomen. In abdominal cavity of the adults parasitized by a conspecific female, the majority of the parasitoid eggs laid disappeared within 1 day after oviposition. Only 10-30% of the parasitoid eggs laid in conspecific adults hatched 3-4 days after oviposition, but those larvae never molted to second instar. When the adults were stung by one or two conspecific females, their subsequent longevity was significantly shorter than that for the control adults. Oviposition in conspecific adults may be prevalent in other parasitic wasps that quickly oviposit without intensive host examination, and have cuticle and size of abdomen to be stung by conspeicifcs.

  17. Trophic interactions between parasitoids and necrophagous flies in Central Argentina.

    PubMed

    Sereno, Ana P; Salvo, Adriana; Battán-Horenstein, Moira

    2016-10-01

    Larvae of necrophagous flies in the families Calliphoridae, Sarcophagidae and Muscidae are the main exploiters of decaying organic matter. Knowledge of insect species associated with each stage of decay can be used to estimate the time since death in the crime scene. Dipteran larvae are attacked by a rich community of parasitoids, including species of Braconidae, Ichneumonidae and Pteromalidae (Hymenoptera: Parasitica). This study examined the parasitic complex associated with flies of forensic and sanitary importance in the city of Córdoba (Argentina). Sampling was conducted at two sites with different urbanization levels from December 2012 to March 2013; parasitoids were collected using fly traps baited with beef liver. Rates of parasitism and of parasitized pupae were estimated and species composition was analyzed for both communities. Sarcophagidae was the most abundant family, represented by two species, followed by Calliphoridae. Nasonia vitripennis Ashmead (Hymenoptera) was the most abundant species and was collected from a wider variety of hosts. To the best of our knowledge, this is the first study providing accurate information about trophic interactions between calyptrate dipteran species and their hymenopteran parasitoids in central Argentina.

  18. Native parasitoids and their potential to control the invasive leafminer, Cameraria ohridella DESCH. & DIM. (Lep.: Gracillariidae).

    PubMed

    Klug, T; Meyhöfer, R; Kreye, M; Hommes, M

    2008-08-01

    In spite of the fact that since the end of the eighties, the horse chestnut leafminer, Cameraria ohridella, has established itself throughout Europe, native predators such as ants and birds are not attuned to this neozoic species. In contrast, several parasitic wasp species already started to exploit the invasive horse chestnut leafminer, but until now parasitation rates are quite low, mainly because of asynchrony in the lifecycles of parasitoids and host. Only the removal of leaf litter, in which pupae hibernate, is at the moment a strategy to reduce the infestation level in the next year. Unfortunately, not only hibernating horse chestnut leafminers but also parasitoids are removed, and important resources for biocontrol are unused. In the current study, we investigated the potential efficiency of the horse chestnut leafminer parasitoid complex extracted from leaf litter in defined environments. Parasitoids were released at different densities to investigate density dependence in parasitation rates. Although seven different species were released in our experiments, only Pnigalio agraules turned out to be responsible for biocontrol of C. ohridella. We recorded parasitation rates of up to 35%. Overall, parasitation rates were independent of the leafminer density but increased fourfold if ten times more parasitoid individuals were released. Unfortunately, none of the parasitoid species could be established in the experimental units in the long run. Results are compared to other parasitoid-leafminer systems, and promotion of horse chestnut leafminer parasitoids to support natural selection and biological control of the horse chestnut leafminer is discussed.

  19. Host-Plant Species Conservatism and Ecology of a Parasitoid Fig Wasp Genus (Chalcidoidea; Sycoryctinae; Arachonia)

    PubMed Central

    McLeish, Michael J.; Beukman, Gary; van Noort, Simon; Wossler, Theresa C.

    2012-01-01

    Parasitoid diversity in terrestrial ecosystems is enormous. However, ecological processes underpinning their evolutionary diversification in association with other trophic groups are still unclear. Specialisation and interdependencies among chalcid wasps that reproduce on Ficus presents an opportunity to investigate the ecology of a multi-trophic system that includes parasitoids. Here we estimate the host-plant species specificity of a parasitoid fig wasp genus that attacks the galls of non-pollinating pteromalid and pollinating agaonid fig wasps. We discuss the interactions between parasitoids and the Ficus species present in a forest patch of Uganda in context with populations in Southern Africa. Haplotype networks are inferred to examine intraspecific mitochondrial DNA divergences and phylogenetic approaches used to infer putative species relationships. Taxonomic appraisal and putative species delimitation by molecular and morphological techniques are compared. Results demonstrate that a parasitoid fig wasp population is able to reproduce on at least four Ficus species present in a patch. This suggests that parasitoid fig wasps have relatively broad host-Ficus species ranges compared to fig wasps that oviposit internally. Parasitoid fig wasps did not recruit on all available host plants present in the forest census area and suggests an important ecological consequence in mitigating fitness trade-offs between pollinator and Ficus reproduction. The extent to which parasitoid fig wasps exert influence on the pollination mutualism must consider the fitness consequences imposed by the ability to interact with phenotypes of multiple Ficus and fig wasps species, but not equally across space and time. PMID:22970309

  20. Functional and evolutionary insights from the genomes of three parasitoid nasonia species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasitoid wasps are significant natural enemies of a broad range of arthropods with considerable ecological and economic impact. There are more species beneficial to humans among the parasitoid wasps than in any other insect group. They have haplodiploid sex determination (development of males from...

  1. Parasitoid complex of the bird cherry ermine moth, Yponomeuta evonymellus, in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The parasitoid complex of Yponomeuta evonymellus L. (Lepidoptera: Yponomeutidae), the bird cherry ermine moth, was sought in the Republic of Korea (South Korea) with the goal of identifying potential biological controls of the moth. 13 primary and two secondary parasitoids were found. Diadegma armil...

  2. Parasitoid guilds of Agrilus woodborers (Coleoptera: Buprestidae): their diversity and potential for use in biological control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Literature studies in North America (U.S. and Canada), Europe and Asia (particular Russia, China, Japan, and the Korean peninsula) were reviewed to identify parasitoid guilds associated with Agrilus woodborers. There are at least 12 species of hymenopteran parasitoids attacking eggs of Agrilus beet...

  3. Biological Control of Olive Fruit Fly in California with a Parasitoid Imported from Guatemala

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The parasitoid, Psyttalia cf. concolor (Szépligeti), was imported into California from the USDA-APHIS-PPQ, Moscamed, San Miguel Petapa, Guatemala for biological control of olive fruit fly, Bactrocera oleae (Gmelin), in olives, Olea europaea L. The parasitoid did not develop in the seedhead fly, Cha...

  4. Parasitoids for biocontrol of coffee berry borer: past, present and future.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detailed surveys for coffee berry borer parasitoids were initiated in October 2006 in two coffee growing areas of Kenya (Kisii and Embu). The most abundant parasitoid species are Prorops nasuta (Hymenoptera: Bethylidae) and Aphanogmus sp. (Hymenoptera: Ceraphronidae). Our preliminary findings indica...

  5. Host-plant species conservatism and ecology of a parasitoid fig wasp genus (Chalcidoidea; Sycoryctinae; Arachonia).

    PubMed

    McLeish, Michael J; Beukman, Gary; van Noort, Simon; Wossler, Theresa C

    2012-01-01

    Parasitoid diversity in terrestrial ecosystems is enormous. However, ecological processes underpinning their evolutionary diversification in association with other trophic groups are still unclear. Specialisation and interdependencies among chalcid wasps that reproduce on Ficus presents an opportunity to investigate the ecology of a multi-trophic system that includes parasitoids. Here we estimate the host-plant species specificity of a parasitoid fig wasp genus that attacks the galls of non-pollinating pteromalid and pollinating agaonid fig wasps. We discuss the interactions between parasitoids and the Ficus species present in a forest patch of Uganda in context with populations in Southern Africa. Haplotype networks are inferred to examine intraspecific mitochondrial DNA divergences and phylogenetic approaches used to infer putative species relationships. Taxonomic appraisal and putative species delimitation by molecular and morphological techniques are compared. Results demonstrate that a parasitoid fig wasp population is able to reproduce on at least four Ficus species present in a patch. This suggests that parasitoid fig wasps have relatively broad host-Ficus species ranges compared to fig wasps that oviposit internally. Parasitoid fig wasps did not recruit on all available host plants present in the forest census area and suggests an important ecological consequence in mitigating fitness trade-offs between pollinator and Ficus reproduction. The extent to which parasitoid fig wasps exert influence on the pollination mutualism must consider the fitness consequences imposed by the ability to interact with phenotypes of multiple Ficus and fig wasps species, but not equally across space and time.

  6. Effect of host Bactrocera dorsalis sex on yield and quality of the Parasitoid Fopius arisanus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examines the effect of host Bactrocera dorsalis sex on performance of the parasitoid Fopius arisanus to enable use of a genetic sexing strain (GSS) to transfer this parasitoid to regions where B.dorsalis is not established. Experiments on the sex ratio and yield of F. arisanus did not ind...

  7. Contrasting Patterns of Host Adaptation in Two Egg Parasitoids of the Pine Processionary Moth (Lepidoptera: Thaumetopoeidae).

    PubMed

    Ruschioni, Sara; Riolo, Paola; Isidoro, Nunzio; Romani, Roberto; Petrucco-Toffolo, Edoardo; Zovi, Daniel; Battisti, Andrea

    2015-06-01

    Adaptation of parasitoids to their phytophagous host is often mediated by environmental conditions and by the food plant of the phytophagous host. Therefore, the host food plant can indirectly affect the survival and fitness of parasitoids that also attack quiescent host stages, such as eggs, in which the resources available to the immature parasitoid stages are limited. Our aim was to investigate how two egg parasitoid species of the pine processionary moth, Thaumetopoea pityocampa (Denis & Schiffermüller), respond to variations in egg traits at the extremes of a west-to-east geographic gradient in northern Italy. We considered one specialist [Baryscapus servadeii (Domenichini)] and one generalist [Ooencyrtus pityocampae (Mercet)] parasitoid, which reproduce mainly by thelytokous parthenogenesis and are common throughout the whole range of this pest. The size and shell structure of the pine processionary moth eggs were studied under light microscopy and tested experimentally under controlled conditions. We can conclude that 1) the pine processionary moth egg shell thickness is inversely proportional to the parasitism performance; 2) the larger eggs from the pine processionary moth eastern population produce parasitoid females of a larger size, which have greater realized fecundity; 3) the generalist parasitoid performs successfully with either the "home" or "away" (i.e., from both extremes of the geographic gradient) pine processionary moth eggs, which is not the case for the specialist parasitoid. The implications of these responses in the regulation of phytophagous populations are numerous and should be considered in population dynamics studies and pest management programs.

  8. Changes in host-parasitoid food web structure with elevation.

    PubMed

    Maunsell, Sarah C; Kitching, Roger L; Burwell, Chris J; Morris, Rebecca J

    2015-03-01

    Gradients in elevation are increasingly used to investigate how species respond to changes in local climatic conditions. Whilst many studies have shown elevational patterns in species richness and turnover, little is known about how food web structure is affected by elevation. Contrasting responses of predator and prey species to elevation may lead to changes in food web structure. We investigated how the quantitative structure of a herbivore-parasitoid food web changes with elevation in an Australian subtropical rain forest. On four occasions, spread over 1 year, we hand-collected leaf miners at twelve sites, along three elevational gradients (between 493 m and 1159 m a.s.l). A total of 5030 insects, including 603 parasitoids, were reared, and summary food webs were created for each site. We also carried out a replicated manipulative experiment by translocating an abundant leaf-mining weevil Platynotocis sp., which largely escaped parasitism at high elevations (≥ 900 m a.s.l.), to lower, warmer elevations, to test if it would experience higher parasitism pressure. We found strong evidence that the environmental change that occurs with increasing elevation affects food web structure. Quantitative measures of generality, vulnerability and interaction evenness decreased significantly with increasing elevation (and decreasing temperature), whilst elevation did not have a significant effect on connectance. Mined plant composition also had a significant effect on generality and vulnerability, but not on interaction evenness. Several relatively abundant species of leaf miner appeared to escape parasitism at higher elevations, but contrary to our prediction, Platynotocis sp. did not experience greater levels of parasitism when translocated to lower elevations. Our study indicates that leaf-mining herbivores and their parasitoids respond differently to environmental conditions imposed by elevation, thus producing structural changes in their food webs. Increasing

  9. Host habitat assessment by a parasitoid using fungal volatiles

    PubMed Central

    Steiner, Sven; Erdmann, Daniel; Steidle, Johannes LM; Ruther, Joachim

    2007-01-01

    Background The preference – performance hypothesis predicts that oviposition preference of insects should correlate with host suitability for offspring development. Therefore, insect females have to be able to assess not only the quality of a given host but also the environmental conditions of the respective host habitat. Chemical cues are a major source of information used by insects for this purpose. Primary infestation of stored grain by stored product pests often favors the intense growth of mold. This can lead to distinct sites of extreme environmental conditions (hot-spots) with increased insect mortality. We studied the influence of mold on chemical orientation, host recognition, and fitness of Lariophagus distinguendus, a parasitoid of beetle larvae developing in stored grain. Results Volatiles of wheat infested by Aspergillus sydowii and A. versicolor repelled female parasitoids in an olfactometer. Foraging L. distinguendus females are known to be strongly attracted to the odor of larval host feces from the granary weevil Sitophilus granarius, which may adhere in remarkable amounts to the surface of the grains. Feces from moldy weevil cultures elicited neutral responses but parasitoids clearly avoided moldy feces when non-moldy feces were offered simultaneously. The common fungal volatile 1-octen-3-ol was the major component of the odor of larval feces from moldy weevil cultures and repelled female parasitoids at naturally occurring doses. In bioassays investigating host recognition behavior of L. distinguendus, females spent less time on grains containing hosts from moldy weevil cultures and showed less drumming and drilling behavior than on non-moldy controls. L. distinguendus had a clearly reduced fitness on hosts from moldy weevil cultures. Conclusion We conclude that L. distinguendus females use 1-octen-3-ol for host habitat assessment to avoid negative fitness consequences due to secondary mold infestation of host patches. The female response to

  10. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  11. Does sex-biased dispersal account for the lack of geographic and host-associated differentiation in introduced populations of an aphid parasitoid?

    PubMed

    Zepeda-Paulo, Francisca; Lavandero, Blas; Mahéo, Frédérique; Dion, Emilie; Outreman, Yannick; Simon, Jean-Christophe; Figueroa, Christian C

    2015-06-01

    Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite its known impact on gene flow between populations. Hence, we studied the extent of gene flow mediated by female and male parasitoids by assessing sibship relationships among parasitoids within and between populations, and its impact on geographic and host-associated differentiation in the aphid parasitoid Aphidius ervi. We report evidences of a high gene flow among parasitoid populations on different aphid hosts and geographic locations. The high gene flow among parasitoid populations was found to be largely male mediated, suggested by significant differences in the distribution of full-sib and paternal half-sib dyads of parasitoid populations.

  12. Does sex-biased dispersal account for the lack of geographic and host-associated differentiation in introduced populations of an aphid parasitoid?

    PubMed Central

    Zepeda-Paulo, Francisca; Lavandero, Blas; Mahéo, Frédérique; Dion, Emilie; Outreman, Yannick; Simon, Jean-Christophe; Figueroa, Christian C

    2015-01-01

    Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite its known impact on gene flow between populations. Hence, we studied the extent of gene flow mediated by female and male parasitoids by assessing sibship relationships among parasitoids within and between populations, and its impact on geographic and host-associated differentiation in the aphid parasitoid Aphidius ervi. We report evidences of a high gene flow among parasitoid populations on different aphid hosts and geographic locations. The high gene flow among parasitoid populations was found to be largely male mediated, suggested by significant differences in the distribution of full-sib and paternal half-sib dyads of parasitoid populations. PMID:26078852

  13. 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.

  14. Tritrophic interactions between parasitoids and cereal aphids are mediated by nitrogen fertilizer.

    PubMed

    Aqueel, Muhammad A; Raza, Abu-bakar M; Balal, Rashad M; Shahid, Muhammad A; Mustafa, Irfan; Javaid, Muhammad M; Leather, Simon R

    2015-12-01

    Host plant nutritional quality can directly and indirectly affect the third trophic levels. The aphid-parasitoid relationship provides an ideal system to investigate tritrophic interactions (as the parasitoids are completely dependent for their development upon their hosts) and assess the bottom up forces operating at different concentrations of nitrogen applications. The effects of varying nitrogen fertilizer on the performance of Aphidius colemani (V.) reared on Sitobion avenae (F.) and Aphidius rhopalosiphi (D.) reared on Rhopalosiphum padi (L.) were measured. Parasitism and percent emergence of parasitoids were positively affected by nitrogen fertilizer treatments while developmental duration (egg, larval, and pupal stages) was not affected by increasing nitrogen inputs. In males and females of both parasitoid species, adult longevity increased with the increasing nitrogen fertilizer. Hind tibia length and mummy weight of both parasitoid species increased with nitrogen fertilizer concentrations, as a result of larger aphids. This study showed that nitrogen application to the soil can have important consequences for aboveground multitrophic interactions.

  15. Harnessing the natural Drosophila-parasitoid model for integrating insect immunity with functional venomics

    PubMed Central

    Heavner, Mary E.; Hudgins, Adam D.; Rajwani, Roma; Morales, Jorge; Govind, Shubha

    2014-01-01

    Drosophila species lack most hallmarks of adaptive immunity yet are highly successful against an array of natural microbial pathogens and metazoan enemies. When attacked by figitid parasitoid wasps, fruit flies deploy robust, multi-faceted innate immune responses and overcome many attackers. In turn, parasitoids have evolved immunosuppressive strategies to match, and more frequently to overcome, their hosts. We present methods to examine the evolutionary dynamics underlying anti-parasitoid host defense by teasing apart the specialized immune-modulating venoms of figitid parasitoids and, in turn, possibly delineating the roles of individual venom molecules. This combination of genetic, phylogenomic, and "functional venomics" methods in the Drosophila-parasitoid model should allow entomologists and immunologists to tackle important outstanding questions with implications across disciplines and to pioneer translational applications in agriculture and medicine. PMID:25642411

  16. Community dynamics of leafminers (Diptera: Agromyzidae) and their parasitoids (Hymenoptera) in a natural habitat from Central Argentina

    NASA Astrophysics Data System (ADS)

    Valladares, Graciela; Salvo, Adriana

    2001-12-01

    We examined the temporal community dynamics of leafminers (Agromyzidae: Diptera) and their mainly polyphagous parasitoids in a natural habitat from Central Argentina. Changes in community composition are shown by changes in dominant species and similarity coefficients. Abundance of leafminers was highest in winter, and was not related to their species richness. Abundance and species richness were correlated in the parasitoid community. Temporal variation in parasitoid diversity and abundance were positively correlated with species number and density in the host community. Apparent parasitism was greater when parasitoid species richness was high and parasitoid community dominance was low.

  17. Tri-trophic movement of carotenoid pigments from host plant to the parasitoid of a caterpillar.

    PubMed

    Wang, Xin-Geng; Wallis, Christopher M; Daane, Kent M

    2014-02-01

    Insect parasitoids normally produce white colored eggs. Habrobracon gelechiae (Hymenoptera: Braconidae) is a gregarious ectoparasitoid of various caterpillars. We found that adult female H. gelechiae lays yellow colored eggs when its larvae developed from host larvae of Choristoneura rosaceana and Epiphyas postvittana (both Lepidoptera: Tortricidae) that were fed green plant leaves, but white colored eggs when these same host larvae species were fed non-plant diets. This study investigated the causes of egg color in H. gelechiae and the possible consequences in terms of parasitoid fitness resulting from differential egg color. Using high-performance liquid chromatography we demonstrated that the yellow coloration resulted from the uptake of carotenoid plant pigments (mainly lutein and β-carotene) that were initially ingested by the caterpillar larvae from plant leaves, later absorbed by the parasitoid larvae (F0) feeding on the host and carried over to the adult parasitoids, and finally translocated to the eggs (F1) of the parasitoids. The amount of plant pigments consumed by the parasitoid larvae (F0) affected the intensity of the yellow color of the parasitoid's eggs (F1). Similarly, egg color was affected by the adult female parasitoids lifetime egg production and deposition rate. Further tests suggest that the observed differences in egg color did not have a genetic basis and did not affect egg viability or fitness. To our best knowledge, this is the first report of a tri-trophic and multi-stage translocation of carotenoid plant pigments in parasitoids. We discuss possible evolutionary significance and putative functions of the absorption of plant pigments by parasitoid species.

  18. Shifts in metabolomic profiles of the parasitoid Nasonia vitripennis associated with elevated cold tolerance induced by the parasitoid's diapause, host diapause and host diet augmented with proline.

    PubMed

    Li, Yuyan; Zhang, Lisheng; Chen, Hongyin; Koštál, Vladimir; Simek, Petr; Moos, Martin; Denlinger, David L

    2015-08-01

    The ectoparasitoid wasp, Nasonia vitripennis can enhance its cold tolerance by exploiting a maternally-induced larval diapause. A simple manipulation of the fly host diapause status and supplementation of the host diet with proline also dramatically increase cold tolerance in the parasitoid. In this study, we used a metabolomics approach to define alterations in metabolite profiles of N. vitripennis caused by diapause in the parasitoid, diapause of the host, and augmentation of the host's diet with proline. Metabolic profiles of diapausing and nondiapausing parasitoid were significantly differentiated, with pronounced distinctions in levels of multiple cryoprotectants, amino acids, and carbohydrates. The dynamic nature of diapause was underscored by a shift in the wasp's metabolomic profile as the duration of diapause increased, a feature especially evident for increased concentrations of a suite of cryoprotectants. Metabolic pathways involved in amino acid and carbohydrate metabolism were distinctly enriched during diapause in the parasitoid. Host diapause status also elicited a pronounced effect on metabolic signatures of the parasitoid, noted by higher cryoprotectants and elevated compounds derived from glycolysis. Proline supplementation of the host diet did not translate directly into elevated proline in the parasitoid but resulted in an alteration in the abundance of many other metabolites, including elevated concentrations of essential amino acids, and reduction in metabolites linked to energy utilization, lipid and amino acid metabolism. Thus, the enhanced cold tolerance of N. vitripennis associated with proline augmentation of the host diet appears to be an indirect effect caused by the metabolic perturbations associated with diet supplementation.

  19. Acoustic biosensors

    PubMed Central

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  20. Acoustic biosensors.

    PubMed

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors.

  1. Aphid-encoded variability in susceptibility to a parasitoid

    PubMed Central

    2014-01-01

    Background Many animals exhibit variation in resistance to specific natural enemies. Such variation may be encoded in their genomes or derived from infection with protective symbionts. The pea aphid, Acyrthosiphon pisum, for example, exhibits tremendous variation in susceptibility to a common natural enemy, the parasitic wasp Aphidius ervi. Pea aphids are often infected with the heritable bacterial symbiont, Hamiltonella defensa, which confers partial to complete resistance against this parasitoid depending on bacterial strain and associated bacteriophages. That previous studies found that pea aphids without H. defensa (or other symbionts) were generally susceptible to parasitism, together with observations of a limited encapsulation response, suggested that pea aphids largely rely on infection with H. defensa for protection against parasitoids. However, the limited number of uninfected clones previously examined, and our recent report of two symbiont-free resistant clones, led us to explicitly examine aphid-encoded variability in resistance to parasitoids. Results After rigorous screening for known and unknown symbionts, and microsatellite genotyping to confirm clonal identity, we conducted parasitism assays using fifteen clonal pea aphid lines. We recovered significant variability in aphid-encoded resistance, with variation levels comparable to that contributed by H. defensa. Because resistance can be costly, we also measured aphid longevity and cumulative fecundity of the most and least resistant aphid lines under permissive conditions, but found no trade-offs between higher resistance and these fitness parameters. Conclusions These results indicate that pea aphid resistance to A. ervi is more complex than previously appreciated, and that aphids employ multiple tactics to aid in their defense. While we did not detect a tradeoff, these may become apparent under stressful conditions or when resistant and susceptible aphids are in direct competition. Understanding

  2. Beyond sex allocation: the role of mating systems in sexual selection in parasitoid wasps

    PubMed Central

    Boulton, Rebecca A; Collins, Laura A; Shuker, David M

    2015-01-01

    Despite the diverse array of mating systems and life histories which characterise the parasitic Hymenoptera, sexual selection and sexual conflict in this taxon have been somewhat overlooked. For instance, parasitoid mating systems have typically been studied in terms of how mating structure affects sex allocation. In the past decade, however, some studies have sought to address sexual selection in the parasitoid wasps more explicitly and found that, despite the lack of obvious secondary sexual traits, sexual selection has the potential to shape a range of aspects of parasitoid reproductive behaviour and ecology. Moreover, various characteristics fundamental to the parasitoid way of life may provide innovative new ways to investigate different processes of sexual selection. The overall aim of this review therefore is to re-examine parasitoid biology with sexual selection in mind, for both parasitoid biologists and also researchers interested in sexual selection and the evolution of mating systems more generally. We will consider aspects of particular relevance that have already been well studied including local mating structure, sex allocation and sperm depletion. We go on to review what we already know about sexual selection in the parasitoid wasps and highlight areas which may prove fruitful for further investigation. In particular, sperm depletion and the costs of inbreeding under chromosomal sex determination provide novel opportunities for testing the role of direct and indirect benefits for the evolution of mate choice. PMID:24981603

  3. Interspecific competition between two generalist parasitoids that attack the leafroller Epiphyas postvittana (Lepidoptera: Tortricidae).

    PubMed

    Feng, Y; Wratten, S; Sandhu, H; Keller, M

    2015-08-01

    Two generalist parasitoids, Dolichogenidea tasmanica (Cameron) (Hymenoptera: Braconidae) and Therophilus unimaculatus (Turner) (Hymenoptera: Braconidae) attack early instars of tortricid moths, including the light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae). The two parasitoids co-exist in natural habitats, while D. tasmanica is dominant in vineyards, whereas T. unimaculatus occurs mainly in adjacent native vegetation. This difference suggests possible competition between the two species, mediated by habitat. Here, we report on the extent of interspecific differences in host discrimination and the outcome of interspecific competition between the two parasitoids. The parasitoids did not show different behavioural responses to un-parasitized hosts or those that were parasitized by the other species. Larvae of D. tasmanica out-competed those of T. unimaculatus, irrespective of the order or interval between attacks by the two species. The host larvae that were attacked by two parasitoids died more frequently before a parasitoid completed its larval development than those that were attacked by a single parasitoid. Dissection of host larvae parasitized by both species indicated that first instars of D. tasmanica attacked and killed larval T. unimaculatus.

  4. Beyond sex allocation: the role of mating systems in sexual selection in parasitoid wasps.

    PubMed

    Boulton, Rebecca A; Collins, Laura A; Shuker, David M

    2015-05-01

    Despite the diverse array of mating systems and life histories which characterise the parasitic Hymenoptera, sexual selection and sexual conflict in this taxon have been somewhat overlooked. For instance, parasitoid mating systems have typically been studied in terms of how mating structure affects sex allocation. In the past decade, however, some studies have sought to address sexual selection in the parasitoid wasps more explicitly and found that, despite the lack of obvious secondary sexual traits, sexual selection has the potential to shape a range of aspects of parasitoid reproductive behaviour and ecology. Moreover, various characteristics fundamental to the parasitoid way of life may provide innovative new ways to investigate different processes of sexual selection. The overall aim of this review therefore is to re-examine parasitoid biology with sexual selection in mind, for both parasitoid biologists and also researchers interested in sexual selection and the evolution of mating systems more generally. We will consider aspects of particular relevance that have already been well studied including local mating structure, sex allocation and sperm depletion. We go on to review what we already know about sexual selection in the parasitoid wasps and highlight areas which may prove fruitful for further investigation. In particular, sperm depletion and the costs of inbreeding under chromosomal sex determination provide novel opportunities for testing the role of direct and indirect benefits for the evolution of mate choice.

  5. The response of an egg parasitoid to substrate-borne semiochemicals is affected by previous experience

    PubMed Central

    Peri, Ezio; Salerno, Gianandrea; Slimani, Takoua; Frati, Francesca; Conti, Eric; Colazza, Stefano; Cusumano, Antonino

    2016-01-01

    Animals can adjust their behaviour according to previous experience gained during foraging. In parasitoids, experience plays a key role in host location, a hierarchical process in which air-borne and substrate-borne semiochemicals are used to find hosts. In nature, chemical traces deposited by herbivore hosts when walking on the plant are adsorbed by leaf surfaces and perceived as substrate-borne semiochemicals by parasitoids. Chemical traces left on cabbage leaves by adults of the harlequin bug (Murgantia histrionica) induce an innate arrestment response in the egg parasitoid Trissolcus brochymenae characterized by an intense searching behaviour on host-contaminated areas. Here we investigated whether the T. brochymenae response to host walking traces left on leaf surfaces is affected by previous experience in the context of parasitoid foraging behaviour. We found that: 1) an unrewarded experience (successive encounters with host-contaminated areas without successful oviposition) decreased the intensity of the parasitoid response; 2) a rewarded experience (successful oviposition) acted as a reinforcing stimulus; 3) the elapsed time between two consecutive unrewarded events affected the parasitoid response in a host-gender specific manner. The ecological role of these results to the host location process of egg parasitoids is discussed. PMID:27250870

  6. Habitats as Complex Odour Environments: How Does Plant Diversity Affect Herbivore and Parasitoid Orientation?

    PubMed Central

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  7. Nonlinear Acoustics

    DTIC Science & Technology

    1974-02-14

    Wester- velt. [60] Streaming. In 1831, Michael Faraday [61] noted that currents of air were set up in the neighborhood of vibrating plates-the first... ducei in the case of a paramettc amy (from Berktay an Leahy 141). C’ "". k•, SEC 10.1 NONLINEAR ACOUSTICS 345 The principal results of their analysis

  8. Parasitism rate, parasitoid community composition and host specificity on exposed and semi-concealed caterpillars from a tropical rainforest.

    PubMed

    Hrcek, Jan; Miller, Scott E; Whitfield, James B; Shima, Hiroshi; Novotny, Vojtech

    2013-10-01

    The processes maintaining the enormous diversity of herbivore-parasitoid food webs depend on parasitism rate and parasitoid host specificity. The two parameters have to be evaluated in concert to make conclusions about the importance of parasitoids as natural enemies and guide biological control. We document parasitism rate and host specificity in a highly diverse caterpillar-parasitoid food web encompassing 266 species of lepidopteran hosts and 172 species of hymenopteran or dipteran parasitoids from a lowland tropical forest in Papua New Guinea. We found that semi-concealed hosts (leaf rollers and leaf tiers) represented 84% of all caterpillars, suffered a higher parasitism rate than exposed caterpillars (12 vs. 5%) and their parasitoids were also more host specific. Semi-concealed hosts may therefore be generally more amenable to biological control by parasitoids than exposed ones. Parasitoid host specificity was highest in Braconidae, lower in Diptera: Tachinidae, and, unexpectedly, the lowest in Ichneumonidae. This result challenges the long-standing view of low host specificity in caterpillar-attacking Tachinidae and suggests higher suitability of Braconidae and lower suitability of Ichneumonidae for biological control of caterpillars. Semi-concealed hosts and their parasitoids are the largest, yet understudied component of caterpillar-parasitoid food webs. However, they still remain much closer in parasitism patterns to exposed hosts than to what literature reports on fully concealed leaf miners. Specifically, semi-concealed hosts keep an equally low share of idiobionts (2%) as exposed caterpillars.

  9. Colony-level impacts of parasitoid flies on fire ants.

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

    The red imported fire ant is becoming a global ecological problem, having invaded the United States, Puerto Rico, New Zealand and, most recently, Australia. In its established areas, this pest is devastating natural biodiversity. Early attempts to halt fire ant expansion with pesticides actually enhanced its spread. Phorid fly parasitoids from South America have now been introduced into the United States as potential biological control agents of the red imported fire ant, but the impact of these flies on fire ant populations is currently unknown. In the laboratory, we show that an average phorid density of as little as one attacking fly per 200 foraging ants decreased colony protein consumption nearly twofold and significantly reduced numbers of large-sized workers 50 days later. The high impact of a single phorid occurred mainly because ants decreased foraging rates in the presence of the flies. Our experiments, the first (to our knowledge) to link indirect and direct effects of phorids on fire ants, demonstrate that colonies can be stressed with surprisingly low parasitoid densities. We interpret our findings with regard to the more complex fire ant-phorid interactions in the field. PMID:12204130

  10. The landscape context of cereal aphid–parasitoid interactions

    PubMed Central

    Thies, Carsten; Roschewitz, Indra; Tscharntke, Teja

    2005-01-01

    Analyses at multiple spatial scales may show how important ecosystem services such as biological control are determined by processes acting on the landscape scale. We examined cereal aphid–parasitoid interactions in wheat fields in agricultural landscapes differing in structural complexity (32–100% arable land). Complex landscapes were associated with increased aphid mortality resulting from parasitism, but also with higher aphid colonization, thereby counterbalancing possible biological control by parasitoids and lastly resulting in similar aphid densities across landscapes. Thus, undisturbed perennial habitats appeared to enhance both pests and natural enemies. Analyses at multiple spatial scales (landscape sectors of 0.5–6 km diameter) showed that correlations between parasitism and percentage of arable land were significant at scales of 0.5–2 km, whereas aphid densities responded to percentage of arable land at scales of 1–6 km diameter. Hence, the higher trophic level populations appeared to be determined by smaller landscape sectors owing to dispersal limitation, showing the ‘functional spatial scale’ for species-specific landscape management. PMID:15695212

  11. Metabolomics of aging assessed in individual parasitoid wasps

    PubMed Central

    Kapranas, Apostolos; Snart, Charles J. P.; Williams, Huw; Hardy, Ian C. W.; Barrett, David A.

    2016-01-01

    Metabolomics studies of low-biomass organisms, such as small insects, have previously relied on the pooling of biological samples to overcome detection limits, particularly using NMR. We show that the differentiation of metabolite profiles of individual 1 mg parasitoid wasps of different ages is possible when using a modified sample preparation and a combination of untargeted NMR and LC-MS based metabolomics. Changes were observed between newly emerged and older wasps in glycerolipids, amino acids and circulatory sugars. This advance in chemical profiling has important implications for the study of the behaviour and ecology of parasitoids and many other species of small organisms because predictions and observations are typically made at the level of the individual. Thus, the metabolomic state of low-biomass individuals can now be related to their behaviour and ecological performance. We discuss specifically the utility of age-related metabolomic profiling but our new approach can be applied to a wide range of biological research. PMID:27713504

  12. Antennal Sensilla in the Parasitoid Sclerodermus sp. (Hymenoptera: Bethylidae)

    PubMed Central

    Zhou, Chang-Xiang; Sun, Xiao; Mi, Feng; Chen, Jingyuan; Wang, Man-Qun

    2015-01-01

    Parasitoid wasps of the genus Sclerodermus (Hymenoptera: Bethylidae) are an important natural enemy of the Japanese pine sawyer beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae). In this study, we used scanning electron microscopy to examine the external morphology of the antennal sensilla of Sclerodermus sp. Antennae of females and males comprised the scape, pedicel, and 11 flagellomere segments. Based on the morphology of the sensilla in each sex, seven types of sensillum were identified: sensilla trichodea (Tr.1, Tr.2 and Tr.3), sensilla basiconica (Ba.1, Ba.2, and Ba.3), sensilla styloconica (St.1 and St.2), sensilla placodea, sensilla coeloconica, sensilla squamiforma, and Bohm’s bristles. Tr.2, Ba.1, and St.1 were only found in females, whereas Ba.2, Ba.3, and St.2 were only observed in males. Sensilla placodea were the most common, given that they occur on the antennae of many parasitoid Hymenoptera, whereas sensilla Tr were the most abundant, being distributed over the entire antennal surface. These sensilla are likely to have roles in the host locating and habitat searching behavior of adult Sclerodermus wasps. Therefore, our findings provide a basis for further studies of the host location behavior of this and other species of parasitic wasp. PMID:25843589

  13. Antennal sensilla in the parasitoid Sclerodermus sp. (Hymenoptera: Bethylidae).

    PubMed

    Zhou, Chang-Xiang; Sun, Xiao; Mi, Feng; Chen, Jingyuan; Wang, Man-Qun

    2015-01-01

    Parasitoid wasps of the genus Sclerodermus (Hymenoptera: Bethylidae) are an important natural enemy of the Japanese pine sawyer beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae). In this study, we used scanning electron microscopy to examine the external morphology of the antennal sensilla of Sclerodermus sp. Antennae of females and males comprised the scape, pedicel, and 11 flagellomere segments. Based on the morphology of the sensilla in each sex, seven types of sensillum were identified: sensilla trichodea (Tr.1, Tr.2 and Tr.3), sensilla basiconica (Ba.1, Ba.2, and Ba.3), sensilla styloconica (St.1 and St.2), sensilla placodea, sensilla coeloconica, sensilla squamiforma, and Bohm's bristles. Tr.2, Ba.1, and St.1 were only found in females, whereas Ba.2, Ba.3, and St.2 were only observed in males. Sensilla placodea were the most common, given that they occur on the antennae of many parasitoid Hymenoptera, whereas sensilla Tr were the most abundant, being distributed over the entire antennal surface. These sensilla are likely to have roles in the host locating and habitat searching behavior of adult Sclerodermus wasps. Therefore, our findings provide a basis for further studies of the host location behavior of this and other species of parasitic wasp.

  14. Uncovering Cryptic Parasitoid Diversity in Horismenus (Chalcidoidea, Eulophidae)

    PubMed Central

    Hansson, Christer; Alvarez, Nadir; Benrey, Betty

    2015-01-01

    Horismenus parasitoids are an abundant and understudied group of eulophid wasps found mainly in the New World. Recent surveys based on morphological analyses in Costa Rica have quadrupled the number of named taxa, with more than 400 species described so far. This recent revision suggests that there is still a vast number of unknown species to be identified. As Horismenus wasps have been widely described as parasitoids of insect pests associated with crop plants, it is of high importance to properly establish the extant diversity of the genus, in order to provide biological control practitioners with an exhaustive catalog of putative control agents. In this study, we first collected Horismenus wasps from wild Phaseolus bean seeds in Central Mexico and Arizona to assess the genetic relatedness of three morphologically distinct species with overlapping host and geographical ranges. Sequence data from two nuclear and two mitochondrial gene regions uncovered three cryptic species within each of the three focal species (i.e., H. missouriensis, H. depressus and H. butcheri). The monophyly of each cryptic group is statistically supported (except in two of them represented by one single tip in which monophyly cannot be tested). The phylogenetic reconstruction is discussed with respect to differences between gene regions as well as likely reasons for the differences in variability between species. PMID:26352700

  15. Wolbachia Infection in a Natural Parasitoid Wasp Population.

    PubMed

    Duplouy, Anne; Couchoux, Christelle; Hanski, Ilkka; van Nouhuys, Saskya

    2015-01-01

    The maternally transmitted bacterium Wolbachia pipientis is well known for spreading and persisting in insect populations through manipulation of the fitness of its host. Here, we identify three new Wolbachia pipientis strains, wHho, wHho2 and wHho3, infecting Hyposoter horticola, a specialist wasp parasitoid of the Glanville fritillary butterfly. The wHho strain (ST435) infects about 50% of the individuals in the Åland islands in Finland, with a different infection rate in the two mitochondrial (COI) haplotypes of the wasp. The vertical transmission rate of Wolbachia is imperfect, and lower in the haplotype with lower infection rate, suggesting a fitness trade-off. We found no association of the wHho infection with fecundity, longevity or dispersal ability of the parasitoid host. However, preliminary results convey spatial associations between Wolbachia infection, host mitochondrial haplotype and parasitism of H. horticola by its hyperparasitoid, Mesochorus cf. stigmaticus. We discuss the possibility that Wolbachia infection protects H. horticola against hyperparasitism.

  16. Plant surface wax affects parasitoid's response to host footprints

    NASA Astrophysics Data System (ADS)

    Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

    2008-10-01

    The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

  17. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  18. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens. 9 figs.

  19. Bionomics of Orasema simplex (Hymenoptera: Eucharitidae) a parasitoid of Solenopsis fire ants (Hymenoptera: Formicidae) in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological characteristics of the parasitoid Orasema simplex Heraty (Hymenoptera: Eucharitidae), a potential candidate for the biological control of fire ants in the United States were investigated. Female survivorship, fertility and oviposition preferences were studied in the laboratory. Naturally ...

  20. Sublethal doses of imidacloprid disrupt sexual communication and host finding in a parasitoid wasp

    PubMed Central

    Tappert, Lars; Pokorny, Tamara; Hofferberth, John; Ruther, Joachim

    2017-01-01

    Neonicotinoids are widely used insecticides, but their use is subject of debate because of their detrimental effects on pollinators. Little is known about the effect of neonicotinoids on other beneficial insects such as parasitoid wasps, which serve as natural enemies and are crucial for ecosystem functioning. Here we show that sublethal doses of the neonicotinoid imidacloprid impair sexual communication and host finding in the parasitoid wasp Nasonia vitripennis. Depending on the dose, treated females were less responsive to the male sex pheromone or unable to use it as a cue at all. Courtship behaviour of treated couples was also impeded resulting in a reduction of mating rates by up to 80%. Moreover, treated females were no longer able to locate hosts by using olfactory cues. Olfaction is crucial for the reproductive success of parasitoid wasps. Hence, sublethal doses of neonicotinoids might compromise the function of parasitoid wasps as natural enemies with potentially dire consequences for ecosystem services. PMID:28198464

  1. Competition between the filth fly parasitoids Muscidifurax raptor and M. raptorellus (Hymenoptera: Pteromalidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Competition bioassays were conducted with the filth fly pupal parasitoids Muscidurax raptor (Girault & Sanders) and M. raptorellus (Kogan & Legner) (Hymenoptera: Pteromalidae) with house fly Musca domestica L. (Diptera: Muscidae) hosts at different host densities. Assays were conducted by varying e...

  2. Toxicity of pesticides to Tamarixia radiata, a parasitoid of the Asian citrus psyllid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixteen pesticides including two fungicides were evaluated for toxicity to adult Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae), a parasitoid of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). Percentage mortality data were evaluated to generally assess IPM-com...

  3. Sublethal doses of imidacloprid disrupt sexual communication and host finding in a parasitoid wasp

    NASA Astrophysics Data System (ADS)

    Tappert, Lars; Pokorny, Tamara; Hofferberth, John; Ruther, Joachim

    2017-02-01

    Neonicotinoids are widely used insecticides, but their use is subject of debate because of their detrimental effects on pollinators. Little is known about the effect of neonicotinoids on other beneficial insects such as parasitoid wasps, which serve as natural enemies and are crucial for ecosystem functioning. Here we show that sublethal doses of the neonicotinoid imidacloprid impair sexual communication and host finding in the parasitoid wasp Nasonia vitripennis. Depending on the dose, treated females were less responsive to the male sex pheromone or unable to use it as a cue at all. Courtship behaviour of treated couples was also impeded resulting in a reduction of mating rates by up to 80%. Moreover, treated females were no longer able to locate hosts by using olfactory cues. Olfaction is crucial for the reproductive success of parasitoid wasps. Hence, sublethal doses of neonicotinoids might compromise the function of parasitoid wasps as natural enemies with potentially dire consequences for ecosystem services.

  4. New state record for the silverleaf whitefly parasitoid Encarsia sophia in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A hymenopteran parasitoid reared, Encarsia sophia (Girault & Dodd) (= transvena Timberlake) [Aphelinidae], from silverleaf whitefly, Bemisia tabaci (Genn.), was collected with their host remains from infested cotton, Gossypium hirsutum L., in a greenhouse and potatoes, Solanum tuberosum L., planted ...

  5. Evaluation of imported parasitoid fitness for biocontrol of olive fruit fly in California olives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A parasitoid, Psyttalia humilis (Silvestri), was reared on irradiated Mediterranean fruit fly (Medfly), Ceratitis capitata (Weidemann), at the USDA, APHIS, PPQ, Moscamed biological control laboratory in San Miguel Petapa, Guatemala, and imported into California for biological control of olive fruit ...

  6. Intrinsic competition between two species of neotropical parasitoids: The fierce and the fugitive?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The outcomes of multiparasitism (host occupation by parasitoids of more than one species) are often predictable, one species typically outcompeting another. Such predictability may have arisen from asymmetrical iterations between competitors over evolutionary time. In some instances, a generalist p...

  7. Utilization of an introduced weed biological control agent by a native parasitoid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A native parasitoid, Kalopolynema ema (Schauff and Grissell) (Hymenoptera, Mymaridae), that usually parasitizes the eggs of Megamelus davisi VanDuzee (Hemiptera, Delphacidae), has begun utilizing a new host, Megamelus scutellaris (Berg) (Hemiptera, Delphacidae), the introduced biological control age...

  8. Sugar in Moderation: Variable Sugar Diets Affect Short-Term Parasitoid Behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biological control potential of parasitic wasps in the field is expected to increase with provisioning of sugar sources, which increase longevity and replenish carbohydrate reserves. Apanteles aristoteliae Viereck is an important parasitoid of Argyrotaenia franciscana (Walsingham), the orange to...

  9. Sublethal doses of imidacloprid disrupt sexual communication and host finding in a parasitoid wasp.

    PubMed

    Tappert, Lars; Pokorny, Tamara; Hofferberth, John; Ruther, Joachim

    2017-02-15

    Neonicotinoids are widely used insecticides, but their use is subject of debate because of their detrimental effects on pollinators. Little is known about the effect of neonicotinoids on other beneficial insects such as parasitoid wasps, which serve as natural enemies and are crucial for ecosystem functioning. Here we show that sublethal doses of the neonicotinoid imidacloprid impair sexual communication and host finding in the parasitoid wasp Nasonia vitripennis. Depending on the dose, treated females were less responsive to the male sex pheromone or unable to use it as a cue at all. Courtship behaviour of treated couples was also impeded resulting in a reduction of mating rates by up to 80%. Moreover, treated females were no longer able to locate hosts by using olfactory cues. Olfaction is crucial for the reproductive success of parasitoid wasps. Hence, sublethal doses of neonicotinoids might compromise the function of parasitoid wasps as natural enemies with potentially dire consequences for ecosystem services.

  10. Ecological and morphological characteristics of parasitoids in Phauda flammans (Lepidoptera, Zygaenidae)

    PubMed Central

    Zheng, Xia-Lin; Li, Jun; Su, Li; Liu, Jun-Yan; Meng, Ling-Yu; Lin, Min-Yi; Zhang, Jing; Lu, Wen

    2015-01-01

    Phauda flammans Walker (Lepidoptera, Zygaenidae) is one of the notorious defoliators on Ficus spp. trees. In order to avoid environmental pollution, potential biological control agents for P. flammans need to be investigated instead of chemical control. Four species of insect parasitoids were identified from P. flammans, including three hymenopteran species (i.e., Gotra octocinctus, Apanteles sp. and Eurytoma verticillata) and one dipteran species (i.e., Exorista yunnanica). Parasitoid ratios of G. octocinctus, Apanteles sp., Eu. verticillata and Ex. yunnanica were 7.2%, 4.2%, 1.6% and 0.9%. The four species were all larval endoparasitoids of P. flammans larvae. Time of cocoon (pupa) to adult, life span, major axis of cocoon and body length of females were all longer compared to males for G. octocinctus, Apanteles sp. and Ex. yunnanica. Based on the parasitoid ratios, the most abundant parasitoid species was G. octocinctus. PMID:26651181

  11. Seven invasive owlet moths (Lepidoptera: Noctuidae) in Israel and their potential parasitoids (Hymenoptera: Chalcidoidea)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over a 10 year period, collections from light traps placed at 88 locations throughout Israel were examined for tropical species of noctuid pest species and associated parasitoids. Tropical noctuidae pest species collected included Spodoptera mauritia (Boisduval), Trichoplusia vittata (Wallengren), A...

  12. Egg parasitoids of Taosa spp. (Hemiptera:Dictyopharidae)in Formosa Argentina with descriptions of new species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Egg parasitoids (Hymenoptera: Eulophidae and Platygastridae) of Taosa (Cuernavaca) longula Remes Lenicov (Hemiptera: Dictyopharidae) are reviewed and keyed. This planthopper feeds on water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach, and was collected in Formosa, Argentina, where some of ...

  13. Tri-trophic movement of carotenoid pigments from host plant to the parasitoid of a caterpillar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect parasitoids normally produce white-colored eggs. Habrobracon gelechiae (Hymenoptera: Braconidae) is a gregarious ectoparasitoid of various caterpillars that lays yellow eggs when its larvae developed on leaf-fed Choristoneura rosaceana and Epiphyas postvittana (both Lepidoptera: Tortricidae) ...

  14. Host suitability affects odor association in Cotesia marginiventris: implications in generalist parasitoid host-finding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect herbivores often induce plant volatile compounds that can attract natural enemies. Cotesia marginiventris (Hymenoptera: Braconidae) is a generalist parasitoid wasp of noctuid caterpillars and is highly attracted to Spodoptera exigua-induced plant volatiles. The plasticity of C. marginiventris...

  15. Molecular Techniques for the Detection and Differentiation of Host and Parasitoid Species and the Implications for Fruit Fly Management.

    PubMed

    Jenkins, Cheryl; Chapman, Toni A; Micallef, Jessica L; Reynolds, Olivia L

    2012-08-14

    Parasitoid detection and identification is a necessary step in the development and implementation of fruit fly biological control strategies employing parasitoid augmentive release. In recent years, DNA-based methods have been used to identify natural enemies of pest species where morphological differentiation is problematic. Molecular techniques also offer a considerable advantage over traditional morphological methods of fruit fly and parasitoid discrimination as well as within-host parasitoid identification, which currently relies on dissection of immature parasitoids from the host, or lengthy and labour-intensive rearing methods. Here we review recent research focusing on the use of molecular strategies for fruit fly and parasitoid detection and differentiation and discuss the implications of these studies on fruit fly management.

  16. Molecular Techniques for the Detection and Differentiation of Host and Parasitoid Species and the Implications for Fruit Fly Management

    PubMed Central

    Jenkins, Cheryl; Chapman, Toni A.; Micallef, Jessica L.; Reynolds, Olivia L.

    2012-01-01

    Parasitoid detection and identification is a necessary step in the development and implementation of fruit fly biological control strategies employing parasitoid augmentive release. In recent years, DNA-based methods have been used to identify natural enemies of pest species where morphological differentiation is problematic. Molecular techniques also offer a considerable advantage over traditional morphological methods of fruit fly and parasitoid discrimination as well as within-host parasitoid identification, which currently relies on dissection of immature parasitoids from the host, or lengthy and labour-intensive rearing methods. Here we review recent research focusing on the use of molecular strategies for fruit fly and parasitoid detection and differentiation and discuss the implications of these studies on fruit fly management. PMID:26466628

  17. Acoustic chaos

    SciTech Connect

    Lauterborn, W.; Parlitz, U.; Holzfuss, J.; Billo, A.; Akhatov, I.

    1996-06-01

    Acoustic cavitation, a complex, spatio-temporal dynamical system, is investigated with respect to its chaotic properties. The sound output, the {open_quote}{open_quote}noise{close_quote}{close_quote}, is subjected to time series analysis. The spatial dynamics of the bubble filaments is captured by high speed holographic cinematography and subsequent digital picture processing from the holograms. Theoretical models are put forward for describing the pattern formation. {copyright} {ital 1996 American Institute of Physics.}

  18. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk W.; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  19. Shifting preference between oviposition vs. host-feeding under changing host densities in two aphelinid parasitoids.

    PubMed

    Yang, Nian-Wan; Ji, Lu-Lu; Lövei, Gabor L; Wan, Fang-Hao

    2012-01-01

    Destructive host-feeding is common in hymenopteran parasitoids. Such feeding may be restricted to host stages not preferred for oviposition. However, whether this is a fixed strategy or can vary according to resource levels or parasitoid needs is less clear. We tested the trade-off between host feeding and oviposition on two whitefly parasitoids under varying host densities. Females of two aphelinid parasitoids, Eretmocerus hayati and Encarsia sophia were exposed to nine different densities of their whitefly host, Bemisia tabaci, in single-instar tests to identify their functional response. Mixed-instar host choice tests were also conducted by exposing whiteflies at four densities to the parasitoids. We hypothesized that the parasitoid females can detect different host densities, and decide on oviposition vs. host-feeding accordingly. The results showed that both Er. hayati and En. sophia females tended to increase both oviposition and host-feeding with increased host density within a certain range. Oviposition reached a plateau at lower host density than host-feeding in Er. hayati, while En. sophia reached its oviposition plateau at higher densities. At low densities, Er. hayati parasitized most on first and second (the optimal ones), and fed most on third nymphal instars (the suboptimal one) of the whitefly host as theory predicts, while at high densities, both parasitism and host-feeding occurred on first and second instars which are preferred for oviposition. En. sophia parasitized most on third and fourth (the optimal ones), while fed on first instars (the suboptimal one) at low densities, and utilized third and fourth instars for both at high densities. In conclusion, oviposition vs. host-feeding strategy of parasitoid females was found to vary at different host densities. The balance between reserving optimal hosts for oviposition or using them for host-feeding depended on parasitoid life history and the availability of host resources.

  20. Behavioral Strategies of Phorid Parasitoids and Responses of Their Hosts, the Leaf-Cutting Ants

    PubMed Central

    Elizalde, Luciana; Folgarait, Patricia Julia

    2012-01-01

    Host-searching and oviposition behaviors of parasitoids, and defensive responses of the hosts, are fundamental in shaping the ecology of host-parasitoid interactions. In order to uncover key behavioral features for the little known interactions between phorid parasitoids (Diptera: Phoridae) and their leaf-cutting ant hosts (Formicidae: Attini), host-related behavioral strategies (i.e., host searching and oviposition) for 13 phorid species, and host defensive responses (i.e., hitchhikers and particular body postures) for 11 ant species, were studied. Data was collected at 14 localities, one of them characterized by its high species richness for this host-parasitoid system. Phorid species showed both great variation and specificity in attacking behaviors. Some chose their hosts using either an ambush or an actively searching strategy, while some species attacked ants on different body parts, and specialized on ants performing different tasks, such as when ants were foraging, removing wastes to refuse piles, or repairing the nest. Combining all the behaviors recorded, most phorid species differed in performance in at least one, making it possible to recognize species in the field through their behavior. Phorid species that attacked hosts with greater activity levels showed overall higher attack rates, although there was no significant correlation between attack rates by most phorid species and ant activity outside the nest while parasitoids were attacking. The presence of phorids was a significant determinant for the presence of defensive behaviors by the ants. Although ant species varied in the incidence levels of these defensive behaviors, most ant species reacted against different phorids by utilizing similar behaviors, in contrast to what parasitoids do. General features of the observed phorid-ant interactions were parasitoid specialization and corresponding high interspecific variation in their behaviors, while their hosts showed generalized responses to attacks

  1. Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

    PubMed Central

    Gabriela Murúa, M.; Molina-Ochoa, Jaime; Fidalgo, Patricio

    2009-01-01

    To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval

  2. Shifting Preference between Oviposition vs. Host-Feeding under Changing Host Densities in Two Aphelinid Parasitoids

    PubMed Central

    Yang, Nian-Wan; Ji, Lu-Lu; Lövei, Gabor L.; Wan, Fang-Hao

    2012-01-01

    Destructive host-feeding is common in hymenopteran parasitoids. Such feeding may be restricted to host stages not preferred for oviposition. However, whether this is a fixed strategy or can vary according to resource levels or parasitoid needs is less clear. We tested the trade-off between host feeding and oviposition on two whitefly parasitoids under varying host densities. Females of two aphelinid parasitoids, Eretmocerus hayati and Encarsia sophia were exposed to nine different densities of their whitefly host, Bemisia tabaci, in single-instar tests to identify their functional response. Mixed-instar host choice tests were also conducted by exposing whiteflies at four densities to the parasitoids. We hypothesized that the parasitoid females can detect different host densities, and decide on oviposition vs. host-feeding accordingly. The results showed that both Er. hayati and En. sophia females tended to increase both oviposition and host-feeding with increased host density within a certain range. Oviposition reached a plateau at lower host density than host-feeding in Er. hayati, while En. sophia reached its oviposition plateau at higher densities. At low densities, Er. hayati parasitized most on first and second (the optimal ones), and fed most on third nymphal instars (the suboptimal one) of the whitefly host as theory predicts, while at high densities, both parasitism and host-feeding occurred on first and second instars which are preferred for oviposition. En. sophia parasitized most on third and fourth (the optimal ones), while fed on first instars (the suboptimal one) at low densities, and utilized third and fourth instars for both at high densities. In conclusion, oviposition vs. host-feeding strategy of parasitoid females was found to vary at different host densities. The balance between reserving optimal hosts for oviposition or using them for host-feeding depended on parasitoid life history and the availability of host resources. PMID:22815964

  3. Fitness costs of intrinsic competition in two egg parasitoids of a true bug.

    PubMed

    Cusumano, Antonino; Peri, Ezio; Boivin, Guy; Colazza, Stefano

    2015-10-01

    Intrinsic competition in insect parasitoids occurs when supernumerary larvae develop in the same host as consequence of multiple ovipositions by females of the same species (intra-specific competition) or by females of different species (inter-specific competition). Studies on intrinsic competition have mainly focused on understanding the factors that play a role in the outcome of competition, while fitness-related effects for the parasitoid surviving the competition have been poorly investigated, especially in egg parasitoids. Interestingly, even the winning parasitoid can experience fitness costs due to larval development in a host in which multiple factors have been injected by the ovipositing females or released by their larvae. In this paper we studied fitness-related traits associated with intra- and inter-specific competition between Trissolcus basalis (Wollaston) and Ooencyrtus telenomicida (Vassiliev), the main egg parasitoids associated with the southern green stink bug Nezara viridula (L.) in Italy. We investigated the impact of intrinsic competition for the surviving parasitoid in terms of body size, developmental time, number and size of oocytes. Our results indicated that T. basalis adults did not experience fitness-related costs when surviving intra-specific competition; however, adults were smaller, took longer to develop and females produced fewer oocytes after surviving inter-specific competition. A different outcome was found for O. telenomicida where the emerging females were smaller, produced fewer and smaller oocytes when suffering intra-specific competition whereas no fitness costs were found when adults survived inter-specific competition. These results support the hypothesis that the impact of intrinsic competition in egg parasitoids depends on the severity of the competitive interaction, as fitness costs were more pronounced when the surviving parasitoid interacted with the most detrimental competitor.

  4. Natural distribution of parasitoids of larvae of the fall armyworm, Spodoptera frugiperda, in Argentina.

    PubMed

    Gabriela Murúa, M; Molina-Ochoa, Jaime; Fidalgo, Patricio

    2009-01-01

    To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval

  5. Acoustic dose and acoustic dose-rate.

    PubMed

    Duck, Francis

    2009-10-01

    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  6. Predation on Rose Galls: Parasitoids and Predators Determine Gall Size through Directional Selection

    PubMed Central

    László, Zoltán; Sólyom, Katalin; Prázsmári, Hunor; Barta, Zoltán; Tóthmérész, Béla

    2014-01-01

    Both predators and parasitoids can have significant effects on species’ life history traits, such as longevity or clutch size. In the case of gall inducers, sporadically there is evidence to suggest that both vertebrate predation and insect parasitoid attack may shape the optimal gall size. While the effects of parasitoids have been studied in detail, the influence of vertebrate predation is less well-investigated. To better understand this aspect of gall size evolution, we studied vertebrate predation on galls of Diplolepis rosae on rose (Rosa canina) shrubs. We measured predation frequency, predation incidence, and predation rate in a large-scale observational field study, as well as an experimental field study. Our combined results suggest that, similarly to parasitoids, vertebrate predation makes a considerable contribution to mortality of gall inducer larvae. On the other hand, its influence on gall size is in direct contrast to the effect of parasitoids, as frequency of vertebrate predation increases with gall size. This suggests that the balance between predation and parasitoid attack shapes the optimal size of D. rosae galls. PMID:24918448

  7. Predation on rose galls: parasitoids and predators determine gall size through directional selection.

    PubMed

    László, Zoltán; Sólyom, Katalin; Prázsmári, Hunor; Barta, Zoltán; Tóthmérész, Béla

    2014-01-01

    Both predators and parasitoids can have significant effects on species' life history traits, such as longevity or clutch size. In the case of gall inducers, sporadically there is evidence to suggest that both vertebrate predation and insect parasitoid attack may shape the optimal gall size. While the effects of parasitoids have been studied in detail, the influence of vertebrate predation is less well-investigated. To better understand this aspect of gall size evolution, we studied vertebrate predation on galls of Diplolepis rosae on rose (Rosa canina) shrubs. We measured predation frequency, predation incidence, and predation rate in a large-scale observational field study, as well as an experimental field study. Our combined results suggest that, similarly to parasitoids, vertebrate predation makes a considerable contribution to mortality of gall inducer larvae. On the other hand, its influence on gall size is in direct contrast to the effect of parasitoids, as frequency of vertebrate predation increases with gall size. This suggests that the balance between predation and parasitoid attack shapes the optimal size of D. rosae galls.

  8. Adaptive evolution of a generalist parasitoid: implications for the effectiveness of biological control agents

    PubMed Central

    Zepeda-Paulo, Francisca A; Ortiz-Martínez, Sebastián A; Figueroa, Christian C; Lavandero, Blas

    2013-01-01

    The use of alternative hosts imposes divergent selection pressures on parasitoid populations. In response to selective pressures, these populations may follow different evolutionary trajectories. Divergent natural selection could promote local host adaptation in populations, translating into direct benefits for biological control, thereby increasing their effectiveness on the target host. Alternatively, adaptive phenotypic plasticity could be favored over local adaptation in temporal and spatially heterogeneous environments. We investigated the existence of local host adaptation in Aphidius ervi, an important biological control agent, by examining different traits related to infectivity (preference) and virulence (a proxy of parasitoid fitness) on different aphid-host species. The results showed significant differences in parasitoid infectivity on their natal host compared with the non-natal hosts. However, parasitoids showed a similar high fitness on both natal and non-natal hosts, thus supporting a lack of host adaptation in these introduced parasitoid populations. Our results highlight the role of phenotypic plasticity in fitness-related traits of parasitoids, enabling them to maximize fitness on alternative hosts. This could be used to increase the effectiveness of biological control. In addition, A. ervi females showed significant differences in infectivity and virulence across the tested host range, thus suggesting a possible host phylogeny effect for those traits. PMID:24062806

  9. Adaptive evolution of a generalist parasitoid: implications for the effectiveness of biological control agents.

    PubMed

    Zepeda-Paulo, Francisca A; Ortiz-Martínez, Sebastián A; Figueroa, Christian C; Lavandero, Blas

    2013-09-01

    The use of alternative hosts imposes divergent selection pressures on parasitoid populations. In response to selective pressures, these populations may follow different evolutionary trajectories. Divergent natural selection could promote local host adaptation in populations, translating into direct benefits for biological control, thereby increasing their effectiveness on the target host. Alternatively, adaptive phenotypic plasticity could be favored over local adaptation in temporal and spatially heterogeneous environments. We investigated the existence of local host adaptation in Aphidius ervi, an important biological control agent, by examining different traits related to infectivity (preference) and virulence (a proxy of parasitoid fitness) on different aphid-host species. The results showed significant differences in parasitoid infectivity on their natal host compared with the non-natal hosts. However, parasitoids showed a similar high fitness on both natal and non-natal hosts, thus supporting a lack of host adaptation in these introduced parasitoid populations. Our results highlight the role of phenotypic plasticity in fitness-related traits of parasitoids, enabling them to maximize fitness on alternative hosts. This could be used to increase the effectiveness of biological control. In addition, A. ervi females showed significant differences in infectivity and virulence across the tested host range, thus suggesting a possible host phylogeny effect for those traits.

  10. Population structure of a large blue butterfly and its specialist parasitoid in a fragmented landscape.

    PubMed

    Anton, Christian; Zeisset, Inga; Musche, Martin; Durka, Walter; Boomsma, Jacobus J; Settele, Josef

    2007-09-01

    Habitat fragmentation may interrupt trophic interactions if herbivores and their specific parasitoids respond differently to decreasing connectivity of populations. Theoretical models predict that species at higher trophic levels are more negatively affected by isolation than lower trophic level species. By combining ecological data with genetic information from microsatellite markers we tested this hypothesis on the butterfly Maculinea nausithous and its specialist hymenopteran parasitoid Neotypus melanocephalus. We assessed the susceptibility of both species to habitat fragmentation by measuring population density, rate of parasitism, overall genetic differentiation (theta(ST)) and allelic richness in a large metapopulation. We also simulated the dynamics of genetic differentiation among local populations to asses the relative effects of migration rate, population size, and haplodiploid (parasitoid) and diploid (host) inheritance on metapopulation persistence. We show that parasitism by N. melanocephalus is less frequent at larger distances to the nearest neighbouring population of M. nausithous hosts, but that host density itself is not affected by isolation. Allelic richness was independent of isolation, but the mean genetic differentiation among local parasitoid populations increased with the distance between these populations. Overall, genetic differentiation in the parasitoid wasp was much greater than in the butterfly host and our simulations indicate that this difference is due to a combination of haplodiploidy and small local population sizes. Our results thus support the hypothesis that Neotypus parasitoid wasps are more sensitive to habitat fragmentation than their Maculinea butterfly hosts.

  11. Aphid Parasitoid Mothers Don't Always Know Best through the Whole Host Selection Process

    PubMed Central

    Chesnais, Quentin; Ameline, Arnaud; Doury, Géraldine; Le Roux, Vincent; Couty, Aude

    2015-01-01

    Parasitoid host selection behaviour has been extensively studied in experimentally simplified tritrophic systems formed by one single food chain (one plant, one herbivore and one parasitoid species). The "Mother knows best" hypothesis predicts that the preference for a plant-host complex should be positively correlated with plant quality for offspring performance. We studied the host selection behaviour of the generalist endoparasitoid Aphidius matricariae towards the black bean aphid Aphis fabae in the intercrop system including Vicia faba as a focal plant and its companion plant Camelina sativa. Dual-choice laboratory bioassays revealed that parasitoid females preferred to orientate towards (1) the plant-aphid complex over the non-infested plant whatever the complex (2) the C. sativa-A. fabae complex over the V. faba-A. fabae complex. In dual choice attack rate bioassays, parasitoid females showed more interest towards the aphids on C. sativa but paradoxically chose to oviposit more in aphids on V. faba. Ultimately, parasitoids that had developed on the V. faba-A. fabae complex exhibited better fitness parameters. By demonstrating that parasitoid females were able to discriminate the aphid host that offered the highest fitness to their offspring but selected beforehand the least suitable plant-aphid complex, we provide key insight into the disruption in their host selection behaviour potentially triggered by diverse habitats. This suggests that the "Mother knows best" hypothesis could be thwarted by increasing the complexity of the studied systems. PMID:26270046

  12. Impact of extreme temperatures on parasitoids in a climate change perspective.

    PubMed

    Hance, Thierry; van Baaren, Joan; Vernon, Philippe; Boivin, Guy

    2007-01-01

    Parasitoids depend on a series of adaptations to the ecology and physiology of their hosts and host plants for survival and are thus likely highly susceptible to changes in environmental conditions. We analyze the effects of global warming and extreme temperatures on the life-history traits of parasitoids and interactions with their hosts. Adaptations of parasitoids to low temperatures are similar to those of most ectotherms, but these adaptations are constrained by the responses of their hosts. Life-history traits are affected by cold exposure, and extreme temperatures can reduce endosymbiont populations inside a parasitoid, eventually eliminating populations of endosymbionts that are susceptible to high temperatures. In several cases, divergences between the thermal preferences of the host and those of the parasitoid lead to a disruption of the temporal or geographical synchronization, increasing the risk of host outbreaks. A careful analysis on how host-parasitoid systems react to changes in temperature is needed so that researchers may predict and manage the consequences of global change at the ecosystem level.

  13. Functional response, host stage preference and interference of two whitefly parasitoids.

    PubMed

    Xu, Hai-Yun; Yang, Nian-Wan; Duan, Min; Wan, Fang-Hao

    2016-02-01

    The functional responses of two parasitoids, Eretmocerus hayati Zolnerowich & Rose and Encarsia sophia Girault & Dodd, of whitefly Bemisia tabaci Gennadius Middle East-Asia Minor 1 were studied under laboratory conditions. In addition, the influence of host density and host stage on the competitive interactions between the two parasitoids, and biological control effect on whitefly were evaluated. In the functional response study, adult parasitoids were tested individually, with a conspecific or heterospecific competitor. Both Er. hayati and En. sophia exhibited a type II response to increasing host density, whether a conspecific or heterospecific competitor was present or not. Difference of searching rates and handling times between treatments suggested interference interactions existed between two parasitoid species. In the host stage preference study, two parasitoid species were jointly tested. Er. hayati had a competitive advantage over En. sophia when provided young host instars (first and second instar), whereas no advantage was found on old host instars (third and fourth instar). The biological control effect of Er. hayati and En. sophia in different introductions varied with host density. However, the effect of host instar on host mortality was not significant. These findings provide information for the practice of biological control and give better insight into how parasitoid species may coexist in diverse environments.

  14. Aphid Parasitoid Mothers Don't Always Know Best through the Whole Host Selection Process.

    PubMed

    Chesnais, Quentin; Ameline, Arnaud; Doury, Géraldine; Le Roux, Vincent; Couty, Aude

    2015-01-01

    Parasitoid host selection behaviour has been extensively studied in experimentally simplified tritrophic systems formed by one single food chain (one plant, one herbivore and one parasitoid species). The "Mother knows best" hypothesis predicts that the preference for a plant-host complex should be positively correlated with plant quality for offspring performance. We studied the host selection behaviour of the generalist endoparasitoid Aphidius matricariae towards the black bean aphid Aphis fabae in the intercrop system including Vicia faba as a focal plant and its companion plant Camelina sativa. Dual-choice laboratory bioassays revealed that parasitoid females preferred to orientate towards (1) the plant-aphid complex over the non-infested plant whatever the complex (2) the C. sativa-A. fabae complex over the V. faba-A. fabae complex. In dual choice attack rate bioassays, parasitoid females showed more interest towards the aphids on C. sativa but paradoxically chose to oviposit more in aphids on V. faba. Ultimately, parasitoids that had developed on the V. faba-A. fabae complex exhibited better fitness parameters. By demonstrating that parasitoid females were able to discriminate the aphid host that offered the highest fitness to their offspring but selected beforehand the least suitable plant-aphid complex, we provide key insight into the disruption in their host selection behaviour potentially triggered by diverse habitats. This suggests that the "Mother knows best" hypothesis could be thwarted by increasing the complexity of the studied systems.

  15. Liriomyza Leafminer (Diptera: Agromyzidae) Parasitoid Complex in Different Agroecological Zones, Seasons, and Host Plants in Kenya.

    PubMed

    Foba, C N; Salifu, D; Lagat, Z O; Gitonga, L M; Akutse, K S; Fiaboe, K K M

    2016-04-01

    Liriomyza leafminers (Diptera: Agromyzidae) are severe pests of vegetables and ornamentals worldwide. Previous studies revealed low leafminer parasitism across different agroecological zones in Kenya. The present paper reports on the composition of leafminer parasitoids at different elevations, in different seasons, and on different host crops. Surveys were conducted monthly from January to November 2012, and nine parasitoid species were recovered. Total mean parasitism in the study sites was 31.23 ± 1.03% from a total of 20 different vegetable Liriomyza-infested crops belonging to seven families. Diglyphus isaea (Walker) (Hymenoptera: Eulophidae), Phaedrotoma scabriventris, a newly released parasitoid, and Opius dissitus Muesebeck (Hymenoptera: Braconidae) were the most abundant at all elevations, accounting for 67.3, 18.6, and 9.2% of total parasitoids, respectively. Elevation, season, and host crop significantly affected the parasitoid species present and their abundance. Diglyphus isaea was more abundant at the high- and mid-elevations at all seasons compared with the low-elevation, whereas the lower-elevation favored higher abundance of P. scabriventris and O. dissitus during the long rainy season compared with the high- and mid-elevations at all seasons. Of all the host crops surveyed, parasitoids were more abundant on tomato, local kidney bean, snow pea and French bean than other crops. The total parasitism rate observed in this study suggests a considerable improvement in leafminer parasitism compared with previous surveys in Kenya. The implications of these findings for leafminer management in vegetable and ornamental production in Kenya are discussed.

  16. The parasitoids of the asparagus miner (Diptera: Agromyzidae): field parasitism and the influence of food resources on life history.

    PubMed

    Morrison, William R; Gibson, Gary A P; Szendrei, Zsofia

    2014-12-01

    The goals of this study were to identify pupal parasitoids of the asparagus miner, Ophiomyia simplex Loew (Diptera: Agromyzidae), and examine the effect of different diets and floral resources on the lifespan of adult asparagus miners and their parasitoids. We also measured the effect of parasitism on stem damage caused by the asparagus miner. The identity and abundance of the parasitoids of the asparagus miner were determined in asparagus fields in Michigan from weekly asparagus miner pupal collections during the 2010-2013 seasons. Twelve species of hymenopterous parasitoids were reared from asparagus miner pupae, including Chorebus rondanii (Giard) (Ichneumonoidea: Braconidae), 10 species in three families of Chalcidoidea, and one species of Bethylidae (Chrysidoidea), that represent new host records for the asparagus miner. C. rondanii and Thinodytes cephalon (Walker) (Pteromalidae) were the most common parasitoids. The effects of different diets and flowers on the lifespan of the pest and parasitoid adults were also evaluated. Buckwheat resulted in the shortest life span for the asparagus miner, whereas Riddell's goldenrod significantly increased its lifespan relative to the control. Parasitoid lifespan was doubled when individuals were fed sugar-rich diets. In the field, parasitoids preferred stems that contained more pupae and damage. The two most commonly reared parasitoids should be considered as targets for future conservation biological control efforts of the asparagus miner.

  17. Impact of Rag1 aphid resistant soybeans on Binodoxys communis (Hymenoptera: Braconidae), a parasitoid of soybean aphid (Hemiptera: Aphididae).

    PubMed

    Ghising, Kiran; Harmon, Jason P; Beauzay, Patrick B; Prischmann-Voldseth, Deirdre A; Helms, Ted C; Ode, Paul J; Knodel, Janet J

    2012-04-01

    Multiple strategies are being developed for pest management of the soybean aphid, Aphis glycines Matsumura; however, there has been little published research thus far to determine how such strategies may influence each other, thereby complicating their potential effectiveness. A susceptible soybean (Glycine max L.) variety without the Rag1 gene and a near isogenic resistant soybean variety with the Rag1 gene were evaluated in the laboratory for their effects on the fitness of the soybean aphid parasitoid, Binodoxys communis (Gahan). The presence or absence of the Rag1 gene was verified by quantifying soybean aphid growth. To test for fitness effects, parasitoids were allowed to attack soybean aphids on either a susceptible or resistant plant for 24 h and then aphids were kept on the same plant throughout parasitoid development. Parasitoid fitness was measured by mummy and adult parasitoid production, adult parasitoid emergence, development time, and adult size. Parasitoids that attacked soybean aphids on susceptible plants produced more mummies, more adult parasitoids, and had a higher emergence rate compared with those on resistant plants. Adult parasitoids that emerged from resistant plants took 1 d longer and were smaller compared with those from susceptible plants. This study suggests that biological control by B. communis may be compromised when host plant resistance is widely used for pest management of soybean aphids.

  18. On the parasitoid complex of butterflies with descriptions of two new species of parasitic wasps (Hymenoptera: Eulophidae) from Goa, India.

    PubMed

    Gupta, Ankita; Gawas, Sandesh M; Bhambure, Ravindra

    2015-11-01

    In comprehensive rearing of butterflies from Goa, India, an interesting parasitoid complex of wasps and tachinid flies was found. Two new species of parasitic wasps are described and illustrated: Tetrastichus thetisae n. sp. (Hymenoptera: Eulophidae), a gregarious parasitoid reared from the pupa of Curetis thetis (Drury) (Lepidoptera: Lycaenidae) on the host plant Derris sp., and Sympiesis thyrsisae n. sp. (Hymenoptera: Eulophidae), a gregarious parasitoid reared from the caterpillar of Gangara thyrsis (Fabricius) (Lepidoptera: Hesperiidae) on the host plant Cocos nucifera L. Additionally, the following host-parasitoid associations are recorded: Amblypodia anita Hewitson (Lepidoptera: Lycaenidae) with Parapanteles sp. (Hymenoptera: Braconidae); Coladenia indrani (Moore) (Lepidoptera: Hesperiidae) with Sympiesis sp. (Hymenoptera: Eulophidae); Danaus chrysippus L. (Lepidoptera: Nymphalidae) with Sturmia convergens (Wiedemann) (Diptera: Tachinidae); Idea malabarica Moore (Lepidoptera: Nymphalidae) with Brachymeria sp. (Hymenoptera: Chalcididae) and Palexorista sp. (Diptera: Tachinidae); Notocrypta curvifascia Felder & Felder (Lepidoptera: Hesperiidae) with Cotesia erionotae (Wilkinson) (Hymenoptera: Braconidae); and Rapala sp. (Lepidoptera: Lycaenidae) with an inominate species close to Aplomya spp. (Diptera: Tachinidae). This discovery is the first record of Tetrastichus as parasitoid of Curetis thetis, Sympiesis as parasitoid of Gangara thyrsis and Coladenia indrani, Brachymeria and Palexorista as parasitoids of Idea malabarica, and Cotesia erionotae as parasitoid of Notocrypta curvifascia. Data on habitat, brief diagnoses and host records for all parasitoids are provided.

  19. Mixed release of two parasitoids and a polyphagous ladybird as a potential strategy to control the tobacco whitefly Bemisia tabaci

    PubMed Central

    Tan, Xiaoling; Hu, Nana; Zhang, Fan; Ramirez-Romero, Ricardo; Desneux, Nicolas; Wang, Su; Ge, Feng

    2016-01-01

    A mixed species release of parasitoids is used to suppress outbreaks of tobacco whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae); however, this biocontrol may be inhibited by interspecific interactions. We investigated the effects of mixed releases of natural enemies of B. tabaci on predation rates, parasite performance and adult parasitoid emergence under greenhouse conditions. We tested the polyphagous predatory ladybird Harmonia axyridis (Coleoptera: Coccinellidae) and two whitefly-specific parasitoids, namely Encarsia formosa and Encarsia sophia (both, Hymenoptera: Aphelinidae). Harmonia axyridis exhibited the lowest rates of predation when released with each parasitoid than with both parasitoid species together and showed a significant preference for non-parasitized nymphs as prey. Both E. formosa and E. sophia parasitized more B. tabaci when released with the ladybird than when the wasps were released either alone or mixed with the other parasitoid. We also found that the presence of H. axyridis significantly reduced adult parasitoid emergence; the highest rate of adult emergence was obtained with parasitoids released alone. Our results indicate that different combinations of natural enemies can influence observed rates of predation, parasitism, and parasitoid emergence. Therefore, the combination of natural enemies to be used for a particular biological control program should depend on the specific objectives. PMID:27312174

  20. Body odors of parasitized caterpillars give away the presence of parasitoid larvae to their primary hyperparasitoid enemies.

    PubMed

    Zhu, Feng; Weldegergis, Berhane T; Lhie, Boris; Harvey, Jeffrey A; Dicke, Marcel; Poelman, Erik H

    2014-09-01

    Foraging success of parasitoids depends on the utilization of reliable information on the presence of their often, inconspicuous hosts. These parasitic wasps use herbivore-induced plant volatiles (HIPVs) that provide reliable cues on host presence. However, host searching of hyperparasitoids, a group of parasitoids that parasitize the larvae and pupae of other parasitoids, is more constrained. Their hosts do not feed on plants, and often are even concealed inside the body of the herbivore host. Hyperparasitoids recently have been found to use HIPVs of plants damaged by herbivore hosts in which the parasitoid larvae develop. However, hyperparasitoids that search for these parasitoid larvae may be confronted with healthy and parasitized caterpillars on the same plant, further complicating their host location. In this study, we addressed whether the primary hyperparasitoid Baryscapus galactopus uses caterpillar body odors to discriminate between unparasitized herbivores and herbivores carrying larvae of parasitoid hosts. We show that the hyperparasitoids made faster first contact and spent a longer mounting time with parasitized caterpillars. Moreover, although the three parasitoid hosts conferred different fitness values for the development of B. galactopus, the hyperparasitoids showed similar behavioral responses to caterpillar hosts carrying different primary parasitoid hosts. In addition, a two-chamber olfactometer assay revealed that volatiles emitted by parasitized caterpillars were more attractive to the hyperparasitoids than those emitted by unparasitized caterpillars. Analysis of volatiles revealed that body odors of parasitized caterpillars differ from unparasitized caterpillars, allowing the hyperparasitoids to detect their parasitoid host.

  1. Sunflower stem weevil and its larval parasitoids in native sunflowers: is parasitoid abundance and diversity greater in the U.S. Southwest?

    PubMed

    Ode, Paul J; Charlet, Laurence D; Seiler, Gerald J

    2011-02-01

    Classical biological control programs often target a pest's region of origin as a likely source for new biological control agents. Here, we use this approach to search for biological control agents of the sunflower stem weevil (Cylindrocopturus adspersus LeConte), an economically important pest of commercial sunflower. We conducted surveys of weevil natural enemy diversity and abundance across a transect running from the northern Great Plains to the southwestern U.S. (the presumed area of endemism of annual sunflower species in the genus Helianthus). Accordingly, natural enemy diversity and abundance were expected to be greater in the southwestern U.S. C. adspersus and their larval parasitoids were collected from stems of four native sunflower species (Helianthus annuus, H. nuttallii, H. pauciflorus, and H. petiolaris) from 147 sites across eight states. Native H. annuus constituted the majority of the sunflower populations. Mean weevil densities were significantly higher in sunflower stalks that were larger in diameter. Mean weevil densities within sites did not differ across the range of longitudes and latitudes sampled. After accounting for the effects of stalk diameter and location, weevil densities did not differ among the four sunflower species nor did they differ as a function of elevation. C. adspersus in H. annuus and H. petiolaris were attacked by seven species of parasitoids. No parasitoids were found attacking C. adspersus in H. nuttallii or H. pauciflorus stalks. C. adspersus were twice as likely to be attacked by a parasitoid when feeding on H. petiolaris than H. annuus. Furthermore, the likelihood that C. adspersus would be parasitized decreased with increasing elevation and increasing stem diameters. All parasitoid species have been previously reported attacking C. adspersus larvae in cultivated sunflower. Species richness was less diverse in these collections than from previous studies of cultivated sunflower. Our findings suggest that the species

  2. Acoustic Tooth Cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1984-01-01

    Acoustically-energized water jet aids in plaque breakdown. Acoustic Wand includes acoustic transducer 1/4 wave plate, and tapered cone. Together elements energize solution of water containing mild abrasive injected into mouth to help prevent calculous buildup.

  3. From Fossil Parasitoids to Vectors: Insects as Parasites and Hosts.

    PubMed

    Nagler, Christina; Haug, Joachim T

    2015-01-01

    Within Metazoa, it has been proposed that as many as two-thirds of all species are parasitic. This propensity towards parasitism is also reflected within insects, where several lineages independently evolved a parasitic lifestyle. Parasitic behaviour ranges from parasitic habits in the strict sense, but also includes parasitoid, phoretic or kleptoparasitic behaviour. Numerous insects are also the host for other parasitic insects or metazoans. Insects can also serve as vectors for numerous metazoan, protistan, bacterial and viral diseases. The fossil record can report this behaviour with direct (parasite associated with its host) or indirect evidence (insect with parasitic larva, isolated parasitic insect, pathological changes of host). The high abundance of parasitism in the fossil record of insects can reveal important aspects of parasitic lifestyles in various evolutionary lineages. For a comprehensive view on fossil parasitic insects, we discuss here different aspects, including phylogenetic systematics, functional morphology and a direct comparison of fossil and extant species.

  4. Evolution of host-parasitoid network through homeochaotic dynamics

    NASA Astrophysics Data System (ADS)

    Ikegami, Takashi; Kaneko, Kunihiko

    1992-07-01

    Host-parasitoid systems with evolving mutation rates are studied. By increasing the growth rate of hosts, the diversity of both species is maintained dynamically. For the lower growth rate, diversity is brought about by mere parasitism. The average mutation rate for parasites is elevated to a high value, while that for hosts is suppressed at a low level. For the higher growth rate, the mutation rates for both hosts and parasites are elevated to form a symbiotic cluster connected by on-going mutation. This symbiotic state is sustained through a chaotic oscillation keeping some coherency among species. For a flat landscape for hosts, dynamical clustering of oscillation is observed. Lyapunov spectra of such oscillations show that high dimensional chaos with small positive exponents underlies in the symbiotic state. This weak high dimensional chaos, termed ``homeochaos,'' is essential to the maintenance of symbiosis in ecosystems.

  5. Transcriptional changes associated with lack of lipid synthesis in parasitoids.

    PubMed

    Visser, Bertanne; Roelofs, Dick; Hahn, Daniel A; Teal, Peter E A; Mariën, Janine; Ellers, Jacintha

    2012-01-01

    Phenotypic regression of morphological, behavioral, or physiological traits can evolve when reduced trait expression has neutral or beneficial effects on overall performance. Studies on the evolution of phenotypic degradation in animals have concentrated mostly on the evaluation of resulting phenotypes, whereas much less research has been dedicated to uncovering the molecular mechanisms that underlie phenotypic regression. The majority of parasitoids (i.e., insects that develop on or inside other arthropods), do not accumulate lipid reserves during their free-living adult life-stage and represent an excellent system to study phenotypic regression in animals. Here, we study transcriptional patterns associated with lack of lipogenesis in the parasitic wasp Nasonia vitripennis. We first confirmed that N. vitripennis does not synthesize lipids by showing a reduction in lipid reserves despite ingestion of dietary sugar, and a lack of incorporation of isotopic labels into lipid reserves when fed deuterated sugar solution. Second, we investigated transcriptional responses of 28 genes involved in lipid and sugar metabolism in short- and long-term sugar-fed females relative to starved females of N. vitripennis. Sugar feeding did not induce transcription of fatty acid synthase (fas) or other key genes involved in the lipid biosynthesis pathway. Furthermore, several genes involved in carbohydrate metabolism had a lower transcription in fed than in starved females. Our results reveal that N. vitripennis gene transcription in response to dietary sugar deviates markedly from patterns typically observed in other organisms. This study is the first to identify differential gene transcription associated with lack of lipogenesis in parasitoids and provides new insights into the molecular mechanism that underlies phenotypic regression of this trait.

  6. Transcriptional Changes Associated with Lack of Lipid Synthesis in Parasitoids

    PubMed Central

    Visser, Bertanne; Roelofs, Dick; Hahn, Daniel A.; Teal, Peter E. A.; Mariën, Janine; Ellers, Jacintha

    2012-01-01

    Phenotypic regression of morphological, behavioral, or physiological traits can evolve when reduced trait expression has neutral or beneficial effects on overall performance. Studies on the evolution of phenotypic degradation in animals have concentrated mostly on the evaluation of resulting phenotypes, whereas much less research has been dedicated to uncovering the molecular mechanisms that underlie phenotypic regression. The majority of parasitoids (i.e., insects that develop on or inside other arthropods), do not accumulate lipid reserves during their free-living adult life-stage and represent an excellent system to study phenotypic regression in animals. Here, we study transcriptional patterns associated with lack of lipogenesis in the parasitic wasp Nasonia vitripennis. We first confirmed that N. vitripennis does not synthesize lipids by showing a reduction in lipid reserves despite ingestion of dietary sugar, and a lack of incorporation of isotopic labels into lipid reserves when fed deuterated sugar solution. Second, we investigated transcriptional responses of 28 genes involved in lipid and sugar metabolism in short- and long-term sugar-fed females relative to starved females of N. vitripennis. Sugar feeding did not induce transcription of fatty acid synthase (fas) or other key genes involved in the lipid biosynthesis pathway. Furthermore, several genes involved in carbohydrate metabolism had a lower transcription in fed than in starved females. Our results reveal that N. vitripennis gene transcription in response to dietary sugar deviates markedly from patterns typically observed in other organisms. This study is the first to identify differential gene transcription associated with lack of lipogenesis in parasitoids and provides new insights into the molecular mechanism that underlies phenotypic regression of this trait. PMID:22820524

  7. Ant Mimicry by an Aphid Parasitoid, Lysiphlebus fabarum

    PubMed Central

    Rasekh, Arash; Michaud, J.P.; Kharazi-Pakdel, Aziz; Allahyari, Hossein

    2010-01-01

    In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bean leaf disks in open arenas in the laboratory. Females exploited aphids as hosts and as a source of food, allocating within-patch time as follows: resting - 10.4%, grooming - 8.2%, searching - 11.5%, antennation (host recognition) - 7.5%, antennation (honeydew solicitation mimicking ants) - 31.9%, abdominal bending (attack preparation) 19.7%, probing with the ovipositor (attack) - 10.8%. The mean handling time for each aphid encountered was 2.0 ± 0.5 min. Females encountered an average of 47.4 ± 6.4 aphids per hour, but laid only 1.2 eggs per hour. The ovipositor insertion time for parasitism ranged from 2 sec to longer than a minute, but most insertions did not result in an egg being laid. A. fabae defensive behaviors included kicking, raising and swiveling the body, and attempts to smear the attacker with cornicle secretions, sometimes with lethal results. Food deprivation for 4–6 h prior to testing increased the frequency of ant mimcry by L. fabarum. Females also used ant-like antennation to reduce A. fabae defensive behavior, e.g. the frequency of kicking. L. fabarum attacks primed A. fabae to be more responsive to subsequent honeydew solicitation, such that experienced females improved their feeding success by alternating between the roles of parasitoid and ant mimic. These results reveal the possibility for mutualisms to evolve between L. fabarum and the ant species that tend A. fabae, since L. fabarum receive ant protection for their progeny and may benefit the ants by improving A. fabae responsiveness to honeydew solicitation. PMID:20879920

  8. An improved culturing method for opiine fruit fly parasitoids and its application to parasitoid monitoring in the field.

    PubMed

    Masry, Ayad; Furlong, Michael J; Clarke, Anthony R; Cunningham, John Paul

    2016-09-21

    Good culturing methods play an important role in the study of insect behavior and its application to pest management. Here, we describe and validate a new method for rearing the parasitoid wasp, Diachasmimorpha kraussii, which attacks some of the world's worst fruit fly pests and is an internationally used biological control agent. Our method differs from standard culturing approaches by presenting adult wasps with host-infested artificial media within a "culturing bag," which mimics a natural (fruit) oviposition substrate. In laboratory trials using wild collected D. kraussii, the culturing bag method was compared to the use of host-infested nectarines, and a commonly used laboratory method of presenting host-infested artificial media within Petri dishes. The culturing bag method proved to be a significant improvement on both methods, combining the advantages of high host survival in artificial media with parasitism levels that were the equivalent to those recorded using host-infested fruits. In our field study, culturing bags infested with the Queensland fruit fly, Bactrocera tryoni, and hung in a mixed peach and nectarine orchard proved to be effective "artificial fruits" attracting wild D. kraussii for oviposition. Significantly more adult wasps were reared from the culturing bags compared to field collected fruits. This was shown to be due to higher fruit fly larval density in the bags, as similar percentage parasitism rates were found between the culturing bags and ripe fruits. We discuss how this cheap, time-efficient method could be applied to collecting and monitoring wild D. kraussii populations in orchards, and assist in maintaining genetic variability in parasitoid laboratory cultures.

  9. Critical rearing parameters of Tetrastichus planipennisi (Hymenoptera: Eulophidae) as affected by host plant substrate and host-parasitoid group structure.

    PubMed

    Duan, Jian J; Oppel, Craig

    2012-06-01

    In laboratory assays, we evaluated the potential impact of host plant substrate types, host-parasitoid group sizes (densities), and parasitoid-to-host ratios on select fitness parameters of the larval endoparasitoid Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), newly introduced for biological control of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in the United States. Results from our study showed that offspring production and critical fitness parameters (body size and sex ratio) of T. planipennisi from parasitized emerald ash borer larvae are significantly influenced by host plant substrate type, host-parasitoid group size, parasitoid-to-host ratio, or a combination in the primary exposure assay. The number of both female and male T. planipennisi progeny was significantly greater when emerald ash borer larvae were inserted into tropical ash [Fraxinus uhdei (Wenz.) Lingelsh.] logs rather than green ash (Fraxinus pensylvanica Marshall). When maintained at a constant 1:1 parasitoid-to-host ratio, assays with larger host-parasitoid group sizes (3:3-12:12) produced significantly greater numbers of both male and female offspring per parental wasp compared with those with the single host-parasitoid (1:1) group treatment. As the parasitoid-to-host ratio increased from 1:1 to 8:1 in the assay, the average brood size (number of offspring per parasitized emerald ash borer larva) increased significantly, whereas the average brood sex ratio (female to male) changed from being female-biased (6:1) to male-biased (1:2); body size of female offspring as measured by the length of ovipositor and left hind tibia also was reduced significantly. Based on these findings, we suggest that the current method of rearing T. planipennisi with artificially infested-emerald ash borer larvae use the tropical ash logs for emerald ash borer insertion, a larger (> or = 3:3) host-parasitoid group size and 1:1 parasitoid-to-host ratio in the primary

  10. Encapsulation and Self-Superparasitism of Pseudapanteles dignus (Muesebeck) (Hymenoptera: Braconidae), a Parasitoid of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

    PubMed Central

    Luna, María G.; Desneux, Nicolas; Schneider, Marcela I.

    2016-01-01

    Endoparasitoids can be killed by host encapsulation, a cellular-mediated host immunological response against parasitism that involves hemocytes aggregation. As a counteracting strategy, many parasitoids can evade this host response through self-superparasitism. The objectives of this study were: 1) to describe the parasitoid Pseudapanteles dignus (Hymenoptera: Braconidae) early immature stages (egg and larva) encapsulation by the host Tuta absoluta (Lepidoptera: Gelechiidae), and 2) to determine the occurrence of self-superparasitism and the rate of escaping to encapsulation of this parasitoid. Knowledge of host-parasitoid immunological interaction is crucial when evaluating the potential of an endoparasitoid as a biological control candidate. Parasitoid-exposed T. absoluta larvae were dissected in vivo under light stereoscope microscope at 24-h intervals, for five days after exposition to detect encapsulation. The preimaginal stages of P. dignus and numbers of healthy and encapsulated immature parasitoids per host were recorded. Samples of parasitoid eggs and larvae were processed for SEM visualization of encapsulation. Necropsies evidenced that only the early first larval instar of P. dignus (up to 96 h-old) was partially or completely encapsulated. A non-melanized capsule, formed by layers of granulocyte-type hemocytes enveloping around the parasitoid body, was recorded. Approximately 50% of the parasitized T. absoluta larvae had significantly only one P. dignus egg, meanwhile supernumerary parasitization yielded up to seven immature parasitoids per host. The proportion of single-early first larval instar of P. dignus reached ≈ 0.5 and decreased significantly as the number of parasitoid individuals per host increased. P. dignus encapsulation and its ability to overcome with the host immune defense through self-superparasitism indicate that T. absoluta is a semi-permissive host for this parasitoid. PMID:27732609

  11. Acoustic iridescence.

    PubMed

    Cox, Trevor J

    2011-03-01

    An investigation has been undertaken into acoustic iridescence, exploring how a device can be constructed which alter sound waves, in a similar way to structures in nature that act on light to produce optical iridescence. The main construction had many thin perforated sheets spaced half a wavelength apart for a specified design frequency. The sheets create the necessary impedance discontinuities to create backscattered waves, which then interfere to create strongly reflected sound at certain frequencies. Predictions and measurements show a set of harmonics, evenly spaced in frequency, for which sound is reflected strongly. And the frequency of these harmonics increases as the angle of observation gets larger, mimicking the iridescence seen in natural optical systems. Similar to optical systems, the reflections become weaker for oblique angles of reflection. A second construction was briefly examined which exploited a metamaterial made from elements and inclusions which were much smaller than the wavelength. Boundary element method predictions confirmed the potential for creating acoustic iridescence from layers of such a material.

  12. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  13. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  14. Influence of temperature on patch residence time in parasitoids: physiological and behavioural mechanisms.

    PubMed

    Moiroux, Joffrey; Abram, Paul K; Louâpre, Philippe; Barrette, Maryse; Brodeur, Jacques; Boivin, Guy

    2016-04-01

    Patch time allocation has received much attention in the context of optimal foraging theory, including the effect of environmental variables. We investigated the direct role of temperature on patch time allocation by parasitoids through physiological and behavioural mechanisms and its indirect role via changes in sex allocation and behavioural defences of the hosts. We compared the influence of foraging temperature on patch residence time between an egg parasitoid, Trichogramma euproctidis, and an aphid parasitoid, Aphidius ervi. The latter attacks hosts that are able to actively defend themselves, and may thus indirectly influence patch time allocation of the parasitoid. Patch residence time decreased with an increase in temperature in both species. The increased activity levels with warming, as evidenced by the increase in walking speed, partially explained these variations, but other mechanisms were involved. In T. euproctidis, the ability to externally discriminate parasitised hosts decreased at low temperature, resulting in a longer patch residence time. Changes in sex allocation with temperature did not explain changes in patch time allocation in this species. For A. ervi, we observed that aphids frequently escaped at intermediate temperature and defended themselves aggressively at high temperature, but displayed few defence mechanisms at low temperature. These defensive behaviours resulted in a decreased patch residence time for the parasitoid and partly explained the fact that A. ervi remained for a shorter time at the intermediate and high temperatures than at the lowest temperature. Our results suggest that global warming may affect host-parasitoid interactions through complex mechanisms including both direct and indirect effects on parasitoid patch time allocation.

  15. Ecological correlates of the non-indigenous parasitoid assemblage associated with a Hawaiian endemic moth.

    PubMed

    Kaufman, Leyla V; Wright, Mark G

    2011-08-01

    Understanding what ecological factors might predispose indigenous habitats to invasion by invasive species is an important aspect of conservation and invasive species management, particularly when biological control is considered for suppression of the invasive species. This study seeks to identify ecological factors that might play a role in determining the structure of the parasitoid assemblage associated with caterpillars of the endemic Hawaiian moth Udea stellata (Crambidae). Parasitoids were reared from field-collected U. stellata larvae at 18 locations. Fourteen environmental variables were measured at each site. Two multivariate analyses, principal component analysis (PCA) and partial redundancy analysis (RDA), were used to analyze the parasitoid assemblage across a range of habitats varying in environmental characteristics. The PCA analysis showed that the occurrence of some species were highly correlated, and associated with less disturbed sites, whereas other species were associated with sites of medium and high levels of disturbance. The RDA analysis showed that only three of the measured environmental variables (U. stellata density, elevation, and level of habitat disturbance) significantly explained variability in the parasitoid assemblage among sites. There was greater parasitoid species richness associated with U. stellata larvae at higher elevation sites with a lower degree of habitat disturbance by exotic vegetation. The purposely introduced parasitoid species were associated with the non-target moth at sites located at higher elevations with low levels of disturbance. Multivariate analysis has the potential to provide valuable insights into the identification of important environmental factors that mediate parasitoid assemblage structure and level of parasitism on a particular target or non-target species, and therefore facilitate identification of suitable target habitats or susceptible non-target habitats.

  16. Influence of temperature on patch residence time in parasitoids: physiological and behavioural mechanisms

    NASA Astrophysics Data System (ADS)

    Moiroux, Joffrey; Abram, Paul K.; Louâpre, Philippe; Barrette, Maryse; Brodeur, Jacques; Boivin, Guy

    2016-04-01

    Patch time allocation has received much attention in the context of optimal foraging theory, including the effect of environmental variables. We investigated the direct role of temperature on patch time allocation by parasitoids through physiological and behavioural mechanisms and its indirect role via changes in sex allocation and behavioural defences of the hosts. We compared the influence of foraging temperature on patch residence time between an egg parasitoid, Trichogramma euproctidis, and an aphid parasitoid, Aphidius ervi. The latter attacks hosts that are able to actively defend themselves, and may thus indirectly influence patch time allocation of the parasitoid. Patch residence time decreased with an increase in temperature in both species. The increased activity levels with warming, as evidenced by the increase in walking speed, partially explained these variations, but other mechanisms were involved. In T. euproctidis, the ability to externally discriminate parasitised hosts decreased at low temperature, resulting in a longer patch residence time. Changes in sex allocation with temperature did not explain changes in patch time allocation in this species. For A. ervi, we observed that aphids frequently escaped at intermediate temperature and defended themselves aggressively at high temperature, but displayed few defence mechanisms at low temperature. These defensive behaviours resulted in a decreased patch residence time for the parasitoid and partly explained the fact that A. ervi remained for a shorter time at the intermediate and high temperatures than at the lowest temperature. Our results suggest that global warming may affect host-parasitoid interactions through complex mechanisms including both direct and indirect effects on parasitoid patch time allocation.

  17. Trophic relationships between predators, whiteflies and their parasitoids in tomato greenhouses: a molecular approach.

    PubMed

    Moreno-Ripoll, R; Gabarra, R; Symondson, W O C; King, R A; Agustí, N

    2012-08-01

    The whiteflies Bemisia tabaci Gennadius and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) are two of the main pests in tomato crops. Their biological control in Mediterranean IPM systems is based on the predators Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis Reuter (Hemiptera: Miridae), as well as on the parasitoids Eretmocerus mundus (Mercet) and Encarsia pergandiella Howard (Hymenoptera: Aphelinidae). These natural enemies may interact with each other and their joint use could interfere with the biological control of those whitefly pests. Analysis of predator-prey interactions under field conditions is therefore essential in order to optimize whitefly control. Species-specific polymerase chain reaction (PCR)-primers were designed to detect DNA fragments of these whiteflies and parasitoids within both predator species in tomato greenhouses. We demonstrated that both predators feed on both whitefly species, as well as on both parasitoids under greenhouse conditions. Prey molecular detection was possible where prey abundance was very low or even where predation was not observed under a microscope. Whitefly DNA detection was positively correlated with adult whitefly abundance in the crop. However, a significant relationship was not observed between parasitoid DNA detection and the abundance of parasitoid pupae, even though the predation rate on parasitoids was high. This unidirectional intraguild predation (predators on parasitoids) could potentially reduce their combined impact on their joint prey/host. Prey molecular detection provided improved detection of prey consumption in greenhouse crops, as well as the possibility to identify which prey species were consumed by each predator species present in the greenhouse, offering a blueprint with wider applicability to other food webs.

  18. Anastrepha egg deposition induces volatiles in fruits that attract the parasitoid Fopius arisanus.

    PubMed

    Pérez, J; Rojas, J C; Montoya, P; Liedo, P; Castillo, A

    2013-06-01

    Fopius arisanus is a solitary egg-pupal endoparasitoid that attacks several species of tephritid fruit flies, particularly Bactrocera spp. This species, indigenous from the Indo-Australian region, was introduced into Mexico for biological control purposes. From the standpoint of the 'new associations' concept this parasitoid has been evaluated against fruit flies in the Anastrepha complex. We investigated the specificity of F. arisanus responses to fruits infested with two species of Anastrepha. We examined whether fruit volatiles attractive to this parasitoid are induced as a result of fruit fly oviposition. We also investigated whether F. arisanus females are able to discriminate between the oviposition-induced volatiles from host eggs parasitised by conspecifics and volatiles from unparasitised eggs. All experiments were performed in a wind tunnel. Results showed that mango fruits infested with A. ludens eggs (2-3 days after egg deposition) were significantly more attractive to naïve F. arisanus females compared with non-infested fruits or fruits infested with larvae. In addition, guava fruits harbouring A. striata eggs were significantly more attractive to the parasitoid than non-infested fruits or fruits infested with larvae. Thus, the parasitoid was attracted to fruits with eggs, but fruit and fly species did not influence the parasitoid attraction. We also found that F. arisanus females were more attracted to fruits exposed to fertile A. ludens females (i.e. fruits with eggs inside) compared with fruits exposed to sterile females (i.e. fruits with no eggs inside) or fruits with mechanical damage. Parasitoid females were not attracted to A. ludens eggs. The results suggest that the presence of eggs induces volatiles that attract parasitoids. Finally, we found that F. arisanus was able to discriminate between fruits with unparasitised eggs vs. eggs parasitised by conspecifics, indicating that host discrimination could be mediated by olfactory cues.

  19. Critical rearing parameters of Tetrastichus planipennisi (Hymenoptera: Eulophidae) as affected by host-plant substrate and host-parasitoid group structure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory studies were conducted to evaluate the potential impact of host-plant substrate types, host-parasitoid group size and host to parasitoid ratios on select fitness parameters of the larval parasitoid Tetrastichus planipennisi Yang, newly introduced for biological control of the invasive eme...

  20. Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host-parasitoid food chain.

    PubMed

    Sanders, Dirk; Moser, Andrea; Newton, Jason; van Veen, F J Frank

    2016-03-16

    Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host-parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition of host tissue and the consumer's resource requirements, which would allow for longer food chains. We measured efficiency of biomass transfer along an aphid-primary-secondary-tertiary parasitoid food chain and used stable isotope analysis to confirm trophic levels. We show high efficiency in biomass transfer along the food chain. From the third to the fourth trophic level, the proportion of host biomass transferred was 45%, 65% and 73%, respectively, for three secondary parasitoid species. For two parasitoid species that can act at the fourth and fifth trophic levels, we show markedly increased trophic assimilation efficiencies at the higher trophic level, which increased from 45 to 63% and 73 to 93%, respectively. In common with other food chains, δ(15)N increased with trophic level, with trophic discrimination factors (Δ(15)N) 1.34 and 1.49‰ from primary parasitoids to endoparasitic and ectoparasitic secondary parasitoids, respectively, and 0.78‰ from secondary to tertiary parasitoids. Owing to the extraordinarily high efficiency of hyperparasitoids, cryptic higher trophic levels may exist in host-parasitoid communities, which could alter our understanding of the dynamics and drivers of community structure of these important systems.

  1. Manure preferences and postemergence learning of two filth fly parasitoids, Spalangia cameroni and Muscidifurax raptor (Hymenoptera: Pteromalidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficiency of host-seeking behavior is a crucial determinant of the reproductive performance of female parasitoids. Initially, parasitoids may use chemical information generated from the microhabitat in which they emerge to locate hosts. Spalangia cameroni and Muscidifurax raptor are commerciall...

  2. Combined use of herbivore-induced plant volatiles and sex pheromones for mate location in braconid parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbivore-induced plant volatiles (HIPVs) are important cues for female parasitic wasps to find hosts. Here, we investigated the possibility that HIPVs may also serve parasitoids as cues to locate mates. To test this, the odor preferences of four braconid wasps – the gregarious parasitoid Cotesia gl...

  3. Effects of plant availability on population size and dynamics of an insect community: diamondback moth and two of its parasitoids.

    PubMed

    Soufbaf, M; Fathipour, Y; Karimzadeh, J; Zalucki, M P

    2014-08-01

    To understand the effect of plant availability/structure on the population size and dynamics of insects, a specialist herbivore in the presence of two of its parasitoids was studied in four replicated time-series experiments with high and low plant availabilities; under the latter condition, the herbivore suffered from some periods of resource limitation (starvation) and little plant-related structural refuges. Population dynamics of the parasitoid Cotesia vestalis was governed mainly by the delayed density-dependent process under both plant setups. The parasitoid, Diadegma semiclausum, under different plant availabilities and different coexistence situations (either +competitor or -competitor) showed dynamics patterns that were governed mainly by the delayed density process (significant lags at weeks 2-4). Both the competing parasitoids did not experience beneficial or costly interferences from each other in terms of their own population size when the plant resource was limited. Variation in the Plutella xylostella population under limited plant availability is higher than that under the other plant setup. For both parasitoids, under limited plant setup, the extinction risk was lower when parasitoids were engaged in competition, while under the unlimited plant setup, the mentioned risk was higher when parasitoids competed. In this situation, parasitoids suffered from two forces, competition and higher escaped hosts.

  4. Immunity of an Alternative Host Can Be Overcome by Higher Densities of Its Parasitoids Palmistichus elaeisis and Trichospilus diatraeae

    PubMed Central

    Andrade, Gilberto Santos; Serrão, José Eduardo; Zanuncio, José Cola; Zanuncio, Teresinha Vinha; Leite, Germano Leão Demolin; Polanczyk, Ricardo Antonio

    2010-01-01

    Interactions of the parasitoids Palmistichus elaeisis Delvare & LaSalle and Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) with its alternative host Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae) affect the success or failure of the mass production of these parasitoids for use in integrated pest management programs. The aim of this study was to evaluate changes in the cellular defense and encapsulation ability of A. gemmatalis pupae against P. elaeisis or T. diatraeae in adult parasitoid densities of 1, 3, 5, 7, 9, 11 or 13 parasitoids/pupae. We evaluated the total quantity of circulating hemocytes and the encapsulation rate versus density. Increasing parasitoid density reduced the total number of hemocytes in the hemolymph and the encapsulation rate by parasitized pupae. Furthermore, densities of P. elaeisis above 5 parasitoids/pupae caused higher reduction in total hemocyte numbers. The encapsulation rate fell with increasing parasitoid density. However, parasitic invasion by both species induced generally similar responses. The reduction in defensive capacity of A. gemmatalis is related to the adjustment of the density of these parasitoids to their development in this host. Thus, the role of the density of P. elaeisis or T. diatraeae by pupa is induced suppression of cellular defense and encapsulation of the host, even without them possesses a co-evolutionary history. Furthermore, these findings can predict the success of P. elaeisis and T. diatraeae in the control of insect pests through the use of immunology as a tool for evaluation of natural enemies. PMID:20975929

  5. Host switching in a generalist parasitoid: contrasting transient and transgenerational costs associated with novel and original host species

    PubMed Central

    Jones, Thomas S; Bilton, Adam R; Mak, Lorraine; Sait, Steven M

    2015-01-01

    Parasitoids face challenges by switching between host species that influence survival and fitness, determine their role in structuring communities, influence species invasions, and affect their importance as biocontrol agents. In the generalist parasitoid, Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae), we investigated the costs in encapsulation, survival, and body size on juveniles when adult parasitoids switched from their original host, Plodia interpunctella (Hübner) (Lepidotera, Pyralidae) to a novel host, Ephestia kuehniella (Zeller) (Lepidoptera, Pyralidae), over multiple generations. Switching had an initial survival cost for juvenile parasitoids in the novel host, but increased survival occurred within two generations. Conversely, mortality in the original host increased. Body size, a proxy for fecundity, also increased with the number of generations in the novel host species, reflecting adaptation or maternal effects due to the larger size of the novel host, and therefore greater resources available to the developing parasitoid. Switching to a novel host appears to have initial costs for a parasitoid, even when the novel host may be better quality, but the costs rapidly diminish. We predict that the net cost of switching to a novel host for parasitoids will be complex and will depend on the initial reduction in fitness from parasitizing a novel host versus local adaptations against parasitoids in the original host. PMID:25691971

  6. Acoustic cryocooler

    DOEpatents

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

    An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

  7. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  8. Acoustic telemetry.

    SciTech Connect

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  9. Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning

    PubMed Central

    Segura, Diego F.; Nussenbaum, Ana L.; Viscarret, Mariana M.; Devescovi, Francisco; Bachmann, Guillermo E.; Corley, Juan C.; Ovruski, Sergio M.; Cladera, Jorge L.

    2016-01-01

    Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging. PMID:27007298

  10. Aphid Honeydew Quality as a Food Source for Parasitoids Is Maintained in Bt Cotton

    PubMed Central

    Hagenbucher, Steffen; Wäckers, Felix L.; Romeis, Jörg

    2014-01-01

    Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance. PMID:25226521

  11. Genomic Insights into Processes Driving the Infection of Alexandrium tamarense by the Parasitoid Amoebophrya sp.

    PubMed Central

    Wohlrab, Sylke; Glöckner, Gernot; Guillou, Laure; John, Uwe

    2014-01-01

    The regulatory circuits during infection of dinoflagellates by their parasites are largely unknown on the molecular level. Here we provide molecular insights into these infection dynamics. Alexandrium tamarense is one of the most prominent harmful algal bloom dinoflagellates. Its pathogen, the dinoflagellate parasitoid Amoebophrya sp., has been observed to infect and control the blooms of this species. We generated a data set of transcripts from three time points (0, 6, and 96 h) during the infection of this parasite-host system. Assembly of all transcript data from the parasitoid (>900,000 reads/313 Mbp with 454/Roche next-generation sequencing [NGS]) yielded 14,455 contigs, to which we mapped the raw transcript reads of each time point of the infection cycle. We show that particular surface lectins are expressed at the beginning of the infection cycle which likely mediate the attachment to the host cell. In a later phase, signal transduction-related genes together with transmembrane transport and cytoskeleton proteins point to a high integration of processes involved in host recognition, adhesion, and invasion. At the final maturation stage, cell division- and proliferation-related genes were highly expressed, reflecting the fast cell growth and nuclear division of the parasitoid. Our molecular insights into dinoflagellate parasitoid interactions point to general mechanisms also known from other eukaryotic parasites, especially from the Alveolata. These similarities indicate the presence of fundamental processes of parasitoid infection that have remained stable throughout evolution within different phyla. PMID:25239978

  12. Lack of lipogenesis in parasitoids: a review of physiological mechanisms and evolutionary implications.

    PubMed

    Visser, Bertanne; Ellers, Jacintha

    2008-09-01

    The ability of organisms to adapt to fluctuating food conditions is essential for their survival and reproduction. Accumulating energy reserves, such as lipids, in anticipation of harsh conditions, will reduce negative effects of a low food supply. For Hymenoptera and Diptera, several parasitoid species lack adult lipogenesis, and are unable to store excess energy in the form of lipid reserves. The aim of this review is to provide a synthesis of current knowledge regarding the inability to accumulate lipids in parasitoids, leading to new insights and prospects for further research. We will emphasize physiological mechanisms underlying lack of lipogenesis, the evolution of this adaptation in parasitoids and its biological implications with regard to life history traits. We suggest the occurrence of lack of lipogenesis in parasitoids to be dependent on the extent of host exploitation through metabolic manipulation. Currently available data shows lack of lipogenesis to have evolved independently at least twice, in parasitic Hymenoptera and Diptera. The underlying genetic mechanism, however, remains to be solved. Furthermore, due to the inability to replenish adult fat reserves, parasitoids are severely constrained in resource allocation strategies, in particular the trade-off between survival and reproduction.

  13. Habitat selection of a parasitoid mediated by volatiles informing on host and intraguild predator densities.

    PubMed

    Cotes, Belén; Rännbäck, Linda-Marie; Björkman, Maria; Norli, Hans Ragnar; Meyling, Nicolai V; Rämert, Birgitta; Anderson, Peter

    2015-09-01

    To locate and evaluate host patches before oviposition, parasitoids of herbivorous insects utilize plant volatiles and host-derived cues, but also evaluate predator-derived infochemicals to reduce predation risks. When foraging in host habitats infested with entomopathogenic fungi that can infect both a parasitoid and its host, parasitoids may reduce the risk of intraguild predation (IGP) by avoiding such patches. In this study, we examined whether the presence of the entomopathogenic fungi Metarhizium brunneum and Beauveria bassiana in soil habitats of a root herbivore, Delia radicum, affects the behavior of Trybliographa rapae, a parasitoid of D. radicum. Olfactometer bioassays revealed that T. rapae avoided fungal infested host habitats and that this was dependent on fungal species and density. In particular, the parasitoid avoided habitats with high densities of the more virulent fungus, M. brunneum. In addition, host density was found to be important for the attraction of T. rapae. Volatiles collected from host habitats revealed different compound profiles depending on fungal presence and density, which could explain the behavior of T. rapae. We conclude that T. rapae females may use volatile compounds to locate high densities of prey, but also compounds related to fungal presence to reduce the risk of IGP towards themselves and their offspring.

  14. The intracellular bacterium Wolbachia uses parasitoid wasps as phoretic vectors for efficient horizontal transmission.

    PubMed

    Ahmed, Muhammad Z; Li, Shao-Jian; Xue, Xia; Yin, Xiang-Jie; Ren, Shun-Xiang; Jiggins, Francis M; Greeff, Jaco M; Qiu, Bao-Li

    2015-02-01

    Facultative bacterial endosymbionts are associated with many arthropods and are primarily transmitted vertically from mother to offspring. However, phylogenetic affiliations suggest that horizontal transmission must also occur. Such horizontal transfer can have important biological and agricultural consequences when endosymbionts increase host fitness. So far horizontal transmission is considered rare and has been difficult to document. Here, we use fluorescence in situ hybridization (FISH) and multi locus sequence typing (MLST) to reveal a potentially common pathway of horizontal transmission of endosymbionts via parasitoids of insects. We illustrate that the mouthparts and ovipositors of an aphelinid parasitoid become contaminated with Wolbachia when this wasp feeds on or probes Wolbachia-infected Bemisia tabaci AsiaII7, and non-lethal probing of uninfected B. tabaci AsiaII7 nymphs by parasitoids carrying Wolbachia resulted in newly and stably infected B. tabaci matrilines. After they were exposed to infected whitefly, the parasitoids were able to transmit Wolbachia efficiently for the following 48 h. Whitefly infected with Wolbachia by parasitoids had increased survival and reduced development times. Overall, our study provides evidence for the horizontal transmission of Wolbachia between insect hosts by parasitic wasps, and the enhanced survival and reproductive abilities of insect hosts may adversely affect biological control programs.

  15. The evolutionary ecology of symbiont-conferred resistance to parasitoids in aphids.

    PubMed

    Vorburger, Christoph

    2014-06-01

    Aphids may harbor a wide variety of facultative bacterial endosymbionts. These symbionts are transmitted maternally with high fidelity and they show horizontal transmission as well, albeit at rates too low to enable infectious spread. Such symbionts need to provide a net fitness benefit to their hosts to persist and spread. Several symbionts have achieved this by evolving the ability to protect their hosts against parasitoids. Reviewing empirical work and some models, I explore the evolutionary ecology of symbiont-conferred resistance to parasitoids in order to understand how defensive symbiont frequencies are maintained at the intermediate levels observed in aphid populations. I further show that defensive symbionts alter the reciprocal selection between aphids and parasitoids by augmenting the heritable variation for resistance, by increasing the genetic specificity of the host-parasitoid interaction, and by inducing environment-dependent trade-offs. These effects are conducive to very dynamic, symbiont-mediated coevolution that is driven by frequency-dependent selection. Finally I argue that defensive symbionts represent a problem for biological control of pest aphids, and I propose to mitigate this problem by exploiting the parasitoids' demonstrated ability to rapidly evolve counteradaptations to symbiont-conferred resistance.

  16. Aphidophagous Parasitoids can Forage Wheat Crops Before Aphid Infestation, Parana State, Brazil

    PubMed Central

    Ceolin Bortolotto, Orcial; de Oliveira Menezes Júnior, Ayres; Thibes Hoshino, Adriano

    2015-01-01

    Aphid parasitoids are common in Brazilian wheat fields, and parasitize aphids at the wheat tillering stage. However, there is little information available about when this natural enemy occurs in wheat crops. This study investigated the initial occurrence of aphid parasitoids in four commercial wheat crops in northern Paraná during the 2009 crop season. We installed two Malaise traps at each wheat farm, and 400 tillers were assessed weekly in each field for aphid abundance. During this study, we captured 4,355 aphid parasitoids and 197 aphids. Three species of braconid parasitoids were identified, including Aphidius colemani (Viereck 1912), Lysiphlebus testaceipes (Cresson 1880), and Diaeretiella rapae (McIntosh 1855). The aphids species identified were Rhopalosiphum padi (Linnaeus 1758) and Sitobion avenae (Fabricius 1775). This study showed that aphid parasitoids are present in wheat crops even when aphid densities are low, and in one farm, occurred before the aphids colonization. These reports can justified the high efficiency of these natural enemies against aphids in wheat fields. PMID:25843593

  17. Temporal autocorrelation in host density increases establishment success of parasitoids in an experimental system

    PubMed Central

    Vercken, Elodie; Fauvergue, Xavier; Ris, Nicolas; Crochard, Didier; Mailleret, Ludovic

    2015-01-01

    Environmental variation is classically expected to affect negatively population growth and to increase extinction risk, and it has been identified as a major determinant of establishment failures in the field. Yet, recent theoretical investigations have shown that the structure of environmental variation and more precisely the presence of positive temporal autocorrelation might alter this prediction. This is particularly likely to affect the establishment dynamics of biological control agents in the field, as host–parasitoid interactions are expected to induce temporal autocorrelation in host abundance. In the case where parasitoid populations display overcompensatory dynamics, the presence of such positive temporal autocorrelation should increase their establishment success in a variable environment. We tested this prediction in laboratory microcosms by introducing parasitoids to hosts whose abundances were manipulated to simulate uncorrelated or positively autocorrelated variations in carrying capacity. We found that environmental variability decreased population size and increased parasitoid population variance, which is classically expected to extinction risk. However, although exposed to significant environmental variation, we found that parasitoid populations experiencing positive temporal autocorrelation in host abundance were more likely to persist than populations exposed to uncorrelated variation. These results confirm that environmental variation is a key determinant of extinction dynamics that can have counterintuitive effects depending on its autocorrelation structure. PMID:26257880

  18. Potential Host Manipulation by the Aphid Parasitoid Aphidius avenae to Enhance Cold Tolerance

    PubMed Central

    Alford, Lucy; Androdias, Annabelle; Franco, Thomas; Pierre, Jean-Sébastien; Burel, Françoise; van Baaren, Joan

    2016-01-01

    During parasitoid development, the immature parasitoid is confined to the host species. As a result, any potential to modify the physiology or behaviour of the host could play an important role in parasitoid fitness. The potential for host manipulation by the aphid parasitoid Aphidius avenae to increase cold thermotolerance was investigated using the aphid host species Metopolophium dirhodum and Sitobion avenae. Aphids were parasitized at L3/L4 instar stage (5 d old) and allowed to develop into pre-reproductive adults (10 d old) containing a 5 d old parasitoid larva. A control group was created of non-parasitized pre-reproductive adults (10 d old). The inherent physiological thermotolerance (LT50) and potential behavioural thermoregulation (behaviour in a declining temperature regime) of parasitized and non-parasitized aphids were investigated. Results revealed no effect of parasitism on the physiological thermotolerance of S. avenae and M. dirhodum. Significant differences in the behaviour of parasitized and non-parasitized aphids were observed, in addition to differences between host species, and such behaviours are discussed in view of the potential for host manipulation. PMID:28006018

  19. Persistence of mulitple identical parasitoid species in a single-host, spatial simulation

    USGS Publications Warehouse

    Slone, D.H.; Allen, J.C.

    2005-01-01

    We explore the problem of persistence of multiple obligate parasitoids on a single host in a discrete time, spatially explicit system. In general, the parasitoids experienced extinction until one species remained well before the 50000-generation time limit, but the rate varied according to the parameters of the system. Smaller arenas had a greater chance of extinction. Artificially increasing interspecific competition produced rapid extinction, while decreasing competition increased persistence to the maximum time limit of the simulation. Increasing the parasitoid search efficiency or decreasing dispersal of the parasitoids relative to the host produced less longevity as did increasing host reproduction, while increasing the rate of "patch extinction" reduced the variation among the times to extinction, but did not change the time to the first extinction. Finally, increasing noise in the search parameter first reduced longevity, but then it rapidly increased near the point where the noise reached an amplitude similar to the parameter itself, where coexistence of the four parasitoids was achieved. Copyright ?? EEF.

  20. Farming practices change food web structures in cereal aphid-parasitoid-hyperparasitoid communities.

    PubMed

    Lohaus, Katharina; Vidal, Stefan; Thies, Carsten

    2013-01-01

    Agricultural intensification has been shown to result in a decline in biodiversity across many taxa, but the changes in community structure and species interactions remain little understood. We have analysed and compared the structure of feeding interactions for cereal aphids and their primary and secondary parasitoids in organically and conventionally managed winter wheat fields using quantitative food web metrics (interaction evenness, generality, vulnerability, link density). Despite little variation in the richness of each trophic group, food web structures between the two farming systems differed remarkably. In contrast to common expectations, aphids and primary parasitoids were characterized by (1) a higher evenness of interaction frequencies (interaction evenness) in conventional fields, which cascaded to interactions at the next trophic level, with (2) a higher interaction evenness, (3) a higher ratio of primary parasitoid taxa per secondary parasitoid (generality) and (4) a higher link density. Aphid communities in the organically managed fields almost exclusively consisted of a single ear-colonizing species, Sitobion avenae, while highly fertilized conventional fields were mainly infested by leaf-colonizing aphids that benefit from the nutritional status of winter wheat. In conclusion, agricultural intensification appears to foster the complexity of aphid-parasitoid food webs, thereby not supporting the general expectation on the importance of organic farming practices for species richness and food web complexity.

  1. Aphid honeydew quality as a food source for parasitoids is maintained in Bt cotton.

    PubMed

    Hagenbucher, Steffen; Wäckers, Felix L; Romeis, Jörg

    2014-01-01

    Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance.

  2. Application of Nuclear Techniques to Improve the Mass Production and Management of Fruit Fly Parasitoids

    PubMed Central

    Cancino, Jorge; Ruíz, Lía; Viscarret, Mariana; Sivinski, John; Hendrichs, Jorge

    2012-01-01

    The use of irradiated hosts in mass rearing tephritid parasitoids represents an important technical advance in fruit fly augmentative biological control. Irradiation assures that fly emergence is avoided in non-parasitized hosts, while at the same time it has no appreciable effect on parasitoid quality, i.e., fecundity, longevity and flight capability. Parasitoids of fruit fly eggs, larvae and pupae have all been shown to successfully develop in irradiated hosts, allowing a broad range of species to be shipped and released without post-rearing delays waiting for fly emergence and costly procedures to separate flies and wasps. This facilitates the early, more effective and less damaging shipment of natural enemies within hosts and across quarantined borders. In addition, the survival and dispersal of released parasitoids can be monitored by placing irradiated sentinel-hosts in the field. The optimal radiation dosages for host-sterility and parasitoid-fitness differ among species, and considerable progress has been made in integrating radiation into a variety of rearing procedures. PMID:26466729

  3. Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning.

    PubMed

    Segura, Diego F; Nussenbaum, Ana L; Viscarret, Mariana M; Devescovi, Francisco; Bachmann, Guillermo E; Corley, Juan C; Ovruski, Sergio M; Cladera, Jorge L

    2016-01-01

    Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging.

  4. Application of Nuclear Techniques to Improve the Mass Production and Management of Fruit Fly Parasitoids.

    PubMed

    Cancino, Jorge; Ruíz, Lía; Viscarret, Mariana; Sivinski, John; Hendrichs, Jorge

    2012-10-25

    The use of irradiated hosts in mass rearing tephritid parasitoids represents an important technical advance in fruit fly augmentative biological control. Irradiation assures that fly emergence is avoided in non-parasitized hosts, while at the same time it has no appreciable effect on parasitoid quality, i.e., fecundity, longevity and flight capability. Parasitoids of fruit fly eggs, larvae and pupae have all been shown to successfully develop in irradiated hosts, allowing a broad range of species to be shipped and released without post-rearing delays waiting for fly emergence and costly procedures to separate flies and wasps. This facilitates the early, more effective and less damaging shipment of natural enemies within hosts and across quarantined borders. In addition, the survival and dispersal of released parasitoids can be monitored by placing irradiated sentinel-hosts in the field. The optimal radiation dosages for host-sterility and parasitoid-fitness differ among species, and considerable progress has been made in integrating radiation into a variety of rearing procedures.

  5. Parasitoid fig-wasp evolutionary diversification and variation in ecological opportunity.

    PubMed

    McLeish, M J; van Noort, S; Tolley, K A

    2010-04-01

    Ecological processes are manifest in the evolution and form of phenotype diversity. The great abundance of parasitoid species has led to speculation whether rates of speciation and extinction are dependent on parasitoid diversity. If these factors are mutually exclusive, species diversity should fluctuate instead of remaining relatively constant over time. It is not known whether radiations constrained by coevolutionary interactions conform to density-dependent diversification processes. Here we test the prediction that parasitoid fig wasp diversification responds to changes in ecological opportunity and density-independent processes. A phylogenetic approach is used to estimate relative divergence times and infer diversification rate changes using gamma-statistics. Monte Carlo constant rates tests that accommodate incomplete sampling could not reject constant rates diversification. Parasitoid fig wasp diversification is consistent with a more complex explanation than density-dependent cladogenesis. The results suggest contemporary African parasitoid fig wasp diversity remains a legacy of an ancient ecological opportunity facilitated by fig tree diversification following the breakup of Pan-African forests and evolution of the savanna biome over the last 55 Ma and the more recent aridification of the African continent in the last 5 Ma. These results imply that amplified phenotypic differentiation of specialist insects coevolving with plants is coupled to evolutionarily infrequent changes in ecological opportunity.

  6. A Critical Assessment of the Effects of Bt Transgenic Plants on Parasitoids

    PubMed Central

    Chen, Mao; Zhao, Jian-Zhou; Collins, Hilda L.; Earle, Elizabeth D.; Cao, Jun; Shelton, Anthony M.

    2008-01-01

    The ecological safety of transgenic insecticidal plants expressing crystal proteins (Cry toxins) from the bacterium Bacillus thuringiensis (Bt) continues to be debated. Much of the debate has focused on nontarget organisms, especially predators and parasitoids that help control populations of pest insects in many crops. Although many studies have been conducted on predators, few reports have examined parasitoids but some of them have reported negative impacts. None of the previous reports were able to clearly characterize the cause of the negative impact. In order to provide a critical assessment, we used a novel paradigm consisting of a strain of the insect pest, Plutella xylostella (herbivore), resistant to Cry1C and allowed it to feed on Bt plants and then become parasitized by Diadegma insulare, an important endoparasitoid of P. xylostella. Our results indicated that the parasitoid was exposed to a biologically active form of the Cy1C protein while in the host but was not harmed by such exposure. Parallel studies conducted with several commonly used insecticides indicated they significantly reduced parasitism rates on strains of P. xylostella resistant to these insecticides. These results provide the first clear evidence of the lack of hazard to a parasitoid by a Bt plant, compared to traditional insecticides, and describe a test to rigorously evaluate the risks Bt plants pose to predators and parasitoids. PMID:18523682

  7. Identification of Key Plant-Associated Volatiles Emitted by Heliothis virescens Larvae that Attract the Parasitoid, Microplitis croceipes: Implications for Parasitoid Perception of Odor Blends.

    PubMed

    Morawo, Tolulope; Fadamiro, Henry

    2016-11-01

    Herbivores emit plant-associated volatile organic compounds (VOCs) after feeding on plants. These plant-associated VOCs can be used by parasitoids to locate their hosts. It is hypothesized that certain compounds play key roles in the attractiveness of host-associated odor blends. The larval parasitoid, Microplitis croceipes (Hymenoptera: Braconidae) and its herbivore host, Heliothis virescens (Lepidoptera: Noctuidae), a major pest of cotton plant were used as model species to identify key compounds mediating attraction of parasitoids to hosts. Comparative GC/MS analyses of cotton-fed vs. artificial diet-fed hosts indicated that 12 of 17 compounds in the headspace of H. virescens larvae were exclusive to plant-fed hosts, and thus considered to be plant-associated. In order to identify key attractive compounds, a full blend of 15 commercially available synthetic compounds was modified by removing each of the 10 plant-associated compounds emitted by host larvae. In Y-tube olfactometer bioassays testing parasitoid responses to modified blends, 1-octen-3-ol, decanal, (E)-β-caryophyllene, α-humulene, α-farnesene, and β-pinene were identified as key compounds contributing to attractiveness of the natural blend of VOCs emitted by cotton-fed hosts. The results showed that while various host-associated compounds act in concert to serve as useful host location cues, only a fraction of the natural blend mediates attraction in parasitoids. Furthermore, the role of a compound is better assessed in the context of other compounds, and odor blends are better perceived as a whole rather than as individual components.

  8. The Roles of Parasitoid Foraging for Hosts, Food and Mates in the Augmentative Control of Tephritidae

    PubMed Central

    Sivinski, John; Aluja, Martin

    2012-01-01

    Ultimately, the success of augmentative fruit fly biological control depends upon the survival, dispersal, attack rate and multi-generational persistence of mass-reared parasitoids in the field. Foraging for hosts, food and mates is fundamental to the above and, at an operational level, the choice of the parasitoid best suited to control a particular tephritid in a certain environment, release rate estimates and subsequent monitoring of effectiveness. In the following we review landscape-level and microhabitat foraging preferences, host/fruit ranges, orientation through environmental cues, host vulnerabilities/ovipositor structures, and inter and intraspecific competition. We also consider tephritid parasitoid mating systems and sexual signals, and suggest the directions of future research. PMID:26466622

  9. Evolution of a polydnavirus gene in relation to parasitoid-host species immune resistance.

    PubMed

    Dupas, Stéphane; Gitau, Catherine Wanjiru; Branca, Antoine; Le Rü, Bruno Pierre; Silvain, Jean-François

    2008-01-01

    CrV1, a polydisperse DNA virus (polydnavirus or PDV) gene contributes to the suppression of host immunity in Cotesia genus parasitoids. Its molecular evolution was analyzed in relation to levels of resistance in the sympatric host species. Natural selection for nonsynonymous substitutions (positive Darwinian selection) was observed at specific amino acid sites among CrV1 variants; particularly, between parasitoid strains immune suppressive and nonimmune suppressive to the main resistant stem borer host, Busseola fusca. In Cotesia sesamiae, geographic distribution of CrV1 alleles in Kenya was correlated to the relative abundance of B. fusca. These results suggest that PDV genes evolve through natural selection and are genetically linked to factors of suppression of local host resistance. We discuss the forces driving the evolution of CrV1 and its use as a marker to understand parasitoid adaptation to host resistance in biological control.

  10. Absence of Transgenerational Phenotypic Plasticity in Fecundity in the Parasitoid Anagrus erythroneurae (Hymenoptera: Mymaridae)

    PubMed Central

    Andreazza, Felipe; Rosenheim, Jay A.

    2015-01-01

    To improve biological pest control, we would like to understand the main factors that limit the reproductive success of key biological control agents, including parasitoid wasps. Previous research with proovigenic parasitoids in the genus Anagrus collected from multiple field sites revealed positive correlations between parasitoid fecundity and local host density. In this article, we test whether this variation in fecundity is a reflection of transgenerational phenotypic plasticity. We exposed females in laboratory microcosms to either low or high host densities and then quantified the fecundity of their adult daughters. Mean fecundity of daughters did not differ across host density treatments, arguing against the operation of phenotypic plasticity. Significant variation in mean fecundity across different families instead suggested the possibility that genetic variation may underlie the observed fecundity differences.

  11. Host-habitat location by the parasitoid, Nasonia vitripennis Walker (Hymenoptera: Pteromalidae).

    PubMed

    Frederickx, Christine; Dekeirsschieter, Jessica; Verheggen, Francois J; Haubruge, Eric

    2014-01-01

    This study investigated the role of odorant cues used during host-habitat location by the generalist parasitoid, Nasonia vitripennis Walker. Nasonia vitripennis is a common parasitoid of Dipteran pupae found in association with decaying carrion. Behavioral assays were used to investigate the host-habitat searching behavior under different scenarios. First, we demonstrated N. vitripennis to be significantly attracted toward odorant cues associated with decaying meat. The biological activity of nine of the volatile molecules constituting the odor of decaying meat was tested on the searching behavior of parasitoid females through two complementary chemoecological approaches: electroantennography (EAG) and olfactometry bioassays. Butanoic acid and butan-1-ol elicited high olfactory responses, but no attraction was induced by these two chemicals. Behavioral assays showed that, among the VOCs tested, methyldisulfanylmethane (DMDS) was the only volatile chemical to induce attraction in N. vitripennis.

  12. Effects of various insecticides on the development of the egg parasitoid Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae).

    PubMed

    Takada, Y; Kawamura, S; Tanaka, T

    2001-12-01

    The toxicity of six insecticides, acephate, methomyl, ethofenprox, cartap, chlorfluazuron, and Bacillus thuringiensis (Bt) was tested on different developmental stages of the egg parasitoid, Trichogramma dendrolimi (Matsumura). Each of the insecticides tested showed different degrees of toxicity to the parasitoid, Ethofenprox showed the highest toxicity and cartap showed relatively higher toxicity compared with the other insecticides. The development of the parasitoids treated with these two insecticides was normal, similar to that of the control group. Only the emergence of adult wasps from host eggs was disturbed. Emergence of the host, Mamestra brassicae larva was reduced following treatment with ethofenprox, cartap and methomyl. However, adult female wasps, which emerged from host eggs treated with the insecticides had the ability to oviposit normally.

  13. Differential thermal performance curves in response to different habitats in the parasitoid Venturia canescens

    NASA Astrophysics Data System (ADS)

    Foray, Vincent; Gibert, Patricia; Desouhant, Emmanuel

    2011-08-01

    Environmental variability is expected to be important in shaping performance curves, reaction norms of phenotypic traits related to fitness. Models predict that the breadth of performance curves should increase with environmental variability at the expense of maximal performance. In this study, we compared the thermal performance curves of two sympatric populations of the parasitoid Venturia canescens that were observed under contrasting thermal regimes in their respective preferred habitats and differing in their modes of reproduction. Our results confirm the large effect of developmental temperature on phenotypic traits of insects and demonstrate that thelytokous and arrhenotokous wasps respond differently to temperature during development, in agreement with model predictions. For traits related to fecundity, thelytokous parasitoids, which usually occur in stable thermal conditions, exhibit specialist performance curves, maximising their reproductive success under a restricted range of temperature. In contrast, arrhenotokous parasitoids, which occur in variable climates, exhibit generalist performance curves, in keeping with the hypothesis "jack of all temperatures, master of none".

  14. The invasive pest Drosophila suzukii uses trans-generational medication to resist parasitoid attack

    PubMed Central

    Poyet, M.; Eslin, P.; Chabrerie, O.; Prud’homme, S. M.; Desouhant, E.; Gibert, P.

    2017-01-01

    Animal medication is a behavioral strategy to resist enemies based on the use of substances from the environment. While it has been observed in several animals, whether invasive species can use medication to resist new enemies during its expansion is unknown. Here, we show that the worldwide invasive pest Drosophila suzukii performs trans-generational prophylactic medication by adapting its oviposition behavior in the presence of enemies. We find that flies preferentially lay their eggs on media containing atropine – an entomotoxic alkaloid – in the presence of parasitoids. We further show that flies developing on atropine more efficiently resist parasitization by parasitoids. Finally, we find that developing in hosts reared on atropine strongly impacts the life-history traits of parasitoids. This protective behavior is reported for the first time in a pest and invasive species, and suggests that animal medication may be an important driver of population dynamics during invasions. PMID:28287118

  15. Functional and evolutionary insights from the genomes of three parasitoid Nasonia species.

    PubMed

    Werren, John H; Richards, Stephen; Desjardins, Christopher A; Niehuis, Oliver; Gadau, Jürgen; Colbourne, John K; Werren, John H; Richards, Stephen; Desjardins, Christopher A; Niehuis, Oliver; Gadau, Jürgen; Colbourne, John K; Beukeboom, Leo W; Desplan, Claude; Elsik, Christine G; Grimmelikhuijzen, Cornelis J P; Kitts, Paul; Lynch, Jeremy A; Murphy, Terence; Oliveira, Deodoro C S G; Smith, Christopher D; van de Zande, Louis; Worley, Kim C; Zdobnov, Evgeny M; Aerts, Maarten; Albert, Stefan; Anaya, Victor H; Anzola, Juan M; Barchuk, Angel R; Behura, Susanta K; Bera, Agata N; Berenbaum, May R; Bertossa, Rinaldo C; Bitondi, Márcia M G; Bordenstein, Seth R; Bork, Peer; Bornberg-Bauer, Erich; Brunain, Marleen; Cazzamali, Giuseppe; Chaboub, Lesley; Chacko, Joseph; Chavez, Dean; Childers, Christopher P; Choi, Jeong-Hyeon; Clark, Michael E; Claudianos, Charles; Clinton, Rochelle A; Cree, Andrew G; Cristino, Alexandre S; Dang, Phat M; Darby, Alistair C; de Graaf, Dirk C; Devreese, Bart; Dinh, Huyen H; Edwards, Rachel; Elango, Navin; Elhaik, Eran; Ermolaeva, Olga; Evans, Jay D; Foret, Sylvain; Fowler, Gerald R; Gerlach, Daniel; Gibson, Joshua D; Gilbert, Donald G; Graur, Dan; Gründer, Stefan; Hagen, Darren E; Han, Yi; Hauser, Frank; Hultmark, Da; Hunter, Henry C; Hurst, Gregory D D; Jhangian, Shalini N; Jiang, Huaiyang; Johnson, Reed M; Jones, Andrew K; Junier, Thomas; Kadowaki, Tatsuhiko; Kamping, Albert; Kapustin, Yuri; Kechavarzi, Bobak; Kim, Jaebum; Kim, Jay; Kiryutin, Boris; Koevoets, Tosca; Kovar, Christie L; Kriventseva, Evgenia V; Kucharski, Robert; Lee, Heewook; Lee, Sandra L; Lees, Kristin; Lewis, Lora R; Loehlin, David W; Logsdon, John M; Lopez, Jacqueline A; Lozado, Ryan J; Maglott, Donna; Maleszka, Ryszard; Mayampurath, Anoop; Mazur, Danielle J; McClure, Marcella A; Moore, Andrew D; Morgan, Margaret B; Muller, Jean; Munoz-Torres, Monica C; Muzny, Donna M; Nazareth, Lynne V; Neupert, Susanne; Nguyen, Ngoc B; Nunes, Francis M F; Oakeshott, John G; Okwuonu, Geoffrey O; Pannebakker, Bart A; Pejaver, Vikas R; Peng, Zuogang; Pratt, Stephen C; Predel, Reinhard; Pu, Ling-Ling; Ranson, Hilary; Raychoudhury, Rhitoban; Rechtsteiner, Andreas; Reese, Justin T; Reid, Jeffrey G; Riddle, Megan; Robertson, Hugh M; Romero-Severson, Jeanne; Rosenberg, Miriam; Sackton, Timothy B; Sattelle, David B; Schlüns, Helge; Schmitt, Thomas; Schneider, Martina; Schüler, Andreas; Schurko, Andrew M; Shuker, David M; Simões, Zilá L P; Sinha, Saurabh; Smith, Zachary; Solovyev, Victor; Souvorov, Alexandre; Springauf, Andreas; Stafflinger, Elisabeth; Stage, Deborah E; Stanke, Mario; Tanaka, Yoshiaki; Telschow, Arndt; Trent, Carol; Vattathil, Selina; Verhulst, Eveline C; Viljakainen, Lumi; Wanner, Kevin W; Waterhouse, Robert M; Whitfield, James B; Wilkes, Timothy E; Williamson, Michael; Willis, Judith H; Wolschin, Florian; Wyder, Stefan; Yamada, Takuji; Yi, Soojin V; Zecher, Courtney N; Zhang, Lan; Gibbs, Richard A

    2010-01-15

    We report here genome sequences and comparative analyses of three closely related parasitoid wasps: Nasonia vitripennis, N. giraulti, and N. longicornis. Parasitoids are important regulators of arthropod populations, including major agricultural pests and disease vectors, and Nasonia is an emerging genetic model, particularly for evolutionary and developmental genetics. Key findings include the identification of a functional DNA methylation tool kit; hymenopteran-specific genes including diverse venoms; lateral gene transfers among Pox viruses, Wolbachia, and Nasonia; and the rapid evolution of genes involved in nuclear-mitochondrial interactions that are implicated in speciation. Newly developed genome resources advance Nasonia for genetic research, accelerate mapping and cloning of quantitative trait loci, and will ultimately provide tools and knowledge for further increasing the utility of parasitoids as pest insect-control agents.

  16. Functional and Evolutionary Insights from the Genomes of Three Parasitoid Nasonia Species

    PubMed Central

    2010-01-01

    We report here genome sequences and comparative analyses of three closely related parasitoid wasps: Nasonia vitripennis, N. giraulti, and N. longicornis. Parasitoids are important regulators of arthropod populations, including major agricultural pests and disease vectors, and Nasonia is an emerging genetic model, particularly for evolutionary and developmental genetics. Key findings include the identification of a functional DNA methylation tool kit; hymenopteran-specific genes including diverse venoms; lateral gene transfers among Pox viruses, Wolbachia, and Nasonia; and the rapid evolution of genes involved in nuclear-mitochondrial interactions that are implicated in speciation. Newly developed genome resources advance Nasonia for genetic research, accelerate mapping and cloning of quantitative trait loci, and will ultimately provide tools and knowledge for further increasing the utility of parasitoids as pest insect-control agents. PMID:20075255

  17. Fitness Effects of Food Resources on the Polyphagous Aphid Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae).

    PubMed

    Charles, Jennifer J; Paine, Timothy D

    2016-01-01

    Conservation biological control involving the polyphagous aphid parasitoid, Aphidius colemani Viereck, may include provisioning resources from a variety of plant sources. The fitness of adult A. colemani was enhanced with the provision of food resources such as floral nectar from a range of both native and introduced plant species and aphid honeydew under laboratory conditions. However, enhanced fitness appeared to be species specific rather than associated with the whether the plant was a native or an introduced species. Parasitoid survival and fecundity were enhanced significantly in response to the availability of floral nectar and honeydew compared to the response to available extrafloral nectar. These positive effects on the parasitoid's reproductive activity can improve the effectiveness of conservation biological control in nursery production systems because of the abundance and diversity of floral resources within typical production areas. Additionally, surrounding areas of invasive weeds and native vegetation could serve as both floral resources and honeydew food resources for A. colemani.

  18. Immunogenetic aspects of the cellular immune response of Drosophilia against parasitoids.

    PubMed

    Carton, Y; Nappi, A J

    2001-01-01

    Host-parasite relationships represent integrating adaptations of considerable complexity involving the host's immune capacity to both recognize and destroy the parasite, and the latter's ability to successfully invade the host and to circumvent its immune response. Compatibility in Drosophila-parasitic wasp (parasitoid) associations has been shown to have a genetic basis, and to be both species and strain specific. Studies using resistant and susceptible strains of Drosophila melanogaster infected with virulent and avirulent strains of the wasp Leptopilina boulardi demonstrate that the success of the host cellular immune response depends on the genetic status of both host and parasitoid. Immunological, physiological, biochemical, and genetic data form the bases of a two-component model proposed here to account for the observed specificity and complexity of two coevolved adaptations, host nonself recognition and parasitoid virulence.

  19. Multi-trait mimicry of ants by a parasitoid wasp

    PubMed Central

    Malcicka, Miriama; Bezemer, T. Martijn; Visser, Bertanne; Bloemberg, Mark; Snart, Charles J. P.; Hardy, Ian C. W.; Harvey, Jeffrey A.

    2015-01-01

    Many animals avoid attack from predators through toxicity or the emission of repellent chemicals. Defensive mimicry has evolved in many species to deceive shared predators, for instance through colouration and other morphological adaptations, but mimicry hardly ever seems to involve multi-trait similarities. Here we report on a wingless parasitoid wasp that exhibits a full spectrum of traits mimicing ants and affording protection against ground-dwelling predators (wolf spiders). In body size, morphology and movement Gelis agilis (Ichneumonidae) is highly similar to the black garden ant (Lasius niger) that shares the same habitat. When threatened, G. agilis also emits a volatile chemical that is similar to an ant-produced chemical that repels spiders. In bioassays with L. niger, G. agilis, G. areator, Cotesia glomerata and Drosophila melanogaster, ants and G. agilis were virtually immune to spider attack, in contrast the other species were not. Volatile characterisation with gas chromatography-mass spectrometry identified G. agilis emissions as 6-methyl-5-hepten-2-one, a known insect defence semiochemical that acts as an alarm pheromone in ants. We argue that multi-trait mimicry, as observed in G. agilis, might be much more common among animals than currently realized. PMID:25622726

  20. Bacteria Endosymbiont, Wolbachia, Promotes Parasitism of Parasitoid Wasp Asobara japonica

    PubMed Central

    Matsumoto, Hitoshi; Hayakawa, Yoichi

    2015-01-01

    Wolbachia is the most widespread endosymbiotic bacterium that manipulates reproduction of its arthropod hosts to enhance its own spread throughout host populations. Infection with Wolbachia causes complete parthenogenetic reproduction in many Hymenoptera, producing only female offspring. The mechanism of such reproductive manipulation by Wolbachia has been extensively studied. However, the effects of Wolbachia symbiosis on behavioral traits of the hosts are scarcely investigated. The parasitoid wasp Asobara japonica is an ideal insect to investigate this because symbiotic and aposymbiotic strains are available: Wolbachia-infected Tokyo (TK) and noninfected Iriomote (IR) strains originally collected on the main island and southwest islands of Japan, respectively. We compared the oviposition behaviors of the two strains and found that TK strain females parasitized Drosophila melanogaster larvae more actively than the IR strain, especially during the first two days after eclosion. Removing Wolbachia from the TK strain wasps by treatment with tetracycline or rifampicin decreased their parasitism activity to the level of the IR strain. Morphological and behavioral analyses of both strain wasps showed that Wolbachia endosymbionts do not affect development of the host female reproductive tract and eggs, but do enhance host-searching ability of female wasps. These results suggest the possibility that Wolbachia endosymbionts may promote their diffusion and persistence in the host A. japonica population not only at least partly by parthenogenesis but also by enhancement of oviposition frequency of the host females. PMID:26492411

  1. Early memory in the parasitoid wasp Nasonia vitripennis.

    PubMed

    Schurmann, Daria; Kugel, Dominic; Steidle, Johannes L M

    2015-04-01

    We studied early memory in Nasonia vitripennis, a parasitoid of fly pupae and emerging model organism for ecological questions in the context of learning. After associative training consisting of one drilling experience in a host in the presence of cinnamon, females showed a preference to cinnamon for at least 24 h. To study sensitisation, wasps were trained by one drilling in a host without cinnamon. These wasps were not attracted to cinnamon immediately afterwards. Obviously, sensitisation is not involved in early memory. Wasps that were anaesthetised by CO2 directly after associative training did not react to cinnamon 30-45 min later, but after 1 and 24 h. CO2 treatment≥5 min after training did not erase the reaction to cinnamon. This indicates the existence of four early memory phases. (a) One phase<5 min after training, in which CO2 has to be applied to become effective. (b) One subsequent phase which is resistant to CO2. (c) One phase<1 h in which memory can be erased by CO2 treatment directly after training. (d) One phase 1-24 h not affected by CO2 treatment. Together with earlier data this enables us to establish a complete memory structure for N. vitripennis.

  2. Larval defense against attack from parasitoid wasps requires nociceptive neurons.

    PubMed

    Robertson, Jessica L; Tsubouchi, Asako; Tracey, W Daniel

    2013-01-01

    Parasitoid wasps are a fierce predator of Drosophila larvae. Female Leptopilina boulardi (LB) wasps use a sharp ovipositor to inject eggs into the bodies of Drosophila melanogaster larvae. The wasp then eats the Drosophila larva alive from the inside, and an adult wasp ecloses from the Drosophila pupal case instead of a fly. However, the Drosophila larvae are not defenseless as they may resist the attack of the wasps through somatosensory-triggered behavioral responses. Here we describe the full range of behaviors performed by the larval prey in immediate response to attacks by the wasps. Our results suggest that Drosophila larvae primarily sense the wasps using their mechanosensory systems. The range of behavioral responses included both "gentle touch" like responses as well as nociceptive responses. We found that the precise larval response depended on both the somatotopic location of the attack, and whether or not the larval cuticle was successfully penetrated during the course of the attack. Interestingly, nociceptive responses are more likely to be triggered by attacks in which the cuticle had been successfully penetrated by the wasp. Finally, we found that the class IV neurons, which are necessary for mechanical nociception, were also necessary for a nociceptive response to wasp attacks. Thus, the class IV neurons allow for a nociceptive behavioral response to a naturally occurring predator of Drosophila.

  3. Maternal Care in the Parasitoid Sclerodermus harmandi (Hymenoptera: Bethylidae)

    PubMed Central

    Hu, Zhenjie; Zhao, Xingli; Li, Yisong; Liu, Xiaoxia; Zhang, Qingwen

    2012-01-01

    Guarding behavior is an important activity in sub-social insects, and this behavior is believed to improve the survival of offspring. Sclerodermus harmandi (Hymenoptera: Bethylidae) is one of most powerful epizoic parasitoid wasps, and it parasitizes Monochamus alternatus, a borer of wood and also the primary vector of the pinewood nematode Bursaphelenchus xylophilus. After laying eggs, S. harmandi exhibits sub-social behavior involving the female tending the clutch of eggs until emergence (guarding behavior). In this study, the benefits of this maternal care with regard to improvements in the survival of offspring were examined. During the developmental stages, only offspring in the egg and larval stages were sensitive to guarding behavior. A positive relationship between the survival of the offspring and the duration of guarding was detected with logistic regression analysis. A female replacement experiment demonstrated that multiparous S. harmandi stepmothers showed guarding behavior and that this behavior improved the survival of the immature offspring, whereas nulliparous stepmothers failed to exhibit the guarding behavior. These results indicate that S. harmandi females display maternal care and that this behavior improves the survival of offspring. PMID:23251468

  4. Maternal care in the parasitoid Sclerodermus harmandi (Hymenoptera: Bethylidae).

    PubMed

    Hu, Zhenjie; Zhao, Xingli; Li, Yisong; Liu, Xiaoxia; Zhang, Qingwen

    2012-01-01

    Guarding behavior is an important activity in sub-social insects, and this behavior is believed to improve the survival of offspring. Sclerodermus harmandi (Hymenoptera: Bethylidae) is one of most powerful epizoic parasitoid wasps, and it parasitizes Monochamus alternatus, a borer of wood and also the primary vector of the pinewood nematode Bursaphelenchus xylophilus. After laying eggs, S. harmandi exhibits sub-social behavior involving the female tending the clutch of eggs until emergence (guarding behavior). In this study, the benefits of this maternal care with regard to improvements in the survival of offspring were examined. During the developmental stages, only offspring in the egg and larval stages were sensitive to guarding behavior. A positive relationship between the survival of the offspring and the duration of guarding was detected with logistic regression analysis. A female replacement experiment demonstrated that multiparous S. harmandi stepmothers showed guarding behavior and that this behavior improved the survival of the immature offspring, whereas nulliparous stepmothers failed to exhibit the guarding behavior. These results indicate that S. harmandi females display maternal care and that this behavior improves the survival of offspring.

  5. A Parasitoid Wasp Induces Overwintering Behaviour in Its Spider Host

    PubMed Central

    Korenko, Stanislav; Pekár, Stano

    2011-01-01

    Parasites and parasitoids control behaviors of their hosts. However, the origin of the behavior evoked by the parasitic organism has been rarely identified. It is also not known whether the manipulation is universal or host-specific. Polysphinctine wasps, koinobiont ectoparasitoids of several spider species that manipulate host web-spinning activity for their own protection during pupation, provide an ideal system to reveal the origin of the evoked behavior. Larva of Zatypota percontatoria performed species-specific manipulation of theridiid spiders, Neottiura bimaculata and Theridion varians, shortly before pupation. Parasitized N. bimaculata produced a dense web, whereas parasitized T. varians built a cupola-like structure. The larva pupated inside of either the dense web or the cupola-like structure. We discovered that unparasitized N. bimaculata produce an analogous dense web around their eggsacs and for themselves during winter, while T. varians construct an analogous ‘cupola’ only for overwintering. We induced analogous manipulation in unparasitized hosts by altering ambient conditions. We discovered that the behavior evoked by larvae in two hosts was functionally similar. The larva evoked protective behaviors that occur in unparasitized hosts only during specific life-history periods. PMID:21931784

  6. Intragenomic Conflict over Soldier Allocation in Polyembryonic Parasitoid Wasps.

    PubMed

    Rautiala, Petri; Gardner, Andy

    2016-04-01

    Understanding the selection pressures that have driven the evolution of sterile insect castes has been the focus of decades of intense scientific debate. An amenable empirical test bed for theory on this topic is provided by the sterile-soldier caste of polyembryonic parasitoid wasps. The function of these soldiers has been a source of controversy, with two basic hypotheses emerging: the "brood-benefit" hypothesis that they provide an overall benefit for their siblings and the "sex-ratio-conflict" hypothesis that the soldiers mediate a conflict between brothers and sisters by killing their opposite-sex siblings. Here, we investigate the divergent sex-ratio optima of a female embryo's maternal-origin and paternal-origin genes, to determine the potential for, and direction of, intragenomic conflict over soldiering. We then derive contrasting empirically testable predictions concerning the patterns of genomic imprinting that are expected to arise out of this intragenomic conflict, for the brood-benefit versus the sex-ratio-conflict hypothesis of soldier function.

  7. Bacteria Endosymbiont, Wolbachia, Promotes Parasitism of Parasitoid Wasp Asobara japonica.

    PubMed

    Furihata, Shunsuke; Hirata, Makiko; Matsumoto, Hitoshi; Hayakawa, Yoichi

    2015-01-01

    Wolbachia is the most widespread endosymbiotic bacterium that manipulates reproduction of its arthropod hosts to enhance its own spread throughout host populations. Infection with Wolbachia causes complete parthenogenetic reproduction in many Hymenoptera, producing only female offspring. The mechanism of such reproductive manipulation by Wolbachia has been extensively studied. However, the effects of Wolbachia symbiosis on behavioral traits of the hosts are scarcely investigated. The parasitoid wasp Asobara japonica is an ideal insect to investigate this because symbiotic and aposymbiotic strains are available: Wolbachia-infected Tokyo (TK) and noninfected Iriomote (IR) strains originally collected on the main island and southwest islands of Japan, respectively. We compared the oviposition behaviors of the two strains and found that TK strain females parasitized Drosophila melanogaster larvae more actively than the IR strain, especially during the first two days after eclosion. Removing Wolbachia from the TK strain wasps by treatment with tetracycline or rifampicin decreased their parasitism activity to the level of the IR strain. Morphological and behavioral analyses of both strain wasps showed that Wolbachia endosymbionts do not affect development of the host female reproductive tract and eggs, but do enhance host-searching ability of female wasps. These results suggest the possibility that Wolbachia endosymbionts may promote their diffusion and persistence in the host A. japonica population not only at least partly by parthenogenesis but also by enhancement of oviposition frequency of the host females.

  8. A new approach for investigating venom function applied to venom calreticulin in a parasitoid wasp

    PubMed Central

    Siebert, Aisha L.; Wheeler, David; Werren, John H.

    2015-01-01

    A new method is developed to investigate functions of venom components, using venom gene RNA interference knockdown in the venomous animal coupled with RNA sequencing in the envenomated host animal. The vRNAi/eRNA-Seq approach is applied to the venom calreticulin component (v-crc) of the parasitoid wasp Nasonia vitripennis. Parasitoids are common, venomous animals that inject venom proteins into host insects, where they modulate physiology and metabolism to produce a better food resource for the parasitoid larvae. vRNAi/eRNA-Seq indicates that v-crc acts to suppress expression of innate immune cell response, enhance expression of clotting genes in the host, and up-regulate cuticle genes. V-crc KD also results in an increased melanization reaction immediately following envenomation. We propose that v-crc inhibits innate immune response to parasitoid venom and reduces host bleeding during adult and larval parasitoid feeding. Experiments do not support the hypothesis that v-crc is required for the developmental arrest phenotype observed in envenomated hosts. We propose that an important role for some venom components is to reduce (modulate) the exaggerated effects of other venom components on target host gene expression, physiology, and survival, and term this venom mitigation. A model is developed that uses vRNAi/eRNA-Seq to quantify the contribution of individual venom components to total venom phenotypes, and to define different categories of mitigation by individual venoms on host gene expression. Mitigating functions likely contribute to the diversity of venom proteins in parasitoids and other venomous organisms. PMID:26359852

  9. Effects of daily fluctuating temperatures on the Drosophila-Leptopilina boulardi parasitoid association.

    PubMed

    Delava, Emilie; Fleury, Frédéric; Gibert, Patricia

    2016-08-01

    Koinobiont parasitoid insects, which maintain intimate and long-term relationships with their arthropod hosts, constitute an association of ectothermic organisms that is particularly sensitive to temperature variations. Because temperature shows pronounced natural daily fluctuations, we examined if experiments based on a constant temperature range can mask the real effects of the thermal regime on host-parasitoid interactions. The effects of two fluctuating thermal regimes on several developmental parameters of the Drosophila larval parasitoid Leptopilina boulardi were analyzed in this study. Regime 1 included a range of 16-23-16°C and regime 2 included a range of 16-21-26-21-16°C (mean temperature 20.1°C) compared to a 20.1°C constant temperature. Under an average temperature of 20.1°C, which corresponds to a cold condition of L. boulardi development, we showed that the success of parasitism is significantly higher under a fluctuating temperature regime than at constant temperature. A fluctuating regime also correlated with a reduced development time of the parasitoids. In contrast, the thermal regime did not affect the ability of Drosophila to resist parasitoid infestation. Finally, we demonstrated that daily temperature fluctuation prevented the entry into diapause for this species, which is normally observed at a constant temperature of 21°C. Overall, the results reveal that constant temperature experiments can produce misleading results, highlighting the need to study the thermal biology of organisms under fluctuating regimes that reflect natural conditions as closely as possible. This is particularly a major issue in host-parasitoid associations, which constitute a good model to understand the effect of climate warming on interacting species.

  10. Lethal and Sublethal Effects of Insecticides on the Egg Parasitoid Telenomus podisi (Hymenoptera: Platygastridae).

    PubMed

    Turchen, L M; Golin, V; Butnariu, A R; Guedes, R N C; Pereira, M J B

    2016-02-01

    Insecticide use remains controversial, and subjected to increasing environmental and health concerns, even when recent insecticide groups are considered. Neonicotinoids and even bioinsecticides are in the forefront of discussions regarding their nontarget safety. The ubiquitous focus on the lethal effects of insecticides on nontarget species has been expanding to sublethal effects, as sublethal exposure extends for a longer time and affects a broader range of (nontarget) species. Here we explored the lethal and sublethal effects of a lambda-cyhalothrin + thiamethoxan mixture, the neonicotinoid imidacloprid, and the bioinsecticide azadirachtin on the egg parasitoid Telenomus podisi Ashmead, an important parasitoid of stink bug Euschistus heros (F.), a key soybean pest in neotropical America. Contact with dry insecticide residue on glass surface and (parasitized and healthy) host egg immersion exposure bioassays were performed, assessing their acute lethal effects, and their potential sublethal impairment of parasitism, adult emergence, and fertility of the egg parasitoid. Both imidacloprid and the insecticide mixture exhibited high acute lethal activity toward the parasitoid under contact with dry insecticide residue. These insecticides compromised parasitism and wasp emergence when exposure took place before parasitism. In contrast, azadirachtin did not affect adult survival. However, this bioinsecticide compromised parasitism and progeny production, impairing the female parasitoid reproductive potential. Our results indicate strong negative effects of imidacloprid, and specially of the mixture lambda-cyhalthrin + thiamethoxan. However, even azadirachtin, which exhibited low acute lethality, exhibited significant negative sublethal effects on parasitism and population growth of egg parasitoid, cautioning against their use and the need of semifield and field assessments to confirm such an impact.

  11. NATIVE LARVAL PARASITOIDS ASSOCIATED WITH TUTA ABSOLUTA (MEYRICK) IN GREENHOUSE TOMATO CROPS OF SOUTHERN SARDINIA.

    PubMed

    Nannini, M; Atzori, F; Pisci, R; Sanna, F

    2014-01-01

    Since its first detection in Sardinia (Italy), Tuta absoluta (Meyrick) has been reported as a major pest of greenhouse tomatoes. In recent years, however, a tendency toward a progressive reduction of tomato borer infestation levels has been observed. The reasons behind this decline are probably diverse, including both the increase in growers' ability to manage the pest and the adaptation of native predators and parasitoids to the new prey/host. In order to assess the species composition of the parasitoid complex associated with T. absoluta larvae in Sardinian greenhouse tomatoes, a two-year (2010/11) survey was conducted in one of the island's major horticultural areas (Pula, Cagliari). An estimate of the levels of parasitism caused by native wasps was also carried out. The occurrence of larval parasitoids of T. absoluta was detected in approximately half of the crops monitored. The average parasitism rate recorded in tomato plants infested by tomato borer larvae was 1.3%. Moreover, while no parasitism was observed in 76.4% of the samples collected, only 3.0% of the samples showed a parasitism rate exceeding 10%. The highest rates were recorded in spring and summer, with a peak in July (4.8%). Of 159 adult parasitoids recovered from infested leaves, 62.9% were found to belong to a Necremnus sp. near artynes (Walker), 34.6% to a Necremnus sp. near tidius (Walker), and 2.5% to Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae). These results show that some native parasitoids have adapted to T. absoluta in the study area. Although parasitoid abundance in tomato crops appeared to be low, their contribution for the control of tomato borer infestation could possibly be enhanced through the application of conservation biological control measures.

  12. Regional tritrophic relationship patterns of five aphid parasitoid species (Hymenoptera: Braconidae: Aphidiinae) in agroecosystem-dominated landscapes of southeastern Europe.

    PubMed

    Tomanović, Zeljko; Kavallieratos, Nickolas G; Starý, Petr; Stanisavljević, Ljubisa Z; Cetković, Aleksandar; Stamenković, Srdjan; Jovanović, Slobodan; Athanassiou, Christos G

    2009-06-01

    A regional survey of the complex tritrophic associations (parasitoid-aphid-plant) of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) was carried out to determine and explore the patterns of those associations in various types of environments. Here, we present trophic relationship patterns of the five aphid parasitoid species in crop and noncrop habitats in southeastern Europe, and we contrast them in a regional (Mediterranean [MED] versus continental [CNT]) context. In total, 79 aphid host taxa were identified in this survey. Forty-two of these were recorded from noncrop plants only, 21 from crop plants only, and 18 were present on both types of plants. This means that approximately 74% of all the parasitoid-aphid trophic interactions that support the persistence of the five selected parasitoids are entirely (54%) or partially (20%) associated with noncrop plants. The correspondence of parasitoid-aphid combinations among habitat/region combinations is very high and specific. Our results suggest that Mediterranean and continental regions are clearly distinguished by a contrasting pattern of trophic interactions in crop habitats, whereas the noncrop habitats contribute in lesser degree to these differences. For the crop/noncrop breakdown, the number of nonspecific interactions was larger than expected in crop habitats, whereas in noncrop habitats the abundance of partially specific and specific interactions was larger. The analysis of variance for the regional and habitat distribution of mean aphid host number per parasitoid was highly significant. When both regions were analyzed separately, the parasitoid/crop design showed significant parasitoid effects as well as interactions, whereas the habitat effect was not significant for the Mediterranean region and highly so for the continental region. This highly complex pattern suggests that the mean number of parasitized aphid species is not distributed among parasitoids, regions, and habitats in a similar manner

  13. Sex ratios in field populations of two parasitoids (Hymenoptera: Chalcidoidea) of Coccus hesperidum L. (Homoptera: Coccidae).

    PubMed

    Bernal, Julio S; Luck, Robert F; Morse, J G

    1998-10-01

    We tested several assumptions and predictions of host-quality-dependent sex allocation theory (Charnov et al. 1981) with data obtained for the parasitoid Metaphycus stanleyi Compere on its host, brown soft scale (Coccus hesperidum L.), in a California citrus grove and in the laboratory. Scales ceased growing after parasitization by M. stanleyi. Thus, M. stanleyi may gauge host quality (=size) at oviposition. Host size positively influenced adult parasitoid size, and parasitoid size in turn influenced adult longevity of M. stanleyi. However, parasitoid fitness gains with host size and adult size were similar in males versus females. Sex allocation to individual hosts by M. stanleyi depended on host size; females consistently emerged from larger hosts than males. Host size was important in a relative sense; the mean host sizes of females versus males, and of solitary versus gregarious parasitoids varied with the available host size distribution. The offspring sex ratio of M. stanleyi reflected the available host size distribution; the sex ratio of emerging parasitoids varied with the available host size distribution. We did not detect a "critical host size" below which males emerged, and above which females emerged; rather, only females emerged from hosts in the upper size range, and a variable ratio of males and females emerged from hosts in the lower size range. We conclude that the sex ratio of field populations of M. stanleyi is driven largely by the available size distribution of C. hesperidum. In addition, we tested predictions resulting from theoretical analyses of sex allocation in autoparasitoids with data obtained on Coccophagus semicircularis (Förster) parasitizing brown soft scale in the field. The sex ratio of C. semicircularis was consistently and strongly female biased (ca. 90% females). Based on available theoretical analyses, we suggest that this sex ratio pattern may have resulted from a very low encounter rate of secondary hosts coupled with a

  14. [Dipteran parasitoidism on larvae of Caligo atreus (Lepidoptera: Nymphalidae) in Cartago, Costa Rica].

    PubMed

    Calvo, Renin

    2004-12-01

    Parasitoids on larvae of Caligo atreus were studied at the Estación de Biologia Tropical in Rio Macho, Cartago, Costa Rica. (1 600 masl), from March through July 2000. Fifth instar larvae of C. atreus were placed on Heliconia tortuosa Griggs var. Red Twist (Heliconiaceae) host plants at a mean temperature of 16.7 degrees C. The parasitoids obtained belong to an unidentified species of the genus Winthemia (Diptera: Tachinidae). Most flies emerge some 40 days after the eggs were laid (maximum 68 days). They make an orifice on the upper ventral part of the lepidopteran pupa. Winthemia is used commercially as biological control of cotton and banana.

  15. Acoustic source for generating an acoustic beam

    DOEpatents

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  16. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    NASA Astrophysics Data System (ADS)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  17. What Is an Acoustic Neuroma

    MedlinePlus

    ... ANAUSA.org Connect with us! What is an Acoustic Neuroma? Each heading slides to reveal information. Important ... Acoustic Neuroma Important Points To Know About an Acoustic Neuroma An acoustic neuroma, also called a vestibular ...

  18. Geographic variation in host-specificity and parasitoid pressure of an herbivore (geometridae) associated with the tropical genus piper (piperaceae).

    PubMed

    Connahs, Heidi; Rodríguez-Castañeda, Genoveva; Walters, Toni; Walla, Thomas; Dyer, Lee

    2009-01-01

    The extraordinary diversity of tropical herbivores may be linked to hostplant specialization driven in part by variation in pressure from natural enemies. We quantified levels of host-specificity and parasitoid attack for the specialist herbivore, Eois (Geometridae). The goals of this research were to examine: 1) whether Eois are specialized on the genus Piper (Piperaceae) and if hostplant specialization varies geographically; 2) whether Eois are equally vulnerable to parasitoid attack across different geographic regions and by the same parasitoid families; and 3) whether parasitism levels vary with precipitation and elevation. Based on over 15,000 rearings, we found Eois caterpillars feeding exclusively on Piper. However, we did not detect geographic differences in host-specificity; each Eois species fed on an average of two Piper species. Parasitism levels of Eois varied significantly with climate and topography; Eois were most vulnerable to parasitoid attack in moist versus dry and wet forests and at low versus high elevations. The diversity of parasitoid families reared from Eois was greater in Ecuador and Costa Rica than in Panama, where parasitoids were primarily in the family Braconidae. The quantitative evidence for host-specificity provides support for the hypothesis that Eois are specialized on Piper. Our results also reveal that Eois are exposed to a mosaic of potential selective pressures due to variation in parasitoid attack over a large spatial scale.

  19. Attraction of the Larval Parasitoid Spintherus dubius (Hymenoptera: Pteromalidae) to Feces Volatiles from the Adult Apion Weevil Host.

    PubMed

    Faraone, N; Svensson, G P; Anderbrant, O

    2017-01-01

    The behavioral response of the larval parasitoid Spintherus dubius (Hymenoptera: Pteromalidae) to volatile compounds derived from its Apion weevil hosts was investigated in two-choice bioassays. Odor source candidates were the larval and adult stages of weevils, clover flowers, and feces from adult weevils. Despite S. dubius being a larval parasitoid, the odor of weevil larvae isolated from the clover flowers was not attractive to female parasitoids. Surprisingly, S. dubius females were instead attracted by the odor from the feces of adult weevils. The female parasitoids were similarly attracted to the feces produced by the two main hosts, the red clover weevil (A. trifolii) and the white clover weevil (A. fulvipes). Chemical analysis of the volatile composition of feces produced by the two hosts revealed qualitatively similar odor profiles, correlating with the observed attraction by the parasitoid towards both odor sources. Some of the identified volatile compounds are commonly present in clover plant headspace fractions and may function as a kairomone to facilitate orientation by S. dubius to Apion-infested clover flowers. Larval and adult weevils were not attractive for parasitoid females, whereas, for the white clover weevil-plant association, infested flowers were highly attractive. These data show the use by the clover weevil parasitoid of an alternative source of olfactory information for locating its host.

  20. Geographic distribution, large-scale spatial structure and diversity of parasitoids of the seed-feeding beetle Acanthoscelides macrophthalmus.

    PubMed

    Wood, A; Haga, E B; Costa, V A; Rossi, M N

    2016-10-21

    Bruchine beetles are highly host-specific seed feeders during the larval stage. Although some specific parasitoid families have been recorded attacking bruchine beetles, most studies have been done at small spatial scales. Therefore, the current knowledge about the diversity and the geographic distribution of parasitoid species parasitizing bruchines is scarce, especially at a wide geographic area that extends over large distances through a latitudinal cline (i.e. large-scale spatial structure). The present study determined the species richness and evenness of parasitoids attacking the bruchine beetle Acanthoscelides macrophthalmus feeding on Leucaena leucocephala seeds, examined their geographic distribution, and characterized the large-scale spatial structure in parasitoid species composition. A total of 1420 parasitoids (all Hymenoptera) belonging to four families, five subfamilies and eight species were collected (genera: Horismenus, Paracrias, Urosigalphus, Stenocorse, Chryseida, Eupelmus). Most parasitoid species showed wide spatial distribution, high evenness in species abundance and the species richness estimators were close to stabilization (approximately eight species). Overall, greater similarity was observed in the species composition of plant populations near to each other than those farther apart, revealing a large-scale spatial structure in parasitoid species composition.

  1. Juvenile and sublethal effects of selected pesticides on the leafminer parasitoids Hemiptarsenus varicornis and Diglyphus isaea (Hymenoptera: Eulophidae) from Australia.

    PubMed

    Bjorksten, Tracey A; Robinson, Michelle

    2005-12-01

    The pest leafminers Liriomyza huidobrensis (Blanchard), Liriomyza sativae (Blanchard), and Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) have spread into South East Asia and Oceania, and they are likely to reach Australia in the near future. Two translaminar pesticides, cyromazine and abamectin, currently provide effective chemical control of these pests, but because parasitoids can play an important role in controlling and preventing leafminer outbreaks, understanding the impact of pesticides on leafminer parasitoids is vital. Here, we tested larval and pupal mortality and sublethal effects of abamectin, cyromazine, and the widely used fungicide mancozeb on two common Australian leafminer parasitoids, Hemiptarsenus varicornis (Girault) and Diglyphus isaea (Walker). Abamectin caused significant mortality to larvae and pupae of both parasitoid species but cyromazine and mancozeb did not. Progeny production and longevity of H. varicornis were not affected by adult exposure to cyromazine and mancozeb, nor did direct pupal exposure decrease number of progeny produced by either parasitoid. Mortality of H. varicornis females emerging from leaves treated with abamectin was high for up to 72 h after eclosion but those surviving beyond 72 h did not differ from control females in the number of progeny produced. Mancozeb did not influence leaf residence time or parasitism by H. varicornis females. Cyromazine and the fungicide mancozeb were concluded to be compatible with the parasitoids tested and suitable for integrated pest management of leafminers should outbreaks of pest species occur in Australia. Abamectin should be used with caution because it caused significant mortality in both parasitoids tested here.

  2. Effects of aposymbiotic and symbiotic aphids on parasitoid progeny development and adult oviposition behavior within aphid instars.

    PubMed

    Cheng, Rui-Xia; Meng, Ling; Li, Bao-Ping

    2010-04-01

    This study aims at exploring the potential relationship between aphidiine parasitoid development and the primary endosymbiont in aphids by focusing on specific aphid instars and the relative effects on parasitoid oviposition behavior and progeny development. Lysiphlebus ambiguus (Aphidiidae, Hymenoptera) is a solitary parasitoid of several species of aphids, including Aphis fabae. In this study, A. fabae was treated with antibiotic rifampicin to obtain aposymbiotic hosts and exposed to parasitism. L. ambiguus launched significantly more attacks on symbiotic L(2) (the second instar), aposymbiotic L(3) (the third instar) and L(4) (the forth instar) hosts than on the corresponding hosts at the same age. L. ambiguus also parasitized more L(1) aphids compared with adults irrespective of whether the aphid was asymbiotic or not. Pupa mortality rate of parasitoid progeny was significantly lower from aposymbiotic hosts than from the corresponding symbiotics at all stages. Female-biased parasitoid progeny was produced from aposymbiotic aphids without respect to host ages, but female progeny increased linearly with host ages at parasitism from symbiotic aphids. Body size of parasitoid progeny increased linearly with host instars at parasitism in symbiotic aphids but did not significantly change across host instars in aposymbiotic aphids. The offspring parasitoids turned out to be generally large in body size from attacking aposymbiotic aphids compared with the symbiotics. Development time of egg-to-adult of parasitoid progeny decreased with host instars in both symbiotic and aposymbiotic aphids but was generally much longer in aposymbiotic aphids than in symbiotic aphids. Our study suggests that age or body size of host aphids may not be the only cue exercised by L. ambiguus to evaluate host quality and that offspring parasitoids may be able to compensate for the nutrition stress associated with disruption of primary endosymbiotc bacteria in aposymbiotic aphids.

  3. How parasitism affects critical patch-size in a host-parasitoid model: application to the forest tent caterpillar.

    PubMed

    Cobbold, C A; Lewis, M A; Lutscher, F; Roland, J

    2005-03-01

    Habitat structure has broad impacts on many biological systems. In particular, habitat fragmentation can increase the probability of species extinction and on the other hand it can lead to population outbreaks in response to a decline in natural enemies. An extreme consequence of fragmentation is the isolation of small regions of suitable habitat surrounded by a large region of hostile matrix. This scenario can be interpreted as a critical patch-size problem, well studied in a continuous time framework, but relatively new to discrete time models. In this paper we present an integrodifference host-parasitoid model, discrete in time and continuous in space, to study how the critical habitat-size necessary for parasitoid survival changes in response to parasitoid life history traits, such as emergence time. We show that early emerging parasitoids may be able to persist in smaller habitats than late emerging species. The model predicts that these early emerging parasitoids lead to more severe host outbreaks. We hypothesise that promoting efficient late emerging parasitoids may be key in reducing outbreak severity, an approach requiring large continuous regions of suitable habitat. We parameterise the model for the host species of the forest tent caterpillar Malacosoma disstria Hbn., a pest insect for which fragmented landscape increases the severity of outbreaks. This host is known to have several parasitoids, due to paucity of data and as a first step in the modelling we consider a single generic parasitoid. The model findings are related to observations of the forest tent caterpillar offering insight into this host-parasitoid response to habitat structure.

  4. One step ahead: a parasitoid disperses farther and forms a wider geographic population than its fig wasp host.

    PubMed

    Sutton, Timothy L; Riegler, Markus; Cook, James M

    2016-02-01

    The structure of populations across landscapes influences the dynamics of their interactions with other species. Understanding the geographic structure of populations can thus shed light on the potential for interacting species to co-evolve. Host-parasitoid interactions are widespread in nature and also represent a significant force in the evolution of plant-insect interactions. However, there have been few comparisons of population structure between an insect host and its parasitoid. We used microsatellite markers to analyse the population genetic structure of Pleistodontes imperialis sp. 1, a fig-pollinating wasp of Port Jackson fig (Ficus rubiginosa), and its main parasitoid, Sycoscapter sp. A, in eastern Australia. Besides exploring this host-parasitoid system, our study also constitutes, to our knowledge, the first study of population structure in a nonpollinating fig wasp species. We collected matched samples of pollinators and parasitoids at several sites in two regions separated by up to 2000 km. We found that pollinators occupying the two regions represent distinct populations, but, in contrast, parasitoids formed a single population across the wide geographic range sampled. We observed genetic isolation by distance for each species, but found consistently lower FST and RST values between sites for parasitoids compared with pollinators. Previous studies have indicated that pollinators of monoecious figs can disperse over very long distances, and we provide the first genetic evidence that their parasitoids may disperse as far, if not farther. The contrasting geographic population structures of host and parasitoid highlight the potential for geographic mosaics in this important symbiotic system.

  5. Symptoms of Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  6. NPL closes acoustics department

    NASA Astrophysics Data System (ADS)

    Extance, Andy

    2016-11-01

    The UK's National Physical Laboratory (NPL) has withdrawn funding for its acoustics, polymer and thermoelectrics groups, triggering concern among airborne acoustics specialists that the move could undermine the country's noise-management policies.

  7. Identifying the Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  8. Acoustic emission frequency discrimination

    NASA Technical Reports Server (NTRS)

    Sugg, Frank E. (Inventor); Graham, Lloyd J. (Inventor)

    1988-01-01

    In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered.

  9. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2015-07-17

    under-ice scattering , bathymetric diffraction and the application of the ocean acoustic Parabolic Equation to infrasound. 2. Tasks a. Task 1...QSR-14C0172-Ocean Acoustics -063015 Figure 10. Estimated reflection coefficient as a function of frequency by taking the difference of downgoing and...OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics -063015 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics

  10. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2015-10-19

    OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics-093015 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics...number. 1. REPORT DATE OCT 2015 2. REPORT TYPE 3. DATES COVERED 01-07-2015 to 30-09-2015 4. TITLE AND SUBTITLE Deep Water Ocean Acoustics...understanding of the impact of the ocean and seafloor environmental variability on deep- water (long-range) ocean acoustic propagation and to develop

  11. Shallow Water Acoustics Studies

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Shallow Water Acoustics Studies James F. Lynch MS #12...N00014-14-1-0040 http://acoustics.whoi.edu/sw06/ LONG TERM GOALS The long term goals of our shallow water acoustics work are to: 1) understand the...nature of low frequency (10-1500 Hz) acoustic propagation, scattering and noise in shallow water when strong oceanic variability is present in the

  12. Lethal combat and sex ratio evolution in a parasitoid wasp

    PubMed Central

    Innocent, Tabitha M.; Savage, Joanna; West, Stuart A.; Reece, Sarah E.

    2013-01-01

    Sex allocation theory provides excellent opportunities for testing how behavior and life histories are adjusted in response to environmental variation. One of the most successful areas from this respect is Hamilton’s local mate competition theory. As predicted by theory, a large number of animal species have been shown to adjust their offspring sex ratios (proportion male) conditionally, laying less female-biased sex ratios as the number of females that lay eggs on a patch increases. However, recent studies have shown that this predicted pattern is not followed by 2 parasitoid species in the genus Melittobia, which always produce extremely female-biased sex ratios. A possible explanation for this is that males fight fatally and that males produced by the first female to lay eggs on a patch have a competitive advantage over later emerging males. This scenario would negate the advantage of later females producing a less female-biased sex ratio. Here we examine fatal fighting and sex ratio evolution in another species, Melittobia acasta. We show that females of this species also fail to adjust their offspring sex ratio in response to the number of females laying eggs on a patch. We then show that although earlier emerging males do have an advantage in winning fights, this advantage 1) can be reduced by an interaction with body size, with larger males more likely to win fights and 2) only holds for a brief period around the time at which the younger males emerge from their pupae. This suggests that lethal male combat cannot fully explain the lack of sex ratio shift observed in Melittobia species. We discuss alternative explanations. PMID:24273326

  13. Decay of Sexual Trait Genes in an Asexual Parasitoid Wasp

    PubMed Central

    Anvar, Seyed Yahya; Frank, Jeroen; Schmitz, Arnoud; Bast, Jens; Wilbrandt, Jeanne; Petersen, Malte; Ziesmann, Tanja; Niehuis, Oliver; de Knijff, Peter; den Dunnen, Johan T.; Ellers, Jacintha

    2016-01-01

    Trait loss is a widespread phenomenon with pervasive consequences for a species’ evolutionary potential. The genetic changes underlying trait loss have only been clarified in a small number of cases. None of these studies can identify whether the loss of the trait under study was a result of neutral mutation accumulation or negative selection. This distinction is relatively clear-cut in the loss of sexual traits in asexual organisms. Male-specific sexual traits are not expressed and can only decay through neutral mutations, whereas female-specific traits are expressed and subject to negative selection. We present the genome of an asexual parasitoid wasp and compare it to that of a sexual lineage of the same species. We identify a short-list of 16 genes for which the asexual lineage carries deleterious SNP or indel variants, whereas the sexual lineage does not. Using tissue-specific expression data from other insects, we show that fifteen of these are expressed in male-specific reproductive tissues. Only one deleterious variant was found that is expressed in the female-specific spermathecae, a trait that is heavily degraded and thought to be under negative selection in L. clavipes. Although the phenotypic decay of male-specific sexual traits in asexuals is generally slow compared with the decay of female-specific sexual traits, we show that male-specific traits do indeed accumulate deleterious mutations as expected by theory. Our results provide an excellent starting point for detailed study of the genomics of neutral and selected trait decay. PMID:28172869

  14. Male killing Spiroplasma protects Drosophila melanogaster against two parasitoid wasps.

    PubMed

    Xie, J; Butler, S; Sanchez, G; Mateos, M

    2014-04-01

    Maternally transmitted associations between endosymbiotic bacteria and insects are diverse and widespread in nature. Owing to imperfect vertical transmission, many heritable microbes have evolved compensational mechanisms to enhance their persistence in host lineages, such as manipulating host reproduction and conferring fitness benefits to host. Symbiont-mediated defense against natural enemies of hosts is increasingly recognized as an important mechanism by which endosymbionts enhance host fitness. Members of the genus Spiroplasma associated with distantly related Drosophila hosts are known to engage in either reproductive parasitism (i.e., male killing) or defense against natural enemies (the parasitic wasp Leptopilina heterotoma and a nematode). A male-killing strain of Spiroplasma (strain Melanogaster Sex Ratio Organism (MSRO)) co-occurs with Wolbachia (strain wMel) in certain wild populations of the model organism Drosophila melanogaster. We examined the effects of Spiroplasma MSRO and Wolbachia wMel on Drosophila survival against parasitism by two common wasps, Leptopilina heterotoma and Leptopilina boulardi, that differ in their host ranges and host evasion strategies. The results indicate that Spiroplasma MSRO prevents successful development of both wasps, and confers a small, albeit significant, increase in larva-to-adult survival of flies subjected to wasp attacks. We modeled the conditions under which defense can contribute to Spiroplasma persistence. Wolbachia also confers a weak, but significant, survival advantage to flies attacked by L. heterotoma. The host protective effects exhibited by Spiroplasma and Wolbachia are additive and may provide the conditions for such cotransmitted symbionts to become mutualists. Occurrence of Spiroplasma-mediated protection against distinct parasitoids in divergent Drosophila hosts suggests a general protection mechanism.

  15. Lethal combat and sex ratio evolution in a parasitoid wasp.

    PubMed

    Innocent, Tabitha M; Savage, Joanna; West, Stuart A; Reece, Sarah E

    2007-07-01

    Sex allocation theory provides excellent opportunities for testing how behavior and life histories are adjusted in response to environmental variation. One of the most successful areas from this respect is Hamilton's local mate competition theory. As predicted by theory, a large number of animal species have been shown to adjust their offspring sex ratios (proportion male) conditionally, laying less female-biased sex ratios as the number of females that lay eggs on a patch increases. However, recent studies have shown that this predicted pattern is not followed by 2 parasitoid species in the genus Melittobia, which always produce extremely female-biased sex ratios. A possible explanation for this is that males fight fatally and that males produced by the first female to lay eggs on a patch have a competitive advantage over later emerging males. This scenario would negate the advantage of later females producing a less female-biased sex ratio. Here we examine fatal fighting and sex ratio evolution in another species, Melittobia acasta. We show that females of this species also fail to adjust their offspring sex ratio in response to the number of females laying eggs on a patch. We then show that although earlier emerging males do have an advantage in winning fights, this advantage 1) can be reduced by an interaction with body size, with larger males more likely to win fights and 2) only holds for a brief period around the time at which the younger males emerge from their pupae. This suggests that lethal male combat cannot fully explain the lack of sex ratio shift observed in Melittobia species. We discuss alternative explanations.

  16. Two new Aprostocetus species (Hymenoptera: Eulophidae: Tetrastichinae), fortuitous parasitoids of invasive eulophid gall inducers (Tetrastichinae) on Eucalyptus and Erythrina.

    PubMed

    Yang, Man-Miao; Lin, Yu-Che; Wu, Yaojun; Fisher, Nicole; Saimanee, Titiporn; Sangtongpraow, Benjakhun; Zhu, Chaodong; Chiu, William Chien-Hsien; La Salle, John

    2014-08-01

    Two closely related new species of Aprostocetus Westwood (Hymenoptera: Eulophidae: Tetrastichinae) are described as fortuitous parasitoids of invasive gall inducers in two other genera of Tetrastichinae, Leptocybe Fisher & LaSalle and Quadrastichus Girault. Aprostocetus causalis La Salle & Wu is a parasitoid of Leptocybe invasa Fisher & La Salle on Eucalyptus spp. (Myrtaceae) in China and Thailand, and A. felix La Salle, Yang & Lin is a parasitoid of Quadrastichus erythrinae Kim on Erythrina spp. (Fabaceae) in Taiwan. Epitetrastichus nigriventris Girault, 1913 is removed from synonymy from Aprostocetus gala (Walker), and treated as the valid species A. nigriventris (Girault). 

  17. Coding Acoustic Metasurfaces.

    PubMed

    Xie, Boyang; Tang, Kun; Cheng, Hua; Liu, Zhengyou; Chen, Shuqi; Tian, Jianguo

    2017-02-01

    Coding acoustic metasurfaces can combine simple logical bits to acquire sophisticated functions in wave control. The acoustic logical bits can achieve a phase difference of exactly π and a perfect match of the amplitudes for the transmitted waves. By programming the coding sequences, acoustic metasurfaces with various functions, including creating peculiar antenna patterns and waves focusing, have been demonstrated.

  18. Tutorial on architectural acoustics

    NASA Astrophysics Data System (ADS)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  19. Hymenopteran parasitoids associated with frugivorous larvae in a Brazilian caatinga-cerrado ecotone.

    PubMed

    De Souza, A R; Lopes-Mielezrski, G N; Lopes, E N; Querino, R B; Corsato, C D A; Giustolin, T A; Zucchi, R A

    2012-04-01

    The purpose of this study was to investigate native species of parasitoids of frugivorous larvae and their associations with host plants in commercial guava orchards and in typical native dry forests of a caatinga-cerrado ecotone in the State of Minas Gerais, Brazil. Nine species of parasitoids were associated with larvae of Anastrepha (Tephritidae) and Neosilba (Lonchaeidae) in fruit of Psidium guajava L. (Myrtaceae), Ziziphus joazeiro Mart. (Rhamnaceae), Spondias tuberosa Arruda (Anacardiaceae), Spondias dulcis Forst. (Anacardiaceae), Syzygium cumini (L.) Skeels (Myrtaceae), and Randia armata (Sw.) DC. (Rubiaceae). Doryctobracon areolatus was the most abundant species, obtained from puparia of Anastrepha zenildae, An. sororcula, An. fraterculus, An. obliqua, and An. turpiniae. This is the first report of Asobara obliqua in Brazil and of As. anastrephae and Tropideucoila weldi in dry forests of Minas Gerais State. The number of species of parasitoids was higher in areas with greater diversity of cultivated species and lower pesticide use. The forest fragments adjacent to the orchards served as shelter for parasitoids of frugivorous larvae.

  20. Heat Stress Affects Facultative Symbiont-Mediated Protection from a Parasitoid Wasp

    PubMed Central

    Heyworth, Eleanor R.

    2016-01-01

    Many insects carry facultative bacterial symbionts, which provide benefits including resistance to natural enemies and abiotic stresses. Little is known about how these beneficial phenotypes are affected when biotic or abiotic threats occur simultaneously. The pea aphid (Acyrthosiphon pisum) can host several well-characterized symbiont species. The symbiont known as X-type can protect against both parasitoid wasps and heat stress. Here, we used three pea aphid genotypes that were naturally infected with X-type and the symbiont Spiroplasma sp. We compared aphids coinfected with these two symbionts with those cured from X-type and infected with only Spiroplasma to investigate the ability of X-type to confer benefits to the host when two threats are experienced simultaneously. Our aim is to explore how robust symbiont protection may be outside a benign laboratory environment. Aphids were subjected to heat shock either before or after attack by parasitoid wasps. Under a benign temperature regime, the aphids carrying X-type tended to be better protected from the parasitoid than those cured. When the aphids experienced a heat shock before being parasitized aphids carrying X-type were more susceptible than those cured. Regardless of infection with the symbiont, the aphids benefitted from being heat shocked after parasitization. The results demonstrate how resistance to parasitoid wasps can be strongly environment-dependent and that a beneficial phenotype conferred by a symbiont under controlled conditions in the laboratory does not necessarily equate to a consistently useful effect in natural populations. PMID:27875577

  1. Artifical transfer and morphological description of virus particles associated with superparasitism behaviour in a parasitoid wasp.

    PubMed

    Varaldi, Julien; Ravallec, Marc; Labrosse, Corinne; Lopez-Ferber, Miguel; Boulétreau, Michel; Fleury, Frédéric

    2006-01-01

    In parasitoids, the adaptive significance of superparasitism (laying of egg(s) in already parasitized hosts) has been the subject of strong controversy. The current view is to interpret this behaviour as an adaptation to increased competition for hosts, because the supernumerary egg still has a chance to win possession for the host. However, we recently discovered that in the solitary parasitoid Leptopilina boulardi, superparasitism is rather caused by an unknown infectious element: stable non superparasitizing lineages (NS) are transformed into stable superparasitizing lineages (S) after eggs from both lineages have competed inside the same host (superparasitism). In this report, we investigate the nature and location of the causative agent. Involvement of bacteria is unlikely because antibiotic treatments do not affect wasp phenotype and because bacterial 16S ribosomal DNA was not detected using PCR. We report successful injection experiments showing that the causative agents are located in wasp poison gland and ovaries and are stably inherited. Electron microscopic studies demonstrate that long filamentous virus particles located in wasp oviducts are strongly associated with superparasitism behaviour, leading to reconsider the adaptive significance of this behaviour in parasitoids. Interestingly, parasitoids are often infected with similar viruses for which no phenotypic effect has been documented. This raises the possibility that they could induce the same behavioural manipulation.

  2. Glassy-winged sharpshooter oviposition effects on photinia volatile chemistry with implications on egg parasitoid effectiveness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An effective way to limit incidence of Pierce’s disease of grapevine is to reduce populations of glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), which transmit the causal bacterium, Xylella fastidiosa. One strategy is to utilize egg parasitoids such as ...

  3. Hymenopteran Parasitoids Attacking the Invasive Emerald Ash Borer (Coleoptera: Buprestidae) in Western and Central Pennsylvania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted field surveys of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, and associated larval parasitoids in western and central Pennsylvania (Cranberry and Granville Townships) in the spring and fall of 2009. The survey procedure involved destructively debarking sections of the m...

  4. Augmentative Biological Control Using Parasitoids for Fruit Fly Management in Brazil.

    PubMed

    Garcia, Flávio R M; Ricalde, Marcelo P

    2012-12-21

    The history of classical biological control of fruit flies in Brazil includes two reported attempts in the past 70 years. The first occurred in 1937 when an African species of parasitoid larvae (Tetrastichus giffardianus) was introduced to control the Mediterranean fruit fly, Ceratitis capitata and other tephritids. The second occurred in September 1994 when the exotic parasitoid Diachasmimorpha longicaudata, originally from Gainesville, Florida, was introduced by a Brazilian agricultural corporation (EMBRAPA) to evaluate the parasitoid's potential for the biological control of Anastrepha spp. and Ceratitis capitata. Although there are numerous native Brazilian fruit fly parasitoids, mass rearing of these native species is difficult. Thus, D. longicaudata was chosen due to its specificity for the family Tephritidae and its ease of laboratory rearing. In this paper we review the literature on Brazilian fruit fly biological control and suggest that those tactics can be used on a large scale, together creating a biological barrier to the introduction of new fruit fly populations, reducing the source of outbreaks and the risk of species spread, while decreasing the use of insecticides on fruit destined for domestic and foreign markets.

  5. Lespesia melloi sp. nov. (Diptera: Tachinidae) from Brazil, a parasitoid of Xanthopastis timais(Lepidoptera: Noctuidae).

    PubMed

    Gil-Santana, Hélcio R; Nihei, Silvio Shigueo; Nunez, Enio

    2014-01-01

    A new species of the New World genus Lespesia, Lespesia melloi SP NOV: (Diptera: Tachinidae), is described from southeastern Brazil. The species is reported here as a parasitoid of Xanthopastis timais (Cramer, 1782) (Lepidoptera: Noctuidae). The caterpillars of this noctuid feed on leaves and bulbs of amaryllis (Amaryllidaceae) in Brazil.

  6. Lespesia melloi sp. nov. (Diptera: Tachinidae) from Brazil, a Parasitoid of Xanthopastis timais (Lepidoptera: Noctuidae)

    PubMed Central

    Gil-Santana, Hélcio R.; Nihei, Silvio Shigueo; Nunez, Enio

    2014-01-01

    A new species of the New World genus Lespesia, Lespesia melloi sp. nov. (Diptera: Tachinidae), is described from southeastern Brazil. The species is reported here as a parasitoid of Xanthopastis timais (Cramer, 1782) (Lepidoptera: Noctuidae). The caterpillars of this noctuid feed on leaves and bulbs of amaryllis (Amaryllidaceae) in Brazil. PMID:25368065

  7. Biological control of the Mediterranean fruit fly in Israel: biological parameters of imported parasitoid wasps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three braconid species that parasitize the Mediterranean fruit fly (medfly), CERATITIS CAPITATA (Wiedemann) were recently imported into Israel. Several of their key biological parameters were studied. The longevities of the egg-attacking parasitoids FOPIUS ARISANUS and FOPIUS CERATITIVORUS, and t...

  8. Egg parasitoids attacking Cactoblastis Cactorum (Lepidoptera:Pyralidae) in north Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in the natural enemies of Cactoblastis cactorum (Berg) has increased since the moth was found in Florida in 1989. The way by which the moth first arrived in Florida is still uncertain. Previous surveys for natural enemies in Argentina identified egg parasitoids in the family Trichogrammat...

  9. Genetic characterization for intraspecific hybridization of an exotic parasitoid prior its introduction for classical biological control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The successful establishment of an exotic parasitoid in the context of classical biological control of insect pests depends upon its adaptability to the new environment. In theory, intraspecific hybridization may improve the success of the establishment as a result of an increase in the available ge...

  10. Aphids and parasitoids in wheat and nearby canola fields in central Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In central Oklahoma, winter canola has recently become the primary rotational winter crop with wheat. Annual aphid pest outbreaks in canola have resulted in widespread insecticide applications. Insect parasitoids, which frequently suppress aphids in nearby wheat, may move to canola due to the larg...

  11. Host suitability of a gregarious parasitoid on beetle hosts: flexibility between fitness of adult and offspring.

    PubMed

    Li, Li; Sun, Jianghua

    2011-04-19

    Behavioral tactics play a crucial role in the evolution of species and are likely to be found in host-parasitoid interactions where host quality may differ between host developmental stages. We investigated foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi in relation to two distinct host developmental stages: larvae and pupae. Two colonies of parasitoids were reared on larvae of Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Paired-choice and non-choice experiments were used to evaluate the preference and performance of S. harmandi on larvae and pupae of the two species. Foraging decisions and offspring fitness-related consequences of S. harmandi led to the selection of the most profitable host stage for parasitoid development. Adult females from the two colonies oviposited more quickly on pupae as compared to larvae of M. alternatus. Subsequently, their offspring development time was faster and they gained higher body weight on the pupal hosts. This study demonstrates optimal foraging of intraspecific détente that can occur during host-parasitoid interactions, of which the quality of the parasitism (highest fitness benefit and profitability) is related to the host developmental stage utilized. We conclude that S. harmandi is able to perfectly discriminate among host species or stages in a manner that maximizes its offspring fitness. The results indicated that foraging potential of adults may not be driven by its maternal effects, also induced flexibly with encountering prior host quality.

  12. Host-size mediated trade-off in a parasitoid Sclerodermus harmandi.

    PubMed

    Liu, Zhudong; Xu, Bingbing; Li, Li; Sun, Jianghua

    2011-01-01

    Optimality models of host-parasitoid relationships have traditionally assumed that host quality increases as a function of host size at parasitism. However, trade-offs may play a crucial role in species evolution and should be found in host-parasitoid interactions where the host quality may differ between different sizes. Here, we investigated the effects of host size differences of Monochamus alternatus larva on foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi. Two-choice and non-choice experiments were conducted with M. alternatus larvae to evaluate preference and performance of S. harmandi, respectively. Results from two-choice test showed that adult females prefer to attack large larvae rather than small larvae. In no-choice tests, adult females needed more time to paralyze large larvae than small larvae before laying eggs on the body surface of M. alternatus larvae and had lower survival and parasitism rate on those large larvae. Foraging decisions of S. harmandi led to the selection of the most profitable host size for parasitoid development, which showed more offspring gained on large M. alternatus larvae than on small larvae and got higher body weight on those large hosts. This study demonstrates the existence of trade-off occurring during host-parasitoids interactions according to host size related quality.

  13. A native and an introduced parasitoid utilize an exotic gall-maker host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dryocosmus kuriphilus (Hymenoptera: Cynipidae) is non-native to North America and induces formation of galls on petioles and leaves of all chestnut (Castanea spp., Fagales: Fagaceae). We investigated the interactions between the gall wasp D. kuriphilus, a native parasitoid, Ormyrus labotus (Hymenopt...

  14. Bioecology of Stenoma catenifer (Lepidoptera: Elachistidae) and associated larval parasitoids reared from Hass avocados in Guatemala.

    PubMed

    Hoddle, Mark S; Hoddle, Christina D

    2008-06-01

    A 10-wk study of the avocado seed-feeding moth Stenoma catenifer Walsingham (Lepidoptera: Elachistidae), was conducted in a commercial 'Hass' avocado (Persea americana Miller [Lauraceae]) orchard in Guatemala. Up to 45% of fruit in the orchard were damaged by larval S. catenifer. Larval-to-adult survivorship for 1,881 S. catenifer larvae in Hass fruit was 37%, and adult sex ratio was 51% female. Four species of larval parasitoid were reared from field-collected S. catenifer larvae. The most common parasitoid reared was a gregarious Apanteles sp., which parasitized 53% of larvae and produced on average eight to nine cocoons per host. Apanteles sp. sex ratio was 47% female and 87% of parasitoids emerged successfully from cocoons. Apanteles sp. longevity was approximately equal to 1.5 d in the absence of food, and when provisioned with honey, parasitoids survived for 5-7 d. The mean number of cocoons produced by Apanteles sp. per host, and larval parasitism rates were not significantly affected by the number of S. catenifer larvae inhabiting seeds. Oviposition studies conducted with S. catenifer in the laboratory indicated that this moth lays significantly more eggs on the branch to which the fruit pedicel is attached than on avocado fruit. When given a choice between Hass and non-Hass avocados, S. catenifer lays up to 2.69 times more eggs on Hass.

  15. Flowering plant effects on adults of the stink bug parasitoid Aridelus rufotestaceus (Hymenoptera: Braconidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many parasitoids require food resources, such as nectar and pollen, besides hosts in order to optimize their life histories. This has led to interest in using these resources in pest management. Here we assess the potential effects of two floral plants, Fagopyrum esculentum and Gaillardia pulchella ...

  16. The relationship between variable host grouping and functional response among parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our study investigated the patterns of attack by hymenopteran parasitoids in the Tupelo leafminer, Antispila nysaefoliella Clemens, to understand the selective pressures that shape host group size and timing of emergence. A large sample of host larvae was collected from a natural field population of...

  17. Innate and Learned Olfactory Responses in a Wild Population of the Egg Parasitoid Trichogramma (Hymenoptera: Trichogrammatidae).

    PubMed

    Wilson, J Keaton; Woods, H Arthur

    2016-01-01

    Parasitoid insects face the fundamental problem of finding a suitable host in environments filled with competing stimuli. Many are deft sensors of olfactory cues emitted by other insects and the plants they live on, and use these cues to find hosts. Using olfactory cues from host-plants is effective because plants release volatile organic compounds (VOCs), in response to herbivory or oviposition, that contain information about the presence of hosts. However, plant-produced cues can also be misleading because they are influenced by a variety of stimuli (abiotic variation, infection and multiple sources of induction via herbivory or oviposition). Flexible behavior is one strategy that parasitoids may use to cope with variation in olfactory cues. We examine the innate and learned responses of a natural population of wasp egg parasitoids (Trichogramma deion and Trichogramma sathon) using a series of laboratory and field Y-olfactometer experiments. Wasps typically attack eggs of the hawkmoth Manduca sexta and Manduca quinquemaculata on native Datura wrightii plants in the southwestern United States. We show that Trichogramma wasps responded innately to VOCs produced by D. wrightii and could distinguish plants recently attacked by M. sexta from non-attacked plants. Furthermore, adult Trichogramma wasps were able to learn components of the VOC blend given off by D. wrightii, though they did not learn during exposure as pupae. By further exploring the behavioral ecology of a natural population of Trichogramma, we gain greater insight into how egg parasitoids function in tri-trophic systems.

  18. Field assessment of three introduced parasitoids of Paracoccus marginatus (Hemiptera: Pseudococcidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract: Field assessment of the ability of three introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes, and Pseudleptomastix mexicana Noyes and Schauff) to control Paracoccus marginatus Williams and Granara de Willink was investigated in 2005 and 2006 in three locat...

  19. Efficiency and establishment of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study on the efficiency and establishment of three previously introduced parasitoids (Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana) to control the mealybug Paracoccus marginatus was made in 2005 and 2006, at three locations in Homestead (Miami-Dade County), Florida. In each ...

  20. Analysis of Genetic Variation across the Encapsidated Genome of Microplitis demolitor Bracovirus in Parasitoid Wasps

    PubMed Central

    Burke, Gaelen R.

    2016-01-01

    Insect parasitoids must complete part of their life cycle within or on another insect, ultimately resulting in the death of the host insect. One group of parasitoid wasps, the ‘microgastroid complex’ (Hymenoptera: Braconidae), engage in an association with beneficial symbiotic viruses that are essential for successful parasitism of hosts. These viruses, known as Bracoviruses, persist in an integrated form in the wasp genome, and activate to replicate in wasp ovaries during development to ultimately be delivered into host insects during parasitism. The lethal nature of host-parasitoid interactions, combined with the involvement of viruses in mediating these interactions, has led to the hypothesis that Bracoviruses are engaged in an arms race with hosts, resulting in recurrent adaptation in viral (and host) genes. Deep sequencing was employed to characterize sequence variation across the encapsidated Bracovirus genome within laboratory and field populations of the parasitoid wasp species Microplitis demolitor. Contrary to expectations, there was a paucity of evidence for positive directional selection among virulence genes, which generally exhibited signatures of purifying selection. These data suggest that the dynamics of host-parasite interactions may not result in recurrent rounds of adaptation, and that adaptation may be more variable in time than previously expected. PMID:27390861

  1. Mass-rearing parasitoids for support of classical and augmentative biological control programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three systems for production of Bemisia parasitoids in the genera Eretmocerus and Encarsia are described: a smaller scale system for initial production and evaluation of the numerous cultures collected during the foreign exploration effort and two systems for larger scale production to support augme...

  2. Chemical cues from the coffee berry borer influence the locomotory behaviour of its bethylid parasitoids.

    PubMed

    Chiu-Alvarado, P; Valle-Mora, J; Rojas, J C

    2010-12-01

    Cephalonomia stephanoderis and Prorops nasuta are two bethylid wasps released into several Latin American countries for classical biological control of coffee berry borer, Hypothenemus hampei, the most serious insect pest of coffee worldwide. Recent studies on the host location behaviour of these parasitoids have shown that females of both species are attracted to volatile compounds released by immature stages and dust and frass of H. hampei. In this study, we investigated the role of the contact chemicals present in dust and frass of H. hampei on the behaviour of P. nasuta and C. stephanoderis females. Parasitoids remained longer on patches treated with methanol extracts than on acetone and hexane extracts. Females spent more time on the patch treated with the methanol extract of dust and frass than on the patches treated with the methanol extract of dry coffee and methanol control. The concentration of the methanol extracts from dust and frass influenced the locomotory activity of parasitoids of both species. The time that females spent in the patch tended to increase as the concentration of the methanol extracts increased. A further experiment aimed to identify other behavioural descriptors and gain a deeper understanding of the mechanisms underlying the response of parasitoids to methanol extracts was performed. Females of both species spent more time, covered more distance, turned more (per unit time and per unit distance), and decreased their speed when they contacted patches treated with methanol extracts in comparison to patches treated with methanol control.

  3. Host-Size Mediated Trade-Off in a Parasitoid Sclerodermus harmandi

    PubMed Central

    Liu, Zhudong; Xu, Bingbing; Li, Li; Sun, Jianghua

    2011-01-01

    Optimality models of host-parasitoid relationships have traditionally assumed that host quality increases as a function of host size at parasitism. However, trade-offs may play a crucial role in species evolution and should be found in host-parasitoid interactions where the host quality may differ between different sizes. Here, we investigated the effects of host size differences of Monochamus alternatus larva on foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi. Two-choice and non-choice experiments were conducted with M. alternatus larvae to evaluate preference and performance of S. harmandi, respectively. Results from two-choice test showed that adult females prefer to attack large larvae rather than small larvae. In no-choice tests, adult females needed more time to paralyze large larvae than small larvae before laying eggs on the body surface of M. alternatus larvae and had lower survival and parasitism rate on those large larvae. Foraging decisions of S. harmandi led to the selection of the most profitable host size for parasitoid development, which showed more offspring gained on large M. alternatus larvae than on small larvae and got higher body weight on those large hosts. This study demonstrates the existence of trade-off occurring during host-parasitoids interactions according to host size related quality. PMID:21853096

  4. Host Suitability of a Gregarious Parasitoid on Beetle Hosts: Flexibility between Fitness of Adult and Offspring

    PubMed Central

    Li, Li; Sun, Jianghua

    2011-01-01

    Behavioral tactics play a crucial role in the evolution of species and are likely to be found in host-parasitoid interactions where host quality may differ between host developmental stages. We investigated foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi in relation to two distinct host developmental stages: larvae and pupae. Two colonies of parasitoids were reared on larvae of Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Paired-choice and non-choice experiments were used to evaluate the preference and performance of S. harmandi on larvae and pupae of the two species. Foraging decisions and offspring fitness-related consequences of S. harmandi led to the selection of the most profitable host stage for parasitoid development. Adult females from the two colonies oviposited more quickly on pupae as compared to larvae of M. alternatus. Subsequently, their offspring development time was faster and they gained higher body weight on the pupal hosts. This study demonstrates optimal foraging of intraspecific détente that can occur during host-parasitoid interactions, of which the quality of the parasitism (highest fitness benefit and profitability) is related to the host developmental stage utilized. We conclude that S. harmandi is able to perfectly discriminate among host species or stages in a manner that maximizes its offspring fitness. The results indicated that foraging potential of adults may not be driven by its maternal effects, also induced flexibly with encountering prior host quality. PMID:21526176

  5. Molecular genetics of the Wolbachia endosymbionts that infect the parasitoids of tephritid fruit flies.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited information exists on the molecular genetics of the Wolbachia endosymbionts that infect the parasitoids of tephritid fruit flies. A better understanding of the bacteria could allow sex ratio manipulations that would improve the mass-rearing of natural enemies. Scientists at the Center for Me...

  6. Use of pupal parasitoids as biological control agents of filth flies on equine facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), are common pests on horse farms. The use of pupal parasitoids as biological control agents for filth flies is becoming more popular on equine facilities; however, there is a lack of information on the e...

  7. Mass-rearing Bemisia parasitoids for support of classical and augmentative biological control programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of efficient mass-rearing systems for Bemisia parasitoids was crucial for the implementation of the classical and augmentative biological control programs for this exotic pest. Early work relied on adapting methods for the production of Encarsia formosa (Gahan) for the greenhouse whi...

  8. Innate and Learned Olfactory Responses in a Wild Population of the Egg Parasitoid Trichogramma (Hymenoptera: Trichogrammatidae)

    PubMed Central

    Wilson, J. Keaton; Woods, H. Arthur

    2016-01-01

    Parasitoid insects face the fundamental problem of finding a suitable host in environments filled with competing stimuli. Many are deft sensors of olfactory cues emitted by other insects and the plants they live on, and use these cues to find hosts. Using olfactory cues from host-plants is effective because plants release volatile organic compounds (VOCs), in response to herbivory or oviposition, that contain information about the presence of hosts. However, plant-produced cues can also be misleading because they are influenced by a variety of stimuli (abiotic variation, infection and multiple sources of induction via herbivory or oviposition). Flexible behavior is one strategy that parasitoids may use to cope with variation in olfactory cues. We examine the innate and learned responses of a natural population of wasp egg parasitoids (Trichogramma deion and Trichogramma sathon) using a series of laboratory and field Y-olfactometer experiments. Wasps typically attack eggs of the hawkmoth Manduca sexta and Manduca quinquemaculata on native Datura wrightii plants in the southwestern United States. We show that Trichogramma wasps responded innately to VOCs produced by D. wrightii and could distinguish plants recently attacked by M. sexta from non-attacked plants. Furthermore, adult Trichogramma wasps were able to learn components of the VOC blend given off by D. wrightii, though they did not learn during exposure as pupae. By further exploring the behavioral ecology of a natural population of Trichogramma, we gain greater insight into how egg parasitoids function in tri-trophic systems. PMID:27965403

  9. The roles of parasitoid foraging for hosts, food and mates in the augmentative control of Tephritidae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ultimately, the success of augmentative fruit fly biological control depends upon the survival, dispersal, attack rate and multi-generational persistence of mass-reared parasitoids in the field. Foraging for hosts, food and mates is fundamental to the above and, at an operational level, to the choic...

  10. Indoor acoustic gain design

    NASA Astrophysics Data System (ADS)

    Concha-Abarca, Justo Andres

    2002-11-01

    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  11. Rising temperature reduces divergence in resource use strategies in coexisting parasitoid species.

    PubMed

    Le Lann, Cécile; Visser, Bertanne; Mériaux, Maëlle; Moiroux, Joffrey; van Baaren, Joan; van Alphen, Jacques J M; Ellers, Jacintha

    2014-03-01

    Coexistence of species sharing the same resources is often possible if species are phylogenetically divergent in resource acquisition and allocation traits, decreasing competition between them. Developmental and life-history traits related to resource use are influenced by environmental conditions such as temperature, but thermal trait responses may differ among species. An increase in ambient temperature may, therefore, affect trait divergence within a community, and potentially species coexistence. Parasitoids are interesting models to test this hypothesis, because multiple species commonly attack the same host, and employ divergent larval and adult host use strategies. In particular, development mode (arrested or continued host growth following parasitism) has been recognized as a major organiser of parasitoid life histories. Here, we used a comparative trait-based approach to determine thermal responses of development time, body mass, egg load, metabolic rate and energy use of the coexisting Drosophila parasitoids Asobara tabida, Leptopilina heterotoma, Trichopria drosophilae and Spalangia erythromera. We compared trait values between species and development modes, and calculated trait divergence in response to temperature, using functional diversity indices. Parasitoids differed in their thermal response for dry mass, metabolic rate and lipid use throughout adult life, but only teneral lipid reserves and egg load were affected by developmental mode. Species-specific trait responses to temperature were probably determined by their adaptations in resource use (e.g. lipogenesis or ectoparasitism). Overall, trait values of parasitoid species converged at the higher temperature. Our results suggest that local effects of warming could affect host resource partitioning by reducing trait diversity in communities.

  12. Short- and long-range cues used by ground-dwelling parasitoids to find their host

    NASA Astrophysics Data System (ADS)

    Goubert, C.; Josso, C.; Louâpre, P.; Cortesero, A. M.; Poinsot, D.

    2013-02-01

    Parasitoids of phytophagous insects face a detectability-reliability dilemma when foraging for hosts. Plant-related cues are easily detectable, but do not guarantee the presence of the host. Host-related cues are very reliable, but much harder to detect from a distance. Little is known in particular about the way coleopteran parasitoid females use these cues when foraging for a suitable place to lay their eggs. The question is of interest because, unlike hymenopteran larvae, coleopteran parasitoid larvae are highly mobile and able to forage for hosts on their own. We assessed whether females of the parasitoid rove beetle Aleochara bipustulata (L.) (Coleoptera: Staphylinidae) are attracted to plant (Swede roots, Brassica napus) and host-related cues [pupae of the cabbage root fly Delia radicum (L.) (Diptera: Anthomyiidae)]. In the field, A. bipustulata adult females were captured in selective pitfall traps containing pieces of roots damaged by D. radicum larvae, but not in traps containing pieces of healthy roots or D. radicum pupae. However, in the laboratory, the odour of D. radicum pupae attracted A. bipustulata females to mini-pitfalls. Video monitoring in the laboratory showed that foraging A. bipustulata females preferred a zone containing D. radicum pupae and larval tracks rather than one containing an extract of D. radicum-infested roots. Our results suggest a behavioural sequence where A. bipustulata females use plant-related cues at a distance, but then switch their preference to host-related cues at a close range. This would be the first observation of this behaviour in coleopteran parasitoids.

  13. Low dimensional homeochaos in coevolving host-parasitoid dimorphic populations: Extinction thresholds under local noise

    NASA Astrophysics Data System (ADS)

    Sardanyés, Josep

    2011-10-01

    A discrete time model describing the population dynamics of coevolution between host and parasitoid haploid populations with a dimorphic matching allele coupling is investigated under both determinism and stochastic population disturbances. The role of the properties of the attractors governing the survival of both populations is analyzed considering equal mutation rates and focusing on host and parasitoid growth rates involving chaos. The purely deterministic model reveals a wide range of ordered and chaotic Red Queen dynamics causing cyclic and aperiodic fluctuations of haplotypes within each species. A Ruelle-Takens-Newhouse route to chaos is identified by increasing both host and parasitoid growth rates. From the bifurcation diagram structure and from numerical stability analysis, two different types of chaotic sets are roughly differentiated according to their size in phase space and to their largest Lyapunov exponent: the Confined and Expanded attractors. Under the presence of local population noise, these two types of attractors have a crucial role in the survival of both coevolving populations. The chaotic confined attractors, which have a low largest positive Lyapunov exponent, are shown to involve a very low extinction probability under the influence of local population noise. On the contrary, the expanded chaotic sets (with a higher largest positive Lyapunov exponent) involve higher host and parasitoid extinction probabilities under the presence of noise. The asynchronies between haplotypes in the chaotic regime combined with low dimensional homeochaos tied to the confined attractors is suggested to reinforce the long-term persistence of these coevolving populations under the influence of stochastic disturbances. These ideas are also discussed in the framework of spatially-distributed host-parasitoid populations.

  14. Side-Effects of Glyphosate to the Parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae).

    PubMed

    Stecca, C S; Bueno, A F; Pasini, A; Silva, D M; Andrade, K; Filho, D M Z

    2016-04-01

    The aim of this study was to compare the side-effects of glyphosate to the parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae) when parasitoids were exposed to this chemical at the pupal (inside host eggs) and adult stages. Bioassays were conducted under laboratory conditions according to the International Organization for Biological Control (IOBC) standard methods for testing side-effects of pesticides to egg parasitoids. Different glyphosate-based pesticides (Roundup Original®, Roundup Ready®, Roundup Transorb®, Roundup WG®, and Zapp Qi®) were tested at the same acid equivalent concentration. Treatments were classified following the IOBC toxicity categories as (1) harmless, (2) slightly harmful, (3) moderately harmful, and (4) harmful. When tested against T. remus adults, Roundup Original®, Roundup Ready®, Roundup Transorb®, and Roundup WG® reduced parasitism 2 days after parasitoid emergence, being classified as slightly harmful. Differently, when tested against T. remus pupae, all tested glyphosate-based products did not differ in their lethal effect and therefore did not reduce T. remus adult emergence or parasitism capacity, being classified as harmless. However, differences on sublethal toxicity were found. Parasitism of individuals emerging from parasitized eggs sprayed at the pupal stage of T. remus with Zapp Qi® was lower compared to control, but parasitism was still higher than 66%, and therefore, Zapp Qi® was still classified as harmless. In conclusion, all tested glyphosate-based products can be used in agriculture without negative impact to T. remus as none was classified as harmful or moderately harmful to this parasitoid when exposure occurred at the pupal or adult stages.

  15. [Quality of different aphids as hosts of the parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae)].

    PubMed

    Silva, Robson J; Bueno, Vanda H P; Sampaio, Marcus V

    2008-01-01

    Lysiphlebus testaceipes (Cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. This study aimed to evaluate the quality of three Macrosiphini, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer), and three Aphidini Schizaphis graminum (Rondani) Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover as hosts to L. testaceipes and to determine the relation possible of host preference, of size and quality of the host. The tests were carried out in climatic chamber at 25 +/- 1 degrees C, RH 70 +/- 10% and 12h photophase. The parasitoid did not oviposite in B. brassicae and L. erysimi, while the other species were nutritionally suitable to the parasitoid. L. testaceipes showed preference for aphids from tribe Aphidini and these hosts presented better quality to the parasitoid when compared to Macrosiphini. Interactions among size, preference and quality between the Aphidini were found. L testaceipes showed preference (parasitism rate 76.7%) for R. maidis, the bigger host (hind tibia with 0.281 mm). This host provided bigger size (hind tibia with 0.49 mm) and higher emergence rate (95.6%) to the parasitoid when compared to A. gossypii (parasitism rate of 55.7%). Also the smaller host A. gossypii (0.266 mm) provided smaller size hind tibia (0.45 mm) and higher mortality of the parasitoid (emergence rate 72.1%). However, the development time was shorter and the longevity was higher in A. gossypii (6.3 and 5.4 days, respectively) when compared to the host R. maidis (6.7 and 3.8 days, respectively), and not been related to host size.

  16. To be in time: egg deposition enhances plant-mediated detection of young caterpillars by parasitoids.

    PubMed

    Pashalidou, Foteini G; Gols, Rieta; Berkhout, Boris W; Weldegergis, Berhane T; van Loon, Joop J A; Dicke, Marcel; Fatouros, Nina E

    2015-02-01

    Animals use information from their environment while foraging for food or prey. When parasitic wasps forage for hosts, they use plant volatiles induced by herbivore activities such as feeding and oviposition. Little information is available on how wasps exploit specific plant volatiles over time, and which compounds indicate changes in host quality. In experiments investigating the role of herbivore-induced plant volatiles in wasp foraging, induction of plant response is usually achieved by placing larvae on clean plants instead of allowing the natural sequence of events: to let eggs deposited by the herbivore develop into larvae. We compared the attraction of the parasitoid Cotesia glomerata to volatiles emitted by black mustard (Brassica nigra) plants induced by eggs and successive larval stages of the Large Cabbage White butterfly (Pieris brassicae) to the attraction of this parasitoid to black mustard plant volatiles induced only by larval feeding in a wind tunnel setup. We show that wasps are attracted to plants infested with eggs just before and shortly after larval hatching. However, wasp preference changed at later time points towards plants induced only by larval feeding. These temporal changes in parasitoid attraction matched with changes in the chemical compositions of the blends of plant volatiles. Previous studies have shown that host quality/suitability decreases with caterpillar age and that P. brassicae oviposition induces plant defences that negatively affect subsequently feeding caterpillars. We investigated parasitoid performance in hosts of different ages. Wasp performance was positively correlated with preference. Moreover, parasitism success decreased with time and host stage. In conclusion, the behaviour of Cotesia glomerata is fine-tuned to exploit volatiles induced by eggs and early host stages that benefit parasitoid fitness.

  17. Toxicity of chemicals commonly used in Indonesian vegetable crops to Liriomyza huidobrensis populations and the Indonesian parasitoids Hemiptarsenus varicornis, Opius sp., and Gronotoma micromorpha, as well as the Australian parasitoids Hemiptarsenus varicornis and Diglyphus isaea.

    PubMed

    Prijono, Djoko; Robinson, Michelle; Rauf, Aunu; Bjorksten, Tracey; Hoffmann, Ary A

    2004-08-01

    Liriomyza huidobrensis (Blanchard) and Liriomyza sativae (Blanchard) are important pests of vegetable crops in Indonesia and are likely to spread to neighboring countries. Three pesticides (dimehypo, abamectin, and cyromazine) are currently used to control these pests, but there is little information on their effectiveness against field populations and on their impact on parasitoids controlling Liriomyza species. The toxicity of these chemicals to L. huidobrensis and three common parasitoids (Hemiptarsenus varicornis Gerault, Opius sp., and Gronotoma micromorpha Perkins) was therefore evaluated in Indonesia with mortality laboratory assays. All three chemicals were effective against larvae of three populations of L. huidobrensis with different histories of chemical exposure. Dimehypo caused mortality in adult Opius sp., G. micromorpha, and H. varicornis, whereas abamectin was toxic only at concentrations substantially higher than the field rate. Cyromazine did not influence survival of the parasitoids. A commonly used fungicide, mancozeb, had no impact on parasitoid mortality. Trials were repeated with a strain of H. varicornis from Australia and a different parasitoid (Diglyphus isaea) recently found in Australia. Neither parasitoid was influenced by mancozeb or cyromazine. Abamectin applied at field rates caused some mortality among the adults of both species, but was less toxic than chlorpyrifos. Abamectin produced lower LC50s against Australian H. varicornis than against Indonesian H. varicornis. These results suggest that cyromazine can be incorporated into Liriomyza control programs in Indonesia that conserve parasitoids, whereas dimehypo and abamectin need to be used cautiously. Local Australian parasitoids should help control L. huidobrensis as long as only cyromazine and nontoxic fungicides are applied.

  18. Reproductive and developmental biology of the emerald ash borer parasitoid Spathius galinae (Hymenoptera: Braconidae) as affected by temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive pest of serious concern in North America. To complement ongoing biological control efforts, Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a recently-described specialist parasitoid of ...

  19. Description of a new genus and species of Eucoilinae (Hymenoptera: Cynipoidea:Figitidae) parasitoid of Ephydridae (Diptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrelliaeucoila egeria, a new genus and species obtained from pupae of Hydrellia sp. nov. (Diptera: Ephydridae) mining in Egeria densa Planchon (Hydrocharitaceae), is described. Diagnostic photographs and data about the biology of this parasitoid are included. ...

  20. First host record for Anteon pilicorne (Ogloblin) (Hymenoptera: Dryinidae), a parasitoid of Cicadellidae, including the corn leafhopper (Hemiptera: Cicadellidae).

    PubMed

    Virla, E G; Espinosa, M S; Moya-Raygoza, G

    2011-01-01

    For the first time the dryinid wasp Anteon pilicorne (Ogloblin) is recorded as a parasitoid of two Macrostelini leafhoppers: Balclutha rosea (Scott) and the corn leafhopper Dalbulus maidis (DeLong & Wolcott). New distributional records are presented.

  1. Strongygaster triangulifera (Diptera: Tachinidae) as a parasitoid of adults of the invasive Megacopta cribraria (Heteroptera: Plataspidae) in Alabama

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strongygaster triangulifera (Loew) (Diptera:Tachinidae) is reported for the first time as a parasitoid of Megacopta cribraria (Fabricius) (Heteroptera: Plataspidae), the kudzu bug, an introduced pest of soybeans and other legume crops in the southeastern U.S....

  2. Developmental time, longevity, and lifetime fertility of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudoccidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Developmental time, longevity, and lifetime fertility of three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff) (Hymenoptera: Encyrtidae) of the mealybug Paracoccus marginatus Williams and Gr...

  3. Biology, host instar suitability and susceptibility, and interspecific competition of three introduced parasitoids of Paracoccus marginatus (Hemiptera: Pseudococcidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biology, host stage suitability and susceptibility, and interspecific competition of three previously introduced parasitoids (Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana) (Hymenoptera: Encyrtidae) of Paracoccus marginatus were studied in the laboratory. Compared to P. mexica...

  4. Effects of soybean resistance on variability in life history traits of the higher trophic level parasitoid Meteorus pulchricornis (Hymenoptera: Braconidae).

    PubMed

    Li, X; Li, B; Xing, G; Meng, L

    2017-02-01

    To extrapolate the influence of plant cultivars varying in resistance levels to hosts on parasitoid life history traits, we estimated variation in parasitoid developmental and reproductive performances as a function of resistance in soybean cultivars, which were randomly chosen from a line of resistant genotypes. Our study showed that the parasitoid Meteorus pulchricornis varied widely in offspring survival and lifetime fecundity, but varied slightly in development time and adult body size, in response to the soybean cultivars that varied in resistance to the host Spodoptera litura. Furthermore, the variability in survival and lifetime fecundity was different between attacking the 2nd and the 4th instar host larvae, varying more in survival but less in lifetime fecundity when attacking the 4th than 2nd instar larvae. Our study provides further evidence supporting that plant resistance to herbivorous hosts have variable effects on different life history traits of higher trophic level parasitoids.

  5. Age-specific interaction between the parasitoid, Encarsia formosa and its host, the silverleaf whitefly, Bemisia tabaci (Strain B)

    PubMed Central

    Hu, Jing S.; Gelman, Dale B.; Blackburn, Michael B.

    2003-01-01

    The effect of hostage, the instar of Bemisia tabaci (Gennadius) parasitized, on the growth and development of Encarsia formosa (Gahan) was studied. E. formosa was able to parasitize and complete its life cycle no matter which instar of B. tabaci (Strain B), [also identified as B. argentifolii (Bellows and Perring)], was provided for oviposition, but parasitoid development was significantly slower when 1st or 2nd instar B. tabaci rather than 3rd or 4th instars were parasitized. Host age influenced the day on which E. formosa nymphs hatching from eggs was first observed. Mean embryonic development was significantly longer when 1st (5.4 days) rather than 2nd, 3rd or 4th instars (4.1, 3.4 and 3.5 days, respectively) were parasitized. The duration of the 1st instar parasitoid and the pupa, but not the 2nd or 3rd instar parasitoid, were also significantly greater when 1st instars were parasitized than when older host instars were parasitized. Interestingly, no matter which instar was parasitized, the parasitoid did not molt to the 3rd instar until the 4th instar host had reached a depth of about 0.23 mm (Stage 4–5) and had initiated the nymphal-adult molt and adult development. Histological studies revealed that whitefly eye and wing structures had either disintegrated or were adult in nature whenever a 3rd instar parasitoid was present. It appears, then, that the molt of the parasitoid to its last instar is associated with the host whitefly's nymphal-adult molt. However, the initiation of the host's final molt, while a prerequisite for the parasitoid's 2nd–3rd instar molt, did not necessarily trigger this molt. In contrast to its significant effect on various aspects of parasitoid development, host instar did not significantly influence the mean size of the parasitoid larva, pupa, or adult. Larval and pupal length and adult head width were similar for all parasitoids, regardless of which host instar was parasitized as was adult longevity. Adult parasitoid emergence

  6. Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae)

    PubMed Central

    Feng, Yi; Wratten, Steve; Sandhu, Harpinder; Keller, Michael

    2015-01-01

    The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions among habitats. PMID

  7. Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae).

    PubMed

    Feng, Yi; Wratten, Steve; Sandhu, Harpinder; Keller, Michael

    2015-01-01

    The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions among habitats.

  8. Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host–parasitoid food chain

    PubMed Central

    Moser, Andrea; van Veen, F. J. Frank

    2016-01-01

    Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host–parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition of host tissue and the consumer's resource requirements, which would allow for longer food chains. We measured efficiency of biomass transfer along an aphid-primary–secondary–tertiary parasitoid food chain and used stable isotope analysis to confirm trophic levels. We show high efficiency in biomass transfer along the food chain. From the third to the fourth trophic level, the proportion of host biomass transferred was 45%, 65% and 73%, respectively, for three secondary parasitoid species. For two parasitoid species that can act at the fourth and fifth trophic levels, we show markedly increased trophic assimilation efficiencies at the higher trophic level, which increased from 45 to 63% and 73 to 93%, respectively. In common with other food chains, δ15N increased with trophic level, with trophic discrimination factors (Δ15N) 1.34 and 1.49‰ from primary parasitoids to endoparasitic and ectoparasitic secondary parasitoids, respectively, and 0.78‰ from secondary to tertiary parasitoids. Owing to the extraordinarily high efficiency of hyperparasitoids, cryptic higher trophic levels may exist in host–parasitoid communities, which could alter our understanding of the dynamics and drivers of community structure of these important systems. PMID:26962141

  9. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  10. Seasonal and regional presence of hymenopteran parasitoids of Drosophila in Switzerland and their ability to parasitize the invasive Drosophila suzukii

    PubMed Central

    Knoll, Valery; Ellenbroek, Thomas; Romeis, Jörg; Collatz, Jana

    2017-01-01

    Since its introduction into Europe the invasive Drosophila suzukii has established and spread widely, thereby entering habitats populated by native Drosophila species and their natural enemies. The highly prolific D. suzukii will likely interact with these species as a competitor, host or prey. To investigate potential interactions of D. suzukii with parasitoids, a field survey was conducted across several fruit-growing regions in Switzerland in two consecutive years. Eight species of hymenopteran parasitoids were collected using D. melanogaster as sentinel hosts in field-traps. Parasitoid capture was much higher in 2015 than in 2014 and varied among regions, time of the growing season, and habitat type. Laboratory no-choice assays with the field-collected species demonstrated that the larval parasitoids Asobara tabida, Leptopilina boulardi, and L. heterotoma could not use D. suzukii for reproduction, although the latter two reduced the number of emerging D. suzukii. In contrast, the pupal parasitoids Pachycrepoideus vindemmiae, Trichopria drosophilae, Vrestovia fidenas and Spalangia erythromera all developed with D. suzukii as hosts. Regional differences between strains were generally not evident, with the exception of two T. drosophilae strains that differed in parasitization rate. Thus, native parasitoids may interact with D. suzukii and should be regarded when implementing pest control measures. PMID:28098183

  11. The native ant, Tapinoma melanocephalum, improves the survival of an invasive mealybug, Phenacoccus solenopsis, by defending it from parasitoids

    PubMed Central

    Feng, Dong-Dong; Michaud, J.P.; Li, Pan; Zhou, Zhong-Shi; Xu, Zai-Fu

    2015-01-01

    Mutualistic ants can protect their partners from natural enemies in nature. Aenasius bambawalei is an important parasitoid of the the invasive mealybug Phenacoccus solenopsis. We hypothesized that mutualism between native ants and mealybugs would favor survival of mealybugs. To test this, we examined effects of tending by the native mutualistic ant Tapinoma melanocephalum on growth of P. solenopsis colonies on Chinese hibiscus, Hibiscus rosa-sinensis, in a field setting. Ant workers with access to honeydew of mealybugs lived much longer than those provisioned only with water in the laboratory, and number of ant workers foraging increased significantly with growth of mealybug colonies in the field. In later observations, there were significant differences in densities of mealybugs between ant-tended and -excluded treatments. Survival rate of mealybugs experiencing parasitoid attack was significantly higher on ant-tended plants than on ant-excluded plants. When the parasitoid was excluded, there was no difference in survival rate of mealybugs between ant-tended and -excluded plants. In most cases, ants directly attacked the parasitoid, causing the parasitoid to take evasive action. We conclude that native ants such as T. melanocephalum have the potential to facilitate invasion and spread of P. solenopsis in China by providing them with protection from parasitoids. PMID:26503138

  12. Evaluation of the community of native eulophid parasitoids on Cameraria ohridella Deschka and Dimic in urban areas.

    PubMed

    Ferracini, Chiara; Alma, Alberto

    2007-10-01

    The parasitoid complex associated with the exotic leafminer Cameraria ohridella Deschka and Dimic (Lepidoptera: Gracillariidae), which attacks horse chestnut (Aesculus hippocastanum L.), was studied in the urban environment of Turin (northern Italy). The studies were carried out over 5 yr after the first detection of the pest in our region in 1999. To evaluate parasitism, 438,029 leaf mines were examined over the 5-yr period, of which 29,033 were found to be parasitized (6.6%). Also, ornamental broadleaf trees attacked by other native gracillariid leafminers and located in the proximity of the target horse chestnut trees were sampled. A total of 11 parasitoid species (Hymenoptera: Eulophidae) were recorded on C. ohridella, and the most common species were Minotetrastichus frontalis (Nees), Closterocerus trifasciatus Westwood, and Pnigalio agraules (Walker). The first species accounted for >77.5% of all parasitoids collected. Cirrospilus talitzkii Boucek was found for the first time in 2005. The high population level of the pest and the low parasitism rate show that the parasitoid complex is currently inadequate to contain C. ohridella populations effectively. The most frequent parasitoids of the moth were also found on the most common broadleaf trees in the studied area, showing how native leafminer parasitoid species are able to switch to other hosts. These results show that both native and broadleaf plants species may potentially provide an important reservoir of parasitic wasps to help protect a simple biotope, such as the urban environment, from pests.

  13. Larval hitch-hiking and adult flight are two ways of aphidiinae parasitoids long-range dispersal.

    PubMed

    Derocles, Stéphane A P; Plantegenest, Manuel; Ait-Ighil E, Evelyne Turpeau; Chaubet, Bernard; Dedryver, Charles-Antoine; Le Ralec, Anne

    2014-10-01

    Dispersal strategies and success of pests' natural enemies widely influence the efficiency of biological control. In this study, we compare two dispersal strategies among Aphidiinae parasitoids: eggs and larvae dispersal through winged aphid flight and active dispersal by adult parasitoids. Using a molecular method applied to a sample of >2,000 winged migratory aphids captured in a suction trap situated in Western France, we assessed the proportion of winged aphids carrying an aphidiine larva. In the six most abundant aphid species, we found an average parasitism rate of migrating aphids close to 1% and identified seven different, mainly generalist, parasitoid species. We also identified the species and the sex of adult Aphidiinae captured by the suction trap based on morphological criteria. We found that dispersing adult parasitoids were almost exclusively female. Parasitoid dispersal strategy seems to be species-dependant but this result needs to be confirmed by an exhaustive analysis of winged aphids captured. We discuss the possible impact of the low parasitism rate of winged aphids on parasitoid population dynamics and the importance of these results in the context of biological control and of the study of food webs between aphids and their natural enemies.

  14. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  15. Tri-trophic effects of seasonally variable induced plant defenses vary across the development of a shelter building moth larva and its parasitoid.

    PubMed

    Rose, Noah H; Halitschke, Rayko; Morse, Douglass H

    2015-01-01

    Plant chemical defenses can negatively affect insect herbivore fitness, but they can also decrease herbivore palatability to predators or decrease parasitoid fitness, potentially changing selective pressures on both plant investment in production of chemical defenses and host feeding behavior. Larvae of the fern moth Herpetogramma theseusalis live in and feed upon leaf shelters of their own construction, and their most abundant parasitoid Alabagrus texanus oviposits in early instar larvae, where parasitoid larvae lay dormant for most of host development before rapidly developing and emerging just prior to host pupation. As such, both might be expected to live in a relatively constant chemical environment. Instead, we find that a correlated set of phenolic compounds shows strong seasonal variation both within shelters and in undamaged fern tissue, and the relative level of these compounds in these two different fern tissue types switches across the summer. Using experimental feeding treatments, in which we exposed fern moth larvae to different chemical trajectories across their development, we show that exposure to this set of phenolic compounds reduces the survival of larvae in early development. However, exposure to this set of compounds just before the beginning of explosive parasitoid growth increased parasitoid survival. Exposure during the period of rapid parasitoid growth and feeding decreased parasitoid survival. These results highlight the spatial and temporal complexity of leaf shelter chemistry, and demonstrate the developmental contingency of associated effects on both host and parasitoid, implying the existence of complex selective pressures on plant investment in chemical defenses, host feeding behavior, and parasitoid life history.

  16. Nearfield Acoustical Holography

    NASA Astrophysics Data System (ADS)

    Hayek, Sabih I.

    Nearfield acoustical holography (NAH) is a method by which a set of acoustic pressure measurements at points located on a specific surface (called a hologram) can be used to image sources on vibrating surfaces on the acoustic field in three-dimensional space. NAH data are processed to take advantage of the evanescent wavefield to image sources that are separated less that one-eighth of a wavelength.

  17. Deep Water Acoustics

    DTIC Science & Technology

    2016-06-28

    Estimates of basin-wide sound speed ( temperature ) fields obtained by the combination of acoustic, altimetry, and other data types with ocean...of acoustic coherence at long ranges in the ocean. Estimates of basin-wide sound speed ( temperature ) fields obtained by the combination of acoustic...index.html Award Number N00014-13-1-0053 LONG-TERM GOALS The ultimate limitations to the performance of long-range sonar are due to ocean sound speed

  18. Acoustic Communications (ACOMMS) ATD

    DTIC Science & Technology

    2016-06-14

    Acoustic Communications (ACOMMS) ATD Tam Nguyen 2531 Jefferson Davis Hwy Arlington, VA 22242 phone: (703) 604-6013 ext 520 fax: (703) 604-6056...email: NguyenTL@navsea.navy.mil Award # N0001499PD30007 LONG-TERM GOALS The goal of the recently completed Acoustic Communications Advanced...Technology Demonstration program (ACOMMS ATD) was to demonstrate long range and moderate data rate underwater acoustic communications between a submarine

  19. Deep Water Ocean Acoustics

    DTIC Science & Technology

    2016-04-30

    OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics-043016 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics...understanding of the impact of the ocean and seafloor environmental variability on deep- water (long-range) ocean acoustic propagation and to...improve our understanding. During the past few years, the physics effects studied have been three-dimensional propagation on global scales, deep water

  20. Acoustic dispersive prism

    NASA Astrophysics Data System (ADS)

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  1. Acoustic dispersive prism.

    PubMed

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R

    2016-01-07

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  2. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  3. Acoustic dispersive prism

    PubMed Central

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium. PMID:26739504

  4. Impact of Two Ant Species on Egg Parasitoids Released as Part of a Biological Control Program

    PubMed Central

    Kergunteuil, Alan; Basso, César; Pintureau, Bernard

    2013-01-01

    Biological control using Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae), an egg parasitoid wasp, was tested in Uruguay to reduce populations of lepidopteran pests on soybeans. It was observed that the commercial parasitoid dispensers, which were made of cardboard, were vulnerable to small predators that succeeded in entering and emptying the containers of all the eggs parasitized by T. pretiosum. Observations in a soybean crop showed that the only small, common predators present were two ant species. The species responsible for the above mentioned predation was determined from the results of a laboratory experiment in which the behavior of the two common ants was tested. A modification of the dispensers to prevent introduction of this ant has been proposed and successfully tested in the laboratory and in the field. PMID:24738954

  5. Parasitoids of the eucalyptus gall wasp Leptocybe invasa (Hymenoptera: Eulophidae) in China

    PubMed Central

    Zheng, Xia-Lin; Huang, Zong-You; Dong, Dan; Guo, Chun-Hui; Li, Jun; Yang, Zhen-De; Yang, Xiu-Hao; Lu, Wen

    2016-01-01

    Leptocybe invasa Fisher & La Salle (Hymenoptera, Eulophidae) is an invasive pest in Eucalyptus plantations throughout the world. Potential biological control agents for L. invasa were investigated in the Fujian, Guangdong, Hainan, Guangxi, Jiangxi, and Sichuan provinces of China, where Eucalyptus spp. have been severely damaged by the eucalyptus gall wasp. Three hymenopteran parasitoids of L. invasa were identified: Quadrastichus mendeli Kim & La Salle (Eulophidae), Aprostocetus causalis La Salle & Wu (Eulophidae), and Megastigmus viggianii Narendran & Sureshan (Torymidae); M. viggianii is newly recorded in China. The percentages of parasitization by Q. mendeli, A. causalis, and M. viggianii were 2.96%–19.53%, 2.30%–26.38%, and 24.93%, respectively. The longevity and body length of females were significantly greater than for males in A. causalis and M. viggianii. No males of Q. mendeli were found in China. These parasitoids could be used as biological agents for L. invasa in China. PMID:28000590

  6. Drosophila Avoids Parasitoids by Sensing Their Semiochemicals via a Dedicated Olfactory Circuit

    PubMed Central

    Ebrahim, Shimaa A. M.; Dweck, Hany K. M.; Stökl, Johannes; Hofferberth, John E.; Trona, Federica; Weniger, Kerstin; Rybak, Jürgen; Seki, Yoichi; Stensmyr, Marcus C.; Sachse, Silke; Hansson, Bill S.; Knaden, Markus

    2015-01-01

    Detecting danger is one of the foremost tasks for a neural system. Larval parasitoids constitute clear danger to Drosophila, as up to 80% of fly larvae become parasitized in nature. We show that Drosophila melanogaster larvae and adults avoid sites smelling of the main parasitoid enemies, Leptopilina wasps. This avoidance is mediated via a highly specific olfactory sensory neuron (OSN) type. While the larval OSN expresses the olfactory receptor Or49a and is tuned to the Leptopilina odor iridomyrmecin, the adult expresses both Or49a and Or85f and in addition detects the wasp odors actinidine and nepetalactol. The information is transferred via projection neurons to a specific part of the lateral horn known to be involved in mediating avoidance. Drosophila has thus developed a dedicated circuit to detect a life-threatening enemy based on the smell of its semiochemicals. Such an enemy-detecting olfactory circuit has earlier only been characterized in mice and nematodes. PMID:26674493

  7. Mutually beneficial host exploitation and ultra-biased sex ratios in quasisocial parasitoids

    PubMed Central

    Tang, Xiuyun; Meng, Ling; Kapranas, Apostolos; Xu, Fuyuan; Hardy, Ian C.W.; Li, Baoping

    2014-01-01

    Selfish interests usually preclude resource sharing, but under some conditions collective actions enhance per capita gains. Such Allee effects underlay early explanations of social evolution but current understanding focusses on kin selection (inclusive fitness). We find an Allee effect that explains unusual quasisociality (cooperative brood care) among parasitoid wasps without invoking or precluding kin selection effects. In Sclerodermus harmandi, individual females produce most offspring when exploiting small hosts alone. However, larger hosts are more successfully exploited by larger groups of females, with the per-female benefits outweighing the costs of host sharing. Further, the extremely biased sex ratios (97% female) are better explained by mutually beneficial female–female interactions that increase the reproductive value of daughters (local resource enhancement), rather than by the usually invoked local mate competition between males. Thus, atypical quasisocial behaviour in a parasitoid wasp directly enhances reproductive success and selects for very extremely female-biased sex ratios. PMID:25216091

  8. Fitness Effects of Food Resources on the Polyphagous Aphid Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae)

    PubMed Central

    Charles, Jennifer J.; Paine, Timothy D.

    2016-01-01

    Conservation biological control involving the polyphagous aphid parasitoid, Aphidius colemani Viereck, may include provisioning resources from a variety of plant sources. The fitness of adult A. colemani was enhanced with the provision of food resources such as floral nectar from a range of both native and introduced plant species and aphid honeydew under laboratory conditions. However, enhanced fitness appeared to be species specific rather than associated with the whether the plant was a native or an introduced species. Parasitoid survival and fecundity were enhanced significantly in response to the availability of floral nectar and honeydew compared to the response to available extrafloral nectar. These positive effects on the parasitoid’s reproductive activity can improve the effectiveness of conservation biological control in nursery production systems because of the abundance and diversity of floral resources within typical production areas. Additionally, surrounding areas of invasive weeds and native vegetation could serve as both floral resources and honeydew food resources for A. colemani. PMID:26808191

  9. The fauna of cynipid oak gall wasps and their parasitoids in Lorestan province, Iran.

    PubMed

    Azizkhani, E; Rasoulian, G R; Kharazi-Pakdel, A; Omid, R; Moniri, V R; Melika, G

    2006-01-01

    This study was carried out in the period 2003-2005 to collect and identify gall wasps and their parasitoids on oak species in Lorestan province. There are two oak species, Quercus brantii and Q. infectoria, with different dispersion patterns in the province. Thus, 3 study sampling sites were selected to cover distributional pattern of oak forests. Collected galls maintained in the laboratory condition. Based on results obtained, overall, 26 different galls-formed on various plant parts (catkins, buds, fruits, leaves) were collected on two oak species; of which, 11 gall wasps are active on Q. brantii and 13 gall wasps on Q. infectoria. 19 parasitoid wasps of 12 genera and 6 families belong to Chalcidoidea superfamily with various frequency and dispersal were collected from mentioned galls.

  10. Apomictic parthenogenesis in a parasitoid wasp Meteorus pulchricornis, uncommon in the haplodiploid order Hymenoptera.

    PubMed

    Tsutsui, Y; Maeto, K; Hamaguchi, K; Isaki, Y; Takami, Y; Naito, T; Miura, K

    2014-06-01

    Although apomixis is the most common form of parthenogenesis in diplodiploid arthropods, it is uncommon in the haplodiploid insect order Hymenoptera. We found a new type of spontaneous apomixis in the Hymenoptera, completely lacking meiosis and the expulsion of polar bodies in egg maturation division, on the thelytokous strain of a parasitoid wasp Meteorus pulchricornis (Wesmael) (Braconidae, Euphorinae) on pest lepidopteran larvae Spodoptera litura (Fabricius) (Noctuidae). The absence of the meiotic process was consistent with a non-segregation pattern in the offspring of heterozygous females, and no positive evidence was obtained for the induction of thelytoky by any bacterial symbionts. We discuss the conditions that enable the occurrence of such rare cases of apomictic thelytoky in the Hymenoptera, suggesting the significance of fixed heterosis caused by hybridization or polyploidization, symbiosis with bacterial agents, and occasional sex. Our finding will encourage further genetic studies on parasitoid wasps to use asexual lines more wisely for biological control.

  11. Superparasitism in laboratory rearing of Spalangia cameroni (Hymenoptera: Pteromalidae), a parasitoid of medfly (Diptera: Tephritidae).

    PubMed

    Tormos, J; Asís, J; Sabater-Muñoz, B; Baños, L; Gayubo, S F; Beitia, F

    2012-02-01

    The frequency of superparasitism and its effects on the quality of laboratory-reared Spalangia cameroni (Hymenoptera: Pteromalidae) parasitoids were investigated under laboratory conditions. Numerous variables were measured, such as the number of 'ovip holes' per host as a measure of superparasitism. Adult emergence and sex ratio, as well as female size, emergence ability from soil and longevity were also measured. Finally, an assessment was made of fertility and survival of adult parasitoids emerging from the medfly Ceratitis capitata (Diptera: Tephritidae) pupae with different levels of superparasitism. A high frequency and prevalence of superparasitism under laboratory rearing conditions was observed. The number of 'ovip holes' per host ranged from one to 17, with an average (±SD) of 2.8±3.4. Sex ratios became increasingly female-biased with increasing levels of superparasitism, although overall levels of wasp emergence (male, female) declined. Nevertheless, no relationship was discerned between female size and level of superparasitism. The 'emergence ability from the soil' was higher in those parasitoids that emerged from strongly superparasitized hosts, but not related to the type of substrate in which the host pupae were buried. The level of superparasitism did not have a significant effect on the longevity, fertility and survival of female parasitoids. Our results support the hypothesis that superparasitism in S. cameroni might be adaptive, since attributes such as 'emergence ability from the soil', longevity, fertility and survival were not affected by the level of superparasitism or the presumably detrimental effects derived from physical combats among conspecific larvae. Our findings are relevant to recommendations for rearing S. cameroni for biological control releases, as well as shedding light on superparasitism under both laboratory and field conditions.

  12. Parasitoid wasp venom SERCA regulates Drosophila calcium levels and inhibits cellular immunity.

    PubMed

    Mortimer, Nathan T; Goecks, Jeremy; Kacsoh, Balint Z; Mobley, James A; Bowersock, Gregory J; Taylor, James; Schlenke, Todd A

    2013-06-04

    Because parasite virulence factors target host immune responses, identification and functional characterization of these factors can provide insight into poorly understood host immune mechanisms. The fruit fly Drosophila melanogaster is a model system for understanding humoral innate immunity, but Drosophila cellular innate immune responses remain incompletely characterized. Fruit flies are regularly infected by parasitoid wasps in nature and, following infection, flies mount a cellular immune response culminating in the cellular encapsulation of the wasp egg. The mechanistic basis of this response is largely unknown, but wasps use a mixture of virulence proteins derived from the venom gland to suppress cellular encapsulation. To gain insight into the mechanisms underlying wasp virulence and fly cellular immunity, we used a joint transcriptomic/proteomic approach to identify venom genes from Ganaspis sp.1 (G1), a previously uncharacterized Drosophila parasitoid species, and found that G1 venom contains a highly abundant sarco/endoplasmic reticulum calcium ATPase (SERCA) pump. Accordingly, we found that fly immune cells termed plasmatocytes normally undergo a cytoplasmic calcium burst following infection, and that this calcium burst is required for activation of the cellular immune response. We further found that the plasmatocyte calcium burst is suppressed by G1 venom in a SERCA-dependent manner, leading to the failure of plasmatocytes to become activated and migrate toward G1 eggs. Finally, by genetically manipulating plasmatocyte calcium levels, we were able to alter fly immune success against G1 and other parasitoid species. Our characterization of parasitoid wasp venom proteins led us to identify plasmatocyte cytoplasmic calcium bursts as an important aspect of fly cellular immunity.

  13. Contrasting Infection Strategies in Generalist and Specialist Wasp Parasitoids of Drosophila melanogaster

    PubMed Central

    Schlenke, Todd A; Morales, Jorge; Govind, Shubha; Clark, Andrew G

    2007-01-01

    Although host–parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids' ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While flies attacked by the melanogaster group specialist L. boulardi (strain Lb17) up-regulate numerous genes encoding proteolytic enzymes, components of the Toll and JAK/STAT pathways, and the melanization cascade as part of a combined cellular and humoral innate immune response, flies attacked by the generalist L. heterotoma (strain Lh14) do not appear to initiate an immune transcriptional response at the time points post-infection we assayed, perhaps due to the rapid venom-mediated lysis of host hemocytes (blood cells). Thus, the specialist parasitoid appears to invoke a full-blown immune response in the host, but suppresses and/or evades downstream components of this response. Given that activation of the host immune response likely depletes the energetic resources of the host, the specialist's infection strategy seems relatively disadvantageous. However, we uncover the mechanism for one potentially important fitness tradeoff of the generalist's highly immune suppressive infection strategy. PMID:17967061

  14. Host gut microorganisms' cues mediate orientation behaviour in the larva of the parasitoid Mallophora ruficauda.

    PubMed

    Groba, H F; Castelo, M K

    2016-02-01

    The robber fly Mallophora ruficauda is one of the most important apicultural pests in the Pampas region of Argentina. This species is a parasitoid of scarab beetle larvae. Females lay eggs away from the host, and the larvae perform active search behaviour toward Cyclocephala signaticollis third instar larvae, parasitoid's preferred host. This behaviour is mediated by host-related chemical cues produced in hosts' fermentation chamber. Also, C. signaticollis larvae are attracted to fermentation chamber extracts. As scarab larvae have microbe-rich fermentation chamber, it has been suggested that microorganisms could be involved in the production of these semiochemicals. The aims of this work were first to ascertain the presence of microorganisms in the fermentation chamber of C. signaticollis larvae and second to determine the role of microorganisms in the orientation response of parasitoid and host larvae. We found that microorganisms-free C. signaticollis larvae showed deterioration in their development and did not produce the attractive semiochemicals. Therefore, we isolated fermentation chamber microorganisms of host larvae by means of different cultures media, and then, assayed different microorganisms' stimuli by binary choice tests. We were able to isolate microorganisms and determine that M. ruficauda larvae are attracted to semiochemicals from protein degradation in the fermentation chamber. However, C. signaticollis larvae were not attracted to any semiochemicals associated with microorganisms' activity in the fermentation chamber. Although we were unable to elucidate the exact role of gut microorganisms in host behaviour, we discuss their relevance in parasitoid host-seeking behaviour and host conspecific interaction in M. ruficauda-C. signaticollis system.

  15. Introduced and Native Parasitoid Wasps Associated With Larch Casebearer (Lepidoptera: Coleophoridae) in Western Larch.

    PubMed

    Miller-Pierce, M; Shaw, D C; Demarco, A; Oester, P T

    2015-02-01

    The larch casebearer [Coleophora laricella (Hubner)], a non-native insect, continues to impact western larch (Larix occidentalis Nutt.) through defoliation events in the Pacific Northwest. Biological control programs starting in the 1960s released seven species of parasitoid wasps to control C. laricella outbreaks. However, information about current population dynamics of C. laricella and associated parasitoids remains lacking. Therefore, the goal of this study was to document the presence, current distributions, densities, and parasitism rates of introduced and native parasitoid wasps occurring on C. laricella throughout the Northwestern U.S. range of L. occidentalis. We sampled L. occidentalis trees at multiple sites in Oregon, Washington, Idaho, and Montana. C. laricella was present at all sites with average state densities ranging from 6.2 to 13.1 moths/100 buds. We recovered two introduced hymenopteran biological control agents; Agathis pumila (Ratzeburg: Braconidae) at 79% of the sites, and Chrysocharis laricinellae (Ratzeburg: Eulophidae) at 63% of the sites. Fourteen species of native parasitic wasps were also recovered. The most common species were: Bracon sp., Spilochalcis albifrons, and Mesopolobus sp. The average native species parasitism rate across the four states was 9.0%, which was higher than the introduced species Ch. laricinellae (2.9%), but not as high as A. pumila (19.3%). While survey results suggest that native species may be more important for the control of C. laricella than previously thought, A. pumila remains the major source of regional control. However, further research is needed to better understand how introduced and native parasitoids interact to control invasive pest populations.

  16. Lepidoptera and associated parasitoids attacking Hass and non-Hass avocados in Guatemala.

    PubMed

    Hoddle, Mark S; Hoddle, Christina D

    2008-08-01

    A 5-mo survey for fruit feeding Lepidoptera attacking Hass and non-Hass avocados (Persea americana Miller [Lauraceae]) was conducted in Guatemala from 1 November 2006 to 1 April 2007. In total, 6,740 fruit were collected from 22 different areas in Guatemala. Eight species of Lepidoptera, of which at least two are species new to science, were reared from avocado fruit. Reared Lepidoptera were Amorbia santamaria Phillips and Powell, Cryptaspasma sp. nr. lugubris, Euxoa sorella Schaus, Histura n. sp., Holcocera n. sp., Micrathetis triplex Walker, Netechma pyrrhodelta (Meyrick), and Stenoma catenifer Walsingham. Hymenopteran parasitoids were reared from larvae of C. sp. nr. lugubris and S. catenifer. One species of parasitoid, Pseudophanerotoma sp., was reared from field collected C. sp. nr. lugubris larvae. The dominant parasitoid reared from S. catenifer was a gregarious Apanteles sp. Other parasitoid species reared from S. catenifer larvae were Brachycyrtus sp., Macrocentrus sp., and Pristomerus sp. The oviposition preference of C. sp. nr. lugubris for avocado fruit hanging in trees, dropped fruit on the ground, or exposed avocado seeds was investigated by studying the oviposition preferences of adult female moths and determining egg hatch times in the laboratory, and by investigating the longevity of avocado fruit on the ground under prevailing field conditions. Together, data from these studies suggested that C. sp. nr. lugubris may be an unrecognized pest of avocados that causes hanging fruit to drop to the ground prematurely. The influence of season and altitude on the phenology and distribution of avocado feeding Lepidoptera in Guatemala is discussed.

  17. Alien dominance of the parasitoid wasp community along an elevation gradient on Hawai'i Island

    USGS Publications Warehouse

    Peck, R.W.; Banko, P.C.; Schwarzfeld, M.; Euaparadorn, M.; Brinck, K.W.

    2008-01-01

    Through intentional and accidental introduction, more than 100 species of alien Ichneumonidae and Braconidae (Hymenoptera) have become established in the Hawaiian Islands. The extent to which these parasitoid wasps have penetrated native wet forests was investigated over a 1,765 m elevation gradient on windward Hawai'i Island. For >1 year, malaise traps were used to continuously monitor parasitoid abundance and species richness in nine sites over three elevations. A total of 18,996 individuals from 16 subfamilies were collected. Overall, the fauna was dominated by aliens, with 44 of 58 species foreign to the Hawaiian Islands. Ichneumonidae was dominant over Braconidae in terms of both diversity and abundance, comprising 67.5% of individuals and 69.0% of species collected. Parasitoid abundance and species richness varied significantly with elevation: abundance was greater at mid and high elevations compared to low elevation while species richness increased with increasing elevation, with all three elevations differing significantly from each other. Nine species purposely introduced to control pest insects were found, but one braconid, Meteorus laphygmae, comprised 98.0% of this assemblage, or 28.3% of the entire fauna. Endemic species, primarily within the genera Spolas and Enicospilus, were collected almost exclusively at mid- and high-elevation sites, where they made up 22.1% and 36.0% of the total catch, respectively. Overall, 75.9% of species and 96.0% of individuals are inferred to parasitize Lepidoptera larvae and pupae. Our results support previous data indicating that alien parasitoids have deeply penetrated native forest habitats and may have substantial impacts on Hawaiian ecosystems. ?? 2008 Springer Science+Business Media B.V.

  18. Host ranges of gregarious muscoid fly parasitoids: Muscidifurax raptorellus (Hymenoptera: Pteromalidae), Tachinaephagus zealandicus (Hymenoptera: Encyrtidae), and Trichopria nigra (Hymenoptera: Diapriidae).

    PubMed

    Geden, Christopher J; Moon, Roger D

    2009-06-01

    Attack rates, progeny production, sex ratios, and host utilization efficiency of Muscidifurax raptorellus (Kogan and Legner) (Hymenoptera: Pteromalidae), Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae), and Trichopria nigra (Nees) (Hymenoptera: Diapriidae) were evaluated in laboratory bioassays with five dipteran hosts: house fly (Musca domestica L.), stable fly (Stomoxys calcitrans L.), horn fly (Hematobia irritans L.), black dump fly [Hydrotaea aenescens (Weidemann)] (Diptera: Muscidae), and a flesh fly (Sarcophaga bullata Parker) (Diptera: Sarcophagidae). M. raptorellus killed and successfully parasitized all five host species and produced an average 2.6 parasitoid progeny from each host. Host attack rates were highest on stable fly and lowest on horn fly; there were no differences among hosts in the total number of progeny produced. T. zealandicus killed larvae of all fly host species in similar numbers, but parasitism was most successful on H. aenescens and S. bullata and least successful on horn fly and house fly hosts. Significantly more parasitoid progeny emerged from S. bullata (10.2 parasitoids per host) than the other hosts; only 2.5 progeny were produced from parasitized horn fly hosts. Most of the killed puparia that produced neither adult flies nor parasitoids ("duds") contained dead parasitoids; in house fly, stable fly, and horn fly hosts, >30% of these dudded pupae contained adult wasps that failed to eclose. T. nigra successfully parasitized pupae of all host species except house fly and was most successful on stable fly. Significantly more parasitoid progeny emerged from S. bullata (30.6 parasitoids per host) than the other hosts; only 5.7 progeny were produced from horn fly hosts.

  19. Intraspecific variation of host plant and locality influence the lepidopteran-parasitoid system of Brassica oleracea crops.

    PubMed

    Santolamazza-Carbone, S; Velasco, P; Selfa, J; Soengas, P; Cartea, M E

    2013-06-01

    The aim of the study was to investigate the attractiveness to herbivores and parasitoids of two cultivars of Brassica oleracea L., namely, B. oleracea variety acephala (kale) and B. oleracea variety capitata (cabbage), that exhibit differences of morphological and biochemical traits. To this end, field samplings were replicated at seven localities in Galicia (northwestern Spain). Three specialist and three generalist lepidopteran species were sampled. In total, 7,050 parasitoids were obtained, belonging to 18 genera and 22 species. The results showed that 1) parasitism rate and parasitoid species richness changed with locality and was higher in cabbage, although this crop had lower herbivore abundance; 2) the proportion of specialist herbivores was higher in cabbage crops, whereas generalists dominated in kale crops; 3) the abundance of the parasitoids Telenomus sp. (Hymenoptera, Scelionidae), Cotesia glomerata L. (Hymenoptera: Braconidae), and Diadegma fenestrale (Holmgren) (Hymenoptera: Ichneumonidae) was higher in kale crops; and 4) parasitism rate of Pieris rapae larvae and pupae and Mamestra brassicae eggs were higher in kale crops. In contrast with the notion that plant structural complexity provides physical refuge to the hosts and can interfere with parasitoid foraging, parasitism rate was higher on cabbage plants, which form heads of overlapped leaves. Possibly, different chemical profiles of cultivars also influenced the host-parasitoid relationship. These results suggest that top-down and bottom-up forces may enhance cabbage crops to better control herbivore pressure during the studied season. In Spain, information on natural occurring parasitoid guilds of Brassica crops is still scarce. The data provided here also represent a critical first step for conservation biological control plans of these cultivations.

  20. Potential of Hymenopteran larval and egg parasitoids to control stored-product beetle and moth infestation in jute bags.

    PubMed

    Adarkwah, C; Ulrichs, C; Schaarschmidt, S; Badii, B K; Addai, I K; Obeng-Ofori, D; Schöller, M

    2014-08-01

    The control of stored-product moths in bagged commodities is difficult because the developmental stages of the moths are protected by the bagging material from control measures such as the application of contact insecticides. Studies were carried out to assess the ability of Hymenopteran parasitoids to locate their hosts inside jute bags in the laboratory. The ability of different parasitoids to penetrate jute bags containing rice was investigated in a controlled climate chamber. Few Habrobracon hebetor (Say) (Hymenoptera: Braconidae) passed through the jute material while a high percentage of Lariophagus distinguendus (Förster), Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae) and Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) were able to enter the Petri-dishes. Significantly more L. distinguendus and T. elegans entered compared to H. hebetor. There was significant difference in the mean percentage parasitoids invading depending on species. Head capsules and/or thorax widths were measured in order to determine whether the opening in the jute material would be large enough for entry of the parasitoids. These morphometric data differed depending on parasitoid species and sex. The parasitoid Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae) did not enter the bags, but located host larvae inside the jute bags and parasitized rice moths Corcyra cephalonica larvae by stinging through the jute material. Venturia canescens significantly reduced the number of C. cephalonica adults emerging from the bagged rice; therefore, it could be released in storage rooms containing bagged rice for biological control of C. cephalonica. The use of parasitoids to suppress stored-product insect pests in bagged commodities could become a valuable supplement to the use of synthetic pesticides.

  1. Comparative studies of the influence of relative humidity and temperature on the longevity and fecundity of the parasitoid, Cotesia flavipes.

    PubMed

    G D, Emana

    2007-01-01

    The parasitoid, Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), was introduced for biological control of the stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), in eastern and southern African countries. The parasitoid became firmly established in Ethiopia, with varying density and distribution in various regions of the country indicating that there are factors regulating the success of the parasitoid. From previous studies, it was known that the population of the parasitoid released, the type of host, and temperature highly affect some of the biological parameters of the parasitoid. The current studies were undertaken to understand the individual and interactive effect of temperature and relative humidity on the longevity and fecundity of C. flavipes. The study was conducted on C. flavipes collected from the Melkassa Agricultural Research Center Experimental Field, Ethiopia. C. flavipes was reared in the laboratory on C. partellus feeding on pieces of sorghum stem. The longevity experiment was conducted at 10, 20, 30 and 40 degrees C, while the fecundity experiment was conducted at 20, 25, 28 and 30 degrees C. For both experiments 40-50%, 60-70% and 80-90% relative humidity regimes were used. The results obtained indicate that the interactive effect of temperature and relative humidity significantly affected the longevity, the number of oocytes, and fecundity of C. flavipes implying that the two factors play an important role in the success of the parasitoid as a biocontrol agent against C. partellus. The results obtained suggests the importance of the selection of target release sites for maximum efficiency of the parasitoid, which can have a positive impact on the on-going augmentative release of C. flavipes in Ethiopia.

  2. Interspecific interactions between two Tuta absoluta (Lepidoptera: Gelechiidae) larval parasitoids with contrasting life histories.

    PubMed

    Savino, V; Luna, M G; Salas Gervassio, N G; Coviella, C E

    2017-02-01

    Interspecific interactions between two larval parasitoids of Tuta absoluta (Meyrick) with partially overlapping host niches were studied: the idiobiont ectoparasitoid Dineulophus phthorimaeae De Santis, and the koinobiont endoparasitoid Pseudapanteles dignus (Muesebeck). T. absoluta is an important pest of tomato crops worldwide, and its management could be improved by understanding the competitive interactions and potential coexistence between these two parasitoids. Firstly, a 15-min fixed time laboratory test evaluated the host-searching ability of adult D. phthorimaeae and P. dignus wasps on T. absoluta larvae. Secondly, D. phthorimaeae host discrimination against endoparasitized and non-endoparasitized hosts by P. dignus, at different adult female ages, was experimentally examined. D. phthorimaeae wasps spent significantly more time in general searching in the presence of its competitor than in its absence, but, parasitism was only effective by P. dignus. Older D. phthorimaeae wasps discriminated significantly less than young wasps between T. absoluta larvae parasitized and unparasitized by P. dignus, and an interaction took place by non-concurrent host-feeding. Intra-guild predation of P. dignus larvae by D. phthorimaeae female feeding behaviour might have a minor effect in this system. Results are discussed in the context of literature supporting diverse evidence of coexistence in other parasitoid-host systems, with implications for T. absoluta biological control.

  3. Competition between the filth fly parasitoids Muscidifurax raptor and M. raptorellus (Hymenoptera: Pteromalidae).

    PubMed

    Geden, C J; Johnson, D M; Kaufman, P E; Boohene, C K

    2014-12-01

    Competition bioassays were conducted with the filth fly pupal parasitoids Muscidurax raptor (Girault & Sanders) and M. raptorellus (Kogan & Legner) (Hymenoptera: Pteromalidae) using house fly Musca domestica L. (Diptera: Muscidae) hosts at different host densities. Muscidifurax raptor had a significant impact on M. raptorellus when hosts were limiting in sequential parasitism tests. Fewer than six M. raptorellus adult progeny emerged from groups of 50 fly pupae that were parasitized by M. raptor at the same time or when M. raptor parasitism preceded M. raptorellus by 48 h, respectively, compared with 42-55 M. raptorellus progeny produced when this species was tested alone. Production of M. raptor was significantly lower when parasitism by this species was preceded by M. raptorellus (25) than when M. raptor was tested alone (43). When the two species parasitized hosts at the same time in different proportions at low host:parasitoid densities (5:1), M. raptorellus produced 13 progeny per parent female when it was the sole species present and fewer than two when M. raptor was present. No negative impact of M. raptorellus on M. raptor was observed. Neither species had a substantial effect on the success of the other at higher host:parasitoid densities.

  4. Can the Understory Affect the Hymenoptera Parasitoids in a Eucalyptus Plantation?

    PubMed Central

    Dall’Oglio, Onice Teresinha; Ribeiro, Rafael Coelho; Ramalho, Francisco de Souza; Fernandes, Flávio Lemes; Wilcken, Carlos Frederico; de Assis Júnior, Sebastião Lourenço; Rueda, Rosa Angélica Plata; Serrão, José Eduardo; Zanuncio, José Cola

    2016-01-01

    The understory in forest plantations can increase richness and diversity of natural enemies due to greater plant species richness. The objective of this study was to test the hypothesis that the presence of the understory and climatic season in the region (wet or dry) can increase the richness and abundance of Hymenoptera parasitoids in Eucalyptus plantations, in the municipality of Belo Oriente, Minas Gerais State, Brazil. In each eucalyptus cultivation (five areas of cultivation) ten Malaise traps were installed, five with the understory and five without it. A total of 9,639 individuals from 30 families of the Hymenoptera parasitoids were collected, with Mymaridae, Scelionidae, Encyrtidae and Braconidae being the most collected ones with 4,934, 1,212, 619 and 612 individuals, respectively. The eucalyptus stands with and without the understory showed percentage of individuals 45.65% and 54.35% collected, respectively. The understory did not represent a positive effect on the overall abundance of the individuals Hymenoptera in the E. grandis stands, but rather exerted a positive effect on the specific families of the parasitoids of this order. PMID:26954578

  5. A novel negative-stranded RNA virus mediates sex ratio in its parasitoid host

    PubMed Central

    Wang, Beibei; Yan, Zhichao; Hong, Jian; Werren, John H.; Song, Qisheng

    2017-01-01

    Parasitoid wasps are important natural enemies of arthropod hosts in natural and agricultural ecosystems and are often associated with viruses or virion-like particles. Here, we report a novel negative-stranded RNA virus from a parasitoid wasp (Pteromalus puparum). The complete viral genome is 12,230 nucleotides in length, containing five non-overlapping, linearly arranged open reading frames. Phylogenetically, the virus clusters with and is a novel member of the mononegaviral family Nyamiviridae, here designated as Pteromalus puparum negative-strand RNA virus 1 (PpNSRV-1). PpNSRV-1 is present in various tissues and life stages of the parasitoid wasp, and is transmitted vertically through infected females and males. Virus infections in field populations of P. puparum wasps ranged from 16.7 to 37.5%, without linearly correlating with temperature. PpNSRV-1 increased adult longevity and impaired several fitness parameters of the wasp, but had no influence on successful parasitism. Strikingly, PpNSRV-1 mediated the offspring sex ratio by decreasing female offspring numbers. RNA interference knockdown of virus open reading frame I eliminated these PpNSRV-1-induced effects. Thus, we infer that PpNSRV-1 has complex effects on its insect host including sex ratio distortion towards males, as well as possible mutualistic benefits through increasing wasp longevity. PMID:28278298

  6. Impact of Insecticides on Parasitoids of the Leafminer, Liriomyza trifolii, in Pepper in South Texas

    PubMed Central

    Hernández, Ricardo; Harris, Marvin; Liu, Tong-Xian

    2011-01-01

    Liriomyza leafminers (Diptera: Agromyzidae) are cosmopolitan, polyphagous pests of horticultural plants and many are resistant to insecticides. Producers in South Texas rely on insecticides as the primary management tool for leafminers, and several compounds are available. The objective of this study is to address the efficacy of these compounds for controlling Liriomyza while minimizing their effects against natural enemies. Research plots were established at Texas AgriLife research center at Weslaco, Texas in fall 2007 and spring 2008 seasons, and peppers were used as a model crop. Plots were sprayed with novaluron, abamectin, spinetoram, lambda-cyhalothrin and water as treatments according to leafminer infestation; insecticide efficacy was monitored by collecting leaves and infested foliage. Plant phenology was also monitored. Novaluron was the most effective insecticide and lambda-cyhalothrin showed resurgence in leafminer density in fall 2007 and no reduction in spring 2008. Other compounds varied in efficacy. Novaluron showed the least number of parasitoids per leafminer larva and the lowest parasitoid diversity index among treatments followed by spinetoram. Liriomyza trifolii (Burgess) was the sole leafminer species on peppers, and 19 parasitoid species were found associated with this leafminer. Application of these insecticides for management of leafminers with conservation of natural enemies is discussed. PMID:21864155

  7. Impact of insecticides on parasitoids of the leafminer, Liriomyza trifolii, in pepper in south Texas.

    PubMed

    Hernández, Ricardo; Harris, Marvin; Liu, Tong-Xian

    2011-01-01

    Liriomyza leafminers (Diptera: Agromyzidae) are cosmopolitan, polyphagous pests of horticultural plants and many are resistant to insecticides. Producers in South Texas rely on insecticides as the primary management tool for leafminers, and several compounds are available. The objective of this study is to address the efficacy of these compounds for controlling Liriomyza while minimizing their effects against natural enemies. Research plots were established at Texas AgriLife research center at Weslaco, Texas in fall 2007 and spring 2008 seasons, and peppers were used as a model crop. Plots were sprayed with novaluron, abamectin, spinetoram, lambda-cyhalothrin and water as treatments according to leafminer infestation; insecticide efficacy was monitored by collecting leaves and infested foliage. Plant phenology was also monitored. Novaluron was the most effective insecticide and lambda-cyhalothrin showed resurgence in leafminer density in fall 2007 and no reduction in spring 2008. Other compounds varied in efficacy. Novaluron showed the least number of parasitoids per leafminer larva and the lowest parasitoid diversity index among treatments followed by spinetoram. Liriomyza trifolii (Burgess) was the sole leafminer species on peppers, and 19 parasitoid species were found associated with this leafminer. Application of these insecticides for management of leafminers with conservation of natural enemies is discussed.

  8. Susceptibility to selected insecticides and risk assessment in the insect egg parasitoid Trichogramma confusum (Hymenoptera: Trichogrammatidae).

    PubMed

    Wang, Yanhua; Chen, Liping; An, Xuehua; Jiang, Jinhua; Wang, Qiang; Cai, Leiming; Zhao, Xueping

    2013-02-01

    The parasitoid Trichogramma confusum Viggiani (Hymenoptera: Trichogrammatidae) is an important natural enemy of many lepidopterans throughout the world. Extensive toxicological tests have clarified the toxic effects of insecticides on trichogrammatids, but only few studies have examined these effects on T. confusum. Among the seven classes of tested chemicals, organophosphates and carbamates exhibited the highest intrinsic toxicity to the parasitoid with LC50 values ranging from 0.037 (0.030-0.046) to 0.29 (0.23-0.38) and from 0.17 (0.15-0.19) to 1.61 (1.45-1.79) mg AI L(-1), respectively. They were followed by phenylpyrazoles, avermectins, pyrethroids, and neonicotinoids, which induced variable toxicity responses with LC50 values ranging from 0.63 to 45.26, 1.06-21.73, 3.89-19.36, and 0.24-754.2 mg AI L(-1), respectively. In contrast, insect growth regulators (IGRs) showed the least toxicity to the parasitoid with LC50 values ranging from 3,907 (3,432-4,531) to 10,154 (8,857-12,143) mg AI L(-1). A risk quotient analysis indicated that neonicotinoids (except thiamethoxam), avermectins, pyrethroids, IGRs, and phenylpyrazoles are safe, but organophosphates and carbamates are slightly to moderately or dangerously toxic to T. confusum. This study provides informative data for implementing both biological and chemical control strategies in integrated pest management of lepidopterans.

  9. A novel negative-stranded RNA virus mediates sex ratio in its parasitoid host.

    PubMed

    Wang, Fei; Fang, Qi; Wang, Beibei; Yan, Zhichao; Hong, Jian; Bao, Yiming; Kuhn, Jens H; Werren, John H; Song, Qisheng; Ye, Gongyin

    2017-03-01

    Parasitoid wasps are important natural enemies of arthropod hosts in natural and agricultural ecosystems and are often associated with viruses or virion-like particles. Here, we report a novel negative-stranded RNA virus from a parasitoid wasp (Pteromalus puparum). The complete viral genome is 12,230 nucleotides in length, containing five non-overlapping, linearly arranged open reading frames. Phylogenetically, the virus clusters with and is a novel member of the mononegaviral family Nyamiviridae, here designated as Pteromalus puparum negative-strand RNA virus 1 (PpNSRV-1). PpNSRV-1 is present in various tissues and life stages of the parasitoid wasp, and is transmitted vertically through infected females and males. Virus infections in field populations of P. puparum wasps ranged from 16.7 to 37.5%, without linearly correlating with temperature. PpNSRV-1 increased adult longevity and impaired several fitness parameters of the wasp, but had no influence on successful parasitism. Strikingly, PpNSRV-1 mediated the offspring sex ratio by decreasing female offspring numbers. RNA interference knockdown of virus open reading frame I eliminated these PpNSRV-1-induced effects. Thus, we infer that PpNSRV-1 has complex effects on its insect host including sex ratio distortion towards males, as well as possible mutualistic benefits through increasing wasp longevity.

  10. Different uses of plant semiochemicals in host location strategies of the two tachinid parasitoids

    NASA Astrophysics Data System (ADS)

    Ichiki, Ryoko T.; Ho, Giang T. T.; Wajnberg, Eric; Kainoh, Yooichi; Tabata, Jun; Nakamura, Satoshi

    2012-09-01

    Some members of the family Tachinidae (Insecta: Diptera) deposit numerous very small eggs, termed "microtype" eggs, on the food plants of their caterpillar hosts. Parasitization is successful only when the hosts ingest these eggs. To increase the chance of hosts encountering the eggs, microtype tachinid parasitoids have to choose a suitable plant that harbors hosts and lay their eggs near the hosts. In their host location process, semiochemicals emitted by host-infested plants offer the tachinids a reliable cue. We investigated the behavioral responses of two microtype tachinid parasitoids, Pales pavida and Zenillia dolosa, to maize plants infested with their caterpillar host, Mythimna separata, in a wind tunnel. P. pavida females showed a significantly higher rate of landing on caterpillar-infested plants than on mechanically wounded or intact plants, whereas Z. dolosa landed on both the caterpillar-infested and mechanically wounded plants at significantly higher rates than on intact plants. We also examined which part of a caterpillar-infested maize leaf induces oviposition. P. pavida deposited eggs on the margin of the leaf, whereas Z. dolosa preferentially laid eggs around a caterpillar-infested area or a mechanically wounded spot. P. pavida eggs retained their parasitization ability for more than 15 days after they were deposited, whereas the eggs of Z. dolosa could not survive more than 5 days after oviposition. Our results suggest that each tachinid parasitoid employs a different host location strategy to exploit semiochemicals coming from plant-herbivore interaction as cues in order to increase their parasitization success.

  11. Surveys for Stenoma catenifer (Lepidoptera: Elachistidae) and associated parasitoids infesting avocados in Perú.

    PubMed

    Hoddle, Mark S; Hoddle, Christina D

    2012-04-01

    Surveys for Stenoma catenifer Walsingham, the avocado seed moth, and its associated larval parasitoids were conducted in the Departments of Junín, Huánuco, Cusco, and Madre de Dios in Perú. Fruit infestation levels in some areas ranged from 0 to 58%, and parasitism of S. catenifer larvae in Junín and Huánuco was 23%. Five species of hymenopteran parasitoid in two families, Braconidae (Apanteles sp., Hypomicrogaster sp., and Chelonus sp.) and Ichneumonidae (Pristeromerus sp. and Xiphosomella sp.), were reared from larvae, and one species of tachinid fly (Chrysodoria sp.) emerged from pupae. The dominant larval parasitoid, a gregarious Apanteles sp., accounted for 55% of parasitized hosts. Branch and twig tunneling by S. catenifer larvae in a commercial Hass avocado orchard was observed in Cusco. The field attractiveness of the sex pheromone of S. catenifer was demonstrated with 73% of monitoring traps deployed in three departments (Junín, Huánuco, and Cusco) catching male moths. Approximately 55% of avocado fruit sourced from the Province of Chanchamayo (Junin) and purchased at the Mercado Modelo de Frutas in La Victoria, in central Lima were infested with larvae of S. catenifer. Infested avocado fruit sold at this market could represent a potential incursion threat to coastal Hass avocado production regions in Perú that are reportedly free of this pest.

  12. Terpene-mediated parasitoid host location behavior on transgenic and classically bred apple genotypes.

    PubMed

    Vogler, Ute; Rott, Anja S; Gessler, Cesare; Dorn, Silvia

    2009-08-12

    Terpene-mediated interactions between transgenic or classically bred apple genotypes and associated insects were investigated. Apple genotypes were either resistant or susceptible to Venturia inaequalis that causes apple scab. They were subjected to infestation by Phyllonorycter leafminers and/or inoculation with V. inaequalis. Apple leaf extracts were analyzed by gas chromatography-mass spectrometry to quantify squalene, a triterpene known to mediate host location by Pholetesor parasitoids that are specialized on leafminers. Squalene contents in leafminer-infested leaves differed between the transgenic apple scab resistant line and a classically bred cultivar sharing the same resistance gene. This resistant cultivar showed an increase in squalene contents from healthy to leafminer-infested leaves. This was not the case in the transgenic resistant line. However, there was also no increase in the susceptible isogenic cultivar. Behavioral bioassays with parasitoid females also reflected these findings. Hence, alterations in leaf chemistry and corresponding responses of the parasitoid are apparent among classically bred cultivars, rather than in the genetically modified resistant line.

  13. Parasitoids of Queensland Fruit Fly Bactrocera tryoni in Australia and Prospects for Improved Biological Control

    PubMed Central

    Zamek, Ashley L.; Spinner, Jennifer E.; Micallef, Jessica L.; Gurr, Geoff M.; Reynolds, Olivia L.

    2012-01-01

    This review draws together available information on the biology, methods for study, and culturing of hymenopteran parasitoids of the Queensland fruit fly, Bactrocera tryoni, and assesses prospects for improving biological control of this serious pest. Augmentative release of the native and naturalised Australian parasitoids, especially the braconid Diachasmimorpha tryoni, may result in better management of B. tryoni in some parts of Australia. Mass releases are an especially attractive option for areas of inland eastern Australia around the Fruit Fly Exclusion Zone that produces B. tryoni-free fruits for export. Diachasmimorpha tryoni has been successful in other locations such as Hawaii for the biological control of other fruit fly species. Biological control could contribute to local eradication of isolated outbreaks and more general suppression and/or eradication of the B. tryoni population in endemic areas. Combining biological control with the use of sterile insect technique offers scope for synergy because the former is most effective at high pest densities and the latter most economical when the pest becomes scarce. Recommendations are made on methods for culturing and study of four B. tryoni parasitoids present in Australia along with research priorities for optimising augmentative biological control of B. tryoni. PMID:26466726

  14. Effects of forest spatial structure on insect outbreaks: insights from a host-parasitoid model.

    PubMed

    Hughes, Josie S; Cobbold, Christina A; Haynes, Kyle; Dwyer, Greg

    2015-05-01

    Understanding how cycles of forest-defoliating insects are affected by forest destruction is of major importance for forest management. Achieving such an understanding with data alone is difficult, however, because population cycles are typically driven by species interactions that are highly nonlinear. We therefore constructed a mathematical model to investigate the effects of forest destruction on defoliator cycles, focusing on defoliator cycles driven by parasitoids. Our model shows that forest destruction can increase defoliator density when parasitoids disperse much farther than defoliators because the benefits of reduced defoliator mortality due to increased parasitoid dispersal mortality exceed the costs of increased defoliator dispersal mortality. This novel result can explain observations of increased outbreak duration with increasing forest fragmentation in forest tent caterpillar populations. Our model also shows that larger habitat patches can mitigate habitat loss, with clear implications for forest management. To better understand our results, we developed an approximate model that shows that defoliator spatial dynamics can be predicted from the proportion of dispersing animals that land in suitable habitat. This approximate model is practically useful because its parameters can be estimated from widely available data. Our model thus suggests that forest destruction may exacerbate defoliator outbreaks but that management practices could mitigate such effects.

  15. Cophylogenetic relationships between Anicetus parasitoids (Hymenoptera: Encyrtidae) and their scale insect hosts (Hemiptera: Coccidae)

    PubMed Central

    2013-01-01

    Background Numerous studies have investigated cospeciation between parasites and their hosts, but there have been few studies concerning parasitoids and insect hosts. The high diversity and host specialization observed in Anicetus species suggest that speciation and adaptive radiation might take place with species diversification in scale insect hosts. Here we examined the evolutionary history of the association between Anicetus species and their scale insect hosts via distance-based and tree-based methods. Results A total of 94 Anicetus individuals (nine parasitoid species) and 113 scale insect individuals (seven host species) from 14 provinces in China were collected in the present study. DNA sequence data from a mitochondrial gene (COI) and a nuclear ribosomal gene (28S D2 region) were used to reconstruct the phylogenies of Anicetus species and their hosts. The distance-based analysis showed a significant fit between Anicetus species and their hosts, but tree-based analyses suggested that this significant signal could be observed only when the cost of host-switching was high, indicating the presence of parasite sorting on related host species. Conclusions This study, based on extensive rearing of parasitoids and species identification, provides strong evidence for a prevalence of sorting events and high host specificity in the genus Anicetus, offering insights into the diversification process of Anicetus species parasitizing scale insects. PMID:24365056

  16. Can the Understory Affect the Hymenoptera Parasitoids in a Eucalyptus Plantation?

    PubMed

    Dall'Oglio, Onice Teresinha; Ribeiro, Rafael Coelho; Ramalho, Francisco de Souza; Fernandes, Flávio Lemes; Wilcken, Carlos Frederico; Assis Júnior, Sebastião Lourenço de; Rueda, Rosa Angélica Plata; Serrão, José Eduardo; Zanuncio, José Cola

    2016-01-01

    The understory in forest plantations can increase richness and diversity of natural enemies due to greater plant species richness. The objective of this study was to test the hypothesis that the presence of the understory and climatic season in the region (wet or dry) can increase the richness and abundance of Hymenoptera parasitoids in Eucalyptus plantations, in the municipality of Belo Oriente, Minas Gerais State, Brazil. In each eucalyptus cultivation (five areas of cultivation) ten Malaise traps were installed, five with the understory and five without it. A total of 9,639 individuals from 30 families of the Hymenoptera parasitoids were collected, with Mymaridae, Scelionidae, Encyrtidae and Braconidae being the most collected ones with 4,934, 1,212, 619 and 612 individuals, respectively. The eucalyptus stands with and without the understory showed percentage of individuals 45.65% and 54.35% collected, respectively. The understory did not represent a positive effect on the overall abundance of the individuals Hymenoptera in the E. grandis stands, but rather exerted a positive effect on the specific families of the parasitoids of this order.

  17. When Parasitoid Males Make Decisions: Information Used when Foraging for Females

    PubMed Central

    Dufour, Claire M-S; Louâpre, Philippe

    2012-01-01

    Optimal foraging models predict how an organism allocates its time and energy while foraging for aggregated resources. These models have been successfully applied to organisms such as predators looking for prey, female parasitoids looking for hosts, or herbivorous searching for food. In this study, information use and patch time allocation were investigated using male parasitoids looking for mates. The influence of the former presence of females in absence of mates and the occurrence of mating and other reproductive behaviours on the patch leaving tendency was investigated for the larval parasitoid Asobara tabida. Although males do not modify their patch residence time based on the number of females that visited the patch, they do show an increase in the patch residence time after mating a virgin female and performing courtship behaviour such as opening their wings. These results are in concordance with an incremental mechanism, as it has been described for females of the same species while foraging for hosts. The similarities between males and females of the same species, and the conditions under which such a patch-leaving decision rule is fitted are discussed. This is the first study describing an incremental effect of mating on patch residence time in males, thus suggesting that similar information use are probably driving different organisms foraging for resource, regardless of its nature. PMID:23056411

  18. The Herbivore-Induced Plant Volatile Methyl Salicylate Negatively Affects Attraction of the Parasitoid Diadegma semiclausum

    PubMed Central

    Mumm, Roland; Poelman, Erik H.; Yang, Yue; Pichersky, Eran; Dicke, Marcel

    2010-01-01

    The indirect defense mechanisms of plants comprise the production of herbivore-induced plant volatiles that can attract natural enemies of plant attackers. One of the often emitted compounds after herbivory is methyl salicylate (MeSA). Here, we studied the importance of this caterpillar-induced compound in the attraction of the parasitoid wasp Diadegma semiclausum by using a mutant Arabidopsis line. Pieris rapae infested AtBSMT1-KO mutant Arabidopsis plants, compromised in the biosynthesis of MeSA, were more attractive to parasitoids than infested wild-type plants. This suggests that the presence of MeSA has negative effects on parasitoid host-finding behavior when exposed to wild-type production of herbivore-induced Arabidopsis volatiles. Furthermore, in line with this, we recorded a positive correlation between MeSA dose and repellence of D. semiclausum when supplementing the headspace of caterpillar-infested AtBSMT1-KO plants with synthetic MeSA. Electronic supplementary material The online version of this article (doi:10.1007/s10886-010-9787-1) contains supplementary material, which is available to authorized users. PMID:20407809

  19. Multiple attractors of host-parasitoid models with integrated pest management strategies: eradication, persistence and outbreak.

    PubMed

    Tang, Sanyi; Xiao, Yanni; Cheke, Robert A

    2008-03-01

    Host-parasitoid models including integrated pest management (IPM) interventions with impulsive effects at both fixed and unfixed times were analyzed with regard to host-eradication, host-parasitoid persistence and host-outbreak solutions. The host-eradication periodic solution with fixed moments is globally stable if the host's intrinsic growth rate is less than the summation of the mean host-killing rate and the mean parasitization rate during the impulsive period. Solutions for all three categories can coexist, with switch-like transitions among their attractors showing that varying dosages and frequencies of insecticide applications and the numbers of parasitoids released are crucial. Periodic solutions also exist for models with unfixed moments for which the maximum amplitude of the host is less than the economic threshold. The dosages and frequencies of IPM interventions for these solutions are much reduced in comparison with the pest-eradication periodic solution. Our results, which are robust to inclusion of stochastic effects and with a wide range of parameter values, confirm that IPM is more effective than any single control tactic.

  20. Lethal and sublethal effects of four essential oils on the egg parasitoids Trissolcus basalis.

    PubMed

    Werdin González, Jorge Omar; Laumann, Raúl Alberto; da Silveira, Samantha; Moraes, Maria Carolina Blassioli; Borges, Miguel; Ferrero, Adriana Alicia

    2013-07-01

    The essential oils from leaves of Schinus molle var. areira, Aloysia citriodora, Origanum vulgare and Thymus vulgaris have showed potential as phytoinsecticides against the green stink bug, Nezara viridula. In this work were evaluated their toxicological and behavioral effects on the parasitoid Trissolcus basalis, a biological control agent of this pest insect. Essential oils were obtained via hydrodestillation from fresh leaves. Insecticide activity in T. basalis females was evaluated in direct contact and fumigation bioassays. Behavioral effects were evaluated in olfactometer bioassays. To evaluate the residual toxicity, females of the parasitoids were exposed to oil residues; in these insects, the sublethal effects were evaluated (potential parasitism and survivorship of immature stages). The essential oils from O. vulgare and T. vulgaris proved to be highly selective when used as fumigant and did not change parasitoid behavior. After one week, the residues of these oils were harmless and did not show sublethal effects against T. basalis. According with these results, essential oils have potential applications for the integrated management of N. viridula.

  1. [Quality of different aphids species as hosts for the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae)].

    PubMed

    Sidney, Lívia A; Bueno, Vanda H P; Lins, Juracy C; Silva, Diego B; Sampaio, Marcus V

    2010-01-01

    The suitability of Macrosiphum euphorbiae (Thomas), Aulacorthum solani (Kaltenbach) and Acyrthosiphon kondoi Shinji (Hemiptera: Aphididae) as hosts for the aphid parasitoid Aphidius ervi Haliday was evaluated by assessing host size, host preference, and host quality. Tests were carried out in an environmental chamber at 22±1ºC, 70±10% RH and 12h photophase. Replicates (11) consisted of one 24h-old mated female of A. ervi without a previous oviposition experience. Female was released into a Petri dish (5 cm) with 20 2nd and 3rd instars of one of each aphid species tested on a leaf disc of the host plant onto a 1% water-agar layer. Parasitoid emergency was lower in A. kondoi (78.7%) compared to M. euphorbiae (92.2%) and A. solani (91.7%). Acyrthosiphon kondoi (0.36 mm) was the smallest host. The parasitoid showed preference (74.0% parasitism) for M. euphorbiae, the largest host (hind tibia length=0.73 mm), which in turn yielded larger A. ervi females (0.75 mm).

  2. Augmentative Biological Control Using Parasitoids for Fruit Fly Management in Brazil

    PubMed Central

    Garcia, Flávio R. M.; Ricalde, Marcelo P.

    2012-01-01

    The history of classical biological control of fruit flies in Brazil includes two reported attempts in the past 70 years. The first occurred in 1937 when an African species of parasitoid larvae (Tetrastichus giffardianus) was introduced to control the Mediterranean fruit fly, Ceratitis capitata and other tephritids. The second occurred in September 1994 when the exotic parasitoid Diachasmimorpha longicaudata, originally from Gainesville, Florida, was introduced by a Brazilian agricultural corporation (EMBRAPA) to evaluate the parasitoid’s potential for the biological control of Anastrepha spp. and Ceratitis capitata. Although there are numerous native Brazilian fruit fly parasitoids, mass rearing of these native species is difficult. Thus, D. longicaudata was chosen due to its specificity for the family Tephritidae and its ease of laboratory rearing. In this paper we review the literature on Brazilian fruit fly biological control and suggest that those tactics can be used on a large scale, together creating a biological barrier to the introduction of new fruit fly populations, reducing the source of outbreaks and the risk of species spread, while decreasing the use of insecticides on fruit destined for domestic and foreign markets. PMID:26466795

  3. The Acoustical Environment.

    ERIC Educational Resources Information Center

    Smith, Melissa

    Asserting that without an adequate acoustical environment, learning activities can be hindered, this paper reviews the literature on classroom acoustics, particularly noise, reverberation, signal-to-noise ratio, task performance, and recommendations for improvement. Through this review, the paper seeks to determine whether portable classrooms…

  4. Cystic acoustic schwannomas.

    PubMed

    Lunardi, P; Missori, P; Mastronardi, L; Fortuna, A

    1991-01-01

    Three cases with large space-occupying cysts in the cerebellopontine angle are reported. CT and MRI findings were not typical for acoustic schwannomas but at operation, besides the large cysts, small acoustic schwannomas could be detected and removed. The clinical and neuroradiological features of this unusual variety and the CT and MRI differential diagnosis of cerebellopontine angle lesions are discussed.

  5. Acoustic Remote Sensing

    NASA Astrophysics Data System (ADS)

    Dowling, David R.; Sabra, Karim G.

    2015-01-01

    Acoustic waves carry information about their source and collect information about their environment as they propagate. This article reviews how these information-carrying and -collecting features of acoustic waves that travel through fluids can be exploited for remote sensing. In nearly all cases, modern acoustic remote sensing involves array-recorded sounds and array signal processing to recover multidimensional results. The application realm for acoustic remote sensing spans an impressive range of signal frequencies (10-2 to 107 Hz) and distances (10-2 to 107 m) and involves biomedical ultrasound imaging, nondestructive evaluation, oil and gas exploration, military systems, and Nuclear Test Ban Treaty monitoring. In the past two decades, approaches have been developed to robustly localize remote sources; remove noise and multipath distortion from recorded signals; and determine the acoustic characteristics of the environment through which the sound waves have traveled, even when the recorded sounds originate from uncooperative sources or are merely ambient noise.

  6. Acoustic suspension system

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Wang, T. G. (Inventor)

    1983-01-01

    An acoustic levitation system is described, with single acoustic source and a small reflector to stably levitate a small object while the object is processed as by coating or heating it. The system includes a concave acoustic source which has locations on opposite sides of its axis that vibrate towards and away from a focal point to generate a converging acoustic field. A small reflector is located near the focal point, and preferably slightly beyond it, to create an intense acoustic field that stably supports a small object near the reflector. The reflector is located about one-half wavelength from the focal point and is concavely curved to a radius of curvature (L) of about one-half the wavelength, to stably support an object one-quarter wavelength (N) from the reflector.

  7. Virtual acoustics displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

    1991-01-01

    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

  8. Cochlear bionic acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Fu, Gang; Bai, Changan

    2014-11-01

    A design of bionic acoustic metamaterial and acoustic functional devices was proposed by employing the mammalian cochlear as a prototype. First, combined with the experimental data in previous literatures, it is pointed out that the cochlear hair cells and stereocilia cluster are a kind of natural biological acoustic metamaterials with the negative stiffness characteristics. Then, to design the acoustic functional devices conveniently in engineering application, a simplified parametric helical structure was proposed to replace actual irregular cochlea for bionic design, and based on the computational results of such a bionic parametric helical structure, it is suggested that the overall cochlear is a local resonant system with the negative dynamic effective mass characteristics. There are many potential applications in the bandboard energy recovery device, cochlear implant, and acoustic black hole.

  9. Acoustic integrated extinction

    PubMed Central

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time-dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency. PMID:27547100

  10. Direct Field Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Larkin, Paul; Goldstein, Bob

    2008-01-01

    This paper presents an update to the methods and procedures used in Direct Field Acoustic Testing (DFAT). The paper will discuss some of the recent techniques and developments that are currently being used and the future publication of a reference standard. Acoustic testing using commercial sound system components is becoming a popular and cost effective way of generating a required acoustic test environment both in and out of a reverberant chamber. This paper will present the DFAT test method, the usual setup and procedure and the development and use of a closed-loop, narrow-band control system. Narrow-band control of the acoustic PSD allows all standard techniques and procedures currently used in random control to be applied to acoustics and some examples are given. The paper will conclude with a summary of the development of a standard practice guideline that is hoped to be available in the first quarter of next year.

  11. Virtual acoustics displays

    NASA Astrophysics Data System (ADS)

    Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

    1991-03-01

    The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

  12. Effect of host decoys on the ability of the parasitoids Muscidifurax raptor and Spalangia cameroni to parasitize house fly (Diptera: Muscidae) puparia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pteromalid pupal parasitoids Muscidifurax raptor Girault and Sanders and Spalangia cameroni Perkins (Hymenoptera: Pteromalidae) are commonly released on livestock farms for management of house flies (Diptera: Muscidae). To be effective, parasitoids must be able to locate live host puparia in co...

  13. Effects of Size and Age of the Host Musca domestica (Diptera: Muscidae) on Production of the Parasitoid Wasp Spalangia endius (Hymenoptera: Pteromalidae).

    PubMed

    Broski, Scott A; King, B H

    2017-02-01

    One method of control of house flies, Musca domestica L. (Diptera: Muscidae), and other filth flies is by repeated release of large numbers of pupal parasitoids such as Spalangia endius Walker. Rearing these parasitoids may be facilitated by understanding how host factors affect their production. Previous studies have examined the effects of host size and host age on parasitoid production, but have not examined the interaction between host size and host age or the effects with older females, which may be less capable of drilling tough hosts. Females were given hosts of a single size-age category (small young, small old, large young, or large old) for 2 wk. The effect of host size and of host age on parasitoid production depended on female age. On their first day of oviposition, females produced more offspring from large than from small hosts, but host age had no significant effect. The cumulative number of parasitoids produced in the first week was not significantly affected by host size or host age. However, the cumulative number of parasitoids produced over 2 wk was affected by both host size and host age, with the greatest number of parasitoids produced from small young hosts. Thus, not only are smaller hosts cheaper to produce, but these results suggest that their use may have no effect or a positive effect on the number of parasitoids that can be produced when females are ovipositing for a week or two.

  14. Functional endogenous viral elements (EVEs) in the genome of the parasitoid wasp cotesia congregata: insights into the evolutionary dynamics of bracoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bracoviruses represent the most complex Endogenous Viral Elements (EVEs) described to date. Nudiviral genes have been hosted within the genomes of parasitoid wasps since ~ 100 MYA (Million Years Ago) and are functionally integrated in the parasitoid wasp life cycle. They are involved in the producti...

  15. Monitoring the establishment and flight phenology of egg and larval parasitoids of emerald ash borer (Coleoptera: Buprestidae) in Michigan, USA using sentinel eggs and larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoids, Tetrastichus planipennisi Yang and Spathius agrili Yang, and one egg parasitoid, Oobius agrili Zhang and Huang, were introduced into the United Sta...

  16. Evaluation of the host specificity of Spathius galinae (Hymenoptera: Braconidae), a larval parasitoid of the emerald ash borer (Coleoptera: Buprestidae) in Northeast Asia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-specificity determination prior to the introduction of non-native natural enemies (predators and parasitoids) is a critical component of the risk assessment for modern classical biological control programs. In the present study, we assessed the host specificity of a newly described parasitoid,...

  17. Parasitoids select plants more heavily infested with their caterpillar hosts: a new approach to aid interpretation of plant headspace volatiles

    PubMed Central

    Girling, Robbie D.; Stewart-Jones, Alex; Dherbecourt, Julie; Staley, Joanna T.; Wright, Denis J.; Poppy, Guy M.

    2011-01-01

    Plants produce volatile organic compounds (VOCs) in response to herbivore attack, and these VOCs can be used by parasitoids of the herbivore as host location cues. We investigated the behavioural responses of the parasitoid Cotesia vestalis to VOCs from a plant–herbivore complex consisting of cabbage plants (Brassica oleracea) and the parasitoids host caterpillar, Plutella xylostella. A Y-tube olfactometer was used to compare the parasitoids' responses to VOCs produced as a result of different levels of attack by the caterpillar and equivalent levels of mechanical damage. Headspace VOC production by these plant treatments was examined using gas chromatography–mass spectrometry. Cotesia vestalis were able to exploit quantitative and qualitative differences in volatile emissions, from the plant–herbivore complex, produced as a result of different numbers of herbivores feeding. Cotesia vestalis showed a preference for plants with more herbivores and herbivore damage, but did not distinguish between different levels of mechanical damage. Volatile profiles of plants with different levels of herbivores/herbivore damage could also be separated by canonical discriminant analyses. Analyses revealed a number of compounds whose emission increased significantly with herbivore load, and these VOCs may be particularly good indicators of herbivore number, as the parasitoid processes cues from its external environment. PMID:21270031

  18. Susceptibility of two hymenopteran parasitoids of Agrilus planipennis (Coleoptera: Buprestidae) to the entomopathogenic fungus Beauveria bassiana (Ascomycota: Hypocreales).

    PubMed

    Dean, Kimberly M; Vandenberg, John D; Griggs, Michael H; Bauer, Leah S; Fierke, Melissa K

    2012-03-01

    Emerald ash borer (EAB), Agrilus planipennis Fairmaire, native to Asia, is killing ash trees (Fraxinus spp.) across 15 states and southeastern Canada. Integrated pest management using biological control is the only viable long-term approach for controlling the spread of EAB outside of host resistance. Three hymenopteran parasitoids, Spathius agrili Yang, Tetrastichus planipennisi Yang, and Oobius agrili Zhang and Huang were discovered attacking EAB in China and were approved for release in the United States in 2007. The objective of this study was to assess susceptibility of the larval parasitoid species S. agrili and T. planipennisi, relative to that of EAB, to Beauveria bassiana, an entomopathogenic fungus that infects and kills EAB adults when sprayed on ash bark or foliage. Adult EAB and parasitoids were exposed to B. bassiana inoculated ash twigs for 2 h and then monitored daily for death and signs of infection for up to 10 days. All EAB adults exposed to B. bassiana were fatally infected while mean survival for control EAB was 77%. Average survival in the treatment groups for T. planipennisi and S. agrili were 99% and 83%, respectively, indicating these parasitoids are relatively unaffected by exposure to B. bassiana. This research elucidates interactions between a fungal pathogen and two parasitoids of EAB, and provides data necessary to developing a successful multi-stage integrated management approach to control of EAB.

  19. Attack and Success of Native and Exotic Parasitoids on Eggs of Halyomorpha halys in Three Maryland Habitats

    PubMed Central

    Herlihy, Megan V.; Talamas, Elijah J.; Weber, Donald C.

    2016-01-01

    Egg parasitoids of the exotic invasive brown marmorated stink bug, Halyomorpha halys (Stål), were investigated using lab-reared fresh (live) and frozen (killed) lab-reared sentinel egg masses deployed for 72h on foliage in three habitats—woods, orchard, and soybean field—in Maryland, USA, in summer 2014. Four native hymenopteran species, Telenomus podisi Ashmead (Scelionidae), Trissolcus euschisti (Ashmead) and Tr. brochymenae Ashmead (Scelionidae), and Anastatus reduvii (Howard) (Eupelmidae), developed and emerged from H. halys eggs. One exotic parasitoid, Trissolcus japonicus (Ashmead), emerged, providing the first known occurrence of this species in North America. Native parasitoids emerged from frozen eggs significantly more often than from fresh eggs (89.3% of egg masses and 98.1% of individual eggs), whereas the exotic Tr. japonicus did not show a similar difference, strongly suggesting adaptation to H. halys as a host by Tr. japonicus but not by the native species. Parasitoids were habitat-specific: all three Trissolcus species were significantly more likely to occur in the woods habitat, whereas Te. podisi was found exclusively in the soybean field. Further investigations are required to elucidate evolving host-parasitoid relationships, habitat specificity, and non-target effects of Tr. japonicus over the expanded range of H. halys in North America. PMID:26983012

  20. Determination of Opiinae parasitoids (Hymenoptera: Braconidae) associated with crop infesting Bactrocera spp. (Diptera: Tephritidae) using COI and Cyt b sequences

    NASA Astrophysics Data System (ADS)

    Shariff, Safiah; Yaakop, Salmah; Zain, Badrul Munir Md.

    2013-11-01

    Members of the Opiinae subfamily (Hymenoptera: Braconidae) are well known as important parasitoids of fruit fly larvae (Diptera: Tephritidae). They are widely used as biological control agents of fruit flies, especially the Bactrocera Macquart species that infest fruits. In this study, the larvae of fruit flies were collected from infested crops including star fruit, guava, wax apple and ridge gourd. The parasitized larvae were then reared under laboratory conditions until emergence of the adult parasitoids. Additionally, Malaise trap also was used to collect parasitoid species. The general concept of the multiplex PCR has been performed is to amplify two mitochondrial DNA markers, namely cytochrome oxidase subunit I (COI) and cytochrome b (Cyt b) simultaneously. Therefore, the lengthy process of reaction will be reduced. The status of the fruit fly species has also been confirmed by using COI marker on the early stage of the larvae. Maximum parsimony (MP) and Bayesian Inference (BI) were implemented to help and support the identification of Opiinae species. The result obtained from this study showed three parasitoid genera of the Opiinae viz. Fopius Wharton, Psyttalia Walker and Diachasmimorpha Viereck. Each genus has been determined by clustering together in a similar clade according to their infested crops. Therefore, accurate determination of parasitoids and the fruit fries species was highly useful and necessary for successful biological control of Bactrocera species.

  1. Parasitoids select plants more heavily infested with their caterpillar hosts: a new approach to aid interpretation of plant headspace volatiles.

    PubMed

    Girling, Robbie D; Stewart-Jones, Alex; Dherbecourt, Julie; Staley, Joanna T; Wright, Denis J; Poppy, Guy M

    2011-09-07

    Plants produce volatile organic compounds (VOCs) in response to herbivore attack, and these VOCs can be used by parasitoids of the herbivore as host location cues. We investigated the behavioural responses of the parasitoid Cotesia vestalis to VOCs from a plant-herbivore complex consisting of cabbage plants (Brassica oleracea) and the parasitoids host caterpillar, Plutella xylostella. A Y-tube olfactometer was used to compare the parasitoids' responses to VOCs produced as a result of different levels of attack by the caterpillar and equivalent levels of mechanical damage. Headspace VOC production by these plant treatments was examined using gas chromatography-mass spectrometry. Cotesia vestalis were able to exploit quantitative and qualitative differences in volatile emissions, from the plant-herbivore complex, produced as a result of different numbers of herbivores feeding. Cotesia vestalis showed a preference for plants with more herbivores and herbivore damage, but did not distinguish between different levels of mechanical damage. Volatile profiles of plants with different levels of herbivores/herbivore damage could also be separated by canonical discriminant analyses. Analyses revealed a number of compounds whose emission increased significantly with herbivore load, and these VOCs may be particularly good indicators of herbivore number, as the parasitoid processes cues from its external environment.

  2. Host instar susceptibility and selection and interspecific competition of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae).

    PubMed

    Amarasekare, Kaushalya G; Mannion, Catharine M; Epsky, Nancy D

    2010-10-01

    Three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff [Hymenoptera: Encyrtidae]) of the mealybug Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) were studied for their host instar susceptibility and sex ratio, host instar selection, and interspecific competition in the laboratory. All three parasitoids were able to develop in the second instars, third-instar females, and adult females of P. marginatus. No progeny emerged from first-instar mealybugs. The proportion of female emergence was increased with increasing host size. Parasitoids selected their host instars for oviposition when they had a choice. Between second- and third-instar hosts, A. papayae and P. mexicana had significantly higher parasitism in second-instar mealybugs, whereas A. loecki had higher parasitism in the third-instar mealybugs. When competed with either one or two parasitoid species, A. papayae was significantly more successful in second-instar hosts and A. loecki was significantly more successful in third-instar mealybugs. P. mexicana was significantly less competitive when with A. papayae in both second and third instars, with A. loecki in third instars and with both A. papayae and A. loecki in second and third instars. Overall, A. papayae provided a better control of the host, when present singly or with the other two parasitoids. This information is important in evaluating the efficiency of A. papayae, A. loecki, and P. mexicana and understanding the outcome of their recovery and establishment in field studies conducted in Florida.

  3. Attack and Success of Native and Exotic Parasitoids on Eggs of Halyomorpha halys in Three Maryland Habitats.

    PubMed

    Herlihy, Megan V; Talamas, Elijah J; Weber, Donald C

    2016-01-01

    Egg parasitoids of the exotic invasive brown marmorated stink bug, Halyomorpha halys (Stål), were investigated using lab-reared fresh (live) and frozen (killed) lab-reared sentinel egg masses deployed for 72h on foliage in three habitats-woods, orchard, and soybean field-in Maryland, USA, in summer 2014. Four native hymenopteran species, Telenomus podisi Ashmead (Scelionidae), Trissolcus euschisti (Ashmead) and Tr. brochymenae Ashmead (Scelionidae), and Anastatus reduvii (Howard) (Eupelmidae), developed and emerged from H. halys eggs. One exotic parasitoid, Trissolcus japonicus (Ashmead), emerged, providing the first known occurrence of this species in North America. Native parasitoids emerged from frozen eggs significantly more often than from fresh eggs (89.3% of egg masses and 98.1% of individual eggs), whereas the exotic Tr. japonicus did not show a similar difference, strongly suggesting adaptation to H. halys as a host by Tr. japonicus but not by the native species. Parasitoids were habitat-specific: all three Trissolcus species were significantly more likely to occur in the woods habitat, whereas Te. podisi was found exclusively in the soybean field. Further investigations are required to elucidate evolving host-parasitoid relationships, habitat specificity, and non-target effects of Tr. japonicus over the expanded range of H. halys in North America.

  4. Application of DNA barcoding to the identification of Hymenoptera parasitoids from the soybean aphid (Aphis glycines) in China.

    PubMed

    Zhou, Qing-Song; Xi, Yu-Qiang; Yu, Fang; Zhang, Xu; Li, Xue-Jun; Liu, Chun-Lai; Niu, Ze-Qing; Zhu, Chao-Dong; Qiao, Ge-Xia; Zhang, Yan-Zhou

    2014-06-01

    Aphis glycines Matsumura is an important pest of soybean in Asia and North America. Hymenoptera parasitoids play a key role in the control of the soybean aphid. The correct identification of parasitoids is a critical step that precedes the assessment of their potential biological control agents. Accurate identification of the majority of the species attacking the soybean aphid often requires elaborate specimen preparation and expert taxonomic knowledge. In this study, we facilitated the identification of soybean aphid parasitoids by applying a DNA barcoding approach following a preliminary morphological identification. We generated DNA sequence data from the mitochondrial COI gene and the D2 region of 28S rDNA to assess the genetic variation within and between parasitoid species emerging from the soybean aphid in China. Fifteen Hymenoptera parasitoid species belonging to 10 genera of five families were identified with little intra-specific variation (0.09% ± 0.06% for 28S and 0.36% ± 0.18% for COI) and large inter-specific divergence (30.46% ± 3.42% for 28S and 20.4% ± 1.20% for COI).

  5. Egg distributions and the information a solitary parasitoid has and uses for its oviposition decisions.

    PubMed

    Hemerik, Lia; van der Hoeven, Nelly; van Alphen, Jacques J M

    2002-01-01

    Approximately three decades ago the question was first answered "whether parasitoids are able to assess the number or origin of eggs in a host" for a solitary parasitoid, Leptopilina heterotoma, by fitting theoretically derived distributions to empirical ones. We extend the set of different theoretically postulated distributions of eggs among hosts by combining searching modes and abilities in assessing host quality. In the models, parasitoids search either randomly (Poisson) (1) or by vibrotaxis (Negative Binomial) (2). Parasitoids are: (a) assumed to treat all hosts equally, (b) able to distinguish them in unparasitised and parasitised hosts only, (c) able to distinguish them by the number of eggs they contained, or (d) able to recognise their own eggs. Mathematically tractable combinations of searching mode (1 and 2) and abilities (a,b,c,d) result in seven different models (M1a, M1b, M1c, M1d, M2a, M2b and M2c). These models have been simulated for a varying number of searching parasitoids and various mean numbers of eggs per host. Each resulting distribution is fitted to all theoretical models. The model with the minimum Akaike's information criterion (AIC) is chosen as the best fitting for each simulated distribution. We thus investigate the power of the AIC and for each distribution with a specified mean number of eggs per host we derive a frequency distribution for classification. Firstly, we discuss the simulations of models including random search (M1a, M1b, M1c and M1d). For M1a, M1c and M1d the simulated distributions are correctly classified in at least 70% of all cases. However, in a few cases model M1b is only properly classified for intermediate mean values of eggs per host. The models including vibrotaxis as searching behaviour (M2a, M2b and M2c) cannot be distinguished from those with random search if the mean number of eggs per host is low. Among the models incorporating vibrotaxis the three abilities are detected analogously as in models with

  6. Acoustic mapping velocimetry

    NASA Astrophysics Data System (ADS)

    Muste, M.; Baranya, S.; Tsubaki, R.; Kim, D.; Ho, H.; Tsai, H.; Law, D.

    2016-05-01

    Knowledge of sediment dynamics in rivers is of great importance for various practical purposes. Despite its high relevance in riverine environment processes, the monitoring of sediment rates remains a major and challenging task for both suspended and bed load estimation. While the measurement of suspended load is currently an active area of testing with nonintrusive technologies (optical and acoustic), bed load measurement does not mark a similar progress. This paper describes an innovative combination of measurement techniques and analysis protocols that establishes the proof-of-concept for a promising technique, labeled herein Acoustic Mapping Velocimetry (AMV). The technique estimates bed load rates in rivers developing bed forms using a nonintrusive measurements approach. The raw information for AMV is collected with acoustic multibeam technology that in turn provides maps of the bathymetry over longitudinal swaths. As long as the acoustic maps can be acquired relatively quickly and the repetition rate for the mapping is commensurate with the movement of the bed forms, successive acoustic maps capture the progression of the bed form movement. Two-dimensional velocity maps associated with the bed form migration are obtained by implementing algorithms typically used in particle image velocimetry to acoustic maps converted in gray-level images. Furthermore, use of the obtained acoustic and velocity maps in conjunction with analytical formulations (e.g., Exner equation) enables estimation of multidirectional bed load rates over the whole imaged area. This paper presents a validation study of the AMV technique using a set of laboratory experiments.

  7. Acoustic cooling engine

    DOEpatents

    Hofler, Thomas J.; Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1988-01-01

    An acoustic cooling engine with improved thermal performance and reduced internal losses comprises a compressible fluid contained in a resonant pressure vessel. The fluid has a substantial thermal expansion coefficient and is capable of supporting an acoustic standing wave. A thermodynamic element has first and second ends and is located in the resonant pressure vessel in thermal communication with the fluid. The thermal response of the thermodynamic element to the acoustic standing wave pumps heat from the second end to the first end. The thermodynamic element permits substantial flow of the fluid through the thermodynamic element. An acoustic driver cyclically drives the fluid with an acoustic standing wave. The driver is at a location of maximum acoustic impedance in the resonant pressure vessel and proximate the first end of the thermodynamic element. A hot heat exchanger is adjacent to and in thermal communication with the first end of the thermodynamic element. The hot heat exchanger conducts heat from the first end to portions of the resonant pressure vessel proximate the hot heat exchanger. The hot heat exchanger permits substantial flow of the fluid through the hot heat exchanger. The resonant pressure vessel can include a housing less than one quarter wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir. The frequency of the acoustic driver can be continuously controlled so as to maintain resonance.

  8. Acoustic sniper localization system

    NASA Astrophysics Data System (ADS)

    Prado, Gervasio; Dhaliwal, Hardave; Martel, Philip O.

    1997-02-01

    Technologies for sniper localization have received increased attention in recent months as American forces have been deployed to various trouble spots around the world. Among the technologies considered for this task acoustics is a natural choice for various reasons. The acoustic signatures of gunshots are loud and distinctive, making them easy to detect even in high noise background environments. Acoustics provides a passive sensing technology with excellent range and non line of sight capabilities. Last but not least, an acoustic sniper location system can be built at a low cost with off the shelf components. Despite its many advantages, the performance of acoustic sensors can degrade under adverse propagation conditions. Localization accuracy, although good, is usually not accurate enough to pinpoint a sniper's location in some scenarios (for example which widow in a building or behind which tree in a grove). For these more demanding missions, the acoustic sensor can be used in conjunction with an infra red imaging system that detects the muzzle blast of the gun. The acoustic system can be used to cue the pointing system of the IR camera in the direction of the shot's source.

  9. Comparative GC-EAD responses of a specialist (Microplitis croceipes) and a generalist (Cotesia marginiventris) parasitoid to cotton volatiles induced by two caterpillar species.

    PubMed

    Ngumbi, Esther; Chen, Li; Fadamiro, Henry Yemisi

    2009-09-01

    Plants emit volatile blends that may be quantitatively and/or qualitatively different in response to attack by different herbivores. These differences may convey herbivore-specific information to parasitoids, and are predicted to play a role in mediating host specificity in specialist parasitoids. Here, we tested the above prediction by using as models two parasitoids (Hymenoptera: Braconidae) of cotton caterpillars with different degree of host specificity: Microplitis croceipes, a specialist parasitoid of Heliothis spp., and Cotesia marginiventris, a generalist parasitoid of caterpillars of several genera including Heliothis spp. and Spodoptera spp. We compared GC-EAD (coupled gas chromatography electroantennogram detection) responses of both parasitoid species to headspace volatiles of cotton plants damaged by H. virescens (a host species for both parasitoids) vs. S. exigua (a host species for C. marginiventris). Based on a recent study in which we reported differences in the EAG responses of both parasitoids to different types of host related volatiles, we hypothesized that M. croceipes (specialist) would show relatively greater GC-EAD responses to the herbivore-induced plant volatile (HIPV) components of cotton headspace, whereas C. marginiventris (generalist) would show greater response to the green leaf volatile (GLV) components. Thirty volatile components were emitted by cotton plants in response to feeding by either of the two caterpillars, however, 18 components were significantly elevated in the headspace of H. virescens damaged plants. Sixteen consistently elicited GC-EAD responses in both parasitoids. As predicted, C. marginiventris showed significantly greater GC-EAD responses than M. croceipes to most GLV components, whereas several HIPV components elicited comparatively greater responses in M. croceipes. These results suggest that differences in the ratios of identical volatile compounds between similar volatile blends may be used by specialist

  10. Drought and Root Herbivory Interact to Alter the Response of Above-Ground Parasitoids to Aphid Infested Plants and Associated Plant Volatile Signals

    PubMed Central

    Tariq, Muhammad; Wright, Denis J.; Bruce, Toby J. A.; Staley, Joanna T.

    2013-01-01

    Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores), their parasitoids, and a dipteran species (root herbivore).We tested the hypotheses that: (1) high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2) drought stress and root herbivory change the profile of volatile organic chemicals (VOCs) emitted by the host plant; (3) parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference), plant volatile emissions, parasitism success (performance), and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40–55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity) of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial communities may

  11. Drought and root herbivory interact to alter the response of above-ground parasitoids to aphid infested plants and associated plant volatile signals.

    PubMed

    Tariq, Muhammad; Wright, Denis J; Bruce, Toby J A; Staley, Joanna T

    2013-01-01

    Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores), their parasitoids, and a dipteran species (root herbivore).We tested the hypotheses that: (1) high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2) drought stress and root herbivory change the profile of volatile organic chemicals (VOCs) emitted by the host plant; (3) parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference), plant volatile emissions, parasitism success (performance), and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40-55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity) of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial communities may be

  12. The room acoustic rendering equation.

    PubMed

    Siltanen, Samuel; Lokki, Tapio; Kiminki, Sami; Savioja, Lauri

    2007-09-01

    An integral equation generalizing a variety of known geometrical room acoustics modeling algorithms is presented. The formulation of the room acoustic rendering equation is adopted from computer graphics. Based on the room acoustic rendering equation, an acoustic radiance transfer method, which can handle both diffuse and nondiffuse reflections, is derived. In a case study, the method is used to predict several acoustic parameters of a room model. The results are compared to measured data of the actual room and to the results given by other acoustics prediction software. It is concluded that the method can predict most acoustic parameters reliably and provides results as accurate as current commercial room acoustic prediction software. Although the presented acoustic radiance transfer method relies on geometrical acoustics, it can be extended to model diffraction and transmission through materials in future.

  13. PRSEUS Acoustic Panel Fabrication

    NASA Technical Reports Server (NTRS)

    Nicolette, Velicki; Yovanof, Nicolette P.; Baraja, Jaime; Mathur, Gopal; Thrash, Patrick; Pickell, Robert

    2011-01-01

    This report describes the development of a novel structural concept, Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), that addresses the demanding fuselage loading requirements for the Hybrid Wing or Blended Wing Body (BWB) airplane configuration with regards to acoustic response. A PRSEUS panel was designed and fabricated and provided to NASA-LaRC for acoustic response testing in the Structural Acoustics Loads and Transmission (SALT) facility). Preliminary assessments of the sound transmission characteristics of a PRSEUS panel subjected to a representative Hybrid Wing Body (HWB) operating environment were completed for the NASA Environmentally Responsible Aviation (ERA) Program.

  14. Acoustic well cleaner

    DOEpatents

    Maki, Jr., Voldi E.; Sharma, Mukul M.

    1997-01-21

    A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

  15. Acoustical heat pumping engine

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

  16. Acoustical heat pumping engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

  17. Effect of host quality of Callosobruchus maculatus (Coleoptera: Bruchidae) on performance of the egg parasitoid Uscana lariophaga (Hymenoptera: Trichogrammatidae).

    PubMed

    Spitzen, J; van Huis, A

    2005-08-01

    Development and reproductive success of the solitary egg parasitoid Uscana lariophaga Steffan were examined after development in eggs of the bruchid storage pest Callosobruchus maculatus Fabricius reared at either low or high densities on cowpea seeds and laid at day 1 and 4 of maternal life. Both bruchid larval competition and maternal age negatively affected egg size, but the latter more than the former. Uscana lariophaga reared in small hosts developed slower, were smaller and produced fewer eggs compared to parasitoids reared in large hosts. Fecundity of the parasitoid was heavily influenced by host egg size. This was reflected in the values for the intrinsic rate of increase of U. lariophaga, which differed for wasps that developed in host eggs laid by bruchid females of different age. Wasps allocated marginally more female offspring to larger hosts.

  18. Acoustic imaging system

    DOEpatents

    Smith, Richard W.

    1979-01-01

    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  19. Compact acoustic refrigerator

    SciTech Connect

    Bennett, G.A.

    1991-12-31

    This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

  20. Acoustic borehole logging

    SciTech Connect

    Medlin, W.L.; Manzi, S.J.

    1990-10-09

    This patent describes an acoustic borehole logging method. It comprises traversing a borehole with a borehole logging tool containing a transmitter of acoustic energy having a free-field frequency spectrum with at least one characteristic resonant frequency of vibration and spaced-apart receiver, repeatedly exciting the transmitter with a swept frequency tone burst of a duration sufficiently greater than the travel time of acoustic energy between the transmitter and the receiver to allow borehole cavity resonances to be established within the borehole cavity formed between the borehole logging tool and the borehole wall, detecting acoustic energy amplitude modulated by the borehole cavity resonances with the spaced-apart receiver, and recording an amplitude verses frequency output of the receiver in correlation with depth as a log of the borehole frequency spectrum representative of the subsurface formation comprising the borehole wall.

  1. Acoustic imaging system

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Jr.

    1977-01-01

    Tool detects noise sources by scanning sound "scene" and displaying relative location of noise-producing elements in area. System consists of ellipsoidal acoustic mirror and microphone and a display device.

  2. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  3. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  4. Acoustic bubble traps

    NASA Astrophysics Data System (ADS)

    Geisler, Reinhard; Kurz, Thomas; Lauterborn, Werner

    2000-07-01

    A small, oscillating bubble in a liquid can be trapped in the antinode of an acoustic standing wave field. Bubble stability is required for the study of single bubble sonoluminescence (SBSL). The properties of the acoustic resonator are essential for the stable trapping of sonoluminescing bubbles. Resonators can be chosen according to the intended application: size and geometry can be varied in a wide range. In this work, the acoustic responses of different resonators were measured by means of holographic interferometry, hydrophones and a laser vibrometer. Also, high-speed photography was used to observe the bubble dynamics. Several single, stable sonoluminescent bubbles were trapped simultaneously within an acoustic resonator in the pressure antinodes of a higher harmonic mode (few bubble sonoluminescence, FBSL).

  5. Department of Cybernetic Acoustics

    NASA Astrophysics Data System (ADS)

    The development of the theory, instrumentation and applications of methods and systems for the measurement, analysis, processing and synthesis of acoustic signals within the audio frequency range, particularly of the speech signal and the vibro-acoustic signal emitted by technical and industrial equipments treated as noise and vibration sources was discussed. The research work, both theoretical and experimental, aims at applications in various branches of science, and medicine, such as: acoustical diagnostics and phoniatric rehabilitation of pathological and postoperative states of the speech organ; bilateral ""man-machine'' speech communication based on the analysis, recognition and synthesis of the speech signal; vibro-acoustical diagnostics and continuous monitoring of the state of machines, technical equipments and technological processes.

  6. Basic Linear Acoustics

    NASA Astrophysics Data System (ADS)

    Pierce, Alan D.

    This chapter deals with the physical and mathematical aspects of sound when the disturbances are, in some sense, small. Acoustics is usually concerned with small-amplitude phenomena, and consequently a linear description is usually acoustics applicable. Disturbances are governed by the properties of the medium in which they occur, and the governing equations are the equations of continuum mechanics, which apply equally to gases, liquids, and solids. These include the mass, momentum, and energy equations, as well as thermodynamic principles. The viscosity and thermal conduction enter into the versions of these equations that apply to fluids. Fluids of typical great interest are air and sea water, and consequently this chapter includes a summary of their relevant acoustic properties. The foundation is also laid for the consideration of acoustic waves in elastic solids, suspensions, bubbly liquids, and porous media.

  7. Acoustics lecturing in Mexico

    NASA Astrophysics Data System (ADS)

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  8. Acoustic Neuroma Association

    MedlinePlus

    ... this sponsor... Platinum Sponsor More from this sponsor... Gold Sponsor University of Colorado Acoustic Neuroma Program Rocky Mountain Gamma Knife Center More from this sponsor... Gold Sponsor NYU Langone Medical Center Departments of Neurosurgery ...

  9. Differential Effects of Pesticide Applications on Liriomyza huidobrensis (Diptera: Agromyzidae) and its Parasitoids on Pea in Central Kenya.

    PubMed

    Guantai, M M; Ogol, C P K O; Salifu, D; Kasina, J M; Akutse, K S; Fiaboe, K K M

    2015-04-01

    Three Liriomyza species [Liriomyza huidobrensis (Blanchard), Liriomyza trifolii (Burgess), and Liriomyza sativae Blanchard] have been reported as the most important leafminer pests in vegetable production systems in Africa. In Kenya, farmers rely on indiscriminate synthetic insecticides use. On-farm field investigations were set up at three different locations (Sagana, Kabaru, and Naromoru) in central Kenya to determine the effect of pesticide application on the abundance of leafminers and their parasitoids under three management practices, namely: farmer practice (FP), reduced pesticide use (RP), and a control with no use of pesticides (CO). In addition, laboratory experiments were designed to test the effect of commonly used pesticides in pea production systems in central Kenya--Dimethoate, Dynamec, Thunder, Cyclone, Bestox, Folicur, Milraz, and Bulldock--on L. huidobrensis and two of its parasitoids, Diglyphus isaea Walker and Phaedrotoma scabriventris Nixon. The mean numbers of leafminer flies in control treatment were higher than in RP and FP in both first and second seasons across all sites, but RP and FP did not differ significantly. Parasitoid numbers were very low and there was no much variation between treatments at each location in both first and second seasons. No significant differences were observed between the three management practices with regards to the yield measurements. In the laboratory, the estimated LD50 values for L. huidobrensis larvae were all more than two times higher than the recommended dosages, while the LD50 of adults were below the recommended dosages. The estimated LD50 values for the parasitoids were much lower than recommended dosages for all pesticides except Thunder. This study, therefore, demonstrates that the pesticides currently used do not control the Liriomyza leafminer larvae that constitute the most destructive stage of the pest, but are rather detrimental to their parasitoids. In addition, the current low level of

  10. At Lunch with a Killer: The Effect of Weaver Ants on Host-Parasitoid Interactions on Mango

    PubMed Central

    Migani, Valentina; Ekesi, Sunday; Merkel, Katharina; Hoffmeister, Thomas

    2017-01-01

    Predator-prey interactions can affect the behaviour of the species involved, with consequences for population distribution and competitive interactions. Under predation pressure, potential prey may adopt evasive strategies. These responses can be costly and could impact population growth. As some prey species may be more affected than others, predation pressure could also alter the dynamics among species within communities. In field cages and small observation cages, we studied the interactions between a generalist predator, the African weaver ant, Oecophylla longinoda, two species of fruit flies that are primary pests of mango fruits, Ceratitis cosyra and Bactrocera dorsalis, and their two exotic parasitoids, Fopius arisanus and Diachasmimorpha longicaudata. In all experiments, either a single individual (observation cage experiments) or groups of individuals (field cage experiments) of a single species were exposed to foraging in the presence or absence of weaver ants. Weaver ant presence reduced the number of eggs laid by 75 and 50 percent in B. dorsalis and C. cosyra respectively. Similarly, parasitoid reproductive success was negatively affected by ant presence, with success of parasitism reduced by around 50 percent for both F. arisanus and D. longicaudata. The negative effect of weaver ants on both flies and parasitoids was mainly due to indirect predation effects. Encounters with weaver ant workers increased the leaving tendency in flies and parasitoids, thus reduced the time spent foraging on mango fruits. Parasitoids were impacted more strongly than fruit flies. We discuss how weaver ant predation pressure may affect the population dynamics of the fruit flies, and, in turn, how the alteration of host dynamics could impact parasitoid foraging behaviour and success. PMID:28146561

  11. Primary and secondary parasitoids (Hymenoptera) of aphids (Hemiptera: Aphididae) on blueberry and other Vaccinium in the Pacific Northwest.

    PubMed

    Raworth, D A; Pike, K S; Tanigoshi, L K; Mathur, S; Graf, G

    2008-04-01

    Blueberry scorch virus, a commercially important Carlavirus in highbush blueberry, Vaccinium corymbosum L., is vectored by aphids (Hemiptera: Aphididae). We surveyed the aphids, primary parasitoids (Hymenoptera: Aphelinidae, Braconidae), and associated secondary parasitoids (Hymenoptera: Charipidae, Megaspilidae, Pteromalidae) on highbush blueberry and other Vaccinium in the Pacific Northwest from 1995 to 2006, with samples concentrated in 2005 and 2006, to lay the groundwork for augmentative biological control. Ericaphis fimbriata (Richards) was the principal aphid. The dominant parasitoid species were Praon unicum Smith, Aphidius n. sp., A. sp., and Aphidius ervi Haliday. Their frequency in relation to the other primary parasitoids varied significantly with geographical area; P. unicum dominated the frequency distribution in southwestern British Columbia, A. n. sp., west of the Cascades, and A. sp. and A. ervi east of the Cascades. Among the secondary parasitoids, pteromalids dominated, and their frequency in relation to the other secondary parasitoids was lowest in southwestern British Columbia. The parasitization rate for P. unicum and A. n. sp. in southwestern British Columbia increased from May or June to a maximum of 0.080 +/- 0.024 and 0.090 +/- 0.084 (SD), respectively, in late July or early August. P. unicum emerged in the spring 4 wk before A. n. sp. The parasitization rate for P. unicum was lower in conventional than organic fields. Whereas aphid density increased monotonically, P. unicum had two spring peaks. A simulation model showed that these peaks could reflect discrete generations. Releases of insectary-reared P. unicum at 150 or 450 DD above 5.6 degrees C, summing from 1 January, may effectively augment the natural spring populations by creating overlapping generations.

  12. How to escape from the host nest: imperfect chemical mimicry in eucharitid parasitoids and exploitation of the ants' hygienic behavior.

    PubMed

    Pérez-Lachaud, Gabriela; Bartolo-Reyes, Juan Carlos; Quiroa-Montalván, Claudia M; Cruz-López, Leopoldo; Lenoir, Alain; Lachaud, Jean-Paul

    2015-04-01

    Communication in ants is based to a great extent on chemical compounds. Recognition of intruders is primarily based on cuticular hydrocarbon (CHC) profile matching but is prone to being cheated. Eucharitid wasps are specific parasitoids of the brood of ants; the immature stages are either well integrated within the colony or are protected within the host cocoons, whereas adult wasps at emergence must leave their host nest to reproduce and need to circumvent the ant recognition system to escape unscathed. The behavioral interactions between eucharitid wasps and workers of their host, the Neotropical ant Ectatomma tuberculatum, are characterized. In experimental bioassays, newly emerged parasitoids were not violently aggressed. They remained still and were grabbed by ants upon contact and transported outside the nest; host workers were even observed struggling to reject them. Parasitoids were removed from the nest within five minutes, and most were unharmed, although two wasps (out of 30) were killed during the interaction with the ants. We analyzed the CHCs of the ant and its two parasitoids, Dilocantha lachaudii and Isomerala coronata, and found that although wasps shared all of their compounds with the ants, each wasp species had typical blends and hydrocarbon abundance was also species specific. Furthermore, the wasps had relatively few CHCs compared to E. tuberculatum (22-44% of the host components), and these were present in low amounts. Wasps, only partially mimicking the host CHC profile, were immediately recognized as alien and actively removed from the nest by the ants. Hexane-washed wasps were also transported to the refuse piles, but only after being thoroughly inspected and after most of the workers had initially ignored them. Being recognized as intruder may be to the parasitoids' advantage, allowing them to quickly leave the natal nest, and therefore enhancing the fitness of these very short lived parasitoids. We suggest that eucharitids take advantage

  13. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface

    NASA Astrophysics Data System (ADS)

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-11-01

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell’s law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  14. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    PubMed

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-11-24

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  15. Ocean Acoustic Observatory Federation

    DTIC Science & Technology

    2001-09-30

    J., C. G. Fox, and F. K. Duennebier, Hydroacoustic detection of submarine landslides on Kilauea volcano , Geophys. Res. Lett., vol. 28, 1811-1814...acoustic tomography experiments in the vicinity of coastal North America, • Monitor, in real time, marine mammals, earthquakes and volcanoes in the...distances, coastal tomography and thermometry, and earthquakes and volcanoes in the northern Pacific. APPROACH The members of the Ocean Acoustic

  16. Numerical Techniques in Acoustics

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J. (Compiler)

    1985-01-01

    This is the compilation of abstracts of the Numerical Techniques in Acoustics Forum held at the ASME's Winter Annual Meeting. This forum was for informal presentation and information exchange of ongoing acoustic work in finite elements, finite difference, boundary elements and other numerical approaches. As part of this forum, it was intended to allow the participants time to raise questions on unresolved problems and to generate discussions on possible approaches and methods of solution.

  17. The neonatal acoustic reflex.

    PubMed

    Weatherby, L A; Bennett, M J

    1980-01-01

    Probe tones from 220 Hz to 2 000 Hz were used to measure the static and dynamic acoustic impedance of 44 neonates. Acoustic reflex thresholds to broad band noise were obtained from every neonate tested when employing the higher frequency probe tones. The reflex threshold levels measured are similar to those of adults. The static impedance values are discussed to give a possible explanation of why reflex thresholds cannot be detected using conventional 220 Hz impedance bridges.

  18. Directional Acoustic Density Sensor

    DTIC Science & Technology

    2010-09-13

    fluctuations of fluid density at a point . (2) DESCRIPTION OF THE PRIOR ART [0004] Conventional vector sensors measure particle velocity, v (vx,Vytvz...dipole-type or first order sensor that is realized by measuring particle velocity at a point , (which is the vector sensor sensing approach for...underwater sensors), or by measuring the gradient of the acoustic pressure at two closely spaced (less than the wavelength of an acoustic wave) points as it

  19. Low Frequency Acoustics

    DTIC Science & Technology

    2016-06-13

    with NOAA , ONR is providing technical services that will help establish a baseline for assessment of long- term VLF acoustic trends in selected...ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 sponsored by NOAA , was added to the...with NOAA (NMFS) and other parties has dealt with ocean acoustics related to issues stimulated by the Marine Mammal Protection Act. A focal point has

  20. Ocean acoustic reverberation tomography.

    PubMed

    Dunn, Robert A

    2015-12-01

    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

  1. A Game of Russian Roulette for a Generalist Dinoflagellate Parasitoid: Host Susceptibility Is the Key to Success

    PubMed Central

    Alacid, Elisabet; Park, Myung G.; Turon, Marta; Petrou, Katherina; Garcés, Esther

    2016-01-01

    Marine microbial interactions involving eukaryotes and their parasites play an important role in shaping the structure of phytoplankton communities. These interactions may alter population densities of the main host, which in turn may have consequences for the other concurrent species. The effect generalist parasitoids exert on a community is strongly dependent on the degree of host specificity. Parvilucifera sinerae is a generalist parasitoid able to infect a wide range of dinoflagellates, including toxic-bloom-forming species. A density-dependent chemical cue has been identified as the trigger for the activation of the infective stage. Together these traits make Parvilucifera-dinoflagellate hosts a good model to investigate the degree of specificity of a generalist parasitoid, and the potential effects that it could have at the community level. Here, we present for the first time, the strategy by which a generalist dinoflagellate parasitoid seeks out its host and determine whether it exhibits host preferences, highlighting key factors in determining infection. Our results demonstrate that in its infective stage, P. sinerae is able to sense potential hosts, but does not actively select among them. Instead, the parasitoids contact the host at random, governed by the encounter probability rate and once encountered, the chance to penetrate inside the host cell and develop the infection strongly depends on the degree of host susceptibility. As such, their strategy for persistence is more of a game of Russian roulette, where the chance of survival is dependent on the susceptibility of the host. Our study identifies P. sinerae as a potential key player in community ecology, where in mixed dinoflagellate communities consisting of hosts that are highly susceptible to infection, parasitoid preferences may mediate coexistence between host species, reducing the dominance of the superior competitor. Alternatively, it may increase competition, leading to species exclusion. If

  2. Cascading effects of early-season herbivory on late-season herbivores and their parasitoids.

    PubMed

    Hernandez-Cumplido, Johnattran; Glauser, Gaetan; Benrey, Betty

    2016-05-01

    There is an increasing awareness that herbivory by one insect species induces changes in a plant that affect the performance of other herbivore species that feed on the same plant. However, previous studies of interspecies interactions mediated by plant defense responses have rarely taken into account different insect guilds or the third trophic level. Using a combination of field and laboratory experiments, we examined how early-season herbivory in lima bean plants (Phaseolus lunatus) by the leaf-chewing herbivore Cerotoma ruficornis and the bean pod weevil Apion godmani affects the abundance and performance of the seed beetle Zabrotes subfasciatus and that of its parasitoid Stenocorse bruchivora, which occurs on the plants at the end of the growing season. In addition, we determined the consequences of early-season herbivore-induced defenses on plant performance. We hypothesized that early-season induction would affect plant reproduction and, hence, would alter the suitability of seeds for late-season seed-eating beetles, and that this would in turn alter the vulnerability of these seed beetles to parasitoids. We found strong support for these hypotheses. In the field, early-season herbivory negatively affected plant reproduction and seeds of these plants suffered lower levels of infestation by seed-eating beetles, which in turn suffered less parasitism. Laboratory assays with field-collected seeds confirmed that the performance of beetles and parasitoids was lower on seeds from plants that had been subjected to early-season herbivory. Further analyses revealed that seeds produced by control plants were larger, heavier, and had a higher concentration of cyanogenic glycosides and total protein content than seeds from plants subjected to herbivory. Our results provide insight into how direct and indirect interactions between and within different trophic levels affect the dynamics and structure of complex communities.

  3. Reciprocal diversification in a complex plant-herbivore-parasitoid food web

    PubMed Central

    Nyman, Tommi; Bokma, Folmer; Kopelke, Jens-Peter

    2007-01-01

    Background Plants, plant-feeding insects, and insect parasitoids form some of the most complex and species-rich food webs. According to the classic escape-and-radiate (EAR) hypothesis, these hyperdiverse communities result from coevolutionary arms races consisting of successive cycles of enemy escape, radiation, and colonization by new enemy lineages. It has also been suggested that "enemy-free space" provided by novel host plants could promote host shifts by herbivores, and that parasitoids could similarly drive diversification of gall form in insects that induce galls on plants. Because these central coevolutionary hypotheses have never been tested in a phylogenetic framework, we combined phylogenetic information on willow-galling sawflies with data on their host plants, gall types, and enemy communities. Results We found that evolutionary shifts in host plant use and habitat have led to dramatic prunings of parasitoid communities, and that changes in gall phenotype can provide "enemy-free morphospace" for millions of years even in the absence of host plant shifts. Some parasites have nevertheless managed to colonize recently-evolved gall types, and this has apparently led to adaptive speciation in several enemy groups. However, having fewer enemies does not in itself increase speciation probabilities in individual sawfly lineages, partly because the high diversity of the enemy community facilitates compensatory attack by remaining parasite taxa. Conclusion Taken together, our results indicate that niche-dependent parasitism is a major force promoting ecological divergence in herbivorous insects, and that prey divergence can cause speciation in parasite lineages. However, the results also show that the EAR hypothesis is too simplistic for species-rich food webs: instead, diversification seems to be spurred by a continuous stepwise process, in which ecological and phenotypic shifts in prey lineages are followed by a lagged evolutionary response by some of the

  4. Floral resources impact longevity and oviposition rate of a parasitoid in the field.

    PubMed

    Lee, Jana C; Heimpel, George E

    2008-05-01

    1. The use of floral resource subsidies to improve herbivore suppression by parasitoids requires certain trophic interactions and physiological changes to occur. While the longevity and fecundity of parasitoids are positively affected by nectar subsidies in laboratory studies, the impacts of floral subsidies on the fecundity and longevity of freely foraging parasitoids have not been studied. 2. We studied the longevity and per capita fecundity of naturally occurring Diadegma insulare foraging in cabbage plots with and without borders of flowering buckwheat, Fagopyrum esculentum, as well as relationships between longevity, fecundity, sugar feeding and parasitism rates on larvae of the diamondback moth, Plutella xylostella. 3. Relative longevity was estimated by counting broken setae on the fringe of the forewing. Floral borders increased the longevity of males and females in adjacent cabbage plots. 4. The egg maturation rate of D. insulare was estimated by comparing egg loads of females collected early in the day with egg loads of females held without hosts in field cages throughout the day. Females in buckwheat cages matured 2.7 eggs per hour while females in control cages resorbed 0.27 eggs over the same time period. 5. The fecundity of females collected in the afternoon was estimated by comparing their actual egg load to the estimated egg load in the absence of oviposition for females in a given plot. Females foraging in buckwheat plots had marginally fewer eggs remaining in their ovaries, and laid marginally more eggs than females in control plots. Females from both treatments carried 30-60 eggs by the afternoon and therefore were time-limited rather than egg-limited. 6. Plots where a greater proportion of females had fed on sugar had longer-lived females. This suggests that feeding enhanced longevity of D. insulare. However, plots with longer-lived and more fecund females did not exhibit higher parasitism rates, although the power of these tests were low.

  5. Community Dynamics of Carrion Flies and their Parasitoids in Experimental Carcasses in Central Argentina

    PubMed Central

    Horenstein, Moira Battán; Salvo, Adriana

    2012-01-01

    Insects are the predominant group regarding both species richness and abundance that develop on carrion. Among them, the most important decomposers using carrion as a source of food for their development are the immature stages of the dipteran families Calliphoridae, Muscidae, and Sarcophagidae. The large numbers of their larvae in carcasses are attacked by a rich community of parasitoids, including species of Braconidae, Ichneumonidae, and Pteromalidae (Hymenoptera: Parasitica). The objective of this study was describing the temporal composition and dynamics of a parasitoid community in relation to their dipterans hosts in carrion in terms of number of species and specific composition, irrespective of the particular interactions between species in both trophic levels. Additionally, seasonality of the climate in the region was investigated as a factor structuring the studied communities. The experiments were undertaken in the south of Cordoba, Argentina during 2004 in a rural area. Two traps per season were placed separately approximately 300 m from each other in the study site. Each trap contained a domestic pig (Sus scrofa) of approximately 8 kg as bait. Samples were taken daily during the first four weeks and then every two or three days over the following weeks until the end of the experiment. The dipteran community was represented by 15 species in 6 families of the Calyptratae Diptera whereas parasitoids belonged to six families of the parasitic Apocrita Hymenoptera. Climatic seasonality was an important factor in determining the number of occurring species in the carcasses and community composition. The highest number of species was observed in the spring for both communities. PMID:22963038

  6. Do parasitoids explain differential abundance of two syntopic orb-weaver spiders (Araneae: Araneidae)?

    NASA Astrophysics Data System (ADS)

    Gonzaga, Marcelo O.; Cardoso, João C. F.; Vasconcellos-Neto, João

    2015-11-01

    In this study, we examined the relative abundance of two congeneric species of orb-weaver spiders, Cyclosa fililineata and Cyclosa morretes, in an area of Atlantic forest in southeastern Brazil, and the relationship of this variable with fecundity and attacks by parasitoids. We also investigated responses to vibrational stimuli that simulated the approach of a wasp and described architectural changes in webs of parasitized individuals of C. fililineata. C.fililineata was more abundant throughout the year, although this species produced a lower number of egg sacs and a lower number of eggs per egg sac when compared with C. morretes. Both species showed similar types of behavioral responses to vibrational stimuli, but C. fililineata remained motionless more often. The frequency of parasitism by the wasp Polysphincta janzeni on adults and juveniles was low and similar for C. fililineata and C. morretes in both dry and wet seasons. The parasitoid caused alterations in the web design of C. fililineata similar of those observed in other orb-weavers attacked by ichneumonid wasps. Webs constructed by spiders parasitized by larvae in their last instar had a lower number of radii and sticky spirals were completely absent. An egg parasitoid, Baeus cyclosae, attacked C. morretes more often than C. fililineata, possibly as a consequence of its greater clutch size and/or larger eggs. These results indicate that egg mortality caused by B. cyclosae, but not subadult and adult mortality promoted by P. janzeni, may be an important factor determining the relative abundance of these two Cyclosa species.

  7. Host-parasitoid spatial ecology: a plea for a landscape-level synthesis.

    PubMed

    Cronin, James T; Reeve, John D

    2005-11-07

    A growing body of literature points to a large-scale research approach as essential for understanding population and community ecology. Many of our advances regarding the spatial ecology of predators and prey can be attributed to research with insect parasitoids and their hosts. In this review, we focus on the progress that has been made in the study of the movement and population dynamics of hosts and their parasitoids in heterogeneous landscapes, and how this research approach may be beneficial to pest management programs. To date, few studies have quantified prey and predator rates and ranges of dispersal and population dynamics at the patch level--the minimum of information needed to characterize population structure. From host-parasitoid studies with sufficient data, it is clear that the spatial scale of dispersal can differ significantly between a prey and its predators, local prey extinctions can be attributed to predators and predator extinction risk at the patch level often exceeds that of the prey. It is also evident that populations can be organized as a single, highly connected (patchy) population or as semi-independent extinction-prone local populations that collectively form a persistent metapopulation. A prey and its predators can also differ in population structure. At the landscape level, agricultural studies indicate that predator effects on its prey often spill over between the crop and surrounding area (matrix) and can depend strongly on landscape structure (e.g. the proportion of suitable habitat) at scales extending well beyond the crop margins. In light of existing empirical data, predator-prey models are typically spatially unrealistic, lacking important details on boundary responses and movement behaviour within and among patches. The tools exist for conducting empirical and theoretical research at the landscape level and we hope that this review calls attention to fertile areas for future exploration.

  8. The Role of Lipid Competition for Endosymbiont-Mediated Protection against Parasitoid Wasps in Drosophila

    PubMed Central

    Schüpfer, Fanny

    2016-01-01

    ABSTRACT Insects commonly harbor facultative bacterial endosymbionts, such as Wolbachia and Spiroplasma species, that are vertically transmitted from mothers to their offspring. These endosymbiontic bacteria increase their propagation by manipulating host reproduction or by protecting their hosts against natural enemies. While an increasing number of studies have reported endosymbiont-mediated protection, little is known about the mechanisms underlying this protection. Here, we analyze the mechanisms underlying protection from parasitoid wasps in Drosophila melanogaster mediated by its facultative endosymbiont Spiroplasma poulsonii. Our results indicate that S. poulsonii exerts protection against two distantly related wasp species, Leptopilina boulardi and Asobara tabida. S. poulsonii-mediated protection against parasitoid wasps takes place at the pupal stage and is not associated with an increased cellular immune response. In this work, we provide three important observations that support the notion that S. poulsonii bacteria and wasp larvae compete for host lipids and that this competition underlies symbiont-mediated protection. First, lipid quantification shows that both S. poulsonii and parasitoid wasps deplete D. melanogaster hemolymph lipids. Second, the depletion of hemolymphatic lipids using the Lpp RNA interference (Lpp RNAi) construct reduces wasp success in larvae that are not infected with S. poulsonii and blocks S. poulsonii growth. Third, we show that the growth of S. poulsonii bacteria is not affected by the presence of the wasps, indicating that when S. poulsonii is present, larval wasps will develop in a lipid-depleted environment. We propose that competition for host lipids may be relevant to endosymbiont-mediated protection in other systems and could explain the broad spectrum of protection provided. PMID:27406568

  9. Duration of plant damage by host larvae affects attraction of two parasitoid species (Microplitis croceipes and Cotesia marginiventris) to cotton: implications for interspecific competition.

    PubMed

    Morawo, Tolulope; Fadamiro, Henry

    2014-12-01

    Volatile organic compounds (VOCs) released by herbivore-damaged plants can guide parasitoids to their hosts. The quantity and quality of VOC blends emitted by plants may be affected by the duration of plant damage by herbivores, which could have potential ramifications on the recruitment of competing parasitoids. We used two parasitoid species, Microplitis croceipes and Cotesia marginiventris (Hymenoptera: Braconidae), to address the question of whether duration of plant damage affects parasitoid use of plant VOCs for host location. Both wasp species are larval endoparasitoids of Heliothis virescens (Lepidoptera: Noctuidae), an important pest of cotton. Attraction of the two parasitoid species to odors emitted by undamaged (UD), fresh (6 h infestation) damage (FD), and old (24 h infestation) damage (OD) cotton plants infested by H. virescens larvae was investigated using a headspace volatile collection system coupled with four-choice olfactometer bioassay. Both sexes of M. croceipes showed a preference for FD- and OD-plant odors over UD-plants. On the other hand, more C. marginiventris females were attracted to UD- and FD-plants than to OD-plants. GC/MS analyses showed qualitative and quantitative differences in the VOC profiles of UD, FD, and OD-plants, which may explain the observed preferences of the parasitoids. These results suggest a temporal partitioning in the recruitment of M. croceipes and C. marginiventris to H. virescens-damaged cotton, and may have potential implications for interspecific competition between the two parasitoid species.

  10. Measuring acoustic habitats.

    PubMed

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-03-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies.

  11. Measuring acoustic habitats

    PubMed Central

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-01-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies. PMID:25954500

  12. Tri-Trophic Effects of Seasonally Variable Induced Plant Defenses Vary across the Development of a Shelter Building Moth Larva and Its Parasitoid

    PubMed Central

    Rose, Noah H.; Halitschke, Rayko; Morse, Douglass H.

    2015-01-01

    Plant chemical defenses can negatively affect insect herbivore fitness, but they can also decrease herbivore palatability to predators or decrease parasitoid fitness, potentially changing selective pressures on both plant investment in production of chemical defenses and host feeding behavior. Larvae of the fern moth Herpetogramma theseusalis live in and feed upon leaf shelters of their own construction, and their most abundant parasitoid Alabagrus texanus oviposits in early instar larvae, where parasitoid larvae lay dormant for most of host development before rapidly developing and emerging just prior to host pupation. As such, both might be expected to live in a relatively constant chemical environment. Instead, we find that a correlated set of phenolic compounds shows strong seasonal variation both within shelters and in undamaged fern tissue, and the relative level of these compounds in these two different fern tissue types switches across the summer. Using experimental feeding treatments, in which we exposed fern moth larvae to different chemical trajectories across their development, we show that exposure to this set of phenolic compounds reduces the survival of larvae in early development. However, exposure to this set of compounds just before the beginning of explosive parasitoid growth increased parasitoid survival. Exposure during the period of rapid parasitoid growth and feeding decreased parasitoid survival. These results highlight the spatial and temporal complexity of leaf shelter chemistry, and demonstrate the developmental contingency of associated effects on both host and parasitoid, implying the existence of complex selective pressures on plant investment in chemical defenses, host feeding behavior, and parasitoid life history. PMID:25781029

  13. Interaction of the Koinobiont Parasitoid Microplitis rufiventris of the Cotton Leafworm, Spodoptera littoralis, with Two Entomopathogenic Rhabditids, Heterorhabditis bacteriophora and Steinernema carpocapsae

    PubMed Central

    Atwa, Atwa A.; Hegazi, Esmat M.; Khafagi, Wedad E.; El-Aziz, Gehan M. Abd

    2013-01-01

    Entomopathogenic nematodes are generally considered beneficial organisms. However, they can affect beneficial insects such as parasitoids. The interaction between the entomopathogenic nematodes Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) and Steinernema carpocapsae Weiser, and the parasitoid Microplitis rufiventris Kokujev (Hymenoptera: Braconidae) was investigated in the laboratory. In non-parasitized hosts, Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) larvae exposed to H. bacteriophora showed a higher percent mortality than those exposed to S. carpocapsae. Both nematodes were able to invade and propagate in non-parasitized S. littoralis larvae and those parasitized by M. rufiventris. Both nematode species reproduced in Microplitis-parasitized hosts, but there was a higher number of nematodes in non-parasitized larvae. S. carpocapsae yielded higher numbers of infective juveniles than H. bacteriophora. Generally, the number of nematodes harvested increased as their host's size increased. The interaction between the nematodes and parasitoid favored the nematodes when the nematodes were inoculated during the parasitoid egg stage or the young parasitoid larvae, thus giving the nematodes a better chance to grow and reproduce, resulting in the death of the parasitoid larvae. Conversely, when the nematodes were inoculated during the late larval instar of the parasitoid, the competition partially favored the wasp, thus giving approximately 50% of the wasps a better chance to develop, emerge, and reproduce, providing evidence that both nematodes and wasps could reproduce in the same host. Egg maturation of female wasps derived from nematode-infected hosts was not significantly different than those from control hosts. The combined application of nematodes and parasitoids may be beneficial if the detrimental effects of the nematodes on the parasitoid could be avoided by precisely timing the application strategies. It is clear that

  14. Acoustic emission monitoring system

    DOEpatents

    Romrell, Delwin M.

    1977-07-05

    Methods and apparatus for identifying the source location of acoustic emissions generated within an acoustically conductive medium. A plurality of acoustic receivers are communicably coupled to the surface of the medium at a corresponding number of spaced locations. The differences in the reception time of the respective sensors in response to a given acoustic event are measured among various sensor combinations prescribed by the monitoring mode employed. Acoustic reception response encountered subsequent to the reception by a predetermined number of the prescribed sensor combinations are inhibited from being communicated to the processing circuitry, while the time measurements obtained from the prescribed sensor combinations are translated into a position measurement representative of the location on the surface most proximate the source of the emission. The apparatus is programmable to function in six separate and five distinct operating modes employing either two, three or four sensory locations. In its preferred arrangement the apparatus of this invention will re-initiate a monitoring interval if the predetermined number of sensors do not respond to a particular emission within a given time period.

  15. ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

    ERIC Educational Resources Information Center

    DOELLE, LESLIE L.

    THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

  16. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae), parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae) in Mexico

    PubMed Central

    Yefremova, Zoya; González-Santarosa, Graciela; Lomeli-Flores, J. Refugio; Bautista-Martínez, Néstor

    2014-01-01

    Abstract Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae). Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given. PMID:24478580

  17. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae), parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae) in Mexico.

    PubMed

    Yefremova, Zoya; González-Santarosa, Graciela; Lomeli-Flores, J Refugio; Bautista-Martínez, Néstor

    2014-01-01

    Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae). Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given.

  18. 40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  19. Laboratory investigation of triple marking the parasitoid Gonatocerus ashmeadi (Hymenoptera: Mymaridae) with a fluorescent dye and two animal proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gonatocerus ashmeadi Girault, a parasitoid of Homalodisca vitripennis (Germar), was used as a model insect to investigate triple marking a minute hymenopteran for potential use for monitoring dispersal patterns of natural enemies in the field. The triple mark contained egg albumin in chicken eggs, c...

  20. Host plants impact courtship vibration transmission and mating success of a parasitoid wasp, Cotesia flavipes (Hymenoptera: Braconidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Dispersion and movement of the Lygus spp.parasitoid Peristenus relictus (Hymenoptera: Braconidae) in trapcropped organic strawberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa trap crops can be used to manage Lygus spp. in organic strawberries on the California Central Coast. The retention of Lygus spp. in alfalfa creates aggregated distributions that provide improved opportunities for biological control by the introduced parasitoid Peristenus relictus (Ruthe). ...

  2. Interactions between Spathius agrili (Hymenoptera: braconidae) and Tetrastichus planipennisi (Hymenoptera: Eulophidae), larval parasitoids of Agrilus planipennis (Coleoptera: Buprestidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three hymenopteran parasitoids introduced from China are currently being released in Michigan and surrounding states in an effort to control the emerald ash borer (EAB), Agrilus planipennis Fairmare, an Asian beetle species responsible for widespread mortality of Ash trees (Fraxinus spp.) in North A...

  3. Methyl 6-methylsalicylate: A female-produced pheromone component of the parasitoid wasp Spalangia endius (Hymenoptera: Pteromalidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex pheromone-related behavior and chemistry were studied in the wasp Spalangia endius Walker (Hymenoptera: Pteromalidae), a pupal parasitoid of house flies Musca domestica L. (Diptera: Muscidae). Males responded behaviorally to female extracts by arrestment, whereas females did not arrest to male e...

  4. Comparison of host-seeking behavior of the filth fly pupal parasitoids, Spalangia cameroni and Muscidifurax raptor (Hymenoptera: Pteromalidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pupal parasitoids, Spalangia cameroni Perkins and Muscidifurax raptor Girault and Sanders, are often sold together for biological control of house flies (Musca domestica L.) and stable flies (Stomoxys calcitrans L.) (Diptera: Muscidae). Little is known about the odors involved in host-seeking b...

  5. The impact of exotic parasitoids on populations of a native Hawaiian moth assessed using life table studies.

    PubMed

    Kaufman, Leyla V; Wright, Mark G

    2009-03-01

    The impact of alien species on native organisms is a cause for concern worldwide, with biological invasions commonplace today. Suppression efforts targeting many invasive species have included introductions of biological control agents. The numerous releases of biological control agents in the Hawaiian archipelago have resulted in considerable concern for non-target impacts, due to high levels of non-target parasitism observed to occur in some cases. This study investigated the impact of introduced Hymenoptera parasitoids on a Hawaiian moth. The endemic Hawaiian moth Udea stellata (Butler) has seven alien parasitoids associated with it, two purposely introduced, three adventive, and two of uncertain origin. The objective of this study was to determine the relative contribution of the seven parasitoid species to the population dynamics of U. stellata by constructing partial life tables. Marginal attack rates and associated k-values were calculated to allow comparison of mortality factors between experimental sites. Sentinel larvae were deployed on potted host plants and left in the field for 3-day intervals in open and exclusion treatments. The factors that contributed to total mortality in the open treatment were: disappearance (42.1%), death due to unknown reasons during rearing (16.5%) and parasitism (4.9%). The open treatment incurred significantly higher larval disappearance compared to the exclusion treatment (7.8%), which suggests that in large part disappearance is the result of predation. Adventive parasitoids inflicted greater total larval mortality attributable to parasitism (97.0%) than purposely introduced species (3.0%).

  6. Laboratory biological parameters of Trichogramma fuentesi (Hymenoptera:Trichogrammatidae), an egg parasitoid of Cactoblastis cactorum (Lepidoptera:Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichogramma fuentesi Torre was identified attacking Cactoblastis cactorum (Berg), a serious pest of Opuntia spp. in North America, raising the possibility of using this egg parasitoid as an inundative biological control agent. Studies were conducted to assess the biological parameters of this para...

  7. Developmental time, longevity, and lifetime fertility of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae).

    PubMed

    Amarasekare, Kaushalya G; Mannion, Catharine M; Epsky, Nancy D

    2012-10-01

    Developmental time, longevity, and lifetime fertility of three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff) (Hymenoptera: Encyrtidae) of the mealybug Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) were studied in the laboratory to understand the outcome of their recovery in field studies conducted in the United States. The developmental time of both male and female A. papayae and A. loecki was shorter than the developmental time of male and female P. mexicana. Male parasitoids of all three species had a shorter developmental time than their females. All parasitoids had a shorter developmental time in adult-female mealybugs than in second instars. Mating status (unmated and mated) had no effect on the male longevity. Unmated and mated females that were not allowed to oviposit had similar longevity and lived longer than those that were allowed to oviposit. Virgin females produced male only progeny with higher number of males from A. loecki or P. mexicana than from A. papayae. The number of females and the cumulative progeny was smaller for A. papayae than for A. loecki or P. mexicana. The progeny sex ratio (proportion of females) was not different among the parasitoids. A. papayae had the shortest reproductive period followed by A. loecki and P. mexicana, respectively. This information is important in evaluating the efficiency, recovery and establishment of A. papayae, A. loecki, and P. mexicana.

  8. Contrasting brood-sex ratio flexibility in two opiine (Hymenoptera: Braconidae) parasitoids of tephritid (Diptera) fruit files

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mass-rearing of fruit fly parasitoids for augmentative release would be more economical if production could be biased towards females. If sex ratios are ever to be manipulated under rearing conditions it is important to determine if, then understand why, sex ratio flexibility exists. Unequal brood-s...

  9. Genotype matching in a parasitoid-host genotypic food web: an approach for measuring effects of environmental change.

    PubMed

    Lavandero, Blas; Tylianakis, Jason M

    2013-01-01

    Food webs typically quantify interactions between species, whereas evolution operates through the success of alleles within populations of a single species. To bridge this gap, we quantify genotypic interaction networks among individuals of a single specialized parasitoid species and its obligate to cyclically parthenogenetic aphid host along a climatic gradient. As a case study for the kinds of questions genotype food webs could be used to answer, we show that genetically similar parasitoids became more likely to attack genetically similar hosts in warmer sites (i.e. there was network-wide congruence between the within-species shared allelic distance of the parasitoid and that of its host). Narrowing of host-genotype-niche breadth by parasitoids could reduce resilience of the network to changes in host genetic structure or invasion by novel host genotypes and inhibit biological control. Thus, our approach can be easily used to detect changes to sub-species-level food webs, which may have important ecological and evolutionary implications, such as promoting host-race specialization or the accelerated loss of functional diversity following extinctions of closely related genotypes.

  10. Parasitoids and ecological risk assessment: can toxicity data developed for one species be used to protect an entire guild?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasitoid wasps are important control agents for a suite of economically important anthropod pests. However, it is well known that hymenoptera in general are highly vulnerable to the effects of chemical pesticides, and so represent an opportunity to better understand the compatibility of biological...

  11. The parasitoid, Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), influences food consumption and utilization by larval Diatraea saccharalis (F.) (Lepidoptera: Crambidae).

    PubMed

    Rossi, Guilherme Duarte; Salvador, Gabriela; Cônsoli, Fernando Luis

    2014-10-01

    Parasitoids exploit host insects for food and other resources; they alter host development and physiology to optimize conditions to favor parasitoid development. Parasitoids influence their hosts by injecting eggs, along with a variety of substances, including venoms, polydnaviruses, ovarian fluids, and other maternal factors, into hosts. These factors induce profound changes in hosts, such as behavior, metabolism, endocrine events, and immune defense. Because endoparasitoids develop and consume tissues from within their hosts, it is reasonable to suggest that internal parasitization would also influence host food consumption and metabolism. We report on the effects of parasitism by Cotesia flavipes on the food consumption and utilization of its host, Diatraea saccharalis. Cotesia flavipes reduces the host food consumption, but parasitized larvae considered a unit with their parasitoid's attained the same final weight as the nonparasitized larvae. Nutritional indices, midgut activities of carbohydrases, and trypsin of parasitized and nonparasitized D. saccharalis were assessed. Parasitized larvae had reduced relative food consumption, metabolic and growth rates, coupled with higher efficiency for conversion of the digested, but not ingested, food into body mass. Parasitism also affected food flux through the gut and protein contents in the midgut of parasitized larvae. The activity of α-amylase and trehalase in parasitized host was enhanced in the first day after parasitism relative to control larvae. Saccharase activity remained unchanged during larval development. Trypsin activity was reduced from the fifth to ninth day after parasitism. We argue on the mechanisms involved in host food processing after parasitism.

  12. An acquired distaste: Sugar discrimination by the larval parasitoid Microplitis croceipes (Hymenoptera: Braconidae) is affected by prior sugar exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As sugar quality feeding is very important in the lives of adult parasitoids, we examined several feeding responses of Microplitis croceipes to sugars commonly found in nectar. We first examined the relationship between feeding time and consumption of sucrose, glucose, fructose and maltose by Microp...

  13. Attack and success of native and exotic parasitoids on eggs of Halyomorpha halys in three Maryland habitats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Egg parasitoids of the exotic invasive brown marmorated stink bug, Halyomorpha halys (Stål), were investigated using lab-reared fresh (live) and frozen (killed) lab-reared sentinel egg masses deployed for 72h on foliage in three habitats -- woods, orchard, and soybean field -- in Maryland, USA, in s...

  14. A geographic distribution database of the Neotropical cassava whitefly complex (Hemiptera, Aleyrodidae) and their associated parasitoids and hyperparasitoids (Hymenoptera).

    PubMed

    Vásquez-Ordóñez, Aymer Andrés; Hazzi, Nicolas A; Escobar-Prieto, David; Paz-Jojoa, Dario; Parsa, Soroush

    2015-01-01

    Whiteflies (Hemiptera, Aleyrodidae) are represented by more than 1,500 herbivorous species around the world. Some of them are notorious pests of cassava (Manihot esculenta), a primary food crop in the tropics. Particularly destructive is a complex of Neotropical cassava whiteflies whose distribution remains restricted to their native range. Despite their importance, neither their distribution, nor that of their associated parasitoids, is well documented. This paper therefore reports observational and specimen-based occurrence records of Neotropical cassava whiteflies and their associated parasitoids and hyperparasitoids. The dataset consists of 1,311 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT's Arthropod Reference Collection (CIATARC, Cali, Colombia). Eleven species of whiteflies, 14 species of parasitoids and one species of hyperparasitoids are reported. Approximately 66% of the whitefly records belong to Aleurotrachelus socialis and 16% to Bemisia tuberculata. The parasitoids with most records are Encarsia hispida, Amitus macgowni and Encarsia bellottii for Aleurotrachelus socialis; and Encarsia sophia for Bemisia tuberculata. The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF).

  15. Multitrophic effects of experimental changes in plant diversity on cavity-nesting bees, wasps, and their parasitoids.

    PubMed

    Ebeling, Anne; Klein, Alexandra-Maria; Weisser, Wolfgang W; Tscharntke, Teja

    2012-06-01

    Plant diversity changes can impact the abundance, diversity, and functioning of species at higher trophic levels. We used an experimental gradient in grassland plant diversity ranging from 1 to 16 plant species to study multitrophic interactions among plants, cavity-nesting bees and wasps, and their natural enemies, and analysed brood cell density, insect diversity (species richness), and bee and wasp community similarity over two consecutive years. The bee and wasp communities were more similar among the high (16 species) diversity plots than among plots of the lower diversity levels (up to 8 species), and a more similar community of bees and wasps resulted in a more similar community of their parasitoids. Plant diversity, which was closely related to flower diversity, positively and indirectly affected bee diversity and the diversity of their parasitoids via increasing brood cell density of bees. Increasing plant diversity directly led to higher wasp diversity. Parasitism rates of bees and wasps (hosts) were not affected by plant diversity, but increased with the diversity of their respective parasitoids. Decreases in parasitism rates of bees arose from increasing brood cell density of bees (hosts), whereas decreasing parasitism rates of wasps arose from increasing wasp diversity (hosts). In conclusion, decreases in plant diversity propagated through different trophic levels: from plants to insect hosts to their parasitoids, decreasing density and diversity. The positive relationship between plant diversity and the community similarity of higher trophic levels indicates a community-stabilising effect of high plant diversity.

  16. Distribution of 18S rDNA sites and absence of the canonical TTAGG insect telomeric repeat in parasitoid Hymenoptera.

    PubMed

    Gokhman, Vladimir E; Anokhin, Boris A; Kuznetsova, Valentina G

    2014-08-01

    Karyotypes of six species belonging to three main clades of parasitoid Hymenoptera, the superfamilies Ichneumonoidea (Ichneumonidae: Ichneumon amphibolus), Cynipoidea (Cynipidae: Diplolepis rosae) and Chalcidoidea (Eurytomidae: Eurytoma robusta, Eu. serratulae and Eu. compressa, and Torymidae: Torymus bedeguaris) were studied using FISH with 18S rDNA and telomeric (TTAGG)n probes. Haploid karyotypes of D. rosae, Eu. robusta and Eu. serratulae carried the only 18S rDNA hybridization signal, whereas those of I. amphibolus and Eu. compressa carried three and two rDNA clusters respectively. In addition, three rDNA sites were visualized in the aneuploid female of T. bedeguaris. The number of rDNA clusters in parasitoid Hymenoptera generally correlates to the chromosome number. Apart from the overwhelming majority of the studied species of aculeate Hymenoptera, no hybridization signals were obtained from FISH with the telomeric (TTAGG)n probe in the examined parasitoid species. These data suggest absence of the canonical (TTAGG)n insect telomeric motif in the Ichneumonoidea, Cynipoidea and Chalcidoidea, and perhaps in parasitoid Hymenoptera in general.

  17. The Gastropod Menace: Slugs on Brassica Plants Affect Caterpillar Survival through Consumption and Interference with Parasitoid Attraction.

    PubMed

    Desurmont, Gaylord A; Zemanova, Miriam A; Turlings, Ted C J

    2016-03-01

    Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small insects and through indirect, plant-mediated effects. Here, we examined the effects of the presence of two species of slugs, Arion rufus (native) and A. vulgaris (invasive) on the survivorship of young Pieris brassicae caterpillars when feeding on Brassica rapa plants, and on plant attractiveness to the main natural enemy of P. brassicae, the parasitoid Cotesia glomerata. In two separate predation experiments, caterpillar mortality was significantly higher on plants co-infested with A. rufus or A. vulgaris. Moreover, caterpillar mortality correlated positively with slug mass and leaf consumption by A. vulgaris. At the third trophic level, plants infested with slugs and plants co-infested with slugs and caterpillars were far less attractive to parasitoids than plants damaged by caterpillars only, independently of slug species. Chemical analyses confirmed that volatile emissions, which provide foraging cues for parasitoids, were strongly reduced in co-infested plants. Our study shows that the presence of slugs has the potential to affect insect populations, directly via consumptive effects, and indirectly via changes in plant volatiles that result in a reduced attraction of natural enemies. The fitness cost for P. brassicae imposed by increased mortality in presence of slugs may be counterbalanced by the benefit of escaping its parasitoids.

  18. Distribution and abundance of mymarid parasitoids (Hymenoptera: Mymaridae) of Sophonia rufofascia Kuoh and Kuoh (Homoptera: Cicadellidae)in Hawaii

    USGS Publications Warehouse

    Yang, P.; Foote, D.; Alyokhin, A.V.; Lenz, L.; Messing, R.H.

    2002-01-01

    The abundance of mymarid parasitoids attacking the two-spotted leafhopper (Sophonia rufofascia [Kuoh and Kuoh]), a polyphagous pest recently adventive to Hawaii, was monitored using yellow sticky cards deployed in several areas on the islands of Kauai and Hawaii. The yellow cards captured Chaetomymar sp. nr bagicha Narayanan, Subba Rao, & Kaur and Schizophragma bicolor (Dozier), both adventive species, and Polynema sp. Haliday, which is endemic to Hawaii (Hymenoptera: Mymaridae). The former two species were most abundant at all sites. On Kauai, there was a negative correlation between the captures of C. sp. nr bagicha and those of Polynema sp. Throughout the season, the increase in parasitoid numbers generally followed the increase in leafhopper numbers. C. sp. nr. bagicha and S. bicolor showed distinct habitat preferences. Removal of Myrica faya Aiton, an invasive weed that is a highly preferred two-spotted leafhopper host, decreased the overall numbers of captured parasitoids, but led to a twofold increase in the ratio of trapped parasitoids/hosts in weed-free areas. ?? 2002 Elsevier Science (USA).

  19. Aphanogmus sp. (Hymenoptera: Ceraphronidae): a hyperparasitoid of the coffee berry borer parasitoid Prorops nasuta (Hymenoptera: Bethylidae) in Kenya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is the first report of a hyperparasitod of the primary parasitoid of the coffee berry borer Prorops nasuta Waterston (Hymenoptera: Bethylidae). Aphanogmus sp is a gregarious ectoparasitoid of larval and pupal stages of P. nasuta, which was found in coffee berry samples collected on the ground o...

  20. A geographic distribution database of the Neotropical cassava whitefly complex (Hemiptera, Aleyrodidae) and their associated parasitoids and hyperparasitoids (Hymenoptera)

    PubMed Central

    Vásquez-Ordóñez, Aymer Andrés; Hazzi, Nicolas A.; Escobar-Prieto, David; Paz-Jojoa, Dario; Parsa, Soroush

    2015-01-01

    Abstract Whiteflies (Hemiptera, Aleyrodidae) are represented by more than 1,500 herbivorous species around the world. Some of them are notorious pests of cassava (Manihot esculenta), a primary food crop in the tropics. Particularly destructive is a complex of Neotropical cassava whiteflies whose distribution remains restricted to their native range. Despite their importance, neither their distribution, nor that of their associated parasitoids, is well documented. This paper therefore reports observational and specimen-based occurrence records of Neotropical cassava whiteflies and their associated parasitoids and hyperparasitoids. The dataset consists of 1,311 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT’s Arthropod Reference Collection (CIATARC, Cali, Colombia). Eleven species of whiteflies, 14 species of parasitoids and one species of hyperparasitoids are reported. Approximately 66% of the whitefly records belong to Aleurotrachelus socialis and 16% to Bemisia tuberculata. The parasitoids with most records are Encarsia hispida, Amitus macgowni and Encarsia bellottii for Aleurotrachelus socialis; and Encarsia sophia for Bemisia tuberculata. The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF). PMID:26798295

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  3. 40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  4. A New Wave of Acoustics.

    ERIC Educational Resources Information Center

    Beyer, Robert

    1981-01-01

    Surveys 50 years of acoustical studies by discussing selected topics including the ear, nonlinear representations, underwater sound, acoustical diagnostics, absorption, electrolytes, phonons, magnetic interaction, and superfluidity and the five sounds. (JN)

  5. New record for Woldstedtius flavolineatus (Ichneumonidae: Diplazontinae), a hymenopteran parasitoid of syrphid flies in Hawaii

    USGS Publications Warehouse

    Cappadonna, Justin; Euaparadorn, Melody; Peck, Robert W.; Banko, Paul C.

    2009-01-01

    The parasitoid wasp Woldstedtius flavolineatus (Gravenhorst) (Ichneumonidae) attacks the larvae of syrphid flies (Syrphidae). Woldstedtius flavolineatus was collected in Hawaii for the first time during an extensive malaise trap-based survey of parasitoids in Hawaiian forests. Since its initial collection on Hawaii Island in January 2006, it has been collected at five additional sites on Hawaii Island and at one site each on Maui and Oahu. Malaise trap results from Hakalau Forest National Wildlife Refuge showed a strong seasonal pattern of abundance, with peak population levels reached during July–September. Rearing of its host, Allograpta obliqua (Say), collected from koa (Acacia koa Gray) at Hakalau over two days, revealed a parasitism rate of approximately 95%. Broader impacts of this alien wasp are unknown, but a reduction in host syrphid abundance could result in an increase in numbers of psyllids and aphids (Homoptera) that are preyed upon by syrphid larvae. Furthermore, a reduction in adult syrphids could impact the reproductive success of some of the plants they pollinate.

  6. Broadband Photoreceptors Are Involved in Violet Light Preference in the Parasitoid Fly Exorista Japonica

    PubMed Central

    Tokushima, Yoshiaki; Uehara, Takuya; Yamaguchi, Terumi; Arikawa, Kentaro; Kainoh, Yooichi

    2016-01-01

    Phototaxis has been described in many insects, which are often attracted to specific wavelengths of light. However, little is known about phototaxis in parasitoid insect species that are potentially useful for integrated pest management. In this study, we investigated the wavelength dependency of the phototactic behavior of the parasitoid fly Exorista japonica and its possible mechanism. Multiple-choice tests with six monochromatic stimuli revealed that the flies were specifically attracted to violet light peaking at 405 nm, which was unexpected because insects are generally attracted to ultraviolet or green light. We measured the spectral sensitivity of the compound eye, and found that the sensitivity peaked at 340 nm, as in other brachyceran flies. We used statistical modeling and optimization of the process parameters to predict the type of photoreceptor contributing to the violet preference. The analysis revealed that the wavelength preference could be explained by linear models of the quanta received by photoreceptors, including the R1-6 broadband receptors. The broadband receptors appear to contribute positively, whereas the R7-8 narrowband receptors contribute negatively to achieve the violet preference; i.e., spectral opponency might be involved. PMID:27532635

  7. Host Chemical Footprints Induce Host Sex Discrimination Ability in Egg Parasitoids

    PubMed Central

    Peri, Ezio; Frati, Francesca; Salerno, Gianandrea; Conti, Eric; Colazza, Stefano

    2013-01-01

    Trissolcus egg parasitoids, when perceiving the chemical footprints left on a substrate by pentatomid host bugs, adopt a motivated searching behaviour characterized by longer searching time on patches were signals are present. Once in contact with host chemical footprints, Trissolcus wasps search longer on traces left by associated hosts rather than non-associated species, and, in the former case, they search longer on traces left by females than males. Based on these evidences, we hypothesized that only associated hosts induce the ability to discriminate host sex in wasps. To test this hypothesis we investigated the ability of Trissolcus basalis, T. brochymenae, and Trissolcus sp. to distinguish female from male Nezara viridula, Murgantia histrionica, and Graphosoma semipunctatum footprints. These three pentatomid bugs were selected according to variable association levels. Bioassays were conducted on filter paper sheets, and on Brassica oleracea (broccoli) leaves. The results confirmed our hypothesis showing that wasps spent significantly more time on female rather than male traces left by associated hosts on both substrates. No differences were observed in the presence of traces left by non-associated hosts. The ecological consequences for parasitoid host location behaviour are discussed. PMID:24244417

  8. Tales from the crypt: a parasitoid manipulates the behaviour of its parasite host

    PubMed Central

    Liu, Sean M.; Forbes, Andrew A.; Egan, Scott P.

    2017-01-01

    There are many examples of apparent manipulation of host phenotype by parasites, yet few examples of hypermanipulation—where a phenotype-manipulating parasite is itself manipulated by a parasite. Moreover, few studies confirm manipulation is occurring by quantifying whether the host's changed phenotype increases parasite fitness. Here we describe a novel case of hypermanipulation, in which the crypt gall wasp Bassettia pallida (a phenotypic manipulator of its tree host) is manipulated by the parasitoid crypt-keeper wasp Euderus set, and show that the host's changed behaviour increases parasitoid fitness. Bassettia pallida parasitizes sand live oaks and induces the formation of a ‘crypt’ within developing stems. When parasitized by E. set, B. pallida adults excavate an emergence hole in the crypt wall, plug the hole with their head and die. We show experimentally that this phenomenon benefits E. set, as E. set that need to excavate an emergence hole themselves are about three times more likely to die trapped in the crypt. In addition, we discuss museum and field data to explore the distribution of the crypt-keeping phenomena. PMID:28123089

  9. Parasitoid wasp affects metabolism of cockroach host to favor food preservation for its offspring.

    PubMed

    Haspel, Gal; Gefen, Eran; Ar, Amos; Glusman, J Gustavo; Libersat, Frederic

    2005-06-01

    Unlike predators, which immediately consume their prey, parasitoid wasps incapacitate their prey to provide a food supply for their offspring. We have examined the effects of the venom of the parasitoid wasp Ampulex compressa on the metabolism of its cockroach prey. This wasp stings into the brain of the cockroach causing hypokinesia. We first established that larval development, from egg laying to pupation, lasts about 8 days. During this period, the metabolism of the stung cockroach slows down, as measured by a decrease in oxygen consumption. Similar decreases in oxygen consumption occurred after pharmacologically induced paralysis or after removing descending input from the head ganglia by severing the neck connectives. However, neither of these two groups of cockroaches survived more than six days, while 90% of stung cockroaches survived at least this long. In addition, cockroaches with severed neck connectives lost significantly more body mass, mainly due to dehydration. Hence, the sting of A. compressa not only renders the cockroach prey helplessly submissive, but also changes its metabolism to sustain more nutrients for the developing larva. This metabolic manipulation is subtler than the complete removal of descending input from the head ganglia, since it leaves some physiological processes, such as water retention, intact.

  10. Effects of Abiotic Factors on HIPV-Mediated Interactions between Plants and Parasitoids

    PubMed Central

    Becker, Christine; Desneux, Nicolas; Monticelli, Lucie; Fernandez, Xavier; Michel, Thomas; Lavoir, Anne-Violette

    2015-01-01

    In contrast to constitutively emitted plant volatiles (PV), herbivore-induced plant volatiles (HIPV) are specifically emitted by plants when afflicted with herbivores. HIPV can be perceived by parasitoids and predators which parasitize or prey on the respective herbivores, including parasitic hymenoptera. HIPV act as signals and facilitate host/prey detection. They comprise a blend of compounds: main constituents are terpenoids and “green leaf volatiles.” Constitutive emission of PV is well known to be influenced by abiotic factors like temperature, light intensity, water, and nutrient availability. HIPV share biosynthetic pathways with constitutively emitted PV and might therefore likewise be affected by abiotic conditions. However, the effects of abiotic factors on HIPV-mediated biotic interactions have received only limited attention to date. HIPV being influenced by the plant's growing conditions could have major implications for pest management. Quantitative and qualitative changes in HIPV blends may improve or impair biocontrol. Enhanced emission of HIPV may attract a larger number of natural enemies. Reduced emission rates or altered compositions, however, may render blends imperceptible to parasitoides and predators. Predicting the outcome of these changes is highly important for food production and for ecosystems affected by global climate change. PMID:26788501

  11. Parasitoids and competitors influence colony-level responses in the red imported fire ant, Solenopsis invicta

    NASA Astrophysics Data System (ADS)

    Mehdiabadi, Natasha J.; Kawazoe, Elizabeth A.; Gilbert, Lawrence E.

    2004-11-01

    Social insect colonies respond to challenges set by a variable environment by reallocating work among colony members. In many social insects, such colony-level task allocation strategies are achieved through individual decisions that produce a self-organized adapting group. We investigated colony responses to parasitoids and native ant competitors in the red imported fire ant (Solenopsis invicta). Parasitoid flies affected fire ants by decreasing the proportion of workers engaged in foraging. Competitors also altered colony-level behaviours by reducing the proportion of foraging ants and by increasing the proportion of roaming majors, whose role is colony defence. Interestingly, the presence of both parasitism and competition almost always had similar effects on task allocation in comparison to each of the biotic factors on its own. Thus, our study uniquely demonstrates that the interactive effect of both parasitism and competition is not necessarily additive, implying that these biotic factors alter colony behaviour in distinct ways. More generally, our work demonstrates the importance of studying the dynamics of species interactions in a broader context.

  12. Accidental genetic engineers: horizontal sequence transfer from parasitoid wasps to their Lepidopteran hosts.

    PubMed

    Schneider, Sean E; Thomas, James H

    2014-01-01

    We show here that 105 regions in two Lepidoptera genomes appear to derive from horizontally transferred wasp DNA. We experimentally verified the presence of two of these sequences in a diverse set of silkworm (Bombyx mori) genomes. We hypothesize that these horizontal transfers are made possible by the unusual strategy many parasitoid wasps employ of injecting hosts with endosymbiotic polydnaviruses to minimize the host's defense response. Because these virus-like particles deliver wasp DNA to the cells of the host, there has been much interest in whether genetic information can be permanently transferred from the wasp to the host. Two transferred sequences code for a BEN domain, known to be associated with polydnaviruses and transcriptional regulation. These findings represent the first documented cases of horizontal transfer of genes between two organisms by a polydnavirus. This presents an interesting evolutionary paradigm in which host species can acquire new sequences from parasitoid wasps that attack them. Hymenoptera and Lepidoptera diverged ∼300 MYA, making this type of event a source of novel sequences for recipient species. Unlike many other cases of horizontal transfer between two eukaryote species, these sequence transfers can be explained without the need to invoke the sequences 'hitchhiking' on a third organism (e.g. retrovirus) capable of independent reproduction. The cellular machinery necessary for the transfer is contained entirely in the wasp genome. The work presented here is the first such discovery of what is likely to be a broader phenomenon among species affected by these wasps.

  13. Combined Non-Target Effects of Insecticide and High Temperature on the Parasitoid Bracon nigricans

    PubMed Central

    Abbes, Khaled; Biondi, Antonio; Kurtulus, Alican; Ricupero, Michele; Russo, Agatino; Siscaro, Gaetano; Chermiti, Brahim; Zappalà, Lucia

    2015-01-01

    We studied the acute toxicity and the sublethal effects, on reproduction and host-killing activity, of four widely used insecticides on the generalist parasitoid Bracon nigricans (Hymenoptera: Braconidae), a natural enemy of the invasive tomato pest, Tuta absoluta (Lepidoptera: Gelechiidae). Laboratory bioassays were conducted applying maximum insecticide label rates at three constant temperatures, 25, 35 and 40°C, considered as regular, high and very high, respectively. Data on female survival and offspring production were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinetoram caused 80% mortality at 25°C and 100% at higher temperatures, while spinosad caused 100% mortality under all temperature regimes. Cyantraniliprole was slightly toxic to B. nigricans adults in terms of acute toxicity at the three temperatures, while it did not cause any sublethal effects in egg-laying and host-killing activities. The interaction between the two tested factors (insecticide and temperature) significantly influenced the number of eggs laid by the parasitoid, which was the lowest in the case of females exposed to chlorantraniliprole at 35°C. Furthermore, significantly lower B. nigricans demographic growth indexes were estimated for all the insecticides under all temperature conditions, with the exception of chlorantraniliprole at 25°C. Our findings highlight an interaction between high temperatures and insecticide exposure, which suggests a need for including natural stressors, such as temperature, in pesticide risk assessments procedures. PMID:26382245

  14. Wolbachia in guilds of Anastrepha fruit flies (Tephritidae) and parasitoid wasps (Braconidae)

    PubMed Central

    Mascarenhas, Rodrigo O; Prezotto, Leandro F; Perondini, André Luiz P; Marino, Celso Luiz; Selivon, Denise

    2016-01-01

    Abstract The endosymbiont Wolbachia is efficiently transmitted from females to their progenies, but horizontal transmission between different taxa is also known to occur. Aiming to determine if horizontal transmission might have occurred between Anastrepha fruit flies and associated braconid wasps, infection by Wolbachia was screened by amplification of a fragment of the wsp gene. Eight species of the genus Anastrepha were analyzed, from which six species of associated parasitoid wasps were recovered. The endosymbiont was found in seven Anastrepha species and in five species of braconids. The WSP Typing methodology detected eight wsp alleles belonging to Wolbachia supergroup A. Three were already known and five were new ones, among which four were found to be putative recombinant haplotypes. Two samples of Anastrepha obliqua and one sample of Doryctobracon brasiliensis showed multiple infection. Single infection by Wolbachia was found in the majority of samples. The distribution of Wolbachia harboring distinct alleles differed significantly between fruit flies and wasps. However, in nine samples of fruit flies and associated wasps, Wolbachia harbored the same wsp allele. These congruences suggest that horizontal transfer of Wolbachia might have occurred in the communities of fruit flies and their braconid parasitoids. PMID:27648768

  15. The role of geography and host abundance in the distribution of parasitoids of an alien pest.

    PubMed

    Nováková, Petra; Holuša, Jaroslav; Horák, Jakub

    2016-01-01

    Chalcid wasps (Hymenoptera: Chalcidoidea) are probably the most effective and abundant parasitoids of the horse chestnut leaf miner (Cameraria ohridella), an alien pest in Europe that lacks specialized enemies. We studied how the species richness and abundance of chalcids are influenced by altitude, direction of an alien spread and host abundance of C. ohridella. We quantified the numbers and species richness of chalcid wasps and the numbers of C. ohridella that emerged from horse chestnut (Aesculus hippocastanum) leaf litter samples collected from 35 sites in the Czech Republic. Species richness of chalcids, which was considered an indicator of the possible adaptation of parasitoids to this alien host, was unrelated to C. ohridella abundance, direction of spread, or altitude. Chalcid abundance, which was considered an indicator of parasitism of the alien host, was strongly and positively related to C. ohridella abundance. Chalcid abundance was negatively related to direction of spread and positively related, although in a non-linear manner, to altitude. The relationship of chalcid abundance with direction of spread and altitude was weaker than that with C. ohridella abundance. The results provide evidence that biological control of the alien pest C. ohridella by natural enemies might develop in the future.

  16. Effects of Abiotic Factors on HIPV-Mediated Interactions between Plants and Parasitoids.

    PubMed

    Becker, Christine; Desneux, Nicolas; Monticelli, Lucie; Fernandez, Xavier; Michel, Thomas; Lavoir, Anne-Violette

    2015-01-01

    In contrast to constitutively emitted plant volatiles (PV), herbivore-induced plant volatiles (HIPV) are specifically emitted by plants when afflicted with herbivores. HIPV can be perceived by parasitoids and predators which parasitize or prey on the respective herbivores, including parasitic hymenoptera. HIPV act as signals and facilitate host/prey detection. They comprise a blend of compounds: main constituents are terpenoids and "green leaf volatiles." Constitutive emission of PV is well known to be influenced by abiotic factors like temperature, light intensity, water, and nutrient availability. HIPV share biosynthetic pathways with constitutively emitted PV and might therefore likewise be affected by abiotic conditions. However, the effects of abiotic factors on HIPV-mediated biotic interactions have received only limited attention to date. HIPV being influenced by the plant's growing conditions could have major implications for pest management. Quantitative and qualitative changes in HIPV blends may improve or impair biocontrol. Enhanced emission of HIPV may attract a larger number of natural enemies. Reduced emission rates or altered compositions, however, may render blends imperceptible to parasitoides and predators. Predicting the outcome of these changes is highly important for food production and for ecosystems affected by global climate change.

  17. Acanthopria and Mimopriella parasitoid wasps (Diapriidae) attack Cyphomyrmex fungus-growing ants (Formicidae, Attini)

    NASA Astrophysics Data System (ADS)

    Fernández-Marín, Hermógenes; Zimmerman, Jess K.; Wcislo, William T.

    2006-01-01

    New World diapriine wasps are abundant and diverse, but the biology of most species is unknown. We provide the first description of the biology of diapriine wasps, Acanthopria spp. and Mimopriella sp., which attack the larvae of Cyphomyrmex fungus-growing ants. In Puerto Rico, the koinobiont parasitoids Acanthopria attack Cyphomyrmex minutus, while in Panama at least four morphospecies of Acanthopria and one of Mimopriella attack Cyphomyrmex rimosus. Of the total larvae per colony, 0 100% were parasitized, and 27 70% of the colonies per population were parasitized. Parasitism rate and colony size were negatively correlated for C. rimosus but not for C. minutus. Worker ants grasped at, bit, and in some cases, killed adult wasps that emerged in artificial nests or tried to enter natural nests. Parasitoid secondary sex ratios were female-biased for eclosing wasps, while field collections showed a male-biased sex ratio. Based on their abundance and success in attacking host ants, these minute wasps present excellent opportunities to explore how natural enemies impact ant colony demography and population biology.

  18. Tales from the crypt: a parasitoid manipulates the behaviour of its parasite host.

    PubMed

    Weinersmith, Kelly L; Liu, Sean M; Forbes, Andrew A; Egan, Scott P

    2017-01-25

    There are many examples of apparent manipulation of host phenotype by parasites, yet few examples of hypermanipulation-where a phenotype-manipulating parasite is itself manipulated by a parasite. Moreover, few studies confirm manipulation is occurring by quantifying whether the host's changed phenotype increases parasite fitness. Here we describe a novel case of hypermanipulation, in which the crypt gall wasp Bassettia pallida (a phenotypic manipulator of its tree host) is manipulated by the parasitoid crypt-keeper wasp Euderus set, and show that the host's changed behaviour increases parasitoid fitness. Bassettia pallida parasitizes sand live oaks and induces the formation of a 'crypt' within developing stems. When parasitized by E. set, B. pallida adults excavate an emergence hole in the crypt wall, plug the hole with their head and die. We show experimentally that this phenomenon benefits E. set, as E. set that need to excavate an emergence hole themselves are about three times more likely to die trapped in the crypt. In addition, we discuss museum and field data to explore the distribution of the crypt-keeping phenomena.

  19. The role of geography and host abundance in the distribution of parasitoids of an alien pest

    PubMed Central

    Nováková, Petra; Holuša, Jaroslav

    2016-01-01

    Chalcid wasps (Hymenoptera: Chalcidoidea) are probably the most effective and abundant parasitoids of the horse chestnut leaf miner (Cameraria ohridella), an alien pest in Europe that lacks specialized enemies. We studied how the species richness and abundance of chalcids are influenced by altitude, direction of an alien spread and host abundance of C. ohridella. We quantified the numbers and species richness of chalcid wasps and the numbers of C. ohridella that emerged from horse chestnut (Aesculus hippocastanum) leaf litter samples collected from 35 sites in the Czech Republic. Species richness of chalcids, which was considered an indicator of the possible adaptation of parasitoids to this alien host, was unrelated to C. ohridella abundance, direction of spread, or altitude. Chalcid abundance, which was considered an indicator of parasitism of the alien host, was strongly and positively related to C. ohridella abundance. Chalcid abundance was negatively related to direction of spread and positively related, although in a non-linear manner, to altitude. The relationship of chalcid abundance with direction of spread and altitude was weaker than that with C. ohridella abundance. The results provide evidence that biological control of the alien pest C. ohridella by natural enemies might develop in the future. PMID:26819849

  20. Adaptation of indigenous larval parasitoids to Tuta absoluta (Lepidoptera: Gelechiidae) in Italy.

    PubMed

    Ferracini, Chiara; Ingegno, Barbara Letizia; Navone, Paolo; Ferrari, Ester; Mosti, Marco; Tavella, Luciana; Alma, Alberto

    2012-08-01

    Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious threat to tomato (Solanum lycopersicum L.) crops in South America. In Europe, after its first detection in Spain in 2006, it rapidly spread through the Mediterranean basin, reaching Italy 2 yr later. The aim of our work was to find indigenous effective biological control agents and to evaluate their potential role in the control of larval populations of T. absoluta in controlled conditions. Nine species of larval parasitoids emerged from field-collected tomato leaves infested by T. absoluta. The most abundant, Necremnus near artynes (Walker) and Necremnus near tidius (Walker) (Hymenoptera: Eulophidae), were tested in laboratory parasitism trials. Furthermore, because the species N. artynes and N. tidius are each reported in literature as an ectoparasitoid of Cosmopterix pulchrimella Chambers (Lepidoptera: Cosmopterigidae) on upright pellitory plants, olfactometer bioassays were performed to assess the response of our parasitoids to the odors of tomato and pellitory leaves infested by T absoluta and C. pulchrimella, respectively, compared with healthy ones. Both Necremnus species showed good adaptation to the invasive pest, and we observed a high larval mortality of T. absoluta because of host feeding and parasitism. Even olfactory responses highlighted a preference of both wasps for tomato plants infested by the exotic pest. These preliminary results demonstrated a high suitability of these indigenous natural enemies for controlling T. absoluta. Further investigations are needed to confirm their role as potential biological agents in commercial tomato plantations.

  1. Response of Plutella xylostella and its parasitoid Cotesia plutellae to volatile compounds.

    PubMed

    Ibrahim, Mohamed A; Nissinen, Anne; Holopainen, Jarmo K

    2005-09-01

    The effects of limonene, a mixture of limonene + carvone (1:1, v/v), and methyl jasmonate (MeJA) on diamondback moth (DBM) (Plutella xylostella L.) oviposition, larval feeding, and the behavior of its larval parasitoid Cotesia plutellae (Kurdjumov) with cabbage (Brassica oleracea L. ssp. capitata, cvs. Rinda and Lennox) and broccoli (B. oleracea subsp. Italica cv Lucky) were tested. Limonene showed no deterrent effect on DBM when plants were sprayed with or exposed to limonene, although there was a cultivar difference. A mixture of limonene and carvone released from vermiculite showed a significant repellent effect, reducing the number of eggs laid on the cabbages. MeJA treatment reduced the relative growth rate (RGR) of larvae on cv Lennox leaves. In Y-tube olfactometer tests, C. plutellae preferred the odors of limonene and MeJA to filtered air. In cv Lennox, the parasitoid preferred DBM-damaged plants with limonene to such plants without limonene. C. plutellae females were repelled by the mixture of limonene + carvone. In both cultivars, exogenous MeJA induced the emission of the sesquiterpene (E,E)-alpha-farnesene, the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and green leaf volatile (Z)-3-hexenyl acetate + octanal. The attractive effect of limonene and MeJA predicts that these two compounds can be used in sustainable plant protection strategies in organic farming.

  2. An Optimized Protocol for Rearing Fopius arisanus, a Parasitoid of Tephritid Fruit Flies

    PubMed Central

    Manoukis, Nicholas; Geib, Scott; Seo, Danny; McKenney, Michael; Vargas, Roger; Jang, Eric

    2011-01-01

    Fopius arisanus (Sonan) is an important parasitoid of Tephritid fruit flies for at least two reasons. First, it is the one of only three opiine parasitoids known to infect the host during the egg stage1. Second, it has a wide range of potential fruit fly hosts. Perhaps due to its life history, F. arisanus has been a successfully used for biological control of fruit flies in multiple tropical regions2-4. One impediment to the wide use of F. arisanus for fruit fly control is that it is difficult to establish a stable laboratory colony5-9. Despite this difficulty, in the 1990s USDA researchers developed a reliable method to maintain laboratory populations of F. arisanus10-12. There is significant interest in F. arisanus biology13,14, especially regarding its ability to colonize a wide variety of Tephritid hosts14-17; interest is especially driven by the alarming spread of Bactrocera fruit fly pests to new continents in the last decade18. Further research on F. arisanus and additional deployments of this species as a biological control agent will benefit from optimizations and improvements of rearing methods. In this protocol and associated video article we describe an optimized method for rearing F. arisanus based on a previously described approach12. The method we describe here allows rearing of F. arisanus in a small scale without the use of fruit, using materials available in tropical regions around the world and with relatively low manual labor requirements. PMID:21750493

  3. Host breadth and parasitoids of fruit flies (Anastrepha spp.) (Diptera: Tephritidae) in Puerto Rico.

    PubMed

    Jenkins, David A; Goenaga, Ricardo

    2008-02-01

    Twenty fruit species representing 12 families were collected from various regions in western Puerto Rico and monitored for the emergence of Anastrepha spp. pupae. We collected 14,154 tephritid pupae from 16 fruit species representing 10 families. The relative infestations of these fruits (pupae per kilogram of fruit) were recorded. Recorded host ranges were not in complete agreement with those reported in the literature. This host-use pattern should give pause to regulators of fruit importation and exportation that base their decisions on literature from regions other than those of immediate interest to them. We recovered the braconid parasitoid Utetes anastrephae (Viereck) from tephritid pupae collected from Mangifera indica L., Spondias mombin L., Psidium guajava L., Chrysobalanus icacos L., Terminalia catappa L., and Garcinia intermedia (Pittier) Hammel. We collected one specimen of the parasitoid Doryctobracon aerolatus (Szepligeti) from the west coast (Añasco), which had not been previously reported in Puerto Rico. We present a preliminary phenology of what are probably the primary fruit hosts of the Anastrepha spp. of Puerto Rico. We also present the first report of Garcinia intermedia (Pittier) Hammel and Coffea arabica L. as reproductive hosts of A. suspensa.

  4. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.

    2016-04-01

    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  5. Architectural-acoustics consulting

    NASA Astrophysics Data System (ADS)

    Hoover, Anthony K.

    2004-05-01

    Consulting involves both the science of acoustics and the art of communication, requiring an array of inherent and created skills. Perhaps because consulting on architectural acoustics is a relatively new field, there is a remarkable variety of career paths, all influenced by education, interest, and experience. Many consultants juggle dozens of chargeable projects at a time, not to mention proposals, seminars, teaching, articles, business concerns, and professional-society activities. This paper will discuss various aspects of career paths, projects, and clients as they relate to architectural-acoustics consulting. The intended emphasis will be considerations for those who may be interested in such a career, noting that consultants generally seem to thrive on the numerous challenges.

  6. High temperature acoustic levitator

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B. (Inventor)

    1984-01-01

    A system is described for acoustically levitating an object within a portion of a chamber that is heated to a high temperature, while a driver at the opposite end of the chamber is maintained at a relatively low temperature. The cold end of the chamber is constructed so it can be telescoped to vary the length (L sub 1) of the cold end portion and therefore of the entire chamber, so that the chamber remains resonant to a normal mode frequency, and so that the pressure at the hot end of the chamber is maximized. The precise length of the chamber at any given time, is maintained at an optimum resonant length by a feedback loop. The feedback loop includes an acoustic pressure sensor at the hot end of the chamber, which delivers its output to a control circuit which controls a motor that varies the length (L) of the chamber to a level where the sensed acoustic pressure is a maximum.

  7. Basic Linear Acoustics

    NASA Astrophysics Data System (ADS)

    Pierce, Alan

    This chapter deals with the physical and mathematical aspects of sound when the disturbances are, in some sense, small. Acoustics is usually concerned with small-amplitude phenomena, and consequently a linear description is usually applicable. Disturbances are governed by the properties of the medium in which they occur, and the governing equations are the equations of continuum mechanics, which apply equally to gases, liquids, and solids. These include the mass, momentum, and energy equations, as well as thermodynamic principles. The viscosity and thermal conduction enter into the versions of these equations that apply to fluids. Fluids of typical great interest are air and sea water, and consequently this chapter includes a summary of their relevant acoustic properties. The foundation is also laid for the consideration of acoustic waves in elastic solids, suspensions, bubbly liquids, and porous media.

  8. Phylogeography, Interaction Patterns and the Evolution of Host Choice in Drosophila-Parasitoid Systems in Ryukyu Archipelago and Taiwan.

    PubMed

    Novković, Biljana; Kimura, Masahito T

    2015-01-01

    Island biotas provide a great opportunity to study not only the phylogeographic patterns of a group of species, but also to explore the differentiation in their coevolutionary interactions. Drosophila and their parasitoids are exemplary systems for studying complex interaction patterns. However, there is a lack of studies combining interaction-based and molecular marker-based methods. We applied an integrated approach combining phylogeography, interaction, and host-choice behavior studies, with the aim to understand how coevolutionary interactions evolve in Drosophila-parasitoid island populations. The study focused on the three most abundant Drosophila species in Ryukyu archipelago and Taiwan: D. albomicans, D. bipectinata, and D. takahashii, and the Drosophila-parasitoid Leptopilina ryukyuensis. We determined mitochondrial COI haplotypes for samples representing five island populations of Drosophila and four island populations of L. ryukyuensis. We additionally sequenced parts of the autosomal Gpdh for Drosophila samples, and the ITS2 for parasitoid samples. Phylogenetic and coalescent analyses were used to test for demographic events and to place them in a temporal framework. Geographical differences in Drosophila-parasitoid interactions were studied in host-acceptance, host-suitability, and host-choice experiments. All four species showed species-specific phylogeographic patterns. A general trend of the haplotype diversity increasing towards the south was observed. D. albomicans showed very high COI haplotype diversity, and had the most phylogeographically structured populations, with differentiation into the northern and the southern population-group, divided by the Kerama gap. Differentiation in host suitability was observed only between highly structured populations of D. albomicans, possibly facilitated by restricted gene flow. Differentiation in host-acceptance in D. takahashii, and host-acceptance and host-choice in L. ryukyuensis was found, despite there

  9. Evolution of reproductive mode variation and host associations in a sexual-asexual complex of aphid parasitoids

    PubMed Central

    2011-01-01

    Background The Lysiphlebus fabarum group is a taxonomically poorly resolved complex of aphid parasitoids, presently split into three described species that comprise sexual (arrhenotokous) and asexual (thelytokous) lineages of unknown relationship. Specifically, it is unclear how asexuals evolved from sexuals in this system, to what extent reproductive modes are still connected by genetic exchange, how much the complex is structured by geography or by host-associated differentiation, and whether species designations are valid. Using a combination of population genetic and phylogenetic approaches, we addressed these issues in a comprehensive sample of parasitoid wasps from across Europe. Results Asexual reproduction predominated in parasitoids of the L. fabarum group, with asexual populations exhibiting high genotypic diversity. Sexual populations were only common in southern France; elsewhere sexual reproduction was restricted to specific aphid hosts. Although reproductive modes were aggregated on the mitochondrial genealogy and significantly differentiated at nuclear microsatellite loci, there was clear evidence for genetic exchange, especially on hosts attacked by sexual and asexual parasitoids. The microsatellite data further revealed that parasitoids collected from certain host aphids were significantly differentiated, yet the mitochondrial sequence variation across the entire L. fabarum group did not exceed 1.32% and exhibited a very shallow topology. Morphological characters used for delineation of described species were found to be phylogenetically non-conservative. Conclusions Our results suggest that the sexual-asexual L. fabarum group represents a young complex of lineages with incomplete isolation between reproductive modes. We propose three mechanisms of genetic exchange that may jointly explain the high genotypic diversity observed in asexual parasitoids: (i) the formation of new asexual lineages via 'contagious parthenogenesis', (ii) introgression from

  10. Venom of Parasitoid, Pteromalus puparum, Suppresses Host, Pieris rapae, Immune Promotion by Decreasing Host C-Type Lectin Gene Expression

    PubMed Central

    Fang, Qi; Wang, Fei; Gatehouse, John A.; Gatehouse, Angharad M. R.; Chen, Xue-xin; Hu, Cui; Ye, Gong-yin

    2011-01-01

    Background Insect hosts have evolved immunity against invasion by parasitoids, and in co-evolutionary response parasitoids have also developed strategies to overcome host immune systems. The mechanisms through which parasitoid venoms disrupt the promotion of host immunity are still unclear. We report here a new mechanism evolved by parasitoid Pteromalus puparum, whose venom inhibited the promotion of immunity in its host Pieris rapae (cabbage white butterfly). Methodology/Principal Findings A full-length cDNA encoding a C-type lectin (Pr-CTL) was isolated from P. rapae. Quantitative PCR and immunoblotting showed that injection of bacterial and inert beads induced expression of Pr-CTL, with peaks of mRNA and Pr-CTL protein levels at 4 and 8 h post beads challenge, respectively. In contrast, parasitoid venom suppressed Pr-CTL expression when co-injected with beads, in a time and dose-dependent manner. Immunolocalization and immunoblotting results showed that Pr-CTL was first detectable in vesicles present in cytoplasm of granulocytes in host hemolymph, and was then secreted from cells into circulatory fluid. Finally, the secreted Pr-CTL bound to cellular membranes of both granulocytes and plasmatocytes. Injection of double-stranded RNA specific for target gene decreased expression of Pr-CTL, and a few other host immune-related genes. Suppression of Pr-CTL expression also down-regulated antimicrobial and phenoloxidase activities, and reducing phagocytotic and encapsulation rates in host. The inhibitory effect of parasitoid venom on host encapsulation is consistent with its effect in suppressing Pr-CTL expression. Binding assay results showed that recombinant Pr-CTL directly attached to the surface of P. puparum egges. We infer that Pr-CTL may serve as an immune signalling co-effector, first binding to parasitoid eggs, regulating expression of a set of immune-related genes and promoting host immunity. Conclusions/Significance P. puparum venom inhibits promotion of host

  11. Acoustic Liners for Turbine Engines

    NASA Technical Reports Server (NTRS)

    Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

    2016-01-01

    An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

  12. Spacecraft Internal Acoustic Environment Modeling

    NASA Technical Reports Server (NTRS)

    Allen, Christopher; Chu, S. Reynold

    2008-01-01

    The objective of the project is to develop an acoustic modeling capability, based on commercial off-the-shelf software, to be used as a tool for oversight of the future manned Constellation vehicles to ensure compliance with acoustic requirements and thus provide a safe and habitable acoustic environment for the crews, and to validate developed models via building physical mockups and conducting acoustic measurements.

  13. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  14. Acoustic bubble removal method

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Elleman, D. D.; Wang, T. G. (Inventor)

    1983-01-01

    A method is described for removing bubbles from a liquid bath such as a bath of molten glass to be used for optical elements. Larger bubbles are first removed by applying acoustic energy resonant to a bath dimension to drive the larger bubbles toward a pressure well where the bubbles can coalesce and then be more easily removed. Thereafter, submillimeter bubbles are removed by applying acoustic energy of frequencies resonant to the small bubbles to oscillate them and thereby stir liquid immediately about the bubbles to facilitate their breakup and absorption into the liquid.

  15. Broadband Acoustic Hyperbolic Metamaterial.

    PubMed

    Shen, Chen; Xie, Yangbo; Sui, Ni; Wang, Wenqi; Cummer, Steven A; Jing, Yun

    2015-12-18

    In this Letter, we report on the design and experimental characterization of a broadband acoustic hyperbolic metamaterial. The proposed metamaterial consists of multiple arrays of clamped thin plates facing the y direction and is shown to yield opposite signs of effective density in the x and y directions below a certain cutoff frequency, therefore, yielding a hyperbolic dispersion. Partial focusing and subwavelength imaging are experimentally demonstrated at frequencies between 1.0 and 2.5 kHz. The proposed metamaterial could open up new possibilities for acoustic wave manipulation and may find usage in medical imaging and nondestructive testing.

  16. Acoustic emission intrusion detector

    DOEpatents

    Carver, Donald W.; Whittaker, Jerry W.

    1980-01-01

    An intrusion detector is provided for detecting a forcible entry into a secured structure while minimizing false alarms. The detector uses a piezoelectric crystal transducer to sense acoustic emissions. The transducer output is amplified by a selectable gain amplifier to control the sensitivity. The rectified output of the amplifier is applied to a Schmitt trigger circuit having a preselected threshold level to provide amplitude discrimination. Timing circuitry is provided which is activated by successive pulses from the Schmitt trigger which lie within a selected time frame for frequency discrimination. Detected signals having proper amplitude and frequency trigger an alarm within the first complete cycle time of a detected acoustical disturbance signal.

  17. Electromechanical acoustic liner

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark (Inventor); Cattafesta, III, Louis N. (Inventor); Nishida, Toshikazu (Inventor); Horowitz, Stephen Brian (Inventor)

    2007-01-01

    A multi-resonator-based system responsive to acoustic waves includes at least two resonators, each including a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice so that a portion of an incident acoustical wave compresses gas in the resonators. The bottom plate or the side walls include at least one compliant portion. A reciprocal electromechanical transducer coupled to the compliant portion of each of the resonators forms a first and second transducer/compliant composite. An electrical network is disposed between the reciprocal electromechanical transducer of the first and second resonator.

  18. Broadband Acoustic Clutter

    DTIC Science & Technology

    2010-09-30

    fluidized mud, which has sound speeds at (or sometimes below) the sound speed of the water column, here 1512 m/s. Interestingly, there is a sound speed...data. 3 specular 25m Figure 1. The map shows the AUV track (red line) overlaid on multibeam bathymetry. Mean water depth is about 165m...Preston, and D.A. Abraham, Long-range acoustic scattering from a shallow- water mud volcano cluster J. Acoust. Soc. Am., 122, 1946-1958, 2007. [3

  19. Acoustic tooth cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (Inventor)

    1982-01-01

    An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

  20. Post Treatment of Acoustic Neuroma

    MedlinePlus

    Home What is an AN What is an Acoustic Neuroma? Identifying an AN Symptoms Acoustic Neuroma Keywords Educational Video Pre-Treatment Treatment Options Summary Treatment Options Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions ...