The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Carl W Dick - One of the best experts on this subject based on the ideXlab platform.
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Bats, Bat Flies, and Fungi: A Case of Hyperparasitism
Trends in parasitology, 2018Co-Authors: Danny Haelewaters, Thomas Hiller, Carl W DickAbstract:Bats are parasitized by numerous lineages of arthropods, of which bat flies (Diptera, Nycteribiidae and Streblidae) are the most conspicuous. Bat flies themselves can be parasitized by Laboulbeniales, fungal biotrophs of arthropods. This is known as Hyperparasitism, a severely understudied phenomenon. Three genera of Laboulbeniales occur on bat flies: Arthrorhynchus on Nycteribiidae, Gloeandromyces and Nycteromyces on Streblidae. In this review we introduce the parasitic partners in this tripartite system and discuss their diversity, ecology, and specificity patterns, alongside some important life history traits. Furthermore, we cover recent advances in the study of the associations between bat flies and Laboulbeniales, which were neglected for decades. Among the most immediate needs for further studies are detailed tripartite field surveys. The vermin only teaze and pinch Their foes superior by an inch So, naturalists observe, a flea Has smaller fleas that on him prey; And these have smaller still to bite ‘em, And so proceed ad infinitum. Jonathan Swift (On Poetry: A Rhapsody, 1733)
Danny Haelewaters - One of the best experts on this subject based on the ideXlab platform.
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Bats, Bat Flies, and Fungi: A Case of Hyperparasitism
Trends in parasitology, 2018Co-Authors: Danny Haelewaters, Thomas Hiller, Carl W DickAbstract:Bats are parasitized by numerous lineages of arthropods, of which bat flies (Diptera, Nycteribiidae and Streblidae) are the most conspicuous. Bat flies themselves can be parasitized by Laboulbeniales, fungal biotrophs of arthropods. This is known as Hyperparasitism, a severely understudied phenomenon. Three genera of Laboulbeniales occur on bat flies: Arthrorhynchus on Nycteribiidae, Gloeandromyces and Nycteromyces on Streblidae. In this review we introduce the parasitic partners in this tripartite system and discuss their diversity, ecology, and specificity patterns, alongside some important life history traits. Furthermore, we cover recent advances in the study of the associations between bat flies and Laboulbeniales, which were neglected for decades. Among the most immediate needs for further studies are detailed tripartite field surveys. The vermin only teaze and pinch Their foes superior by an inch So, naturalists observe, a flea Has smaller fleas that on him prey; And these have smaller still to bite ‘em, And so proceed ad infinitum. Jonathan Swift (On Poetry: A Rhapsody, 1733)
Wolfgang Völkl - One of the best experts on this subject based on the ideXlab platform.
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Are behavioural changes in parasitised aphids a protection against Hyperparasitism
European Journal of Entomology, 2013Co-Authors: C.b. Müller, Wolfgang Völkl, H. C. J. GodfrayAbstract:Parasitised aphids often leave the aphid colony before mummification. It has been suggested that this behaviour is an example of host manipulation by the primary aphidiid parasitoid to reduce the risk of Hyperparasitism after mummy formation. Mummification site and Hyperparasitism risk are surveyed in 16 species of aphid. Mummification away from the colony was not associated with reduced Hyperparasitism. In ant-attended species, and in species with well developed parasitoid defence behaviour (such as kicking), mummies formed within the colony tended to suffer less Hyperparasitism. In laboratory experiments, two hymenopteran ectohyperparasitoids, Dendrocerus carpenteri (Curtis) (Megaspilidae) and Asaphes vulgaris (Walker) (Pteromalidae), were more successful attacking parasitised aphids [Uroleucon jaceae (L.) (Aphididae)] when the mummies were outside the colony, not surrounded by living aphids.
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Sex ratio shift caused by Hyperparasitism in the solitary parasitoid Lysiphlebus hirticornis (Hymenoptera: Braconidae: Aphidiinae)
European Journal of Entomology, 2005Co-Authors: M. Mackauer, Wolfgang VölklAbstract:We examined the influence of offspring mortality caused by Hyperparasitism on the secondary sex ratio of Lysiphlebus hirticornis Mackauer, a solitary endoparasitoid of the aphid Metopeurum fuscoviride Stroyan, in the field. Females of L. hirticornis produce pseudo-gregarious broods, which may comprise more than 200 offspring. Hyperparasitoids (mainly Syrphophagus aphidi- vorus (Mayr)) attacked and killed up to 60% of the primary parasitoids inside mummified aphids, especially late in the season. Hyperparasitized broods were larger than hyperparasitoid-free broods, which suggests that the risk of Hyperparasitism increased with mummy density. We tested the hypothesis that mortality caused by Hyperparasitism is greater for female than male offspring of L. hirticornis. If mummy quality scales with mummy size, hyperparasitoids should choose the relatively larger over the relatively smaller mummies. In the absence of Hyperparasitism, broods of L. hirticornis included approximately two daughters for each son; the sex ratio did not vary with brood size. In hyperparasitized broods, the sex ratio was nearly even. This result indicates that rela- tively more female offspring (developing in the larger mummies) than male offspring (developing in the smaller mummies) were killed by hyperparasitoids. We propose that sex-differential offspring mortality in L. hirticornis is the result of differences in optimal host choice between the primary parasitoid and the hyperparasitoids.
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Hyperparasitism: Multitrophic Ecology and Behavior
Annual review of entomology, 1999Co-Authors: Daniel J. Sullivan, Wolfgang VölklAbstract:▪ Abstract Hyperparasitoids are secondary insect parasitoids that develop at the expense of a primary parasitoid, thereby representing a highly evolved fourth trophic level. This review evaluates multitrophic relationships and hyperparasitoid ecology. First, hyperparasitoid communities of various taxa of phytophagous and predacious insects are described. Second, specific patterns of hyperparasitoid community organization and hyperparasitoid ecology are described in detail, using the aphid-parasitoid–hyperparasitoid food web as a model system. Aphid hyperparasitoid communities consist of ecto- and endohyperparasitoids, with ectohyperparasitoids being less host specific than endohyperparasitoids. Lifetime fecundity and intrinsic rate of increase of hyperparasitoids are generally lower than those of their primary hosts. Aphid ectohyperparasitoids search randomly for hosts and do not use specific cues, whereas endohyperparasitoids gain information that originates from host plants or hosts for long-range searc...
Hannah L Buckley - One of the best experts on this subject based on the ideXlab platform.
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adding floral nectar resources to improve biological control potential pitfalls of the fourth trophic level
Basic and Applied Ecology, 2009Co-Authors: Salaheddin Araj, S D Wratten, Alison Lister, Hannah L BuckleyAbstract:Abstract The effects of floral nectar resources on ecosystem function were investigated by examining the consequences of increasing habitat complexity in field microcosms on the dynamics of a four-trophic-level community, consisting of lucerne (alfalfa), a herbivore (the pea aphid, Acyrthosiphon pisum), its parasitoid (Aphidius ervi) and a hyperparasitoid (Dendrocerus aphidum). The influence of buckwheat (Fagopyrum esculentum) flowers on the parasitism and Hyperparasitism by A. ervi and D. aphidum, respectively, was compared with buckwheat-free treatments. Experimental units for this study were 1.8×1.8×2 m3 steel-framed cages covered with a fine mesh. Parasitism and Hyperparasitism rates were significantly higher in the presence of flowering buckwheat. Parasitism rates by A. ervi were lower but not significantly, in the presence of D. aphidum in buckwheat and buckwheat-free treatments. A. pisum density was significantly reduced by A. ervi when buckwheat was present, but the density of the aphid was not affected by the hyperparasitoid. The parasitoid's potential to reduce the host population was, therefore, significantly influenced by the presence of floral nectar. Although Hyperparasitism rates were significantly increased by buckwheat, this did not ‘cascade’ to the second trophic level, the pea aphid. However, before floral resources are deployed in agro-ecosystems to enhance biological control of pests, the influence of flowers on the second and fourth trophic levels should always be considered.
Anthony R Ives - One of the best experts on this subject based on the ideXlab platform.
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the potential for Hyperparasitism to compromise biological control why don t hyperparasitoids drive their primary parasitoid hosts extinct
Biological Control, 2011Co-Authors: Shon S Schooler, Paul J De Barro, Anthony R IvesAbstract:Abstract Predation or parasitism on species introduced as biological control agents is a common explanation for failure of biological control programs. Although there is clear evidence from some biological control programs that Hyperparasitism can impact a parasitoid biological control agent, it is not clear whether hyperparasitoids have the potential to cause control failure. We performed glasshouse experiments using cages containing 48 plants to address whether the hyperparasitoid Asaphes suspensus can potentially eliminate a population of the primary parasitoid Aphidius ervi, a biological control agent of the pea aphid Acyrthosiphon pisum. Although As. suspensus has a low intrinsic rate of increase, only one-half that of A. ervi and one-third that of pea aphids, it was nonetheless capable of eliminating the A. ervi population within seven A. ervi generations. In contrast, in the absence of As. suspensus, A. ervi eliminated the pea aphid population. Field surveys, however, found that As. suspensus does not eliminate entire natural populations of A. ervi in lucerne crops, probably due to the high frequency of disturbance that favours high intrinsic rates of increase and short generation times. Nonetheless, the ability of As. suspensus to eliminate A. ervi in cages despite its low intrinsic rate of increase underscores the potential for Hyperparasitism to disrupt biological control. Small populations are expected to be particularly susceptible to Hyperparasitism, such as when releases of a new biological control agent are made.
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The potential for Hyperparasitism to compromise biological control: Why don’t hyperparasitoids drive their primary parasitoid hosts extinct?
Biological Control, 2011Co-Authors: Shon S Schooler, Paul J De Barro, Anthony R IvesAbstract:Abstract Predation or parasitism on species introduced as biological control agents is a common explanation for failure of biological control programs. Although there is clear evidence from some biological control programs that Hyperparasitism can impact a parasitoid biological control agent, it is not clear whether hyperparasitoids have the potential to cause control failure. We performed glasshouse experiments using cages containing 48 plants to address whether the hyperparasitoid Asaphes suspensus can potentially eliminate a population of the primary parasitoid Aphidius ervi, a biological control agent of the pea aphid Acyrthosiphon pisum. Although As. suspensus has a low intrinsic rate of increase, only one-half that of A. ervi and one-third that of pea aphids, it was nonetheless capable of eliminating the A. ervi population within seven A. ervi generations. In contrast, in the absence of As. suspensus, A. ervi eliminated the pea aphid population. Field surveys, however, found that As. suspensus does not eliminate entire natural populations of A. ervi in lucerne crops, probably due to the high frequency of disturbance that favours high intrinsic rates of increase and short generation times. Nonetheless, the ability of As. suspensus to eliminate A. ervi in cages despite its low intrinsic rate of increase underscores the potential for Hyperparasitism to disrupt biological control. Small populations are expected to be particularly susceptible to Hyperparasitism, such as when releases of a new biological control agent are made.
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hyperparasitoid aggregation in response to variation in aphidius ervi host density at three spatial scales
Ecological Entomology, 1996Co-Authors: Shon S Schooler, Anthony R Ives, Jason P HarmonAbstract:. 1 This article investigates the pattern of Hyperparasitism of the host Aphidius ervi Haliday (Hymenoptera, Aphidiidae), a primary parasitoid of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae) at three spatial scales. 2 In the laboratory, the hyperparasitoid Asaphes lucens (Provancher) (Hymenoptera: Pteromalidae) was introduced into cages containing sixteen alfalfa plants with varying numbers of A. ervi mummies (the stage susceptible to Hyperparasitism). The pattern of Hyperparasitism at the end of the 48-h trials showed no density-dependent hyperparasitoid aggregation, although there was strong density-independent hyperparasitoid aggregation. 3 In the field, the density of A. ervi mummies was manipulated in twelve 2 × 2-m plots containing 1309–1654 alfalfa stems. Variation in Hyperparasitism among plots showed no density-dependent aggregation, although there was strong density-independent aggregation. 4 Finally, at the largest scale of the study, the distribution of Hyperparasitism was sampled among twelve alfalfa fields within a 5 × 3-km area. At this scale there was both density-dependent and density-independent hyperparasitoid aggregation. 5 The natural variation in A. ervi mummy density is greatest at the larger scales of study. Therefore, density-dependent Hyperparasitism occurs only when there is high natural variation in mummy density.