Foraging behavior of egg parasitoids exploiting chemical information
Fatouros, N.E. ; Dicke, M. ; Mumm, R. ; Meiners, T. ; Hilker, M. - \ 2008
Behavioral Ecology 19 (2008)3. - ISSN 1045-2249 - p. 677 - 689.
trichogramma-evanescens hymenoptera - telenomus-euproctidis hymenoptera - australis fabricius heteroptera - podisus-maculiventris hemiptera - trissolcus-basalis hymenoptera - heliothis-zea lepidoptera - european corn-borer - pieris-brassicae l - footed plant bug
Female parasitic wasps seek hosts for their offspring often in a dynamic environment. Foraging egg parasitoids rely on a variety of chemical cues originating from the adult host, host products, or the host plant rather than from the attacked host stage¿the insect egg itself. Besides pupae, insect eggs are the most inconspicuous host stage attacked by parasitic wasps. To overcome the problem of low detectability of host eggs, egg parasitoids have evolved several strategies such as exploiting long-range kairomones of the adult hosts, for example, host aggregation and sex pheromones, plant synomones induced by egg deposition or host feeding, or short-range contact cues derived from the adult host or the host plant. Moreover, egg parasitoids have evolved the ability to use chemical espionage in combination with hitchhiking on the adult host (phoresy) to compensate their limited flight capability and to gain access to freshly laid host eggs. Here, we provide a comprehensive overview on the variety of host-foraging strategies of egg parasitoids exploiting chemical signals. Furthermore, the use of such infochemicals is discussed with respect to the wasps¿ dietary breadth and their ability to learn
The response specificity of Trichogramma egg parasitoids towards infochemicals during host location
Fatouros, N.E. ; Bukovinszkine-Kiss, G. ; Dicke, M. ; Hilker, M. - \ 2007
Journal of Insect Behavior 20 (2007)1. - ISSN 0892-7553 - p. 53 - 65.
pieris-brassicae l - evanescens westwood - behavioral variations - mamestra-brassicae - biological-control - strains - hymenoptera - oviposition - lepidoptera - kairomones
Parasitoids are confronted with many different infochemicals of their hosts and food plants during host selection. Here, we investigated the effect of kairomones from the adult host Pieris brassicae and of cues present on Brussels sprout plants infested by P. brassicae eggs on the behavioral response of the egg parasitoid Trichogramma evanescens. Additionally, we tested whether the parasitoid¿s acceptance of P. brassicae eggs changes with different host ages. The wasps did not discriminate between olfactory cues from mated and virgin females or between mated females and males of P. brassicae. T. evanescens randomly climbed on the butterflies, showing a phoretic behavior without any preference for a certain sex. The parasitoid was arrested on leaf parts next to 1-day-old host egg masses. This arrestment might be due to cues deposited during oviposition. The wasps parasitized host eggs up to 3 days old equally well. Our results were compared with former studies on responses by T .brassicae showing that T. evanescens makes less use of infochemicals from P. brassicae than T. brassicae.
|Behavioral adaptations in host finding by Trichogramma evanescens: the influence of oviposition experience on response to host contact kairomones
Gardner, S.M. ; Dissevelt, M. ; Lenteren, J.C. van - \ 2007
Bulletin of Insectology 60 (2007)1. - ISSN 1721-8861 - p. 23 - 30.
pieris-brassicae l - foraging preferences - nemeritis-canescens - site selection - hymenoptera - drosophila - lepidoptera - chemicals - westwood - habitat
The influence of oviposition experience on the response of the egg parasitoid Trichogramma evanescens Westwood (Hymenoptera Trichogrammatidae) towards the contact kairomones of two different host species, Mamestra brassicae (L.) and Pieris brassicae L., is described. The response of T. evanescens was influenced by the number of eggs it had laid, but time since oviposition did not result in a significant change in behaviour. Parasitoids readily accepted an egg of a second species and the time spent searching in a particular kairomone area would appear to depend on the reproductive state and expected survival of a parasitoid, rather than the development of any host preference. Trichogramma seems to select patches on the basis of reward probability rather than maximising reward size. Such behaviour would assist parasitoids to respond to fluctuations in host availability.