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Metacommunity Ecology Group
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Contact informationMetapopulation Research Group phone +358 9 191 57734 |
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Parasitoid foraging behaviour at the landscape scale
Navigation, spatial memory and anticipatory foraging by Hyposoter horticolaThe parasitoid H. horticola copes with a host that is available for parasitism for an extremely short period of time by searching for the host during the weeks before it is susceptible, and returning by following memorized visual landmarks. This "anticipatory foraging" has only once before been documented in insects, and ours is the first record of visual landmark use by a parasitoid.van Nouhuys, S. & R. Kaartinen 2008. A parasitoid wasp uses landmarks while monitoring potential resources. Proceedings of the Royal Society B, 275: 377-385 PDFvan Nouhuys, S, & J. Ehrnsten 2004. Parasitoid behavior that leads to uniform parasitism of a host available only a few hours per year. Behavioral Ecology, 15: 661-665 PDFWhat are the important aspects of parasitoid foraging?a) contrasting foraging constraints:The number of progeny produced by a parasitoid is generally thought of as limited by the number of eggs produced, or by the amount of time available for foraging. Both of these may be constraints for the hyperparasitoid M. stigmaticus , but the wasp H. horticola may instead be most constrained by competition among foraging females. Currently we are assessing the competition among female H. horticola in field experiments. We are also conducting experiments to estimate the the area over which individual female M. stigmaticus forage, the number of females that use a single host nest, and the time budget involved in foraging. van Nouhuys, S. & R. Kaartinen 2008. A parasitoid wasp uses landmarks while monitoring potential resources. Proceedings of the Royal Society B, 275: 377-385 PDFKankare, M., van Nouhuys, S., Gaggiotti, O., Hanski, I. 2005. Metapopulation genetic structure of two coexisting parasitoids of the Glanville fritillary butterfly. Oecologia, 143: 77-84 PDFb) The relationship between foraging cues and rate of parasitism Parasitoids use a a range of host associated cues to find their hosts. Many of these cues are related to the host substrate (such as the food plant). Cues perceived by parasitoids can be identified in laboratory experiments, but their use by the parasitoids, as well as the reliability importance of particular cues are difficult to pin down, and must be addressed in relatively realistic foraging environments, at appropriate temporal scales. Furthermore, relating perception of cues to actual foraging can be difficult because host finding is not a limiting factor for some parasitoids. Similarly attracting parasitoids does not significantly reduce herbivory on some plants. Under these conditions, we may expect a weak match between signals produced by plants and cues received by parasitoids. Castelo, M. K., van Nouhuy, S. &. Corley, J. C. Foraging cues for a parasitoid that uses hosts as larvae but searches fro them as eggs, in review |
