A Comparative Functional Approach to the Host Detection Behaviour of Parasitic Wasps. 1. A Qualitative Study on Eucoilidae and Alysiinae

We studied host detection behaviour in Alysiinae (Braconidae; Ichneumonoidea) and Eucoilidae (Cynipoidea), the larvae of which are endoparasitoids of fly larvae and in- vestigated whether this behaviour is determined by their descent or can be considered an adaptation to different environments. We compared the searching behaviour of fe- males of 32 alysiine and 25 eucoilid species from a variety of microhabitats and from different dipteran hosts by using qualitative behavioural variables. Three main modes of searching were detected: vibrotaxis, ovipositor searching and antennal searching, and the species could be classified according to the role these different modes play in the detection of host larvae. The searching modes are largely dependent upon the taxonomic position of the species. In most cases species belonging to one genus show a similar behaviour pattern. However, we also encountered examples of radiation; closely related species that search differently. The function of the three searching modes has not been elucidated so far. Therefore we cannot say that similar searching modes in unrelated species are examples of adaptive convergence. Especially in Drosophila parasitoids we encountered great differences in searching behaviour be- tween different species living in the same microhabitat. We believe differences at all levels of searching, including host detection behaviour may contribute to niche segre- gation and create possibilites for different parasitoid species to coexist in the same microhabitat, even when they attack the same host species

Superparasitism and host discrimination by Asobara tabida nees (Braconidae: Alysiinae), a larval parasitoid of Drosophilidae.

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Het smalle pad. Beperkingen van individuen en de evolutie van levensgemeenschappen

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