Oviposition behaviour of aphidiine wasps (Hymenoptera : Braconidae, Aphidiinae): Morphological adaptations and evolutionary trends

We examined oviposition behaviour in 49 species representing 19 genera of A phidiinae. All species are solitary parasitoids of aphids (Hemiptera: Aphid oidea). Six general types are described that differ in oviposition time, be haviour, and morphology. The Ephedrini have the least specialized ovipositi on behaviour within the subfamily, with Praini and Aphidiini displaying var ious adaptations for host capture and oviposition. Use of the forelegs to g rasp and orient aphids for oviposition has arisen twice, in Praini and, ind ependently, in the genus Monoctonus Haliday (Aphidiini: Monoctonina). Morph ological modifications of the terminal abdominal segments for host capture are found in Trioxina and in several species of Pauesia Quills (Aphidiina). A "quick" sting is characteristic of species in the genus Aphidius Nees an d related genera. The greatest degree of behavioural diversification occurr ed among Pauesia species, including cryptic behaviour, ant mimicry, and "sn eak" oviposition. Acquired chemical camouflage and mimicry of the host's cu ticular hydrocarbon pattern to avoid detection by guarding ants is found in Aclitus obscuripennis Foerster, the genus Paralipsis Foerster, and the two closely related genera Adialytus Foerster and Lysiphlebus Foerster. It is suggested that the main driving forces in the evolution of parasitoid ovipo sition behaviour were aphid defensive behaviour and avoidance of aggression by trophobiotic ants. The results are compared with phylogenetic relations hips inferred from morphological and molecular data.