Abdominal structures in Podagrionini (Hymenoptera : Chalcidoidea : Torymidae). Implications for the phylogeny of the tribe. Relationships with the constraints of access to the host

The structure of the petiole and of the gastral segments in Podagrionini sh ow original features often figuring unique derived states. A large part of the characters used for the phylogenetic study of the tribe were taken from abdominal structures. Our own investigations led us to revise the classifi cation recently proposed. These particular abdominal structures may be rela ted to the constraints of access to the hosts, i. e. embryos of mantids wit hin egg-cases. These are often protected with a spongy cover, hence the nee d for the ovipositor to be long enough to reach the embryos. A large part o f the abdominal segments can be folded and are independent from one another , thus allowing the gaster to be considerably stretched and distorted durin g the initial stage of the oviposition.