Figure 2.

Cautious estimate of the phylogeny of Hymenoptera based on [41,56,120,121] and recent molecular analyses by the HymAToL project (not yet published). Only relationships that are supported independently by morphological and molecular analyses are shown. The present study examined brains of species representing all groups indicated in the tree with the exception of the phytophagous Pamphilioidea. Proctotrupomorpha includes Chalcidoidea, Proctotrupoidea, Cynipoidea, Platygastroidea, Diaprioidea and Mymarommatoidea. Circle indicates the appearance of large, elaborate mushroom bodies at the base of the Euhymenoptera. Eusocial species are found only within the Vespoidea and Apoidea.