Phylogenetics and diversification of eucharitid ant parasitoids in the New World (Hymenoptera: Eucharitidae)

While ant colonies serve as host to a diverse array of myrmecophiles, very few parasitoids have been able to exploit this vast resource. A notable exception is the wasp family Eucharitidae, which are the only insects known to exclusively parasitize ants, including some pest ant species. Eucharitidae (Hymenoptera) are found worldwide, with all 700 (estimated) species attacking the immature stages of ants from five different subfamilies. Molecular evidence from over 200 taxa and a combined-gene dataset (18S, 28S-D2-D5, and COI & COII) is used to assess eucharitid relationships and develop a dated phylogeny. Estimates from molecular divergence dating studies suggest an origin of Eucharitidae at over 75 mya, while major ant lineages diverged much earlier. The eucharitid timetree is then used to investigate other evolutionary patterns of host association and historical biogeography. Ants in the New World evolved without parasitism pressure from eucharitids until the mid-Eocene. At this point, there began multiple dispersals of eucharitid wasps from the Old World into the New World, continuing to about 25 mya. Some of these eucharitid groups have been successful in diversifying in the Neotropics.