Revision of the Neotropical genus Eschatocerus Mayr (Hymenoptera, Cynipidae, Eschatocerini) with biological notes and the first description of the terminal larva.

The gall wasp genus Eschatocerus (Hymenoptera, Cynipidae, Eschatocerini), a cynipid genus of gall inducers on Prosopis and Acacia species (Fabaceae), endemic to southern South America, is revised. Complete descriptions of the external morphology of the genus and its three known species, illustrated with scanning electron photographs, are given for the first time, and an updated key for the identification of the species is provided. The biology of the species of Eschatocerus and their galls is described. Host plant associations are given, and the terminal larva of Eschatocerus niger is described for the first time. Preliminary notes on the inquiline and parasitoid community associated with the galls of Eschatocerus species are also given.