CONVERGENT ADAPTATIONS IN PHORIDAE (DIPTERA) LIVING IN THE NESTS OF SOCIAL INSECTS - A REVIEW OF THE NEW-WORLD AENIGMATIINAE

A review of the New World Aenigmatiinae shows that only one of the fiv e Neotropical Region genera currently classified in this subfamily, Cy rtophorina, could belong in a monophyletic group with the type genus A enigmatias. The first known male specimens of Borgmeieriphora, Colyeri a, and Melittophora are described. Based on the structure of the males , these three genera, referred to as the Melittophora-group of genera, belong in the subfamily Metopininae, and are related to the Apocephal us-group of genera. Three new species of Borgmeieriphora are described : B. multisetosa from Costa Rica; B. greigae from Costa Rica; and B. l eptotarsa from Panama. Based on observations of two species, adults of Borgmeieriphora are associated with, and may be parasitoids of, army ants of the genus Eciton. Cootiphora gen. nov., represented by the typ e species C. angustata sp.nov. from Ecuador, is described and is place d in the Melittophora-group. A reconstructed phylogeny of the Melittop hora-group of genera is given, showing their hypothesized relationship s: Colyeria is the adelphotaxon (= sister-group) of Borgmeieriphora, w hereas the relationships among Melittophora, Cootiphora, and Colyeria + Borgmeieriphora are unresolved. Within Borgmeieriphora, B. multiseto sa and B. greigae are adelphotaxa, whereas B. kempfi is the adelphotax on of B. multisetosa + B. greigae, and B. leptotarsa is the adelphotax on of all other species. The relationships of Platydipteron, another p otential member of the Melittophora-group, are unknown. Examination of males of representative aenigmatiine genera from other zoogeographic regions shows that they may belong in a monophyletic group with Aenigm atias. Convergence between true aenigmatiine genera and Melittophora-g roup genera is based on the shared, limuloid body form, which is proba bly a defensive adaptation for living in social insect nests.