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

Abstract

AbstractA review of the New World Aenigmatiinae shows that only one of the five Neotropical Region genera currently classified in this subfamily, Cyrtophorina, could belong in a monophyletic group with the type genus Aenigmatias. The first known male specimens of Borgmeieriphora, Colyeria, 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 Apocephalus-group of genera. Three new species of Borgmeieriphora are described: B. multisetosa from Costa Rica; B. greigae from Costa Rica; and B. leptotarsa 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 type species C. angustata sp.nov. from Ecuador, is described and is placed in the Melittophora-group. A reconstructed phylogeny of the Melittophora-group of genera is given, showing their hypothesized relationships: Colyeria is the adelphotaxon (= sister-group) of Borgmeieriphora, whereas the relationships among Melittophora, Cootiphora, and Colyeria + Borgmeieriphora are unresolved. Within Borgmeieriphora, B. multisetosa and B. greigae are adelphotaxa, whereas B. kempfi is the adelphotaxon of B. multisetosa + B. greigae, and B. leptotarsa is the adelphotaxon of all other species. The relationships of Platydipteron, another potential 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 Aenigmatias. Convergence between true aenigmatiine genera and Melittophora-group genera is based on the shared, limuloid body form, which is probably a defensive adaptation for living in social insect nests.