Myrmeco- and termitophilous habits evolved multiple times within Histeridae. Two putatively monophyletic subfamilies, Chlamydopsinae and Hetaeriinae, consist entirely of obligate inquilines. Hetaeriinae is characterized by a substantial diversification in the Neotropics, where it represent about two thirds of all the genera known for the region. Approximately 60% of 107 described genera being monotypic. Phylogenetic relationships within five recently established suprageneric lineages are mainly unresolved. Results are presented of a systematic revision of the genus Mesynodites, an unusually large (43 described species) and apparently polyphyletic hetaeriine genus complex. Morphology-based cladistic analysis of included species as well as representatives of all lineages of so-called “Group E” (one of the five major supragereric clades) has revealed the existence of at least nine monophyletic lineages deserving formal generic status. With slight revision, “Group E” itself is well-supported as a monophyletic taxon containing most Mesynodites sensu lato species. The entire group has evolved as guests of army ants (Ecitoninae), presumably an ancestral condition for Hetaeriinae. Refuse deposits of the numerous and widespread ant Eciton burchelli seem to play a crucial role in the evolution of inquilinism in the subfamily. Four ecitonine genera are known to harbor Mesynodites s.l. guests. Host specificity at the host genus level is typical for Mesynodites and allies, with few examples of guest species/host species specificity or single hetaeriine genus/multiple host genera types of associations. Mapping host use onto the beetle phylogenetic tree has revealed several cases of major host switches. The most notable occurred in a monophyletic lineage within Mesynodites sensu stricto, members of which switched from Neivamyrmex army ants to Atta leaf-cutters, where they adapted to life in subterranean refuse chambers.
Species 1: Coleoptera Histeridae Mesynodites
Keywords: Neotropics, Army ants
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA