Operclipygus

Operclipygus evidently contains several inquilinous species. It appears that most members of the Operclipygus mirabilis group are myrmecophilous guests of Attini (leaf-cutting/fungus-growing ants). Operclipygus mirabilis itself has been collected multiple times in refuse piles of Atta colombica, while Operclipygus plaumanni and Operclipygus mutuca have both been collected with Acromyrmex Mayr. Leaf-cutting ants are also clearly hosts for the hamistrius group species Operclipygus campbelli, with over 100 individuals found in a single excavation of an Atta nest in Guatemala. However, only one of four specimens of Operclipygus novateutoniae, and two of ten specimens of Operclipygus inquilinus, were found in association with refuse deposits of Acromyrmex species. Army ants may also host several species, with one particularly strong case: Operclipygus has been found in association with Eciton burchelli on three separate occasions. Finally, Aphaenogaster Mayr (Myrmicinae) are clear hosts of the U.S. marginellus group species (Operclipygus marginellus and Operclipygus striatellus), with nearly all specimens having been collected from their nests. These observations have included both riding on and being carried by the host ants (J. Gruber, pers. comm.). For most other species, the numbers of specimens found in such associations has been so small that the association may simply be accidental or facultative.

There are ten myrmecophilous species in this large genus of Histeridae.