Agathidium iota, MILLER & WHEELER, 2005

MILLER, KELLY B. & WHEELER, QUENTIN D., 2005, Slime-Mold Beetles Of The Genus Agathidium Panzer In North And Central America, Part Ii. Coleoptera: Leiodidae, Bulletin of the American Museum of Natural History 2005 (291), pp. 1-167 : 69

AGATHIDIUM IOTA SPECIES GROUP

DIAGNOSIS: The single species in this group has the anterior portion of the mesosternum very broad (broader than the posterior portion), the mesosternum in the same plane as the metasternum, strong contractility, obsolete humeral angles of the elytra, minute size (TBL <1.6 mm), and 4­3­3 tarsal

formulae in both males and females. Males lack a metasternal fovea, and the posterior margin of the metafemur is unmodified.

DISCUSSION: This species further confounds the already dubious definition of the genus Agathidium . The species possesses a distinctive 3­segmented antennal club, moderately, but distinctly, excavated anterior clypeal margin, and distinctive temporum and supraocular carina extending posterad of the eye. However, it also has the unusual character state of 4­3­3 tarsal formulae in both males and females. The wings, when present, are long and fringed with fine setae, a feature characteristic of many small insects that balloon with the wind. The single species has the anterior portion of the mesosternum very broad, much broader than the posterior portion, which is very short and not at all concave or declivitous. The mesosternum is in the same plane as the metasternum. Also, specimens are very stout and strongly contractile and the metasternum is short. Thus, the species is very similar to members of the A. oniscoides group. However, the species lacks oblique femoral lines on the metasternum and has a particularly unusual tarsal formula, prompting us to place it in its own group.