Aphotaenius Cartwright, 1952

Skelley, Paul E. & Vaz-de-Mello, Fernando Z., 2020, Review of Aphotaenius Cartwright, 1952 (Coleoptera: Scarabaeidae: Aphodiinae: Eupariini), The Coleopterists Bulletin 74 (2), pp. 389-403 : 390-391

Aphotaenius Cartwright, 1952

Aphotaenius Cartwright 1952: 181–182 ; Cartwright 1963: 49–51; Woodruff 1973: 135–136; Cartwright 1974: 11; Chalumeau 1983: 1–2; Stebnicka 1998: 204–205; Stebnicka 2009: 39–41.

Saprosites Redtenbacher 1858: 436 (in part).

Type Species. Ataenius carolinus Van Dyke , by original designation.

Diagnosis. Modified from Stebnicka (2007b). Eupariini . Body small (length 1.6–3.9 mm), oblong oval, strongly convex, glossy. Clypeal margin obtusely angulate to sharply dentate on each side of median emargination, surface above emargination triangularly flattened upward. Epipharynx with broad, sclerotized mesoepitorma; tylus narrow, projecting in some, with few short celtes; less than four prominent chaetopedia on each side; chaetoparia well-developed, no adelochaetae evident. Pronotal margins with row of punctures, not crenate nor fimbriate. Elytra strongly convex, humeral denticles inconspicuous, striae punctate-crenate, intervals smooth. Prosternum with large, projecting, laterally compressed process posterior of procoxae. Meso- and metatibiae with incomplete but distinct transverse ridges medially on lateral margin, apically with two well-separated teeth on medial apical margin replacing the usual setal fringe (compare Figs. 1–2 with Fig. 3 ). External sexual differences slight, male penultimate abdominal sternite shorter than in female, disc of pygidium longer. Male genitalia weakly differentiated, apex of parameres obliquely truncated in lateral view, somewhat hooked ventrally, and weakly widened in dorsal view.

Distribution. Aphotaenius is widely but discontinuously distributed from eastern North America to northeastern Mexico, Colombia, Venezuela, Bolivia, and Brazil. Its apparent absence from Central America and other South American countries may be an artifact of inadequate survey work. This is evident by the few known specimens representing most of the species.

Etymology. The generic epithet appears to be derived from the combination of Aphodius Illiger with Ataenius . This name combination possibly reflects their character combination of Ataenius (Eupariini) , while having transverse meso- and metatibial carinae similar to Aphodius (Aphodiini) .

Remarks. Aphotaenius appears related to Passaliolla Balthasar and some members of Saprosites by sharing apical teeth on the meso- and metatibia ( Fig. 3 ) that replace the usual setal fringe of other Aphodiinae ( Figs. 1–2 ). Aphotaenius differs from these genera by their body shape (strongly dorsoventrally flattened in Passaliolla and most Saprosites ) and development of the prosternal process (flattened against the body and not projecting in Passaliolla and Saprosites ). Behaviorally, members of Aphotaenius appear to feed on mammal dung, while Passaliolla and Saprosites appear to feed on detritus under bark or in leaf litter.

Unfortunately, Chalumeau’ s (1983) treatment of Aphotaenius contains a series of errors in all figure captions, using the genus name “ Haroldiataenius ” in association with the treated species. Haroldiataenius Chalumeau was described earlier ( Chalumeau 1981) for a different group of species formerly treated within Ataenius . All genus and species combinations of “ Haroldiataenius ” in Chalumeau (1983) do not exist anywhere else, not even in the text of that work. These combinations are included in the following species synonymies as lapsus calami simply to be complete. These combinations were never validly proposed.

Based on the rarity of Aphotaenius in collections, the number of known species, and their wide distributions, more species are expected to be discovered with future field work.

Figures

Figs. 1–5. Representative mesotibiae and elytra. 1) Ataenius erratus Fall; 2) Ataenius strigicauda Bates; 3–4) Aphotaenius carolinus; 5) Aphotaenius elegans, new species. Scale bars = 0.2 mm.