Aclopus Erichson, 1835

Ocampo, Federico C. & Mondaca, José, 2012, Revision of the scarab subfamily Aclopinae Blanchard (Coleoptera: Scarabaeidae) in Argentina and Chile, Zootaxa 3409, pp. 1-29 : 4-6

Aclopus Erichson, 1835

(Figs. 1–4)

Type species. Aclopus vittatus Erichson, 1835 , here designated.

Diagnosis. This genus is distinguished from other aclopine genera by the following combination of characters: shape of the outer margin of the mandibles broadly rounded (angulate in Gracilaclopus , sinuate in Desertaclopus ); labral shape rounded and poorly or not reflexed (subrectangular and strongly reflexed in Gracilaclopus ; rounded, not reflexed in Desertaclopus ); frons and clypeus lacking transversal carinae (present in Desertaclopus ); eye canthus developed, not dividing eye, with or without apical tooth; mesotibia and metatibia with two transverse carinae (two in Gracilaclopus ; one in Desertaclopus ), metatibial spurs separated or subcontiguous.

Description, male. Scarabaeidae , Aclopinae , small to medium size 3.0– 12.5 mm, width 1.4–3.6 mm, shape elongated with sub-parallel margins. Color: variable, light brown, brown, black or bicolored. Head (Figs. 1–4): Eye canthus well developed, anterior margin slightly reflexed, posterior margin bearing a few setae (1–5), setae short; frontocanthal carina present, poorly developed. Eyes well developed, clearly visible on dorsal view, rounded, barely divided by eye canthus. Frons generally flat on apical half, convex at base. Clypeus transverse; lateral margins rounded; anterior margin straight or broadly rounded, slightly reflexed or not; frontoclypeal suture obsolete. Labrum protruding beyond clypeal margin, shape variable. Mandibles protruding beyond clypeal margin, rounded externally, concave dorsoventrally, lacking incisory teeth, molar area poorly developed, ventral surface moderately setose or glabrous. Labium longer than wide, strongly reduced, with three labial palpomeres, palpomere 3 as long as 1–2 combined; labial surface setose, setae dense to moderately dense, long and slender. Maxillae poorly developed, with four maxillary palpomeres. Antennae with 8–9 antennomeres; antennal club with three lamellae, surface glabrous or setose. Pronotum: Convex, wider than long. Surface punctate, glabrous, or with few setae. Marginal bead present on all margins (could be reduced on posterior margin); anterior margin concave, with membrane well developed; lateral margins broadly rounded; posterior margin slightly sinuous. Anterior angle, slightly acute or right-angled; posterior angles broadly rounded. Scutellum: Large , triangular, apex rounded. Elytra: Convex, longer than wide, lateral margins rounded. Surface punctate; punctures sparse or moderately dense, glabrous, or setose; setae, long, moderately long, or short. Elytral striae absent, except for sutural striae; pseudoepipleura not developed. Vent er: Prosternal process well developed columnar, densely setose. Metasternum long, 0.56 times as long as wide; 5–6 ventrites exposed medially, ventrite 1 slightly visible; surface setose, setae long; ventrites 3 and 4 membranous on apical margin. Pygidium not exposed beyond clypeal margin, triangular, surface sparsely setose; setae long, slender. Legs: Protibiae with two teeth, protibial spur not developed. Mesotibiae and metatibiae with two transverse carinae. Mesotibial and metatibial apex with fringe of thick setae. Mesotibial spurs contiguous, metatibial spurs separated or subcontiguous. Metatibial tarsal insertion with notch, notch associated with tibial process. Tarsus longer than tibiae. Protarsomeres, mesotarsomeres, and metatarsomeres 1 and 5 longer than 2, 3, 4 individually; all tarsi with long, apical setae. Protarsal claws curved or straight, simple, symmetrical. Male genitalia: Parameres symmetrical, slender; genital segment with ventral plate developed, with apical margin rounded.

Remarks. Several new species of the genus Aclopus are known from Brazil (Fernando Vaz-de-Mello, personal communication) and the description of these taxa is forthcoming. We suspect that A. wuenschei Ohaus is a junior synonym of A. vittatus , but we were not able to study the type specimen for confirmation.

FIGURES 1–4. 1) Aclopus brunneus , 2) A. intermedius , 3) A. robustus , 4) A. vittatus .

In this work Aclopus parvulus Ohaus is transferred to Gracilaclopus new genus, as a consequence no species of Aclopus is known to occur on Argentina and/or Chile.

Distribution. Brazil.