Acrobolbia Ohaus, 1912

Moore, Matthew R., Cave, Ronald D. & Branham, Marc A., 2018, Synopsis of the cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae), ZooKeys 745, pp. 1-99 : 39

Acrobolbia Ohaus, 1912

Type species.

Acrobolbia macrophylla Ohaus, 1912, by monotypy.

Valid taxa.

One species.

The northern South American genus Acrobolbia is known from Peru, Ecuador, and possibly Venezuela ( Ohaus 1912, Machatschke 1972, Jameson et al. 2002) (Fig. 51). Acrobolbia has a complicated classification history. Ohaus (1912) described A. macrophylla based upon a single male specimen collected in Peru. Ohaus (1912) compared Acrobolbia to Cyclocephala , but he ultimately classified the genus in the subtribe Areodina ( Rutelinae: Rutelini ). Ohaus (1918) later transferred the genus into its own subtribe, Acrobolbiina, within Rutelini . Acrobolbia triangularis was the second species to be described into the genus, but this species was later treated as a synonym and a “variant” of A. macrophylla ( Benderitter 1922, Ohaus 1934a, b).

Based on the elongated antennal club of the male in Acrobolbia , the genus was transferred into the ruteline subtribe Oryctomorphina ( Dechambre and Ponchel 1999). Most recently, Acrobolbia was reviewed and transferred into Cyclocephalini by Jameson et al. (2002). Acrobolbia is hypothesized to be related to Ancognatha based upon characters of the clypeus, mentum, pronotum, prosternal process, protarsus, and mandibles ( Jameson 1998, Jameson et al. 2002). Specimens of Acrobolbia are rare in collections, and almost nothing is known of their biology ( Jameson et al. 2002). Acrobolbia macrophylla adults are attracted to lights at night, though specimens do not land or rest at light traps ( Jameson et al. 2002). Specimens have been collected from 400-1,200 m in elevation ( Jameson et al. 2002). The immature stages are undescribed and unknown.

Acrobolbia species can be recognized by the following combination of characters: 1) dorsal coloration varying from all black with variable reddish brown margins of the elytra and elytral suture, or with the elytra partially testaceous; 2) body not anteroposteriorly compressed or dorsoventrally flattened; 3) clypeal apex acuminate in dorsal view; 4) frontoclypeal suture distinct, but incomplete medially; 5) mandibles long, sickle-shaped, with pointed apex; 6) mandibular molar area with rows of circular micropunctures; 7) apical margin of mentum weakly emarginate to nearly straight; 8) galea of maxilla reduced to small, rectangular mound in dorsal view; 9) galea on inner surface with teeth greatly reduced to peg-like projections at the middle and apex; 10) galea on inner surface lacking teeth at base; 11) males with antennal club (segments 8-10) elongated, nearly twice as long as antennomeres 1-7; 12) pronotum with broadly incomplete beaded basal margin; 13) males and females with 3 protibial teeth, basal tooth reduced, removed from the apical 2 teeth, and oriented laterally; 14) protibial spur straight to weakly deflexed; 15) males with inner protarsal claw enlarged and narrowly cleft at apex; 16) mesocoxae touching, nearly contiguous; 17) meso- and metatibiae with distal, divided carinae; 18) metacoxae with lateral edge perpendicular to ventral surface; 19) anterior edge of hindwing distal to apical hinge lacking setae and with produced, membranous border; 20) vein RA with 2 rows of pegs extending distally nearly to margin of apical hinge.