Chalepides Casey, 1915

Moore, Matthew R., Cave, Ronald D. & Branham, Marc A., 2018, Synopsis of the cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae), ZooKeys 745, pp. 1-99 : 47-49

Chalepides Casey, 1915

Type species.

Parachalepus (Chalepides) eucephalus Casey, 1915, by original designation.

Valid taxa.

15 species.

The nomenclatural history of Chalepides was complicated by a case of homonymy. Chalepides was originally proposed as a subgenus of Parachalepus ( Casey 1915). Parachalepus Casey, 1915 is a homonym of Parachalepus Baly, 1885 ( Coleoptera : Chrysomelidae ) ( Prell 1936, Arrow 1937a). To rectify this problem, Chalepides was elevated to the status of genus and comprised the seven species originally included in Parachalepus ( Casey 1915, Prell 1936, Arrow 1937a). Parachalepus was proposed based on abdominal characters. Parachalepus included Dyscinetus -like species with a rigid fusion of the propygidium and the pygidium ( Casey 1915). The subgenus Parachalepus (Chalepides) was proposed for species with a dramatic reduction of the pygidium in addition to propygidial/pygidial fusion ( Casey 1915). Chalepides has been recognized as a valid genus by subsequent authors and was recently revised ( Arrow 1937a, b, Endrődi 1966, 1985a, Joly and Escalona 2002).

The 15 species of Chalepides are distributed across South America and the West Indies ( Martínez 1978b, Endrődi 1966, 1973a, 1985a, Joly and Escalona 2002, Riehs 2005, Ratcliffe and Cave 2015) (Fig. 56). Species of Chalepides described by Prokofiev (2012) require a special discussion. Chalepides euhirtus Prokofiev and C. unduavicus Prokofiev were described based on specimens from Peru and Bolivia ( Prokofiev 2012), and the Peruvian data would represent a new country record for Chalepides . However, both species were placed into the wrong genus, based on the original descriptions and images of the holotypes. The holotype of C. euhirtus appears to be a female specimen of A. fuliginea ( Prokofiev 2012). Chalepides unduavicus was later synonymized under A. scarabaeoides and was also considered an infrasubspecific ( “ab.”) entity ( Prokofiev 2013, 2014). The discussion below covering the biology and genus-level recognition of Chalepides will exclude information on the misclassified species C. euhirtus and C. unduavicus .

Relatively little is known about the biology and natural history of Chalepides species. It is unclear, based on available data, if Chalepides species are floral visitors. Mannerheim (1829) reported that C. dilatatus (Mannerheim) was collected in flowers without further detail. Valla and Cirino (1972) reported a single specimen of an unidentified Chalepides species from the inflorescence of a Victoria cruziana A.D. Orb. Chalepides barbatus adults and larvae are associated with sugar cane fields in Puerto Rico ( Wolcott 1923, 1948). In Puerto Rico, adult C. barbatus are prey for the invasive cane toad R. marina ( Wolcott 1937, 1948). Like Dyscinetus , Chalepides species may have some semi-aquatic habits. Chalepides luridus (Burmeister) and C. alliaceus (Burmeister) have been collected along the edges of river banks ( Endrődi 1973a). Chalepides barbatus reportedly attacks the invasive, aquatic weed water hyacinth ( Eichhornia crassipes [Mart.] Solms [ Pontederiaceae ]) in Uruguay ( Silveira Guido 1965, Perkins 1974, Buckingham and Bennett 1989). Chalepides species are attracted to lights at night ( Kusui 1992, Riehs 2005, Albuquerque et al. 2016).

Chalepides species can be recognized by the following combination of characters: 1) dorsal coloration yellowish brown, dark brown, or almost black with greenish reflections in some species; 2) body convex, not strongly anteroposteriorly compressed or dorsoventrally flattened; 3) clypeus trapezoidal with apex truncate in dorsal view; 4) frontoclypeal suture complete or narrowly incomplete medially; 5) males with anterolateral margin of the mandibles lacking weak tooth; 6) mandibular molar area with rows of circular micropunctures; 7) mandibular molar area on proximal margin with 2 semicircular depressed pits; 8) galea of maxilla on inner surface with 2 fused basal teeth, 2 free medial teeth, and 2 fused apical teeth (2-2-2 arrangement); 9) pronotum with broadly incomplete beaded basal margin; 10) males and females with 3 protibial teeth on lateral margin, basal tooth not greatly reduced, only slightly removed from apical 2 teeth, and oriented laterally; 11) protibial spur straight to weakly deflexed; 12) males with inner protarsal claw enlarged and entire at apex, not cleft; 13) mesocoxae not widely separated, nearly touching; 14) metacoxae on lateral edge with transverse, depressed sulcus; 15) metacoxae with lateral edge perpendicular to ventral surface; 16) meso- and metatibiae with distal, transverse carinae; 17) anterior edge of hindwing distal to apical hinge with erect setae and lacking produced, membranous border; 18) vein RA with single row of pegs proximal to the apical hinge; 19) propygidium expanded, propygidium and pygidium fused, pygidium with long, dense setae.