Stenocrates Burmeister, 1847

Moore, Matthew R., Cave, Ronald D. & Branham, Marc A., 2018, Synopsis of the cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae), ZooKeys 745, pp. 1-99 : 60-62

publication ID

https://dx.doi.org/10.3897/zookeys.745.23683

publication LSID

lsid:zoobank.org:pub:16F1AE59-5650-485F-9D8C-6149E962D461

persistent identifier

https://treatment.plazi.org/id/4FA25544-FD25-CE9F-1A02-5B5C5C36D2E3

treatment provided by

ZooKeys by Pensoft

scientific name

Stenocrates Burmeister, 1847
status

 

Stenocrates Burmeister, 1847 View in CoL

Type species.

Scarabaeus laborator Fabricius, subsequent designation by Casey 1915: 114.

Valid taxa.

52 species and subspecies.

The enigmatic genus Stenocrates comprises 52 taxa distributed from Mexico south throughout South America (except Chile) and Jamaica (Fig. 63). Species diversity in the group is highest in the tropical forests of Brazil, especially the northern and western states of Amazonas, Pará, Acre, and Rondônia. Many Stenocrates species are also known from eastern Brazil, especially Bahia, Espírito Santo, São Paulo, and Santa Catarina. Stenocrates species are problematic to identify due to conserved external morphology among species, making the group, “… possibly the most difficult genus of Dynastinae in the Americas with which to work" ( Ratcliffe and Cave 2015). Male paramere morphology is diagnostic for species-level identification in the genus, and females not associated with males at the time of collection cannot be reliably identified with existing literature. Nothing is known about the natural history and biology of Stenocrates species. Adults can be collected at lights at night ( Endrődi 1969a, Ratcliffe and Cave 2006, Ratcliffe 2014, 2015). Immature stages are undescribed for the genus.

Stenocrates was erected by Burmeister (1847) for species that he considered highly similar to the historical concept of Chalepus , except for the lack of dimorphic protarsi. Burmeister (1847) included 4 species in Stenocrates and speculated that Melolontha rufipennis Fabricius could also be a member of the genus. Descriptions of new species of Stenocrates were slow to accumulate in the 19th and early 20th century. Kirsch (1870) described the sixth Stenocrates species from Colombia. Bates (1888) examined S. laborator specimens from Mexico and noted that the simple protarsi of the males and dorsoventrally flattened tibiae separated diagnosed Stenocrates within Cyclocephalini . Stenocrates was compared to Euetheola by Bates (1888) stating that the form of the mandibles and the proximal tarsomeres served to separate these genera. Arrow (1911, 1913) added two new species to Stenocrates , but he did not offer a diagnosis for the genus or make meaningful character comparisons for the genus. Stenocrates was revised by Endrődi (1966, 1985a), and many new species have been described since that work, which have not been incorporated into a comprehensive identification key.

Stenocrates species can be recognized by the following combination of characters: 1) dorsal coloration black or dark brown and without maculae; 2) body convex, not strongly anteroposteriorly compressed or dorsoventrally flattened; 3) clypeus trapezoidal with apex truncate in dorsal view; 4) frontoclypeal suture complete 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 without semicircular depressed pits; 8) galea of maxilla on inner surface with 2 fused basal teeth, 2 fused medial teeth, and 2 fused apical teeth (2-2-2 arrangement); 9) pronotum with broadly incomplete beaded basal margin; 10) pronotum with narrowly incomplete beaded apical margin; 11) 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; 12) protibial spur straight to weakly deflexed; 13) males and females with protarsal claws simple (not cleft) and not enlarged; 14) mesocoxae not widely separated, nearly touching; 15) metacoxae on lateral edge without transverse, depressed sulcus; 16) metacoxae with lateral edge perpendicular to ventral surface; 17) meso- and metatibiae with distal, transverse carinae; 18) meso- and metatibiae dorsoventrally flattened and laterally expanded; 19) anterior edge of hindwing distal to apical hinge with erect setae and lacking produced, membranous border; 20) vein RA with single row of pegs proximal to apical hinge; 21) propygidium not expanded, propygidium and pygidium not rigidly fused.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Scarabaeidae