Surutu Martinez , 1955

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

Surutu Martinez, 1955

Type species.

Surutu dytiscoides Martínez, 1955: 245-249, by monotypy.

Valid taxa.

Five species.

The five species of the South American genus Surutu are distributed in Colombia, Bolivia, and Brazil ( Martínez 1955, D’Andretta and Martínez 1956, Endrődi 1966, 1975a, 1985a, Ratcliffe 1981, Andreazze 2001, Otavo et al. 2013) (Fig. 64). These spectacular black species are truly the monsters of the Cyclocephalini , with some specimens of Surutu seabrai D’Andretta and Martínez measuring over 4 cm in length. Nothing is known about the biology of Surutu species. At least some species are attracted to lights at night ( Ratcliffe 1981). The immature stages are undescribed for the genus as currently circumscribed.

Surutu species can be recognized by the following combination of characters: 1) dorsal coloration dark piceous to black; 2) body dorsoventrally flattened; 3) clypeus rounded to parabolic in dorsal view; 4) frontoclypeal suture incomplete medially; 5) apex of mentum narrowly and deeply emarginated (in S. dytiscoides and S. seabrai ; other species unknown); 6) anterolateral margin of mandible lacking tooth; 7) galea of maxilla dorsoventrally flattened (in S. dytiscoides and S. seabrai ; other species unknown); 8) galea on inner surface at base with large, flattened, blade-like, bifurcated tooth (in S. dytiscoides and S. seabrai ; other species unknown); 9) galea on inner surface with 7 teeth in 2-1-1-1-2 arrangement from base to apex (in S. dytiscoides and S. seabrai ; other species unknown); 10) apical and basal beaded margins of pronotum incomplete at middle (in S. dytiscoides and S. seabrai ; other species unknown); 11) anterior membrane of the pronotum interrupted before lateral pronotal margins (in S. dytiscoides and S. seabrai ; other species unknown); 12) protibia with 3 teeth in both sexes; 13) protibial spur straight to weakly reflexed; 14) males with protibial spur articulated at base, not fused to protibia; 15) males with inner protarsal claw thickened and narrowly cleft at apex (claw apex entire in S. fenni Ratcliffe and S. schulzei Endrődi); 16) mesocoxae not widely separated, nearly touching; 17), metacoxae with lateral edge perpendicular to ventral surface; 18) apices of the meso- and metatibiae with a corbel (in S. dytiscoides and S. seabrai ; other species unknown); 19) anterior edge of hindwing distal to apical hinge lacking membranous border; 20) anterior edge of hindwing distal to apical hinge with decumbent setae surrounding the vein and originating away from the hinge; 21) vein RA with single row of pegs proximal to apical hinge.

Some characters of the head, mouthparts, and elytra of Surutu have been compared to Ancognatha , Cyclocephala , and Mimeoma ( Martínez 1955, D’Andretta and Martínez 1956). The parabolic and rounded clypeal apex in Surutu species is like the clypeal form in several Ancognatha species. Surutu dytiscoides and S. seabrai , at least, have a deeply emarginated apex of the mentum that is also shared with Ancognatha species. The single row of RA pegs is also shared between Ancognatha and Surutu , although Ancognatha species lack setae on the anterior edge of the hindwing distal to the apical hinge. Instead, Ancognatha have a hindwing membrane like that found in Cyclocephala , Augoderia , Arriguttia , Aspidolea , and Acrobolbia . The dramatic dilations and knobs on the elytral epipleuron of S. seabrai are similar to those found in some Ancognatha and Cyclocephala species.

The distinctive setae of the hindwings found in Surutu are also found in Harposceles and species of the " Cyclocephala cribrata species group" (which included species previously placed in the genera Mononidia and Surutoides ) ( Dechambre 1997). These groups also share corbeled meso- and metatibial apices and entirely black coloration. Harposceles paradoxus shares other interesting characters with Surutu species, suggestive of a close relationship between the two genera. These shared characters include: 1) body strongly dorsoventrally flattened; 2) dorsoventrally flattened maxillary galea; 3) a 7-toothed maxillary galea in a 2-1-1-1-2 arrangement from the base to apex; 4) an incomplete frontoclypeal suture; and 5) the apical pronotal membrane interrupted before the lateral pronotal margins.

Platyphileurus felscheanus Ohaus ( Dynastinae: Oryctini ) warrants special discussion here. This species was described twice. Platyphileurus felscheanus was described from specimens collected from Santa Catarina, Brazil (Ohaus 1910). This new genus was compared to Phileurus Latreille and later included in the tribe Phileurini (Ohaus 1910, Arrow 1937b). Endrődi (1975) later described Surutu jelineki from Rio de Janeiro based on two female specimens. Comparison of the types of these species revealed that they are conspecific, with the name Platyphileurus felscheanus having priority over Surutu jelineki ( Grossi et al. 2010).

The immatures of Platyphileurus felscheanus are associated with bromeliads ( Grossi et al. 2010, Albertoni et al. 2014). Based on examination of larval, pupal, and adult characters, P. felscheanus was excluded from Phileurini and proposed to be a member of Oryctini ( Albertoni et al. 2014). However, there are some intriguing adult character similarities between P. felscheanus and other Surutu species. For example, P. felscheanus is black, dorsoventrally flattened, and has dimorphic protarsal claw morphology (enlarged in males, simple in females) ( Endrődi 1975, Grossi et al. 2010, Albertoni et al. 2014). The apices of the metatibiae in P. felscheanus are "weakly dentate" ( Albertoni et al. [2014]: figure 30). Alternatively, the outer edge of the metatibia figured in Albertoni et al. (2014) could be considered not to be "weakly dentate", but corbeled (outer edge produced beyond the inner edge of the tibial apex). This tibial character is found in Surutu , Harposceles , and in the " Cyclocephala cribrata species group". The venter of the meso- and metatarsi in P. felscheanus is covered with dense, reddish, flattened setae ( Albertoni et al. 2014). Similar flattened, scale-like setae are also found on the venter of the meso- and metatarsi of S. seabrai and S. dytiscoides . Future analyses of the tribal placement of P. felscheanus should focus on adult character comparisons with Surutu species and H. paradoxus , especially characters of the mandibles, maxillary galea, tibiae, tarsi, parameres, and hind wings.