Deltochilum (Deltochilum) Eschscholtz, 1822

Génier, François, 2012, A new species and notes on the subgenus Deltochilum (Deltochilum) Eschscholtz, 1822 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini), Zootaxa 3357, pp. 25-36 : 26

Deltochilum (Deltochilum) Eschscholtz, 1822

Eschscholtz 1822: 37 original description

Synonym: Telhyboma Kolbe, 1893 , new synonymy Kolbe 1893: 192 original description

Remarks. While examining species belonging to the subgenus Deltochilum , it became apparent that the status of the single species ( D. orbiculare van Lansberge) included in the subgenus Telhyboma Kolbe should be reconsidered. After a careful examination, it appears that the only apomorphic character separating D. orbiculare from all other species included in the subgenus Deltochilum is the development of the 7 th interstrial carina. In D. orbiculare this carina is present on most of the length of the 7 th interstria and overlaps the elytral edge and the 9 th interstrial carina on most of the elytral length. The development of this carina is clearly linked to gender. Hyperthelic males always exhibit a much more developed structure than females, suggesting that the development of this carina in D. orbiculare is an additional secondary sexual character. In their study of the subgenera Calhyboma , Hybomidium and Telhyboma for Colombia, González et al. (2009) also noted the asymmetrical parameres and the additional internal sac sclerites, which conform to other species in the subgenus Deltochilum .

The following apomorphies define the subgenus Deltochilum in its current sense: overall body shape in dorsal view with widest portion at mid-distance or slightly past mid-distance to elytral apex; elytral surface with a distinct network of irregular glossy bulges (not glossy in D. enceladus Kolbe ) sharply contrasting from remaining surface; protibia lacking tarsus in both sexes; male protibia with a modification on internal edge basal third; male profemur with a teeth past mid-distance on internal edge; male mesofemur with a denticle on basal half; male metafemur with posterior surface completely matte, with punctures weakly impressed, more widely separated than remaining surface or absent; male sternite 3 with a strong bulging structure medially (note: this structure is absent in both Central American species, D. scabriusculum Bates and D. tumidum Howden. However , in some specimens of D. scabriusculum and D. tumidum the surface shows wrinkles that would correspond to the lateral edges of the bulge, suggesting that in these species there is a reversal to the primitive state); parameres with strong ventral projections, slightly asymmetrical.