Compsodactylus Fuhrmann, 2012

Fuhrmann, Juares, 2019, Taxonomy of Neotropical genera Compsodactylus and Dasyus and notes on claw movement in Macrodactylini (Coleoptera: Scarabaeidae: Melolonthinae), Zootaxa 4679 (1), pp. 139-163 : 140

Compsodactylus Fuhrmann, 2012

Compsodactylus Fuhrmann, 2012: 44 .

Type species. Dicrania martinezi Frey, 1972 (original designation).

Diagnosis. Mentum longer than wide; clypeus, frons and anterior area of pronotum with spine-like setae (clypeus of C. parvulus with or without spine-like setae); posterior margin of pronotum beaded; protibiae with two outer teeth and a spur; limit of mesoscutum–scutellum not angulate; outer, distal and inner margins of elytra beaded; metatibiae of males without spur and with an inner distal tooth ( Figs. 11, 14 ); abdominal spiracular area VII narrowed.

Remarks. Compsodactylus has an evident sexual dimorphism; males have apex of metatibia with an inner distal tooth and without spur and pygidium downwardly directed and longer than wide, females have two spurs at metatibial apex, but lack a tooth. Female pygidium directed backward and as wide as or wider than long. Compsodactylus martinezi ( Frey, 1972) and C. vallejoi Figueroa & Neita-Moreno, 2019 have strongly enlarged metafemur with inner distal spines ( C. martinezi ) or a raised carina ( C. vallejoi ). A similar pattern is found in several species of African Hopliini (Melolonthinae) , e. g., males of some species of Heterochelus Burmeister, 1844 and of C. martinezi have similar widened metafemur, metatibia with proximal emargination and an inner distal spine, and a long pygidium covered with colorful scale-like setae (see Dombrow 2001: 438, figs. 10–13). These male characteristics are possibly related to sexual selection.

Figures

FIGURES 9–20. Male appendages. 9, Dasyus collaris metacoxa; 10, Compsodactylus argentinus metacoxa; 11, C. argentinus apex of metatibia; 12, C. argentinus metafemur and tibia; 13, C. argentinus tibia, posterior view; 14, C. parvulus apex of metatibia; 15, C. parvulus metafemur and tibia; 16, C. parvulus tibia, posterior view; 17–18, C. argentinus aedeagus (lateral and parameres in dorsal view); 19–20, C. parvulus aedeagus (lateral and parameres in dorsal view). cxk, coxa-katepisternum articulation; cxp, coxopleural articulation; cxt, coxa-trochanter articulation; mbd, marginal bead; mip, metacoxal inner process (limit in dotted line). Scale = 1 mm.