Dichotomius agenor (Harold, 1869)

Solís, Ángel & Kohlmann, Bert, 2022, Dichotomius woodruffi, a new Dichotomius species of the agenor group from Costa Rica and Nicaragua (Coleoptera: Scarabaeidae: Scarabaeinae), Insecta Mundi 2022 (918), pp. 1-12 : 8-10

Key for the Dichotomius agenor species-group in Central America

1. Elytral striae crenulate ( Fig. 12 ); pronotal surface subrugose ( Fig. 13 ), male pronotal anterior declivity with a medial carina ( Fig. 13 ); elytral surface matt ( Costa Rica, Nicaragua, El Salvador, Honduras, Guatemala, Belize, Mexico).......................................... D. centralis (Harold)

— Elytral striae punctate, not crenulate ( Figs. 1, 2 ); pronotal surface punctate ( Fig. 7 ), male pronotal anterior declivity with weakly impressed to moderately impressed medial sulcus ( Fig. 7 ); elytral surface shiny............................................................................... 2

2(1). Ventral clypeal process bifurcate to cordate ( Fig. 14 ); female cephalic carina bituberculate ( Fig. 15 ) (Pan- ama, Colombia, Venezuela)............................................ D. agenor (Harold)

— Ventral clypeal process spiniform or truncate ( Figs.5 , 16 ); female cephalic carina quadrituberculate ( Fig.4 )..................................................................................... 3

3(2). Ventral clypeal process truncate ( Fig. 16 ); male anterior pronotal border simple, not medially sinuate ( Fig. 17 ); setigerous lateral areas on the anterior and lateral lobes of metasternum continuous at the posteromedial mesocoxal margins; male pygidium less than twice as long as width, strongly convex ( Fig. 18 ) ( Guatemala, Mexico).................. D. enioi Montoya-Molina and Vaz-de-Mello

— Ventral clypeal process spiniform ( Fig. 5 ); male anterior pronotal border medially sinuate ( Fig. 6 ); setigerous lateral areas on the anterior and lateral lobes of the metasternum interrupted at the posteromedial mesocoxal margins; male pygidium more than twice as long as width, slightly convex ( Fig. 8 ) ( Costa Rica, Nicaragua)............... D. woodruffi Solís and Kohlmann , new species

Figures

Figures 7–12. Dichotomius woodruffi, new species, and D. centralis. 7–11) D. woodruffi. 7) Anterior pronotal sulcus (lateral-oblique view), holotype male. 8) Male pygidium twice as broad as long, slightly convex, holotype male. 9) Lateral view of the aedeagus, holotype male. 10) Ventral view of the aedeagus, holotype male. 11) Lamella copulatrix, holotype male. 12) D. centralis, elytral stria crenulate.

Figures 13–18. Comparative structures of Dichotomius spp. 13) D. centralis anterior pronotal surface (lateraloblique view) subrugose, male pronotal anterior declivity with a medial carina. 14) D. agenor ventral clypeal process bilobed. 15) D. agenor female cephalic carina bituberculate. 16) D. enioi ventral clypeal process truncate. 17) D. enioi male anterior pronotal border simple, not medially sinuate. 18) D. enioi male pygidium less than twice as long as wide, convex.

Figures 1–6. Dichotomius woodruffi, new species. 1) Dorsal habitus, holotype, male. Scale bar equals 1 cm. 2) Dorsal habitus, allotype, female. Scale bar equals 1 cm. 3) Frontal view, holotype, male. 4) Frontal view, allotype, female. 5) Ventral clypeal process spiniform, holotype male. 6) Anterior pronotal border (frontal view), holotype male.