Orizabus Species

Ratcliffe, Brett C. & Cave, Ronald D., 2010, New species of Orizabus Fairmaire (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) from Mexico and Guatemala, with a revised key and checklist of the species in the genus, Insecta Mundi 2010 (127), pp. 1-16 : 9-10

Key to Males of Adult Orizabus Species

(modified from Delgado 2008)

1. Elytra weakly striate, at most with feebly impressed rows of punctures ................................... 2

— Elytra furrowed, distinctly impressed striae with rows of punctures ......................................... 3

2(1). Pronotum with tubercle and fovea on anterior half. Protibia without teeth or lobes on external margin. Length 24-27 mm. Southern Mexico. O. dechambrei Morón, Tapia and Aragón

— Pronotum lacking fovea and tubercle on anterior half. Protibia tridentate on external margin. Honduras................................................................................... O. botox Ratcliffe and Cave

3(1). Protibia lacking lobes or teeth on external margin ..................................................................... 4

— Protibia with lobes or teeth on external margin ....................................................................... 13

4(3). Antenna 9-segmented. Length 15-18 mm. Central Mexico ............................................................ ........................................................................... O. vulcanicus Morón, Tapia and Aragón

— Antenna 10-segmented ................................................................................................................. 5

5(4). Subapical carina of clypeus straight ........................................................................................... 6

— Subapical carina of clypeus bilobed ............................................................................................. 7

6(5). Pronotum with deep fovea and prominent tubercle on anterior half. Length 22-25 mm. Southeastern Mexico, Guatemala, Nicaragua............................................................ O. tuberculatus Prell

— Pronotum with shallow depression and feeble tubercle on anterior third. Length 13-16 mm. Northwestern Mexico ............................................................................. O. ratcliffei Delgado

7(5). Pronotum with fovea and tubercle on anterior half .................................................................... 8

— Pronotum without fovea or tubercle on anterior half ................................................................ 10

8(7). Metatibia at apex usually with more than 40 spinules. Parameres just before apex notched ( Fig. 24-25 ). Length 23-30 mm. El Salvador, Honduras..................................................................... .............................................................................. O. teamscaraborum Ratcliffe and Cave

— Metatibia at apex usually with less than 30 spinules. Parameres round, entire just before apex ( Fig. 19 ) .................................................................................................................................... 9 9(8). Clypeus with apex extending beyond broadly bilobed subapical carina. Parameres as in Fig. 19 . Length 20-27 mm. United States, Mexico, Guatemala, El Salvador, Honduras....................... ............................................................................................................. O. clunalis (LeConte)

— Clypeus with apex not extending beyond clypeal carina, carina with 2 contiguous teeth. Length 20-27 mm. Southwestern United States, northern Mexico....................... O. ligyroides Horn

10(7). Elytra on second interval smooth. Parameres at apical third with lateral carina; apex notched and glabrous ........................................................................................................................... 11

— Elytra on second interval with row of punctures on basal half. Parameres without lateral carina at apical third; apex entire, setose or glabrous ...................................................................... 12

11(10). Parameres with large tooth at middle on external margin ( Fig. 23 ); apex in lateral view strongly concave. Length 21-26 mm. Central and northwestern Mexico.............. O. rubricollis Prell

— Parameres lacking large tooth at middle on external margin; apex in lateral view not concave (Fig. 5-6). Length 19-22 mm. Oaxaca, Mexico................... O. delgadoi Ratcliffe and Cave

12(10). Anterior marginal bead of pronotum expanded at center into distinct tubercle. Pygidium completely, densely rugulopunctate; apex at center just before marginal bead with short, deep, transverse groove ( Fig. 11 ). Length 20 mm. Southern Guatemala....... O. mezclus Ratcliffe and Cave

— Anterior marginal bead of pronotum without tubercle. Pygidium with sparse, minute punctures on disc; apex entire, lacking deep transverse groove, with long setae. Parameres as in Fig. 20 .

Figures

Figure 17-25. Parameres of Orizabus spp. 17) O. batesi. 18) O. brevicollis. 19) O. clunalis. 20) O. cuernavacensis. 21) O. fairmairei. 22) O. pyriformis. 23) O. rubricollis. 24-25) O. teamscaraborum.

Figure 10-11. Orizabus mezclus. 10) Dorsal habitus. 11) Oblique view of left pygidial apex.