Onthophagus (Parascatonomus) dux Sharp, 1875

Krikken, J. & Huijbregts, J., 2008, Two new taxa from the Lesser Sundas in the genus Onthophagus (Coleoptera: Scarabaeidae: Scarabaeinae), Journal of Natural History 42 (43 - 44), pp. 2735-2746 : 2745-2746

Onthophagus (Parascatonomus) dux Sharp, 1875

( Figures 18–20 , 24 )

Diagnostic remarks

Length 11–16 mm. The pronotum of O. dux , with the characteristic blunted anteromedian protrusion and adjacent pronounced anterolateral declivities, is either cupreous or black (sic); the head may also be cupreous. The median protrusion on the vertex, although varying in size, is much higher than in accedens . The distal paramerites are different from the two accedens subspecies, being distinct and somewhat pointed below (in lateral view, Figure 24B ). See also previous subgroup diagnosis.

Measurements in mm of specimen figured (Sabah). Maximum width of head 5.1. Median length of pronotum 5.1, maximum width 7.9. Sutural length of elytra 5.6, maximum width combined 7.9. Body length ca 13 mm.

Comments

This is a species associated with dung and carrion in lowland forest environments on Borneo, possibly also occurring in western Sundaland , i.e. Sumatra and the Malay Peninsula. There is some variation in this species requiring a closer analysis (for instance, correlation with aedeagus characters), when more material (particularly from Kalimantan) becomes available .

Material examined

In our collections we have seen over 360 specimens from Sabah, Sarawak, and Kalimantan , not specified in detail in this paper treating the Lesser Sundas fauna. Only the specimen figured is here recorded explicitly: Malaysia: Sabah: Danum Valley : Danum Valley Field Centre (W5), alt. 100–200 m, 20–24 October 1987, Krikken and Rombaut, #sa05b, multistratal evergreen forest, fish trap .

Figures

Figures 9–20. Onthophagus dux subgroup. (9–14) O. accedens nusatenggaricus, male holotype; (15–17) accedens accedens, male W Java; (18–20) dux, male Sabah. (9) habitus, oblique; (10, 15, 18) head, full-face; (11, 16, 19) pronotum, dorsal; (12, 17, 20) elytron, dorsal. (13) protibia, upperside; (14) metatibia and distal part of femur, underside. Scale with Figure18 51mm.

Figures 21–24. Aedeagus of Onthophagus species. (A) Upper side; (B) lateral; (21) O. montishannoniae, holotype; (22) accedens nusatenggaricus, holotype; (23) accedens accedens, Bali; (24) dux, Sabah.