Onthophagus velutinus Horn, 1875

Edmonds, W. D., 2018, The dung beetle fauna of the Big Bend region of Texas (Coleoptera: Scarabaeidae: Scarabaeinae), Insecta Mundi 642, pp. 1-30 : 9-10

Onthophagus velutinus Horn

Fig, 44–48

Diagnosis. Dorsum black to brownish black, often with greenish reflections. Length 4–6.5 mm. Prono- tum evenly but not densely covered by small shining granules, each with associated short seta, on field of extremely fine shagreening ( Fig. 48 ); elytral interstriae with two longitudinal rows of small, setose granules on field of fine shagreening; pygidium evenly punctate, punctures setose. Front legs similar in both sexes. Male ( Fig. 44–45 ) – Clypeus weakly upturned medially. Clypeal carina weak, frontal carina replaced by pair of slender, nearly parallel horns (reduced in small individuals). Pronotum convex except for shallowly concave, vertical anterior surface; concavity partially divided by weak, median, vertical carina extending partway down from upper margin. Female ( Fig. 46–47 ) – Clypeus not upturned. Head with two transverse carinae, clypeal carina weak, frontal carina stronger, ends often distinctly raised higher than middle. Pronotum evenly convex, rarely with slightest hint of anteromedian process. A formal description of this species appears in Howden and Cartwright (1963).

Big Bend collection sites (altitudinal range: 555–1540 m).

Brewster Co.: [1] * Big Bend National Park, Panther Junction , 29°19′28″N 103°12′21″W, 1170 m (May) ; [2] * Big Bend National Park , Boquillas Ranger Station, 29°10′59″N 102°57′37″W, 555 m (May) ; [3] * Big Bend National Park , Oak Spring, 29°16′55″N 103°20′13″W, 1325 m (May) ; [4] Stillwell RV Park, FM 2627 , 29°38′40″N 103° 04′47″W, 770 m (Jun) .

Jeff Davis Co.: [1] ~ 8 km SE Fort Davis (via TX 118), Chihuahuan Desert Research Institute ( Quarry Unit ), 30°32′06″N 103°50′37″W, 1480 m (Aug) ; [2] Davis Mountains State Park , 30°35′43″N 103°56′05″W, 1540 m .

Presidio Co.: [1] C.E. Miller Ranch (~ 16 km W Valentine), 30°32′50″N 104°39′40″W (Camp Holland) 1410 m (Aug) ; [2] ~16 kmW Valentine (Miller Ranch, near headquarters), 30°33°30″N 104°38′44″W, 1350m (Jul–Aug) ; [3] ~ 7 km W Marfa (Hip-O Ranch ), 30°21′54″N 104° 7′12″W, 1530 m (Aug–Sep) ;– [4] Pinto Canyon Ranch (~ 58 km SSW Marfa on FM 2810 ), 30°01′18″N 104°27′42″W (headquarters area), 1475 m (Aug) .

Collection method(s). a) baited pitfall trap (human, laboratory rat feces); (b) incandescent and UV light trap; (c)*direct capture in nest of Neotoma albigula .

Surface activity. Nocturnal.

Habitat. In association with wood rats ( Neotoma ) in all zones, but more common in montane and grassland zones.

Comments. Onthophagus velutinus is a common species in southern Arizona and is recorded also from Colorado. It is a close relative of O. cartwrighti Howden , which occurs in southern California and Baja California, of O. arnetti Howden and Cartwright (southern Arizona), as well as of O. browni ( Howden 1973) . (See also comments below concerning O. browni .)

Figures

Figures 36–48. Onthophagus. 36) O. brevifrons, dorsal view, male. 37) Same, oblique frontal view. 38) Same, dorsal view of forebody, female. 39) Same, prolegs (A, female; B, male. 40) Same, pronotal sculpturing. 41) O. browni, dorsal view, male. 42) Same, oblique frontal view. 43) Same, oblique frontal view, female. 44) O. velutinus, dorsal view, male. 45) Same, oblique frontal view. 46) Same, dorsal view of female forebody. 47) Same, oblique frontal view. 48) Same, pronotal sculpturing.