Ptomaphaminus chapmani (Peck, 1981)

Schilthuizen, Menno, Perreau, Michel & Njunjic, Iva, 2018, A review of the Cholevinae from the island of Borneo (Coleoptera, Leiodidae), ZooKeys 777, pp. 57-108 : 84-85

Ptomaphaminus chapmani (Peck, 1981) Figures 12 g–h, 13 r–s, 14e

Ptomaphaginus chapmani Peck, 1981. Peck (1981: 222, fig. 1-4); type from Mulu, Sarawak, Borneo (in NHMUK).

Material.

Sarawak. Mulu, Mayday Cave, rotten prawn bait, 24.vii.1980 (RMNH.INS.634810, 634795), 2 individuals; Mulu, Clearwater Cave, Snake Track passage, mice-rat bait, 5.i.1981 (RMNH.INS.634763, 634819, 634784), 3 individuals; Mulu, Clearwater Cave, 9.v.1978 (leg. P. Chapman, RMNH.INS.634799), 1 paratype; Mulu, Mayday Cave, rotted prawn bait, 24.vii.1980 (CMPR), 7 individuals.

Description.

Length 1.40-2.0 mm. Colour light brown. Winged. Eyes with ten ommatidia. Pronotum 1.47 times as wide as long, elytra 1.84 times as long as wide. Female sutural angle of elytra expanded in a sharp apical tooth (Figure 14e). Protarsi 0.8 times as wide as the protibia. Spiculum gastrale of the male genital segment moderately dilated in a parallel-sided spatula (Figure 13r). Aedeagus long, approximately 3.3 times smaller than the body length, parallel, weakly arcuate in lateral view and shortly narrowed on the apical quarter of its length, rectangular at the apex, with an apical hook strongly retroverted ventrally (Figure 12g, h). Internal stylus of the endophallus long and straight. Female genital segment with reduced gonocoxites. Spermiduct not helical. Spermatheca rounded at the apex without sclerotised plate (Figure 13s).

Differential diagnosis.

Unique among Bornean Ptomaphaminus in showing a combination of troglomorphic features: reduced eyes and elongated habitus. Aedeagus very similar to that of P. ater , which, however, is darker and has a more strongly cuneiform habitus.

Habitat and distribution.

Known only from a single cave (Clearwater cave) in Gunung Mulu, Sarawak, Malaysia.