Discheramocephalus nigritus, Darby, Michael, 2019

Darby, Michael, 2019, New Ptiliidae (Coleoptera) from Sarawak in the spirit collection of the Natural History Museum, London, European Journal of Taxonomy 512, pp. 1-50 : 21-22

Discheramocephalus nigritus sp. nov.

urn:lsid:zoobank.org:act:9FAADB43-B9A8-4B23-8223-16A129D2D088

Fig. 10

Diagnosis

Easily distinguished from all other Ptiliidae in Sarawak by the longitudinal foveae on the pronotum, and by the pair of deep sulci on abdominal ventrite VIII (most easily seen in dissections but not showing in Fig. 10F ).

Etymology

Named after the Latin adjective ‘ niger ’, meaning ‘dark’, and referring to the insect's colouration.

Type material

Holotype MALAYSIA-BORNEO • Sarawak, 4 th division, Gunung Mulu National Park ; 800–1700 m a.s.l.; 26 Apr. 1978; I. Hanski leg., BM 1978-524 ; pitfall trap fish baited, LMR forest slope 4-6; BMNH.

Description

SIZE. Habitus ( Fig. 10A ), length 0.55 mm.

COLOUR. Almost black, shining, antennae and legs dusky yellow. HEAD. With a deep transverse fossa behind the eyes extending laterally to the ventral surface and a group of setae in clearly defined foveae behind each eye ( Fig. 10D ). Antennomeres III–XI, length 0.21 mm. Distance across eyes 0.17 mm.

PRONOTUM. Length 0.12 mm, width 0.19 mm, with a pair of longitudinal foveae on the disk and another pair close to the lateral margins, in between these two much smaller foveae close to the posterior margin on each side ( Fig. 10B ). Scutellum with a sharp central keel ( Fig. 10E ).

ELYTRA. Length 0.33 mm, width 0.27 mm.

VENTRUM. Proventrum depressed in front of procoxae and with raised angular humeri, extending posteriorly. Mesoventrum with a broad strongly reticulated medial keel and concave lateral margins before posterior termination, keels present extending to sides of mesocoxae, mesocoxae separated by their width, posterior margins obliterated. Metaventrum with scattered pubescence, anterior margins extending in form of a lobe between the mesocoxae, metacoxae almost adjacent.

ABDOMEN. Depressed laterally apparently for reception of metatibiae and tarsi, first visible segment with a serrated posterior margin, ventrite VIII with a pair of deep sulci. Pygidium with ± 10 spines and two coarse setae near the anterior corners ( Fig. 10F ). Wings of usual ptiliid type. Dissection failed to reveal any genitalia to determine sex, but size of eyes suggests male (females in this genus usually have smaller eyes).

Figures

Fig. 10. Discheramocephalus nigritus sp. nov. A. Habitus. B. Pronotum ×625. C. Back of head ×600. D. Fovea behind eye ×1800. E. Scutellum ×1500. F. Pygidium.