Allometopon nyx, Owen Lonsdale, 2016

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 48

Allometopon nyx spec. nov.

Figs 200–204

Description. General: ( Figs 200, 201 ) Body length 2.8. Arista short plumose. M1+2 ratio 4.5. First flagellomere slightly enlarged, subovate with anterodorsal margin more produced. Female unknown.

Chaetotaxy: Three fronto-orbital setae, anterior seta slightly shorter. Ocellar seta absent. Postvertical seta very thin, slightly shorter than ocellar tubercle. Interfrontal seta absent. First flagellomere along distal margin with hairs longer than width of base of arista. Anterior dorsocentral slightly less than half length of posterior dorsocentral; closely set near posterior margin of scutum. Acrostichal seta not distinguishable from surrounding setulae. One lateral scutellar seta.

Colour: Setae brownish-yellow, paler on yellow sclerites. Head yellow, white below level of antenna; antenna white with faint yellowish dorsobasal region on first flagellomere; ocellar spot brown; back of head with one pair of stripes; gena and postgena silvery tomentose. Scutum brown on anterior margin; postpronotum and sublateral notopleuron with brownish tint; mostly brown postsuturally with anterior region yellow, lateral margin brownishyellow, narrow medial line yellow, and posterior margin yellowish. Scutellum and metanotum brown. Pleuron and legs white with brown spot in posterodorsal corner of anepisternum. Wing lightly infuscated on distal half from costa into second radial cell. Halter white. Abdomen brown with annulus paler, epandrium darker with distal 1/3 yellow, and surstylus and cercus yellow.

Male terminalia: ( Figs 202–204 ) Annulus well-developed, enclosing seventh spiracle. Surstylus small, narrow and triangular, with inner-distal tubercles. Cerci small, rounded and converging. Ventral lobe of hypandrium short and broadly rounded with two minute setae; inner face with transverse margin. Phallapodeme rod-like, welldeveloped, with ventral shield abruptly produced distally. Basiphallus well-developed. Epiphallus small. Pregonite ovate and weakly sclerotized with several medial setulae. Postgonite small and lobate. Distiphallus 2/5 length of phallapodeme. Paraphallus smooth, curved, broad, and spinulose apically.

Etymology: The specific epithet is Greek for "night", in reference to collection of the holotype at a black light.

Distribution: Sri Lanka.

Holotype: SRI LANKA. Gal. Dist., Kanneliya, 200ft., black light, 15–17.x.1976, G.F. Hevel, R.E. Dietz, S. Karunaratne & D.F. Balasooriya (1♂, USNM).

Comments: Allometopon nyx is best characterized by one pair of large, light brown, subrectangular scutal stripes that nearly touch and reach the transverse suture, and barely meet the posterior margin. The pleuron, legs and most of the head are also bright white and the surstylus is very small and triangular.

Figures

FIGURES 200 – 204. Allometopon nyx spec. nov., holotype; 200: holotype, photo, dorsal; 201: same, lateral; 202: external genitalia, left lateral; 203: same, posterior; 204: internal genitalia, left lateral.