Allometopon dicrostylis Sasakawa, 2009

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 21-22

Allometopon dicrostylis Sasakawa, 2009

Figs 47–51

Allometopon dicrostylis Sasakawa 2009: 42 .

Description [partially from Sasakawa (2009)]. General: ( Figs 47, 48 ) Body length 3.0mm(♂)– 3.4 mm (♀). Arista pubescent (missing in holotype). M1+2 ratio 3.6. Holotype in poor condition, with most setae, aristae, and most of legs except for left mid leg and most of left front leg.

Chaetotaxy: Three well-developed, evenly spaced fronto-orbitals (evident from sockets). Ocellar seta small (evident from sockets). Postvertical seta absent. Interfrontal seta not evident. Two dorsocentral setae, closely spaced posteriorly on scutum with anterior seta smaller (evident from sockets). Acrostichal seta not evident. One lateral scutellar seta.

Colour: Setae yellow. Body mostly yellow with ocellar tubercle and large brown circular spot on anepisternum dark brown; head paler below frons, with parafacial, gena and postgena whitish and silvery tomentose; abdomen yellow with brown tint, and epandrium black on dorsal half. Wing clear, lightly infuscated anterodistally along apex of R2+3 and R4+5 (paler). Halter pale. Female first flagellomere brown on dorsal 1/3; tergites 2–5 pale brown with sides broadly yellow, and tergites 1, 6, 7 yellow.

Male terminalia: ( Figs 49–51 ) Epandrium wider than high and long, deepest above midpoint. Surstylus approximately as high as epandrium, narrow, pointed and with similar narrow, pointed posterobasal process that is half length of surstylus and directed ventrally. Hypandrium well-developed, bare. Phallapodeme rod-like with ventral shield evident distally as shallow dome. Pregonite slightly elongate and oblique with basal and apical setae; weakly sclerotized and striated. Basiphallus, epiphallus and postgonite small. Distiphallus less than half length of phallapodeme, subrectangular. Paraphallus well-developed but weakly sclerotized, with apex arched and spinulose.

Female terminalia: Not dissected.

Distribution: Thailand.

Holotype: THAILAND. Thailand, Chiangmai Prov, Fang, 12–l 9.iv.1958, T.C. Maa [Type No. BPBM 17192] (1♂, BPBM).

Comments: Allometopon dicrostylis is a very pale species with a strong spot on the anepisternum and a highly diagnostic forked surstylus.

Figures

FIGURES 47 – 51. Allometopon dicrostylis Sasakawa, holotype; 47: photo, dorsal; 48: photo, lateral; 49: external genitalia,