Allometopon grypostylis Sasakawa

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 30-31

Allometopon grypostylis Sasakawa

Figs 90–94

Allometopon grypostylis Sasakawa 2009: 43 .

Description. General: ( Figs 90, 91 ) Body length approximately 2.9mm (holotype)– 3.9mm (non-type). Female unknown. Arista pubescent. M1+2 ratio 5.7. First flagellomere not enlarged but slightly more swollen ventrally.

Chaetotaxy: Three fronto-orbital setae, slightly decreasing in length anteriorly. Ocellar seta slightly longer than ocellar tubercle. Postvertical seta very thin, about as long as tubercle. Interfrontal seta absent. Margin of first flagellomere on distal half with hairs as long as width of base of arista. Anterior dorsocentral missing, but socket much smaller than that of long posterior dorsocentral; closely set posteriorly. Acrostichal seta not much longer than surrounding setulae. One well-developed lateral scutellar seta.

Colour: Setae yellow. Antenna, including base of arista, and head below frons and foramen yellowish-white (darker yellow in holotype); frons with orange tint; ocellar tubercle dark brown; back of head above foramen with broad dark brown curved stripe with remaining space above yellow; parafacial, gena and postgena silvery tomentose. Scutum yellow with wide brown anteromedial patch bordering anterior half of postpronotum, and one apically rounded posteromedial stripe (with yellowish spot at base of dorsocentrals) that ends at transverse suture and is basally confluent with one pair of short, ill-defined lateral stripes; pigment more difficult to discern in holotype (darker due to state of preservation), with posterolateral stripes possibly paler or absent. Scutellum brown. Metanotum dark brown with venter of mediotergite yellowish; deep yellow in non-type with mediotergite brownish dorsomedially, and anatergite and posterodorsal region of katatergite dark brown. Pleuron and legs yellowish-white with large dark brown spot on anepisternum. Halter yellow. Wing clear with anterodistal region lightly clouded. Abdomen brown with tergites 1 and 2 paler in holotype; non-type with tergite 1 yellow, tergite 2 yellow with thin light brown posteromedial stripe and wider brown posterolateral spots, tergites 3–6 and sternite 8 dark brown, epandrium dark brown with venter yellow, and surstylus and cercus yellowish-white.

Male terminalia: ( Figs 92–94 ) Sternite 8 relatively long, possibly including fused tergite 6. Cercus apparently absent or membranous. Surstylus narrow, nearly as high as epandrium, broadest near base, hooked on distal half; outer surface mostly bare with long posteromedial setae and minute scattered setae; one row of small tubercle-like setae along inner margin on distal third. Hypandrial lobe short, stout, subtriangular, with two short apical setae; venter reaching enlarged pregonite. Phallapodeme rod-like, weakly sclerotized, thin towards base and with wide, stout ventral shield apically. Pregonite large, plate-like subtriangular, with posterodorsal band-like cluster of setae and minute spinules. Postgonite well-developed with several apical to medial setae. Basiphallus and epiphallus well-developed. Distiphallus narrow, nearly half length of phallapodeme. Paraphallus well-defined, even if weakly sclerotized, and with long dorsal band of spinules.

Distribution: Laos, Thailand.

Holotype: LAOS. Vientiane Prov.: Ban Van Eue, 31.xii.1965, native collector [Type No. BPBM 17193] (1♂, BPBM).

Additional material examined: THAILAND. 115–1300m, Chiang Mai Prov., Doi Suthep / 20, 20–28.xii.2003, P. Schwendinger (1♂, MHNG).

Comments: Allometopon grypostylis is externally diagnosed by a medial postsutural stripe that attains the transverse suture and has one pair of small laterobasal offshoots, an orange tint on the frons, a brown scutellum, a brown anteromedial spot on the scutum, a large dark spot on the anepisternum, a relatively small first flagellomere that is recessed dorsally, and a pale tergite 2. The surstylus is narrow and hook-like, and the hypandrium has a short ventral lobe that meets a large, subtriangular pregonite with posterodorsal setae and spinules (also see comments for A. giallo ).

Figures

FIGURES 90 – 94. Allometopon grypostylis Sasakawa, non-type; 90: photo, dorsal; 91: same, lateral; 92: external genitalia, left lateral; 93: same, posterior; 94: internal genitalia, left lateral.