Allometopon

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 42-43

Allometopon magnum spec. nov.

Figs 168–172 , 347

Description. General: ( Figs 168, 169 ) Body length approximately 4.2mm. Arista sparsely short plumose. M1+2 ratio 2.6–2.8. First flagellomere slightly enlarged, subovate, higher than long. Robust-bodied.

Chaetotaxy: Three fronto-orbital setae, slightly decreasing in length anteriorly. Ocellar seta two times length of tubercle. Postvertical seta thin, as long as tubercle. Interfrontal seta short but well-developed. Frons with minute setulae. First flagellomere along distal margin with hairs longer than width of arista base. Anterior dorsocentral half length of posterior dorsocentral; closely spaced posteriorly. Acrostichal seta well-developed, stout. Two lateral scutellar setae, stout, arranged transversely.

Colour—male: Setae black, slightly paler on head. Head yellow, whitish below level of antenna; first flagellomere black; ocellar tubercle brown; mouthparts yellow with distal ¼ of palpus dark brown; gena, parafacial and postgena silvery tomentose. Scutum yellow with dorsal half of postpronotum and notopleuron brown (stripe ill-defined, sometimes narrow); lateral margin brownish above alar base; one pair of long medial stripes, joined basally, nearly attaining margin anteriorly and widened to surround dorsocentral rows postsuturally. Scutellum brown. Metanotum yellow with posterodorsal corner of anatergite brown. Pleuron light yellow. Halter light yellow. Wing dusky on distal third, becoming clear posteriorly. Legs light yellow with mid and hind tibiae faintly brownish. Abdomen with broad dorsal strip on tergites 3–6; epandrium with orangish-brown tint dorsally.

Variation—female: As described for male except as follows: body length approximately 5.3mm; M1+2 ratio 2.4; apex of palpus brownish; back of head white with dorsomedial section yellow; scutal stripes divided by more than width of stripe, but converging anteriorly; base colour of scutum dirty white, yellow between and along lateral margin of medial scutal stripes; brownish stripe on notopleuron reduced, narrowing to a point on dorsum of postpronotum; scutellum yellow medially with margins of stripe ill-defined; legs yellow with coxae and base of femora white; abdomen with dorsal stripe on tergites 2–5, with stripe strongly narrowing anteriorly on each segment.

Male terminalia: ( Figs 170–172 ) Annulus and epandrium well-developed. Cerci slightly projecting, well separated, only significantly sclerotized along distal and outer-distal margins. Surstylus approximately 2/3 length of epandrium, narrow subtriangular in shape with thin, shallow posteromedial carina; inner-apical surface short setose, not tuberculate. Hypandrium broad with arm much widened apically; posterovental lobe very small with two short apical setae. Phallapodeme rod-like with short ventral shield apically. Pregonite weakly sclerotized and ovate with minute medial setae. Postgonite extremely narrow and elongate, curved, with apical and medial setae. Basiphallus well-developed. Epiphallus elongate and projecting, slightly curved. Distiphallus slightly more than half length of phallapodeme, minutely tuberculate and weakly sclerotized on distal half. Paraphallus more than half length of distiphallus, narrow and densely, minutely spinulose dorsally past base, which is abruptly widened.

Female terminalia: Not dissected.

Etymology: The specific epithet reflects the unusual large size of this species.

Distribution: Malaysia (Sabah, Selangor).

Holotype: MALAYSIA. Selangor: Templer Park near Kuala Lumpur, 14.vi.1973, D.K. McAlpine (1♂, AMSA).

Paratype: MALAYSIA. Sabah: Penampang Distr., Crocker Range, Moyog, Moyog River, 300m, 5˚53′02ʺN, 116˚14′48ʺE [SDG11–19] 17.x.2011, S. Gaimari & M. Hauser (1♀, CSCA), Selangor: Genting Highlands, Bentong Pass, 14.iv.1985, D.K. McAlpine & K. Khoo (1♂, AMSA).

Comments: The new species Allometopon magnum is allied to the A. palpale species group on the basis of a relatively large, robust body, an apically dark palpus, a strong acrostichal seta, two pairs of strong lateral scutellar setae arranged in a row across the scutellum and a small, narrow subtriangular surstylus. Unlike those other species with a black first flagellomere, however, there are only three fronto-orbitals (not four), the medial scutal stripe narrows anteriorly and is split along most of the length by a very narrow yellow line, or is entirely bifid.

Figures

FIGURES 168 – 172. Allometopon magnum spec. nov.; 168: paratype male, photo, dorsal; 169: same, lateral; 170: holotype external genitalia, left lateral; 171: same, posterior; 172: internal genitalia, left lateral.