Allometopon gaimarii, Owen Lonsdale, 2016

Owen Lonsdale, 2016, Revision of the genus Allometopon Kertész (Diptera: Clusiidae), Zootaxa 4106 (1), pp. 1-127 : 26-27

Allometopon gaimarii spec. nov.

Figs 69–73

Description. General: ( Figs 69, 70 ) Body length 3.3mm. Arista short plumose. M1+2 ratio 5.3. First flagellomere slightly enlarged with dorsal and ventral margins produced. Cell bm partially open. Female unknown.

Chaetotaxy: Two fronto-orbital setae, widely spaced, anterior seta slightly shorter. Ocellar seta minute. Postvertical seta absent. Interfrontal seta minute. First flagellomere with longer hairs along margin except at base. Three postsutural dorsocentral setae; anterior seta thinner, near suture, half length of second seta; second dorsocentral distant from posterior dorsocentral, approximately 3/5 length. Acrostichal seta absent. Scutum glossy medially between dorsocentrals. One lateral scutellar seta, shorter that scutellum, thin.

Colour: Setae yellow. Antenna light yellow with first flagellomere mostly white, except brown on dorsal margin of inner surface and brown above point of pedicel on outer surface; frons yellow with lateral margin along eye lighter; ocellar tubercle dark brown; back of head yellowish-white, mostly yellow above foramen; remainder of head yellowish-white. Scutum with one pair of postsutural intra-alar stripes and one complete medial stripe that narrows subbasally; presutural scutum dark brown anteriorly with one pair of short sublateral processes; notopleuron with brown mottling medially and laterally; postpronotum dark brown. Scutellum brown with apex (including base of lateral scutellar seta) yellow. Metanotum dark brown. Pleuron mostly yellowish-white; anepisternum mostly yellow with dorsal margin thinly brown (wider anteriorly). Legs yellowish-white, becoming yellower distally from apex of femora. Wing faintly infuscated. Halter white. Tergite 1 yellow with brown medial spot and brown posterior margin; tergite 2 to sternite 8 dark brown; sternites brown, paler anteriorly on abdomen; epandrium dark brown; cercus white; surstylus white with brownish transverse subbasal stripe.

Male terminalia: ( Figs 71–73 ) Cerci united, tapered to a point. Surstylus as large as epandrium in profile, broadly rounded and setose posterobasally, apical margin nearly straight; small tubercle-like setae on posterodistal and anterodistal margins. Phallapodeme rod-like. Hypandrium with lateral lobe long, membranous and confluent with pre- and postgonites; with two long basal and one shorter distal seta. Pregonite long, clear, with four apical setae. Postgonite lobate, relatively long and pointed, with several apical and anterodistal setae. Basiphallus flattened, as long as similarly flattened epiphallus, which projects from anterior margin. Distiphallus weakly developed, approximately 2/5 length of phallapodeme. Paraphallus longer than distiphallus, clear and membranous, with spinulose dorsal margin.

Etymology: The specific epithet recognizes one of the collectors of the holotype, S. Gaimari.

Distribution: Malaysia (Sabah).

Holotype: MALAYSIA. Sabah (Borneo): Penampang Distr., Long Cong Kugan, 1630m [SDG11–23] 5˚49′44ʺN, 116˚19′37ʺE, Malaise, 21–25.x.2011, S. Gaimari & M. Hauser (1♂, CSCA).

Comments: Allometopon gaimarii is a distinct species with a bold trivittate pattern on the scutum, an apically yellow scutellum, a yellow to white pleuron, a broad surstylus that is curved in cross-section, a long, strongly projecting epiphallus and unusual enlargement and fusion of the gonites. It also shared features typical of putatively ancestral species, including long, widely spaced dorsocentrals, a large, glossy region posteromedially on the scutum and two fronto-orbitals.

Figures

FIGURES 69 – 73. Allometopon gaimarii spec. nov., holotype; 69: photo, dorsal; 70: photo, lateral; 71: external genitalia, left lateral; 72: same, posterior; 73: internal genitalia left lateral.