Allometopon bivittatum spec. nov.

Figs 293, 294, 333

Description. General: (Figs 293, 294) Body length 3.1mm. Arista pubescent. M1+2 ratio 3.0. First flagellomere slightly enlarged with anterodorsal margin more produced. Male unknown.

Chaetotaxy: Three fronto-orbital setae (anterior seta approximately half length of others). Ocellar seta thin, slightly longer tubercle. Postvertical seta absent. Interfrontal seta minute. Frons covered with minute setulae. Anterior margin of first flagellomere with hairs longer than width of base of arista (only a few hairs above arista). Anterior dorsocentral approximately 3/5 length of posterior dorsocentral (closely set posteriorly). Acrostichal seta well-developed. Two lateral scutellar setae (anterior seta minute).

Colour: Setae brown. Head predominantly yellow; dorsal 2/5 of first flagellomere brown; ocellar tubercle brown; gena and postgena white and silvery tomentose. Scutum yellow with one pair of large dark postsutural stripes that are narrowly separated medially and bounded by faded yellowish line along posterior margin of scutum (Figs 293, 294); stripes of holotype reaching posterior margin of scutum, and fused on basal half. Scutellum brown. Metanotum light brown beneath scutellum. Pleuron and legs light yellow. Wing very lightly clouded along anterior margin. Halter white. Tergite 1 yellow with wide central spot; tergites 2–7 brown dorsomedially; remainder of abdomen yellow.

Female terminalia: (Fig. 333) Sternites 6 and 7 slightly longer than wide. Sternite 7 slightly longer than wide. Spermatheca long, dark and ovate-cylindrical, with transverse wrinkles on distal 2/3.

Etymology: The specific epithet refers to the characteristic thick, paired postsutural stripes.

Distribution: Papua New Guinea.

Holotype: PAPUA NEW GUINEA. Central Province: Aieme R., 7.xi.1982, J.W. Ismay, forest edge, NHM 1995-E16 (1♀, BMNH).

Paratypes: PAPUA NEW GUINEA. Central Province: Aroa R., Aroana Estate, 2.xii.1963, D.K. McAlpine (1♀, AMSA), Morobe Province: Bumbu R., 8 km N. Lae, Morobe District, 27.xi.1972, G.A. Holloway (1♀, AMSA).

Comments: While known from only three females, the notal pattern of Allometopon bivittatum is unique enough within the genus to justify description, consisting of two dark, broad postsutural stripes (fused on basal half in holotype). A relatively long anterior dorsocentral and two small pairs of lateral scutellars are also diagnostic.