Heteromeringia stegna, Lonsdale, 2009

Lonsdale, Owen, 2009, The Heteromeringia (Diptera: Clusiidae: Clusiodinae) of Australia, Records of the Australian Museum 61 (3), pp. 229-262 : 260

Heteromeringia stegna n.sp.

Figs 81–84

Type material. HOLOTYPE: Northern Territory: Litchfield Natl. Pk., 20.i.1998, A. Zwick (1♂, AMS) . PARATYPE: Queensland: Bamaga-Capt Billy Ck Rd jnct 16km NE Heathlands H.S., 11°41'S 142°42'E, 16.iii.1992, G. Daniels & M.A. Schneider (1♂, UQIC) .

Description

Male. Body length 3.1 mm. Anepisternal disc present. First flagellomere orbicular. Bristles black. Arista closely pubescent. Vibrissa relatively long and curved. Ocellar bristle minute. Two dorsocentral bristles with small bristle in front of anterior dorsocentral. Gena shallow and not strongly angled or bent. Face and buccal cavity pilose and meeting at an angle. Frons black and shiny with posterior margin yellowish, and lateral margin yellow and pilose (or pilose anteromedially); back of head, occiput and posterior 2 ⁄ 3 of gena dark brown; clypeus and mentum brown; anterior margin of first flagellomere and distal half of inner face brown; basal 2 ⁄ 3 of palpus brown (holotype) or entirely dark brown excluding apex; remainder of head yellow (holotype) or orange-brown; dorsal margin of gena pilose. Thorax dark brown. Legs yellow with fore tarsi and tibia dark brown; fore femur dark brown on distal 1 ⁄ 3 (holotype) or with inner-distal spot. Fore tarsi very slightly compressed laterally. Abdomen brown. M 1+2 ratio 5.3. Wing with small anterodistal infuscation (holotype), or dusky with base and posterior margin clear. Knob of halter brown, and base and side of stalk infuscated.

Female. Unknown.

Male terminalia ( Figs 81–84 ). Epandrium elongate oval with margins nearly meeting distally. Surstylus subtriangular, small, setulose on inner face and with base fused to anterior margin of epandrium. Cerci arched over surstyli, setose, widest at apex, and shallowly but broadly emarginate. Hypandrium+pregonite bilobed with broad anterior lobe with two stout bristles, and linear posterior lobe with several posterodistal setulae. Phallapodeme as long a hypandrium. Distiphallus with strong medial curve where one rib ends and the other rib extending into a long process accompanied by irregular U-shaped sclerite.

Etymology. The specific name is Latin for “constricted”, in reference to the apical narrowing of the epandrium.

Comments. While relatively non-descript externally, the male genitalia of this species are heavily modified: the epandrium is constricted apically, the cerci are very broad apically, and the nearly vestigial surstylus is positioned anteriorly (not apically) and partially fused to the epandrium.

Figures

Figures 78–87.Figs 78–80:male terminalia,Heteromeringia spinulosa McAlpine