Chimarra bicornis sp. nov.

Figures 91–93

Holotype. Male (figured specimen CT-364), PNG (Morobe Province), Wau, Big Wau Creek, 1300 m, about 7° 20' S, 146° 43' E, November 1965, P. Shanahan (BPBM).

Diagnosis. Chimarra bicornis is similar to C. ulmeri but different to all other New Guinea Chimarra species in having a pair of sclerotised, curved dorsal and ventral branches of the lateral lobes on segment X. In C. ulmeri, the apices of the dorsal or upper branch of the lateral lobes are directed dorsally (Kimmins, 1962: fig. 16A; Neboiss, 1986a: fig. p. 106) or posterodorsally (fig. 90), whereas in C. bicornis, they are directed dorso-laterally. (There is also a species from northern Australia with a similar pair of curved mesal processes on segment X – C. adaluma Cartwright [Cartwright, 2002]).

Description. General body colour and wings brownish. Wings similar to those of C. ukarumpana (fig. 7). Length of forewing: male 5.9 mm. Forewing with forks 1, 2, 3 and 5 present, Rs slightly sinuous or curved, slightly thickened, basad of discoidal cell.

Male. Segment IX anterior margin in lateral view, with rounded extension anteroventrally (fig. 91), ventral process small, sub-triangular, situated basally on segment IX (figs 91, 92), in lateral view, length about 0.6 times width (fig. 91). Segment X lateral lobes sclerotised, short, slender, with dorsal and ventral branches, dorsal branch directed dorso-laterally, ventral branch directed ventro-posteriorly, with sensilla not discerned (figs 91, 93). Phallus with two slender spines included subapically (figs 92, 93). Inferior appendages short, robust, acute apices angled dorso-mesally (figs 91–93), in lateral view, angled at about 45° to horizontal, subquadrate, length about 2.5 times width, broadest in distal half, tapered slightly basally (fig. 91), in ventral view, appear sub-ovate, length about 2.8 times width (fig. 92).

Female. Unknown.

Etymology. Bicornis – Latin for two horned, two pronged (paired curved, dorsal branches of lateral lobes on segment X).

Remarks. Chimarra bicornis is known only from the holotype male in north-east PNG.