Chimarra trigona sp. nov. Figures 35–37 Holotype. Male (dried, pinned specimen CT-354 figured), PNG, Morobe Province, Wau, 1200 m, about 7° 20' S, 146° 43' E, Malaise Trap, 17 August 1961, J. Sedlacek (BPBM). Diagnosis. The male of C. trigona is most similar to C. toliana but can be separated from it and all other New Guinea species by the shape of the inferior appendages in lateral view, with the basal half robustly triangular and distal half relatively slender. Description. Male. General body colour and wings light brownish. Wings similar to those of C. ukarumpana (fig. 7). Length of forewing: male 4.3 mm. Forewing with forks 1, 2, 3 and 5 present, Rs moderately sinuous or curved, moderately thickened basad of discoidal cell. Male. Segment IX anterior margin in lateral view, with angular extension ventrally (fig. 35); ventral process short with apex extending past distal margin of segment IX (figs 35, 36), in lateral view length about 2.5 times width, apex acute (fig. 35), in ventral view triangular, pointed distally (fig. 40); preanal appendages rounded apically (figs 35, 36). Segment X mesal lobe indistinct, lateral lobes elongate with sensilla not obvious (fig. 37), in lateral view lateral lobes robust, tapered slightly towards apices (fig. 35), in dorsal view slender, dilated slightly in distal half with rounded apices (fig. 37). Phallus with two slender spines embedded subapically (fig. 35). Inferior appendages broadest basally, narrowed near middle, tapered distally, apices acute, directed posteromesally (figs 35–37), in lateral view angled at about 45° to horizontal, broadly triangular in basal half, slender in distal half (fig. 35), in ventral view angled at about right angles basomesally (fig. 36). Female. Unknown. Etymology. Trigona – Latin for triangular, having three corners (inferior appendages). Remarks. Chimarra trigona is known only from the type locality in north-east PNG.

Published as part of Cartwright, David, 2020, A review of the New Guinea species of Chimarra Stephens (Trichoptera: Philopotamidae), pp. 1-49 in Memoirs of Museum Victoria 79 on page 14, DOI: 10.24199/j.mmv.2020.79.01, http://zenodo.org/record/8065297