Chimarra laensis, Cartwright, 2020

Cartwright, David, 2020, A review of the New Guinea species of Chimarra Stephens (Trichoptera: Philopotamidae), Memoirs of Museum Victoria 79, pp. 1-49 : 31-33

Chimarra laensis sp. nov.

Figures 98, 99

Holotype. Male (dried, pinned specimen CT-369 figured), PNG, Morobe District, Lae, Singnawa River , 30 m (6° 45' S, 147° 10' E), 3 April 1966, lt tr Kunai grass, O.R. Wilkes ( BPBM).

Diagnosis. The male of C. laensis can be separated from all other New Guinea species, including C. aiyura , by the combination of the irregular, almost broadly serrated meso-ventral margin on the inferior appendages and the absence of a flange in the basal half of the lateral lobes of segment X, in dorsal view.

Description. General body colour and wings light brownish. Wings similar to those of C. ukarumpana (fig. 7). Length of forewing: male 4.9 mm. Forewing with forks 1, 2, 3 and 5 present, Rs very slightly sinuous or curved, thickened, basad of discoidal cell.

Male. Segment IX anterior margin in lateral view, anteroventrally broadly angular or sub-truncate, ventral process short, basal to distal margin of segment IX, in lateral view, keel-like, length about 0.6 times basal width, preanal appendages, slightly laterally compressed, appear rounded in lateral view (fig. 98), in dorsal view appear ovate (fig. 99). Segment X lateral lobes laterally compressed in basal three quarters, appear truncate distally, with sensilla not discerned (figs 98, 99), in lateral view robust (fig. 98), in dorsal view lateral lobes appear slender. Phallus with two short, slender spines included subapically and spine-like ventral process (apex of phallobase?; fig. 99). Inferior appendages short with apices acute, angled slightly posteromesally (figs 98, 99) in lateral view, broadest in basal half, tapered slightly distally, angled at about 45° to horizontal, length about 3.6 times width, dorsal margin slightly convex and ventral margin in basal half with three small projections with slight concavities between them, slightly concave in distal half (fig. 98), in dorsal view mesal and lateral margins slightly curved (fig. 99).

Female. Unknown.

Etymology. Laensis – named for the type locality (Lae).

Remarks. Chimarra laensis is known from the type locality in north-east PNG. I realise that the type specimen may not be in good shape, and the illustration is very incomplete, but the shape of the inferior appendage is distinctive in lateral view.

Figures

Figures 94–102. Chimarra spp.; 94, Chimarra sinuosa Kimmins, male, genitalia, lateral. 95–97, Chimarra karamui sp. nov., male, holotype, genitalia; 95, lateral; 96, ventral; 97, dorsal. 98–99, Chimarra laensis sp. nov., male, holotype, genitalia; 98, lateral; 99, dorsal. 100–102, Chimarra sappela sp. nov., male, holotype, genitalia; 100, lateral; 101, ventral; 102, dorsal.