Dilar clavatus sp. nov.

(Figs 3, 16–19)

Diagnosis. The new species is characterized by the forewing with inconspicuous brown markings, the male genital sclerites with gonocoxite 9 nearly spindle-shaped with acutely pointed base and obtuse tip, the gonocoxite 10 swollen at base and slenderly elongated with incurved spinous tip, and the fused gonocoxites 11 medially with a rod-shaped projection.

Description. Male. Body length 2.6–3.0 mm; forewing length 4.5–4.8 mm, hindwing length 4.0– 4.2 mm.

Head generally brown, with pale yellow setose tubercles. Vertex brown. Frons yellow, medially with a dark brown rounded marking. Compound eyes blackish brown. Antenna brown, flagellum pectinate on most flagellomeres, medial branches much longer than those on both ends, longest branch nearly 4.0 times as long as corresponding flagellomere, distal seven flagellomeres simple.

Thorax brown, meso- and metathorax yellow, mesonotum brown, paler on posterior, metanotum yellow. Legs pale brown, femora and tibiae dark brown at their tips. Wings hyaline, slightly smoky brown. Forewing 3.0 times as long as wide, with dense inconspicuous pale brown markings, arranged irregularly; longitudinal veins pale yellow, interrupted by numerous brown spots; crossveins brown. Hindwing 2.6 times as long as wide, almost immaculate.

Abdomen pale brown. Tergum 9 in dorsal view with an arcuate anterior incision, a nearly U-shaped posterior incision, leaving a pair of broad hemitergites, which are obtuse distally and densely haired. Sternum 9 (Fig. 17) subtrapezoidal, membranous, only half of the length of tergum 9, membranous. Ectoproct subtriangular (Figs 16–17, 19), in dorsal view with an arcuate anterior incision, posteroventrally with a pair of nearly semicircular and flattened projections (Fig. 17); posterodorsally with a pair of unguiform projections (Fig. 16). Gonocoxite 9 (Fig. 16) nearly spindle-shaped, strongly inflated on proximal half, with acutely pointed base, slightly narrowed on distal half, with obtuse tip. Gonocoxite 10 (Fig. 17) longer than gonocoxite 9, nearly spoon-shaped on proximal half, slenderly elongate on distal half, with incurved and spinous apex. Fused gonocoxites 11 (Fig. 17) nearly W-shaped, medially with a rod-shaped projection, laterally connecting to proximal half of gonocoxites 9 and 10. Hypandrium internum absent.

Female. Unknown.

Materials examined. Holotype ♂, Ceylon, Anu [radhapura] Dist [rict]. Irrigation Bungalow Padaviya, 180 ft [55 m], 27.II–9.III.1970, Davis & Rowe (PCWH) . Paratypes 2♂, same data as holotype (PCWH); 1♂, Ceylon, Anu [radhapura] Dist [rict]. Wildlife Soc. Bungalow Hunuwilagama, Wilpattu, 200 ft [61 m], 10–19.III.1970, Davis & Rowe (PCWH) .

Distribution. Sri Lanka (North Central).

Etymology. The species name “ clavatus ” refers to the peculiar configuration of the fused male gonocoxites 11, which medially has a rod-shaped projection.

Remarks. A significant feature of Dilar clavatus sp. nov. is the fused male gonocoxites 11 medially with a rod-shaped projection (Figs 16, 17). Of all known species of Dilar, only two others have a similar structure, namely Dilar nietneri and Dilar abnormis Zhang, Liu & Winterton (Zhang et al. 2016). D. clavatus sp. nov. and D. nietneri both from Sri Lanka have similar male fused gonocoxites 11, which medially bear a rod-shaped projection (Figs 16, 27), but D. abnormis from Thailand has a pair of long hook-like projections (Zhang et al., 2016: fig. 11).

Accordingly, D. clavatus sp. nov. and D. nietneri appear to be closely related, but the male gonocoxites 9 and 10 of these two species have obvious differences. In D. clavatus, the male gonocoxite 9 is spindle-shaped, shorter than gonocoxite 10 (Fig. 16), and the distal half of male gonocoxite 10 is slenderly elongate with spinous apex (Fig. 17). However, in D. nietneri the male gonocoxite 9 is nearly rectangular, longer than gonocoxite 10, and the male gonocoxite 10 is falcate bean-shaped (Fig. 27).