Dilar marmoratus (Banks)

Zhang, Wei, Liu, Xingyue, Winterton, Shaun L., Aspöck, Horst & Aspöck, Ulrike, 2016, A review of the pleasing lacewing genus Dilar Rambur (Neuroptera, Dilaridae) from Southeast Asia, Zootaxa 4105 (2), pp. 124-144 : 134-135

Dilar marmoratus (Banks)

( Figs. 6 , 30–33 )

Rexavius marmoratus Banks, 1931b: 385 . Type locality: Thailand (Nakhon Si Thammarat).

Diagnosis. This species is characterized by the forewings with reduced dark markings except for the discontinued brownish marginal stripes, the male gonocoxite 9 slenderly elongate distad with a subrectangular lobe submedially, and the gonocoxite 10 spindled anteroposteriorly but strongly inflated medially.

Description. Male. Forewing length 9.5 mm, hindwing length 8.6 mm.

Head pale yellowish brown, with pale yellow setose tubercles. Compound eyes blackish brown. Antenna with ca. 27 segments, yellowish brown, pedicel with brown annular stripes, flagellum unipectinate on most flagellomeres, longest branch nearly 6.0 times as long as relevant flagellomere.

Prothorax pale yellow, pronotum yellowish brown, with anterior margin and posterolateral corners yellow, medially with a pair of ovoid markings; mesothorax pale yellowish brown, mesonotum dark brown on anterior and lateral margins; metanotum pale yellowish brown, slight darker on lateral margins. Legs yellowish brown, femora blackish brown at tip. Wings pale yellow, nearly hyaline. Forewing ~2.2 times as long as wide, with only a few brown spots on costal area, a big brown stripe present around median nygma, and a few discontinued brownish marginal stripes. Hindwing ~2.2 times as long as wide, pale yellow, almost immaculate. Veins pale brown, crossveins much darker than longitudinal veins.

Abdomen pale yellow, pregenital segments dorsally yellowish brown. Tergum 9 in dorsal view with an arcuate anterior incision and a deeply V-shaped posterior incision, leaving a pair of broad hemitergites, which are obtuse distally and densely haired. Sternum 9 much shorter than tergum 9, arcuately convex posteriad. Ectoproct in dorsal view with an arcuate anterior incision, posterodorsally with a pair of unguiform projections, posteroventrally with a pair of subovoid, flattened projections, a pair of bifid unguiform projections and a pair of short, feebly sclerotized, digitiform projections. Gonocoxite 9 anteriorly strongly inflated, posteriorly slenderly elongate and acutely pointed at tip, submedially with a nearly rectangular lobe; gonocoxite 10 spindled anteroposteriorly, but inflated medially; gonarcus beam-shaped, nearly U-shaped, laterally expanded on both ends and connecting to bases of gonocoxites 9. Hypandrium internum nearly trapezoidal, with lateral margins slightly arcuate.

Female. Unknown.

Materials examined. Holotype ♂, “Peninsular Siam, Nakon Sri Tamarat, Khao Luang [8°31′N, 99°47′E], 2000 ft [= 610 m], III.1929, H.M. Pendlebury” ( MCZ).

Distribution. Thailand (Nakhon Si Thammarat).

Remarks. This species could be a member of the Dilar hastatus species-group (see Zhang et al. 2015) based on the bifurcated male gonocoxite 9 and the U-shaped gonarcus laterally expanded on both ends. However, D. marmoratus differs from all other members of the D. hastatus group by the male gonocoxite 9 bifurcated into a long spinous and a short unguiform projections. In the other species of the D. hastatus group, if the male gonocoxite 9 is bifurcated, the two projections formed by the bifurcation are almost equal in length.

Figures

FIGURES 6 – 10. Adults of Dilar spp. 6. D. marmoratus (Banks), male holotype; 7. D. ohli Zhang, Liu, Aspöck & Aspöck, sp. nov., male holotype; 8. D. rotundatus Zhang, Liu & Winterton, sp. nov., male holotype; 9. D. sumatranus Zhang, Liu, Aspöck & Aspöck, sp. nov., male holotype; 10. D. zimmermannae Zhang, Liu, Aspöck & Aspöck, sp. nov., male holotype. Scale bars: 1.0 mm.

FIGURES 30 – 33. Dilar marmoratus (Banks). 30. Male genitalia, dorsal view; 31. Male genitalia, ventral view; 32. Male genitalia, lateral view; 33. Male ectoproct, caudal view. Scale bars: 0.5 mm.