Dilar nietneri Hagen, 1858

Li, Di, Aspöck, Horst, Aspöck, Ulrike & Liu, Xingyue, 2020, A review of the pleasing lacewing genus Dilar Rambur (Neuroptera, Dilaridae) from South Asia, Zootaxa 4743 (2), pp. 200-216 : 208-209

Dilar nietneri Hagen, 1858

( Figs 5–6 , 24–30 )

Dilar nietneri Hagen, 1858: 482 . Type locality: Sri Lanka.

Diagnosis. This species is characterized by the forewing solely with distinct dark brown stripes proximally, the male gonocoxite 9 distinctly longer than gonocoxite 10, and the male gonocoxites 11 medially with a rod-shaped projection.

Description. Male. Body length 6.0 mm; forewing length 11.5 mm, hindwing length 9.0 mm.

Head generally brown, with yellow setose tubercles. Vertex brown. Frons yellow. Compound eyes blackish brown. Antenna brown, flagellum pectinate on most flagellomeres.

Thorax yellowish brown; pronotum brown, meso- and metanotum yellowish brown, darker on scutellum and lateral margins. Legs yellow, femora dark brown at tip. Wings hyaline, slightly smoky brown. Forewing 2.3 times as long as wide, proximally with distinct dark brown stripes; longitudinal veins pale yellow, interrupted by numerous brown spots; crossveins brown. Hindwing 2.5 times as long as wide, almost immaculate.

Abdomen pale brown. Tergum 9 ( Fig. 26 ) 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 reduced, membranous. Ectoproct in dorsal view with an arcuate anterior incision, posteroventrally with a pair of nearly semicircular and flattened projections ( Fig. 28 ); posterodorsally with a pair of unguiform projections and a pair of short, feebly sclerotized, digitiform projections ( Fig. 28 ). Gonocoxite 9 ( Fig. 27 ) inflated, with outer margin on proximal half curved dorsally. Gonocoxite 10 ( Fig. 27 ) shorter than gonocoxite 9, bean-shaped, incurved and falcate. Fused gonocoxites 11 ( Fig. 27 ) nearly U-shaped, medially with a rod-shaped projection, laterally connecting to proximal half of gonocoxites 9 and 10. Hypandrium internum absent.

Female. Body length 7.8 mm; forewing length 12.8 mm, hind wing length 11.5 mm.

Sternum 7 in lateral view nearly trapezoidal, in ventral view nearly rectangular, with truncate posterior margin. Abdominal segment 8 narrower than segment 7 with convex posterior margin, without sclerotized subgenitale. Bursa copulatrix in lateral view rod-shaped, anteriorly with an additional rounded sac, in ventral view sac-like with a concave incision ( Figs 29, 30 ). Ectoproct small, ovoid.

Materials examined. Lectotype ♂ (herewith designated), Ceylon, Nietner / Syn-Typus von: Dilar nietneri Hagen 1858 / Rexavius nietneri Hg. / H. & U. Aspöck vid. 1967 / glue containing abdomen on paper-strip soluble in KOH (MFN). Paralectotype 1♀, Ceylon, Nietner S. / Syn-Typus von: Dilar nietneri Hagen 1858 / Rexavius nietneri Hg. / H. & U. Aspöck vid. 1967 / 634 (MFN). 1♀, Ceylon / Dilar nietneri , M[c] L[achlan] / McLachlan Coll. B.M. 1938–674. (NHM).

Distribution. Sri Lanka.

Remarks. Dilar nietneri was originally described by Hagen (1858) from Sri Lanka based on external morphology only. We re-described it based on the male lectotype and female paralectotype. It is notable that this species appears to be closely related to D. clavatus in having similar male fused gonocoxites 11, which medially have a rod-shaped projection (See Remarks, under Dilar clavatus sp. nov.).

Moreover, we examined one female specimen deposited in the Natural History Museum, London, which was previously identified as D. nietneri . But this specimen shows one distinct difference in having obvious dark brown markings covering almost the whole wing; however, in the lectotype and paralectotype, the wing shows obvious dark brown markings only on the proximal part or no obvious markings ( Figs 5, 6 ). Considering that available female specimens and related knowledge are scarce in Sri Lanka, and since this specimen may be from the same series from which the lectotype and paralectotype were selected, we currently treat this female specimen as D. nietneri .

Figures

FIGURES 5–6. Dilar nietneri Hagen, 1858, habitus. 5. male lectotype; 6. female paralectotype. Scale bar: 2.0 mm.

FIGURES 24–28. Dilar nietneri Hagen, 1858, lectotype male. 24. left forewing; 25. genitalia, lateral view; 26. tergum 9, dorsal view; 27. gonocoxites complex, ventral view; 28. ectoproct, dorsal view. gx9: gonocoxite 9; gx10: gonocoxite 10; gx11: fused gonocoxites 11; S9: sternum 9; T9: tergum 9. Scale bar: 1.0 mm (Fig. 24). Note: Figs 24–28 are after H. Aspöck & U. Aspöck unpublished.

FIGURES 29–30. Dilar nietneri Hagen, 1858, female. 29. genitalia, lateral view; 30. genitalia, ventral view. bc: bursa copulatrix; e: ectoproct; gx9: gonocoxite 9; T8–9: tergum 8–9. Scale bars: 0.2 mm.