Dilar japonicus McLachlan, 1883

Zhang, Wei, Liu, Xingyue, Aspoeck, Horst, Winterton, Shaun L. & Aspoeck, Ulrike, 2014, Species of the pleasing lacewing genus Dilar Rambur (Neuroptera, Dilaridae) from islands of East Asia, Deutsche Entomologische Zeitschrift 61 (2), pp. 141-153 : 142

Dilar japonicus McLachlan, 1883 Figs 1, 7-12

Dilar japonicus McLachlan, 1883: 220. Type locality: Japan (Fukushima).

Dilar nohirae Nakahara, 1914: 297. Type locality: Japan (Nara).

Dilar japonicus Dilar japonicus var. gracilis Kuwayama, 1921: 71. Type locality: Japan (Fukushima).

Diagnosis.

This species is characterized by the forewings with numerous pale brown markings, and the male ectoproct in dorsal view with three projections at tip which is sparsely haired.

Description.

Male. Body length 4.3-5.3 mm; forewing length 10.0-11.4 mm, hindwing length 8.8-9.4 mm.

Head pale yellowish brown, with pale yellow setose tubercles. Compound eyes blackish brown. Antenna with ca. 29 segments, pale yellowish brown, pedicel with brown annular stripes, flagellum unipectinate on most flagellomeres, medial branches much longer than those on both ends, longest branch nearly 3.0 times as long as relevant flagellomere, but branch of 1st flagellomere short and dentate, distal seven flagellomeres simple.

Prothorax pale yellow, pronotum pale yellowish brown, with anterior margin and posterolateral corners pale yellow, medially with a pair of ovoid markings; mesothorax pale yellowish brown, mesonotum dark brown on anterior and lateral margins; metanotum pale yellowish brown, slightly darker on lateral margins. Legs pale yellowish brown, femora blackish brown at tip. Wings hyaline, slightly smoky brown, with numerous brown spots. Forewing ~2.1 times as long as wide, densely spotted, with markings on proximal half much darker, arranging as transversely arcuate pattern, a broad immaculate area present on either side of median nygma; two nygmata present on proximal and median portion of forewing, median one much larger than proximal one. Hindwing ~2.0 times as long as wide, slightly paler than forewing, with similar marking pattern; one nygma present at middle. Veins pale brown, crossveins much paler than longitudinal veins. Forewing with trichosors present along wing margin between R and CuA; Rs with three main branches; MP with two main branches; two gradate crossveins present at middle. Hindwing with trichosors present along wing margin between R and CuA; Rs with three main branches.

Abdomen pale yellow, pregenital segments dorsally yellowish brown. Ninth tergite in dorsal view with an arcuate anterior incision and a deeply V-shaped posterior incision, leaving a narrow median portion and a pair of subtriangular hemitergites, which are obtuse distally and densely haired; in lateral view broad, with straight ventral margin and arcuate posterior margin. Ninth sternite obviously shorter than ninth tergite, truncately posteriad. Ectoproct in dorsal view with three projections at tip which is sparsely haired, posteroventrally with a pair of subsemicircular and flattened projections, a pair of bifid unguiform projections and a pair of short, feebly sclerotized, digitiform projections. Ninth gonocoxite with anterior half broadly spoon-shaped and with posterior half slenderly elongate and curved posteroventrally; tenth gonocoxite slenderly elongate, much longer ninth gonocoxite, with incurved base and spinous tip, medially with a lobe connecting to ninth gonocoxite; gonarcus beam-shaped, slightly expanded on both ends, laterally connecting to base of ninth gonocoxites. Hypandrium internum nearly trapezoidal, with lateral margins slightly arcuate.

Female. Body length 6.5 mm; forewing length 14.0 mm, hindwing length 12.7 mm.

Seventh sternite (Fig. 11) in lateral view subtrapezoidal, in ventral view nearly rectangular and slightly convex on posterior margin. Eighth abdominal segment ventrally without subgenitale. Bursa copulatrix (Fig. 11) with colleterial gland tubular and elongate, sinuate medially; basal part of bursa copulatrix sac-like in lateral view and nearly ovoid in ventral view, posteriorly slightly sclerotized on both sides; bursal accessory gland not observed. Ectoproct rather small, ovoid.

Materials examined.

Holotype ♂, "Japan, Fukushima [37°44'N, 140°28'E]/28.7.[18]81/Type/japonicus McL[achlan]" (BMNH). JAPAN: 1f#, Aomori, Tsuta-onsen [40°13'N, 140°30'E], 6.VIII.1953, K. Sadanaga (NIAES); 1♀, Gunma, Kuni-mura [36°38'N, 138°38'E], 10.VIII.1992, K. Konishi (NIAES); 1♂, Gunma [36°23'N, 139°03'E], 3.VIII.1960, K. Fujimoto (NIAES); 1♂, Shikoku, Mt. Sara [33°45'N, 133°30'E], 27.VII.1955, Toshiro Yano (NIAES); 1♂, Yamanashi, Shojiko [35°29'N, 138°36'E], 23.VII.1969, P. H. Hasegawa (NIAES); 1f#, Fukushima, Yokomuki Onsen [37°53'N, 140°33'E], 26.VII.1964, H. Kobayashi (NIAES).

Distribution.

Japan (Honshu, Kyushu, Shikoku).

Remarks.

This species appears to be very closely related to Dilar hikosanus Nakahara in having similar wing marking patterns and male genitalia. The only difference between these two Japanese species refers to the male ectoproct. In Dilar japonicus , the male ectoproct distally bears three projections which are sparsely haired. However, in Dilar hikosanus the ectoproct has a pair of parallel projections which are truncate and serrate at tip. Primarily we even suspected Dilar hikosanus to be conspecific with Dilar japonicus due to the remarkable similarity of the external morphological and genitalic characters. Nevertheless, we examined several males of both species, and the difference of the male ectoproct mentioned above is stable. Therefore, we consider Dilar hikosanus and Dilar japonicus to be different species. Dilar japonicus is a widely distributed species in Honshu, Kyushu and Shikoku, while Dilar hikosanus seems to be endemic to Kyushu, and more exactly to the Mt. Hikosan.