Sisyra arcuata, Yang & Zheng & Liu, 2024

Yang, Ying, Zheng, Yuchen & Liu, Xingyue, 2024, New species of spongillafly genus Sisyra Burmeister, 1839 (Neuroptera: Sisyridae) from China and Laos, Zoological Systematics 49 (2), pp. 129-142 : 130-133

Sisyra arcuata sp. nov. ( Figs 1–2 )

Diagnosis. Basal 15 flagellomeres yellow, then medial 10 flagellomeres black, and remaining distal flagellomeres pale. Wings shallow infuscate. Forewing with a longitudinal brown band present along distal half of costal vein and RA, extending to bases of RP branches; a subtriangular dark brown spot present on basal part of ScP and MP. Male sternum 9 with a pair of slender and slightly curved processes at distal 1/3. Gonocoxites 9 curved medially in dorsal view; dorsally with two projections respectively at distal 1/3 and apex, with distal one much longer in lateral view; ventrally with a large bifurcated projection. Gonocoxites 11 with a medial projection in dorsal view.

Description. Male. Body length 2.3–2.6 mm, forewing length 3.6–3.7 mm and width 1.3–1.4 mm, hindwing length 2.9– 3.1 mm and width 1.2–1.4 mm.

Head mostly brown, covered with many long setae; area between scape yellow; compound eyes prominent and black. Scape yellow, covered with densely long, stiff setae, swollen medially, about twice as long as wide; pedicel yellow, slightly longer than flagellomere; flagellum incomplete, at least 34 segments, basal 15 flagellomeres yellow, then medial 10 flagellomeres black, and remaining distal flagellomeres pale; each covered with many long setae. Maxillary and labial palpi brown; distal segment of maxillary palpus long triangular.

Thorax brown, covered with many long pale setae. Legs slender and pale; protibiae and protarsi, and distal 1/3 of metafemora brown, meso- and metacoxae dark brown; covered with densely long setae; tarsomere 1 as long as total length of tarsomeres 2–4; pretarsal claws simple.

Wings slightly infuscate; veins mostly pale. Forewing ovoid, distally rounded, costal space broadened basally; trichosors present along distal margin; basal half of costal space and medial portion of subcostal space immaculate; a longitudinal brown band present along distal half of costal vein and RA, proximally extending to bases of RP branches, with several slender longitudinal brown stripes on second radial cell and first RP cell; a subtriangular dark brown spot present on basal part of ScP and MP; pterostigma indistinct; costal space with 10 crossveins proximad pterostigma, mostly dark brown; two scp–ra crossveins present basally and distally; RA with five pectinate and simple branches distally; RP with three main branches; two ra–rp crossveins present; MA dichotomously branched on distal part; one rp–ma crossvein present; MP branched into MP1 and MP2, both branches bifurcated; one ma–mp crossvein present; CuA with five to six pectinate and simple branches; three mp–cua crossveins; CuP, A1, A2 and A3 simple; one cua–cup, one cup–a1, and one a1–a2 present. Hindwing ovoid, distally rounded; trichosors present along distal margin; pterostigma indistinct, with several crossveins; a longitudinal brown band present between distal half of costal vein and RA; costal space with six crossveins proximad pterostigma, mostly brown; two scp–ra crossveins present basally and distally; RA with three pectinate and simple branches distally; RP with three main branches; one ra–rp crossveins; MA dichotomously branched distally; MP branched into MP1 and MP2, both branches bifurcated; one ma–mp crossvein present, interrupted centrally by a rounded hyaline spot; CuA with five to six pectinate and simple branches; one mp–cua crossveins present; CuP, A1 and A2 simple; one cua–cup, one cup– a1, one a1–a2 present.

Abdomen brown; pregenital segment with small tergum and larger sternum, covered with many long setae. Tergum 9 subrectangular in lateral view, ventral margin concave dorsally, with many long setae. Sternum 9 well developed, strongly protruding posteriad, slightly longer than gonocoxites 9, approximately 3.5 times as long as wide in lateral view; anterodorsal portion largely concaved in lateral view; anteroventral margin concaved; dorsal margin sinuous; caudal margin slightly concaved anteriorly; a pair of slender and distally curved processes present at distal 1/3 on dorsal portion; ventral portion bearing sparsely long setae; a densely setose region present along dorsal portion of sternum 9. Gonocoxites 9 curved medially in dorsal view; dorsally with two projections respectively at distal 1/3 and apex, with distal one much longer; ventrally with a large bifurcated projection; a thick spinous bristle present at tip. Gonocoxites 11 slightly curved, medially with a projection, directed posteriad with tapering tip; gonostyli 11 paired, each Y-shaped in caudal view, dorsal half with membranous lobe. Ectoproct covered with dense long setae, ovoid in lateral view; callus cerci with four trichobothria. Hypandrium internum composed of a pair of broadly subtriangular lobes, V-shaped in dorsal and caudal view.

Female. Body length 2.9 mm, forewing length 3.9 mm and width 1.3 mm, hindwing length 3.5 mm and width 1.3 mm. Abdomen brown; pregenital segment with small tergum and larger sternum, covered with many long setae. Tergum 8 covered with many short setae; dorsally separated. Gonapophyses 8 degraded into a small sclerite, posteriorly concaved, nearly 3.5 times as long as wide. Tergum 9 covered with short setae, slightly longer than wide, anteriorly tapering. Gonoxoxites 9 covered with short setae, nearly 3.5 times as long as wide, slightly rounded, distally curved. Ectoproct covered with long setae; posteroventrally rounded and tapering; callus cerci with 5–6 trichobothria.

Type material. Holotype ♂, Laos: Bolikhamxai, Pak Kading (130 m), 18°25′N, 104°28′E, light trap, 31 March 2016, Xingyue Liu leg. ( CAU) . Paratypes. 1♀, same data as holotype ( CAU) ; 1♂, Laos: Xaignabouli, near Hatdai (250m), 18°29′N, 101°28′E, 26 March 2016, Xingyue Liu leg. ( CAU) .

Distribution. Laos (Bolikhamxai, Xaignabouli).

Etymology. The specific epithet “ arcuata ” refers to the distinct dark longitudinal band, which is arcuate along the distal part of several longitudinal veins on the forewing in the new species.

Remarks. This new species is similar to S. nobilia sp. nov. by having similar wing marking pattern. However, in S. arcuata sp. nov., the male sternum 9 has a pair of slender processes at distal 1/3 of dorsal portion, the male gonocoxites 9 are curved medially in dorsal view, with several slender projections on dorsal and ventral portions, and the male gonocoxites 11 has a median projection; while in S. nobilia sp. nov., the male sternum 9 lacks any projection, the male gonocoxites 9 are straightly directed in dorsal view, proximally separated into a huge lobe, and the male gonocoxites 11 medially lacks any projection. Besides, S. nobilia sp. nov. and S. arcuata sp. nov. can be easily differentiated from S. stenoloma sp. nov. and S. yunana by the forewing characters. In the former two species, the forewing costal space is broadened basally and has a subtriangular dark brown spot on basal part of ScP and MP. However, in the latter two species, the forewing costal space is narrowed and immaculate.

Figures

Figure 1. Sisyra acuata sp. nov. A, C, E–F. Holotype, male, Laos (Bolikhamxai). B, D. Paratype, female, Laos (Bolikhamxai). A–B. Habitus, lateral view; C–D. Head, ventral view (left) and dorsal view (right). E–F. Fore- and hindwing. Scale bars=1.0mm.

Figure 2. Sisyra acuata sp. nov. A–B. Male genitalia, lateral view. C–D. Male genitalia, dorsal view. E–F. Male genitalia, caudal view. G–H. Female genitalia, lateral view. Scale bars =0.1 mm.