Rapisma xizangense Yang, 1993

Liu, Xingyue, 2018, A review of the montane lacewing genus Rapisma McLachlan (Neuroptera, Ithonidae) from China, with description of two new species, Zoosystematics and Evolution 94 (1), pp. 57-71 : 60-63

Rapisma xizangense Yang, 1993 Figs 2, 3, 4, 6, 10

Rapisma xizangense Yang, 1993: 148. Type locality: China (Xizang: Jigong).

Rapisma zayuanum Yang, 1993: 149. Type locality: China (Xizang: Jigong).

Diagnosis.

Body and wing coloration greatly differed between males and females, generally brownish in males but greenish in females. Male head medially with dark markings on vertex, frons and clypeus, while female head immaculate. Antenna extremely short, less than 1/5 × forewing length. Male gonocoxites 9 paired, glabrous; each with an ovoid lobe, which dorsally bears a subtriangular accessory lobe, and with a slender, arcuately curved lateral arm; fused gonocoxites 11 generally arched, anteriorly shallowly concaved, posteromedially truncate, posterolaterally distinctly produced in dorsal view; gonostyli 11 having subtriangular dorsal lobe with a few short setae, and flat ventral lobe distally with a pair of tufts of long setae.

Description.

Male. Body length 13.0-14.0 mm; forewing length 19.0-20.0 mm, hindwing length 16.6-17.0 mm.

Head nearly semiglobular, largely retracted under prothorax, barely visible in dorsal view. Head yellowish brown; a narrow blackish stripe present around compound eye; vertex with a large brown marking, which is sometimes expanded, making vertex almost entirely brown; frons and clypeus medially with a brown marking that is much narrower than vertexal marking. Compound eyes dark brown; EI ratio 0.80. Antennae nearly moniliform, short, 4.4-4.5 mm long, with 27-28 flagellomeres; pale yellowish brown. Mandibles with tips black.

Thorax pale brown, meso- and metathorax slightly paler than prothorax, without any distinct markings. Legs yellowish; pretarsal claws reddish brown, proximally slightly produced.

Forewing brownish, with many small brown spots on crossveins. Trichosors absent. A proximal nygma present between RP+MA and MP, blackish. RP with 8-9 pectinate branches. Hindwing much paler than forewing, immaculate. A proximal nygma present between RP+MA and MP, blackish. RP with 6-8 pectinate branches.

Abdomen brown. Tergum 9 subtrapezoidal, with sparse short setae, posterior margin slightly concaved. Sternum 9 nearly as long as tergum 9, about 1.5 times as wide as long, subtrapezoidal. Ectoprocts nearly as long as tergum 9, ventrally divided into a pair of ovoid lobes; callus cerci present, slightly prominent. Gonocoxites 9 paired, glabrous; each with an ovoid lobe, which dorsally bears a subtriangular accessory lobe, and with a slender, arcuately curved lateral arm. Fused gonocoxites 11 generally arched, anteriorly shallowly concaved, posteromedially truncate, posterolaterally distinctly produced in dorsal view. Gonostyli 11 with a pair of dorsal lobes and a single ventral lobe; dorsal lobe subtriangular, with a few short setae; ventral lobe flat, distally with a pair of tufts of long setae.

Female. Body length 19.1-22.0 mm; forewing length 30.0-31.3 mm, hindwing length 26.0-26.2 mm.

Body and forewings in general greenish. Head without dark marking. Forewing sometimes with very indistinct trace of dark spots on a few crossveins.

Sternum 7 large, posteromedially with a narrow groove. Gonocoxites+gonapophyses 8 fused, broadly subtriangular, but divided by an arched transverse suture, notched distally, with a pair of digitiform projections and a weak median projection. Gonocoxites 9 nearly semicircular in lateral view, distally with tiny gonostyli 9; a pair of small setose ovoid gonapophyses 9 present posteriad gonocoxites 8 and beneath gonocoxites 9. Ectoprocts subtrapezoidal in lateral view, slightly broadened posteriad.

Materials examined.

Holotype male, China, Xizang, Chayu, Jigong [28°39.17'N, 97°27.21'E], 2300 m, 2.VII.1978, Guangwu Li (IZCAS). 1 female [holotype of R. zayuanum ], China, Xizang, Chayu, Jigong [28°39.17'N, 97°27.21'E], 2300 m, VIII.1982, Baohai Wang (IZ CAS); 1 male, China, Xizang, Chayu [ca. 28°39.17'N, 97°27.21'E], 3.VII.2011, Ye Liu (CAU); 1 female, China, Xizang, Chayu, Shaqiong [ca. 28°39.17'N, 97°27.21'E], 10.VII.2011, Ye Liu (CAU); 1 male, China, Xizang, Chayu [ca. 28°39.17'N, 97°27.21'E], 19.VII.1997, Chaodong Zhu (IZCAS).

Distribution.

China (Xizang).

Remarks.

This species appears to be closely related to Rapisma nepalense Barnard, 1981 from Nepal and Rapisma almoranum Barnard, 1981 from northern India in having similar yellowish brown body and medially punctuate head in males as well as male gonocoxite 9 posteriorly with glabrous, ovoid lobe. However, it can be distinguished from R. nepalense by the absence of large median dark spot on forewing and the relative broad lobe of male gonocoxite 9, and it differs from R. almoranum by the male gonocoxite 9 with a broad lobe and a subtriangular accessory lobe.

Rapisma xizangense is known for the remarkable sexual dimorphism of body and wing coloration ( Wang et al. 2013). It may be interesting to figure out whether its related species also have such feature. Barnard (1981) mentioned that R. almoranum might be conspecific to Rapisma viridipenne (Walker, 1853) from Nepal and northeastern India by having similar forewing marking patterns. So far, R. viridipenne is only known from female specimens and its forewing is greenish yellow (Barnard, 1981). If R. almoranum and R. viridipenne are confirmed to be same species, the sexual dimorphism of body and wing coloration should be also present in this species.