Wesmaelius ravus ( Withycombe, 1923 )

Zhao, Yang, Tian, Yanlin & Liu, Zhiqi, 2017, New data on brown lacewing genus Wesmaelius Krüger, 1922 from China (Neuroptera, Hemerobiidae), with a key to Chinese species, Zootaxa 4273 (1), pp. 19-30 : 24-25

Wesmaelius ravus ( Withycombe, 1923)

( Figs. 2 , 12–19 )

Boriomyia rava Withycombe, 1923: 202 .

Diagnosis. This species is characterized by the yellowish-brown head with all the areas before the antennae dark brown; brown longitudinal stripe present in the middle of vertex. Forewing hyaline with no obvious spots and hind wing immaculate, with 1r-rs absent, only 2r-rs present. Male: anteroventral edge of ectoproct developed upwards as a strong arm; basal apophyseal lamella of parabaculum laterally splayed from dorsal view and supraapophyseal plate laterally splayed. Femal: subgenitale consist of a pair of rhombic lamella, which separate mutually.

Measurements. Forewing length 7.2–7.6 mm, width 3.1–3.3 mm. Hind wing length 6.1–6.3 mm, width 2.7– 2.9 mm. Body length 5.7–7.2 mm.

Description. Head. Yellowish-brown. All the areas before the antennae dark brown, a subtriangular brown spot present near the hind margin of antennal socket, brown longitudinal stripe present in the middle of vertex. Antennae amber, scape and pedicel brown, obviously darker than flagellum, with more than sixty-five segments. Eyes black with a metallic luster.

Thorax. Yellowish-brown, with brown longitudinal stripes along the sides of pronotum and mesonotum, scutum of metanotum obviously brown. Legs yellowish-brown with no spots and last tarsi darker than others.

Wings ( Fig. 2 ). Forewing ovoid, yellowish-brown, hyaline with no obvious spots. Veins brown with transparent intervals, crossveins of gradate series all brown. Anterior radial trace bearing 3 ORB’s; ORB3 forked into 3–4 branches, with 2 r–rs. M simple with 2 branches. CuA forked into 5 braches after the inner gradate series and CuP simple. Four gradate series, inner gradate series 3 crossveins; middle 6; outer 6–8 and cubitus 3. Hind wing ovoid with outer margin slightly pointed, pale yellowish-brown, hyaline and immaculate. Veins pale yellowish-brown. Rs with 5 branches, 1r-rs absent, only 2r-rs present. M forked into 2 branches. CuA 5 branches and CuP simple. Two gradate series, inner gradate series 2 crossveins; and outer 7.

Male terminalia ( Fig. 12 ). 8th tergite rectangle, posteroventral edge declining and not include the spiraculae. 9th tergite partly fused with ectoproct, dorsal of hind margin slightly depressed forward. Ectoproct developed, extending backward; anteroventral edge developed upwards as a strong arm, with a blunt end, densely covered with small spines. Mediuncus of gonarcus ( Fig. 13–14 ) strong, tapering distally; paramediuncus strong, curved inward from dorsal view, with apex slightly pointed. Parabaculum ( Fig. 15–16 ) special, terminal lobe separated from half, tapering gradually and sparsely covered with small spines; base of apophyseal lamella laterally splayed from dorsal view; supraapophyseal plate laterally splayed, more than half length of the parabaculum, with a small upward hook in the end. Hypandrium internum ( Fig. 17 ) approximate triangle from ventral view.

Female terminalia ( Fig. 18–19 ). 9th tergite approximate "L" shaped from lateral view, lateral extended backwards. gonapophyses laterales developed, hind margin obviously exceed the hind margin of ectoproct. Ectoproct ovoid, middle of the hind margin slightly depressed. Subgenitale consist of a pair of rhombic lamella, which separate mutually.

Distribution. Europe, Japan, Transbaikalian Russia and China (Hubei, Inner Mongolia)

Material examined. CHINA: 3♂, Hubei province, Yichang city, Xingshan county, Longmen. 28.ix.1994, Chikun Yang ( CAU) . 1♀, Inner Mongolia Autonomous Region, Alxa Left Banner , Helan Mountains. 31.vii.2010. Yanlin Tian ( CAU) .

Remarks. This species was found in United Kingdom by Withycombe with two male specimens and Nakahara found female specimens from Japan in 1956. This is the first time for the species reported in China. This species seems related to W. mortoni based on the forewing; however, it can be distinguished from W. mortoni by the absence of the prominent dorsal tuft of hairs at the apex of abdomen and the more elongate and slender ectoproct with the turner inwards and upwards.

Figures

FIGURE 2. Wings. 2. W. ravus (Withycombe, 1923).

FIGURES 12 – 19. W. ravus (Withycombe, 1923). 12. Male terminalia, lateral view; 13. Gonarcus, lateral view; 14. Ditto, dorsal view; 15. Parabaculum, lateral view; 16. Ditto, dorsal view; 17. Hypandrium internum, ventral view. 18. Female terminalia, lateral view; 19. Ditto, ventral view. Scale bars: 0.5 mm.