Rauserodes epiproctalis ( Zwick, 1997 )

Huo, Qing-Bo, Chen, Zhen-Ning, Kong, Xiang-Bo & Du, Yu-Zhou, 2020, New records and a confirmation of three perlodid species in China, with additional notes and images of Rauserodes epiproctalis (Zwick, 1997) (Plecoptera: Perlodidae), Zootaxa 4808 (3), pp. 455-474 : 461-467

Rauserodes epiproctalis ( Zwick, 1997)

Rauserella epiproctalis: Zwick, 1997 , Ephemeroptera & Plecoptera , Biology-Ecology-Systematics: 489–496.

Rauserodes epiproctalis: Zwick, 1999 , Aquatic Insects, 21 (3):168.

Male: Micropterous, forewing length ca. 3 mm, hindwing length 3 mm, body length 14 mm. General color reddish brown to brown ( Fig. 12 ). Head mostly yellowish to light brown, laterally frontoclypeus brown and median occiput with several dark brown spots. Antennae and palpi dark brown. Pronotum disc dark brown, with a yellowish medial longitudinal stripe, with several dispersed yellow spots near its lateral margin ( Fig. 13 ). Legs yellowish to brown; wings smoky gray, bearing fine hairs on the surface, pores on veins and area around anal veins larger than the others; veins brown and thick ( Fig. 14 ). Abdomen brown or dark brown, slightly sclerotized, bearing yellowish long hairs; terga 1–6 with a large triangle dark spot medially; terga 1–9 with proximal dark spots and small, round lateral sclerites ( Figs. 12 , 15 , 16 ).

Tergum 7–9 without median dark spots ( Fig. 15 ). Tergum 8 with a patch of developed median basiconica sensilla ( Fig. 15 ). Tergum 9 posteriorly membranous, bearing sensilla basiconica of two types, separate or connected by irregular sclerites on the anterior or posterior of the membranous area ( Fig. 17 ). Tergum 10 with a pair of dark lateral spots, and a dark longitudinal median band, sometimes lacking not; posterior margin heavily sclerotized, curved upward and fully covered with sensilla basiconica ( Fig. 18). Paraprocts triangle, inner margin membranous and bearing fine spines, sclerotized apically and basally ( Fig. 19 ).

The membranous epiproct divided into two lobes: the basal lobe swollen, dorsally with a pair of short process near tergum 10, and a pair of fingerlike process extended from the apex; apical lobe short, approximately rhombic in shape, blunt apically ( Fig. 20 ). Aedeagus ( Fig. 21 ) a membranous tube with narrow base, with a subterminal ring-like swelling which is roughened by cuticular asperities on its outer face; apex heart-shaped and smooth, as described by Zwick (1997).

Female: Macropterous, forewing length 21 mm, hindwing length 18 mm, body length 19 mm. Coloration of head, thorax dark brown to black ( Fig. 22 ). Area between hind ocelli and median occiput with a yellow spot; occiput with lateral rugosities; palpi light brown. Pronotum disc dark brown, rugosities present laterally, and a yellowish longitudinal band among the centerline ( Fig. 23 ). Legs brown. Wings smoky gray and translucence; veins dark brown ( Fig. 24 ). Some individuals have more cross veins between subcosta and radius veins of forewing, or additional branches of the anal veins of hindwing ( Fig. 25 ). Abdomen brown; subgenital plate short and sclerotized, variable; median posterior margin heavily sclerotized and bilobate ( Fig. 26 ).

Egg: See Zwick (1997). No mature eggs were present in the below material.

Nymph: Unknown.

Material examined: 10 ♂♂, 4 ♀♀ ( ICYZU), China, Qinghai Province, Haibei Tibetan Autonomous Prefecture, Menyuan Hui Autonomous County, Liuhuanggou , 3720 m, 101°21'16"E, 37°46'22"N ( UTM: 47 N 707365 4183215), 2019-VIII-14, leg. Wang Lu-Yu, Chen Zhen-Ning ; 4♂♂, 2 ♀♀ ( CAF), Liuhuanggou , 101°18'8"E, 37°41'56"N ( UTM: 47 N 702967 4174901), 2019-VII-29, leg. Kong Xiang-Bo, Fang Jia-Xing, He Yun-Chuan .

Distribution: China (Qinghai Province).

Remarks. This species apparently inhabits pristine cool valley streams and nymphs occur under mats of instream vegetation and under rocks ( Fig. 27 ).

Figures

FIGURE 12. Rauserodes epiproctalis (Zwick, 1999), male habitus.

FIGURE 13. Rauserodes epiproctalis, head and pronotum of male, dorsal.

FIGURE 14. Rauserodes epiproctalis, wings of male. A: forewing; B: hindwing; C. hair and pores on wings..

FIGURE 15. Rauserodes epiproctalis, different patterns of male terminalia, dorsal view. A: fewer sensilla basiconia on tergum 8 and tergum 10 without median dark stripe; B: additional sensilla on tergum 8 and tergum 10 with a distinct median stripe

FIGURE 16. Rauserodes epiproctalis, male terminalia. A: lateral view; B: ventral view.

FIGURE 17. Rauserodes epiproctalis, tergum 9 of male, with different types of sensilla basiconia, dorsal view.

FIGURE 19. Rauserodes epiproctalis, male paraprocts. A: ventral view; B: back view.

FIGURE 20. Rauserodes epiproctalis, epiproct. A: dorsal view; B: lateral view; C: ventral view.

FIGURE 21. Rauserodes epiproctalis, aedeagus.A: dorsal view; B: lateral view; C: ventral view.

FIGURE 22. Rauserodes epiproctalis, female habitus.

FIGURE 23. Rauserodes epiproctalis, head and pronotum of female.

FIGURE 24. Rauserodes epiproctalis, wings of female. A: forewing; B: hindwing.

FIGURE 25. Rauserodes epiproctalis, veins of female. A: illustrated by Fig. 24; B: modified from Zwick (1997). Differences in cells of wings are marked in red.

FIGURE 26. Rauserodes epiproctalis, female terminalia, ventral view. A: subgenital plate (median sclerite smaller); B: subgenital plate (median sclerite larger).

FIGURE 27. Liuhuanggou, Qinghai Province, China, the collecting location on the high-altitude Tibetan Pleateau of Rauserodes epiproctalis, and the adults mating under the rocks (photo provided by Wang Lu-Yu).