Isoperla kozlovi Zhiltzova, 1972

Chen, Zhi-Teng, Du, Si-Kai & Li, Xin-Tong, 2021, Description of a remarkable new species of Isoperla (Plecoptera: Perlodidae), with supplements for Isoperla kozlovi Zhiltzova, 1972 from China, Zootaxa 5027 (2), pp. 160-174 : 167-172

Isoperla kozlovi Zhiltzova, 1972

Figs. 12–20 .

Isoperla kozlovi Zhiltzova, 1972 . Nasekomye Mongolii, 1: 134; Zwick, 1973. Das Tierreich, 94: 416; Zhiltzova, 1995. Katalog tipovykh ekzemplyarov kollektsii zoologicheskogo instituta RAN. Vesnyanki ( Plecoptera ): 8; Teslenko, 2009. Aquat. Insects, 31(Supplement 1): 699; Surenkhorloo, 2009. Aquat. Insects, 31(Supplement 1): 711; Judson & Nelson, 2012. Zootaxa, 3541: 47; Hwang & Murányi, 2020. Anim. Syst. Evol. Diversity, 36(1): 49.

Material examined. 22 males, 32 females, China: Heilongjiang Province, Qiqihar City, Jianhua District, west of Peace Square , Nenjiang River ( Fig. 12 ), 47.36° N, 123.91° E, 137 m, 7.V.2019, Ming-Wei Li ( ICJUST) .

Adult habitus. Body generally brown from dorsal view, ventral surface generally pale ( Figs. 13–14 ). Triocellate; head mostly covered by brown stigma, ocellate area and area anterior to the three ocelli pale and oval ( Fig. 13C ). Antennae slender, generally pale brown, basal segments dark brown, slightly shorter than the body. Maxillary palps slender, four-segmented with a reduced apical segment; labial palps shorter, three-segmented with a thinner apical segment. Pronotum near rectangular, anterior margin arched; surface of pronotum with a pale median stripe, each lateral part with brown background color and with dark brown rugosities. Meso- and metanota wider than pronotum, mostly dark brown. Macropterous; wing membrane subhyaline, veins dark brown ( Fig. 13–15 ). In the forewing, 6 crossveins present between C and Sc; one extra crossvein present beyond Sc; RP with two branches; CuA with 4 branches; AA1 simple, AA2 forked. In the hind wing, 6 crossveins present between C and Sc; one extra crossvein presents beyond Sc; RP with two branches; anal area large and folded with 8 anal branches. Legs generally pale brown, base of tibiae dark brown; two tibial spurs present. Abdominal segments generally brown. Cerci slender, length subequal to the abdomen, pale to dark brown.

Male. Body length (from anterior of head to posterior of paraprocts) 9.5–10.5 mm (N = 22); forewings length ca. 10.5 mm, hindwings length ca. 8.0 mm. Abdominal terga 1–2 mostly membranous or pale brown; terga 3–6 with paired, small median pale spots; terga 3–8 evenly brown; terga 5–9 with more or less pale lateral surfaces ( Fig. 13 ). Tergum 9 with two posterior pale areas, size of the area variable among individuals ( Fig. 16 ). Tergum 10 with a pale, longitudinal median groove, length of the pale groove variable among individuals. Paraprocts long, triangular, strongly hooked and curved anteriorly over margin of tergum 10; lengths of the two paraprocts unequal in some specimens ( Figs. 16 , 17A , 18B ). Vesicle well developed, recessed, length subequal to its width, outline of vesicle pale, obscure ( Fig. 17B ). Sternum 9 broadly produced, expanded backwards with a round or truncate apex ( Fig. 18 ). Aedeagus in situ oval in shape, covered with spinules, ventroapically with two finger-shaped sclerotized lobes, dorsal surface unmodified ( Fig. 19 ).

Female. Body length (anterior of head to posterior of paraprocts) 10.5–12.0 mm (N = 32), forewings length ca. 10.0 mm, hindwing length ca. 9.5 mm. General color pattern similar to males ( Fig. 14 ). Tergum 10 similar to males, the median groove less distinct ( Fig. 14C ). Subgenital plate broad, extending from sternum 8 across most of sternum 9, slightly widened laterally, posterior margin varied from truncate to bilobed ( Fig. 20 ). Paraprocts long, triangular.

Habitat. This species was collected crawling across the sandy bank of the Nenjiang River ( Fig. 12 ), a large, perennial, braided, sand river. The sandy habitat made the specimens always accompanied with sand when collected by hand ( Fig. 12D ). Riparian vegetation of the collecting location was poorly developed, but the vegetation on the opposite shore was well developed ( Fig. 12 ).

Remarks. Adult morphology of the new specimens is generally identical to the drawings in Teslenko & Zhiltzova (2009). Color images are provided herein to better understand the Chinese population of this widespread Palaearctic species.

Figures

FIGURE 12. Isoperla kozlovi Zhiltzova, 1972, A. map of collecting site; B–C. habitat Nenjiang River, Heilongjiang Province, China; D. collected specimens temporarily stored in a plastic bottle. Photos taken by Ming-Wei Li.

FIGURE 13. Isoperla kozlovi Zhiltzova, 1972, A. male habitus, dorsal view; B. male habitus, ventral view; C. male head and pronotum, dorsal view.

FIGURE 14. Isoperla kozlovi Zhiltzova, 1972, A. female habitus, dorsal view; B. female habitus, ventral view; C. female terminalia, dorsal view.

FIGURE 15. Isoperla kozlovi Zhiltzova, 1972, A. right forewing of male, dorsal view; B. right hindwing of male, dorsal view.

FIGURE 16. Isoperla kozlovi Zhiltzova, 1972, A. male abdomen, dorsal view; B. male terminalia, dorsal view; C. male terminalia, caudal view.

FIGURE 17. Isoperla kozlovi Zhiltzova, 1972, A. male abdomen, lateral view; B. male sternum 8 and vesicle, ventral view.

FIGURE 18. Isoperla kozlovi Zhiltzova, 1972, A. male terminalia with truncate sternum 9, ventral view; B. another male terminalia with rounded sternum 9, ventral view.

FIGURE 19. Isoperla kozlovi Zhiltzova, 1972, A. aedeagus in situ, ventral view; B. broken aedeagus, ventral view.

FIGURE 20. Isoperla kozlovi Zhiltzova, 1972, A. female abdomen with bilobed subgenital plate, ventral view; B. bilobed subgenital plate, ventral view; C. female abdomen with truncate subgenital plate, ventral view; D. truncate subgenital plate, ventral view.