Sinoperlodes Chen, 2020

Chen, Zhi-Teng, 2020, Sinoperlodes, a new genus of subfamily Perlodinae (Plecoptera, Perlodidae) from coastal southeastern China, Zootaxa 4779 (4), pp. 584-594 : 585-588

Sinoperlodes Chen , gen. nov.

Figs. 1–10 .

Diagnosis. Body size 12.5‒14.5 mm ( Figs. 1–2 ). Head brown, with a V-shaped anterior pale marking, a pale lateral stripe connecting each posterior ocellus with yellow band behind each eye, interocellar area brown with an oval, yellow spot; occiput yellow with triangular medial yellow spot; submental gills reduced ( Fig. 3 ). Arms of the mesosternal ridges reaching posterior corners of the furcal pits, suture between basisternum and furcasternum indistinct ( Fig. 3B ). Legs banded ( Figs. 1–3 ). Wings of male shortened, macropterous in females, dark brown, veins pale, contoured brightly, apical half with extremely complicated netlike venation formed by apical branches of Sc, RA, RP, M, CuA and CuP, anal area large ( Figs. 1 , 2 , 4 ). Abdominal segments 1–5 divided into terga and sterna, segment 6 partially divided ( Fig. 5 ). Tergum 10 of male entire, moderately elevated, posteromedially with small transverse membrane, covered with dense stout sensilla basiconica and sharp spines posteriorly ( Fig. 6 ). Paraproct sclerite weakly sclerotized dorsally with sparse bristles; the eversible paraproct lobe short, elliptical, apex rounded ( Fig. 7 ). Aedeagus membranous with seven small apical lobes ( Fig. 8 ). Female subgenital plate elongated, broad, covering sternum 9 ( Fig. 9B ).

Type species. Sinoperlodes zhouchangfai sp. nov., by monotypy.

Etymology. The genus name is a combination of the words Sino and perlodes ; the first Latin word means China, while the second word refers to the extant genus Perlodes , which is the type genus of Perlodidae .

Affinities. Sinoperlodes undoubtedly belongs to subfamily Perlodinae by the male subanal lobes produced inward and upward, meeting each other along their mesal edges and blunt at the tips, and by the hind margin of tergum 10 elevated ( Ricker 1952). Sinoperlodes is placed in the tribe Perlodini by its entire tergum 10 and unmodified sternum 7 in the male ( Stark & Szczytko 1984). The entire tergum 10 and presence of eversible paraproct lobes (EPL) in the male, indistinct submental gills, arms of the mesosternal ridge reaching the posterior corners of furcal pits, and the indistinct suture between basisternum and furcasternum together supported Sinoperlodes to be included in the Perlodes group ( Zwick 1997).

The distinctly divided abdominal segments 1–5 and 6 partly indicate the similarity of Sinoperlodes with Megaperlodes Yokoyama, Isobe & Yamamoto, 1990 ( Yokoyama et al. 1990, Teslenko 2015) and Rauserodes ( Zwick 1997) , both of which have 1‒5 or 1‒6 abdominal segments separated by pleural membrane on terga and sterna. Representatives of the two genera, other genera in the Perlodes group and the poorly known Chinese genus Hedinia have netlike venation on wing apex anteriorly, but wings of Sinoperlodes are distinctive and distinguished from genera of the Perlodes group by extremely complicated netlike venation formed by apical branches of Sc, RA, RP, M, CuA and CuP and large anal area. EPL of Sinoperlodes short and rounded, entirely fused with weakly sclerotized paraproct sclerite resembles that of Filchneria Klapálek (1908) , which also has short blunt EPL ( Zwick 1997, Teslenko et al. 2010). Other special features of the new genus include the banded legs, membranous aedeagus bearing seven small apical lobes and broad and elongated female subgenital plate covering sternum 9, which also distinguish Sinoperlodes in the Perlodes group.

Figures

FIGURE 1. Sinoperlodes zhouchangfai gen. et sp. nov., A. male habitus, dorsal view; B. male habitus, ventral view.

FIGURE 2. Sinoperlodes zhouchangfai gen. et sp. nov., A. female habitus, dorsal view; B. female habitus, ventral view.

FIGURE 3. Sinoperlodes zhouchangfai gen. et sp. nov., A. male head and thorax, dorsal view; B. male head and thorax, ventral view; the posterior corners of furcal pits indicated by black arrowheads.

FIGURE 4. Sinoperlodes zhouchangfai gen. et sp. nov., A. left forewing of male, dorsal view; B. left hind wing of male, dorsal view; C–D. left forewing and left hind wing of male, original color; E. right forewing of female, dorsal view; F. right hind wing of female, dorsal view. Sc, subcosta; RA, anterior radius; RP, posterior radius; M, media; CuA, anterior cubitus; CuP, posterior cubitus; A1, first anal vein, and so forth for other anal veins. Apical branches of anal veins indicated by short lines.

FIGURE 5. Sinoperlodes zhouchangfai gen. et sp. nov., A. male abdomen, dorsal view; B. male abdomen, lateral view; C. male abdomen, ventral view. Numbers of abdominal segments indicated for each segment.

FIGURE 6. Sinoperlodes zhouchangfai gen. et sp. nov., A–B. male terminalia, dorsal view; C. male terminalia, ventral view; C. male terminalia, lateral view; D. male abdominal terga 7–10, dorsolateral view; shape of spines or sensilla basiconica illustrated above each tergum.

FIGURE 7. Sinoperlodes zhouchangfai gen. et sp. nov., A. right paraproct lobe of male, ventral view; B. right paraproct lobe of male, dorsal view.

FIGURE 8. Sinoperlodes zhouchangfai gen. et sp. nov., aedeagus, A. dorsal view; B. ventral view; C. drawing in dorsal view; D. drawing in lateral view; E–F. dorsolateral view.

FIGURE 9. Sinoperlodes zhouchangfai gen. et sp. nov., A. female abdomen, dorsal view; B. female abdomen, ventral view. Numbers of abdominal segments indicated for each segment.

FIGURE 10. Sinoperlodes zhouchangfai gen. et sp. nov., A. habitat stream in Tianmu mountain; B–C. sites of the collected specimens, indicated by red arrowheads; D–E. female habitus when alive.