Etrocorema yunnanensis, Chen, 2020

Chen, Zhi-Teng, 2020, Etrocorema yunnanensis sp. nov., a new species of the tropical genus Etrocorema (Plecoptera: Perlidae) from China, Zootaxa 4759 (3), pp. 433-439 : 433-439

publication ID	https://doi.org/ 10.11646/zootaxa.4759.3.10
publication LSID	lsid:zoobank.org:pub:76C6F1EC-18FB-4556-B129-C0B7CB6625B3
DOI	https://doi.org/10.5281/zenodo.3810503
persistent identifier	https://treatment.plazi.org/id/4E140E42-FFE9-FFEC-FF21-F8AEFC95FF39
treatment provided by	Plazi
scientific name	Etrocorema yunnanensis
status	sp. nov.

Treatment

Etrocorema yunnanensis View in CoL sp. nov.

Figs. 2–7 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 .

Adult habitus. General color yellow, patterned with brown ( Figs. 2 View FIGURE 2 , 6 View FIGURE 6 ). Biocellate; head slightly wider than pro-

notum, with a frontal stigma and a dark, hexagonal stigma covering the ocelli ( Fig. 3 View FIGURE 3 A–B). Pronotum pale, sutures dark brown, covered with conspicuous rugosities. Wing membrane pale brown and subhyaline, veins dark brown ( Fig. 3 View FIGURE 3 C–D). Coxae pale; apical half of femora brown; tibiae and tarsi dark brown. Cercus pale, covered with pale bristles.

Male. Body length ca. 12.0 mm. Metasternum and abdominal sternum 6 each with a median patch of dense bristles; sternum 7 with a sparse bristle patch ( Fig. 2B View FIGURE 2 ). Posterolateral margins of terga 7–9 fringed with dense, dark brown bristles ( Figs. 2 View FIGURE 2 , 4 View FIGURE 4 ). Posterior area of tergum 7 with two small patches of sensilla basiconica, each containing one or two sensilla basiconica ( Figs. 2B View FIGURE 2 , 4 View FIGURE 4 ). Posterior half of tergum 8 with two large patches of sensilla basiconica ( Fig. 4 View FIGURE 4 ). Tergum 9 with two elliptical membranous area divided by the median extension of its sclerotized anterior margin; posterior margin of each membrane with a small patch of sensilla basiconica ( Fig. 4 View FIGURE 4 ). Hemitergal lobes curved and finger-shaped; apices covered with stout sensilla basiconica on all aspects; inner surfaces humped, less sclerotized and with longitudinal patches of tiny sensilla basiconica. Paraprocts membranous and unmodified ( Fig. 4 View FIGURE 4 ). Aedeagus ( Fig. 5 View FIGURE 5 ) mostly membranous and tube-like, slightly curved and constricted subapically; basal half weakly sclerotized and covered with dense granules which gradually reduced towards mid-length; middle of aedeagus transparent, ventral and dorsal aspects with scattered granules which connecting the basal and apical granular patches of aedeagus ( Fig. 5 View FIGURE 5 D–E); apical one-third of aedeagus covered with dense granules which rearranged into rows on apex, dorsal aspect elevated with two conspicuous ridges ( Fig. 5E View FIGURE 5 ); apical rim of aedeagus dentate and irregular ( Fig. 5D View FIGURE 5 ).

Female. Body length ca. 11.5 mm; body color and head pattern identical with the male ( Fig. 6 View FIGURE 6 A–B). Sternum 8 sclerotized medially, posterior margin with a broad, shallow notch; a detached subgenital plate present beneath the posterior margin of sternum 8 ( Fig. 6C View FIGURE 6 ).

Egg. Egg length ca. 375 µm, equatorial width ca. 213 µm ( Fig. 7 View FIGURE 7 ). Color pale brown, long oval in shape; collar dark brown, wide and short. Primary striae narrow, dentate and narrowly spaced, joining rim on sides of collar. Collar short and surrounded by 1–2 irregular rows of follicle cell impressions. Lid small, truncate.

Type material. Holotype: male, China: Yunnan Province, Mengla County, Laman Highway , 21°20′53.25″N, 101°18′33.79″E, 1400m, April 27, 2019, leg. Shen Ji (ICJUST) GoogleMaps . Paratypes: one male and one female, same data as holotype (ICJUST).

Etymology. The new species is named after its type locality in Yunnan Province.

Diagnosis. Etrocorema yunnanensis can be distinguished from E. hochii by the divided patches of sensilla basiconica on tergum 8, presence of sensilla basiconica on abdominal tergum 7, tergum 9 and hemitergal lobes, which are absent in E. hochii (see original descriptions “abdominal segments 1–9 unmodified except with a transverse row of spinules on the posterior margin of the 8th tergite…finger-like recurved process, with a more slender rounded tip not beset with spinules” and figs. 310–311 in Wu 1938). The male of E. yunnanensis differs from the Malaysian E. belumensis in having different head pattern, extra sensilla basiconica on abdominal tergum 7, an extra bristle patch on sternum 7, aedeagus with a granular base and two ridges on dorsal apex (see figs. 1–3 in Wan Nur Asiah et al. 2009); female of E. yunnanensis is distinctive from E. belumensis by a small detached subgenital plate rather than a large rounded one (see fig. 4 in Wan Nur Asiah et al. 2009); egg of E. yunnanensis differs from E. belumensis by presence of the narrowly spaced primary striae and absence of rounded pits on chorion (see figs. 8–10 in Wan Nur Asiah et al. 2009). The new species is most similar to E. nigrogeniculatum , but can be separated by the male with a different head pattern, an additional bristle patch on sternum 7, much longer apical sac of aedeagus, dense granules on base of aedeagus which extend towards apex from both dorsal and ventral aspects, and presence of dorsoapical ridges on aedeagus; the extremely large subgenital plate in female, and the absence of primary striae in eggs of E. nigrogeniculatum ( Kawai 1968, Zwick 1973, Sivec et al. 1988, Wan Nur Asiah et al. 2009).

Remarks. The holotype was found with a parasitic mite of Parasitidae on lateral side of abdominal segments 6–7 ( Fig. 1 View FIGURE 1 C–D). However, little is known about the specific correlation between parasitic mites and Chinese stoneflies, which should be an interesting topic for future studies.