Nemoura lixiana, Chen, 2020

Chen, Zhi-Teng, 2020, Two new species of Nemouridae (Insecta: Plecoptera) from China, European Journal of Taxonomy 651, pp. 1-16 : 3-8

publication ID

https://doi.org/ 10.5852/ejt.2020.651

publication LSID

lsid:zoobank.org:pub:0FF3B52C-BDBD-4661-9998-BBCBB82B8ADB

DOI

https://doi.org/10.5281/zenodo.3857240

persistent identifier

https://treatment.plazi.org/id/1532AE67-2249-4AFA-B935-03AF014801EE

taxon LSID

lsid:zoobank.org:act:1532AE67-2249-4AFA-B935-03AF014801EE

treatment provided by

Valdenar

scientific name

Nemoura lixiana
status

sp. nov.

Nemoura lixiana View in CoL sp. nov.

urn:lsid:zoobank.org:act:1532AE67-2249-4AFA-B935-03AF014801EE

Figs 1–5 View Fig View Fig View Fig View Fig View Fig , 7 View Fig

Diagnosis

Nemoura lixiana sp. nov. exhibits the typical body color and genitalic characters of genus Nemoura ( Figs 2–5 View Fig View Fig View Fig View Fig ). The new species is most similar to Nemoura geei Wu, 1929 by sharing similar characteristics of male epiproct and female pregenital plate ( Shimizu 1997; Teslenko & Zhiltzova 2009; Yang et al. 2015). However, males of the new species can be distinguished from N. geei by the presence of extra stout spines on inner membrane of cerci ( Figs 2C View Fig , 3A View Fig , 4E View Fig ), which are absent in N. geei ( Fig. 6 View Fig A–C); the median lobe of paraprocts is projected inwards and covers half of inner lobe in N. lixiana sp. nov. ( Fig. 4E View Fig ), but hardly reaches the inner lobe in N. geei ( Fig. 6 View Fig A–C); in the epiproct of N. lixiana sp. nov., the dorsal sclerite has two apparently angled lateral sclerites which are thick, with transverse anterior margins and very stout posterior humps ( Fig. 4B View Fig ), while in N. geei , the lateral sclerites are thinner and not angled, with oblique anterior margins and low posterior humps ( Fig. 6 View Fig D–F). The females of N. lixiana sp. nov. have two oval lateral sclerites on sternum 8 but without small lateral pits on sterna 7–8 ( Fig. 5 View Fig B–C), whereas in N. geei , sternum 8 has two long transverse sclerites and sterna 7–8 have paired lateral pits ( Fig. 6 View Fig G–H). In addition, type locality of N. lixiana sp. nov. is in southwestern China ( Fig. 1 View Fig ), which is apparently isolated from the known ‘northeastern Asian’ distribution of N. geei in Beijing, Henan, Shandong, Inner Mongolia, Korea, Japan and the Russian Far East ( Yang et al. 2015; DeWalt et al. 2020).

Etymology

The new species is named after the type locality, Lixian County.

Material examined

Holotype

CHINA • ♂; Sichuan Province, Lixian County, side of Xuemeng Road, a small unnamed stream ( Fig. 7 View Fig ); 31°33′56′′ N, 103°17′32′′ E; 1634 m a.s.l; 5 Oct. 2019; Zhi-Teng Chen leg.; ICJUST.

GoogleMaps

Paratypes GoogleMaps

CHINA • 8 ♂♂, 4 ♀♀; same collection data as for holotype; ICJUST.

Description

Male

MEASUREMENTS. Holotype: BL = 3.5 mm; FL = 6.3 mm; HL = 4.5 mm. Other specimens: BL = 3.5‒4.5 mm; FL = 6.0‒7.0 mm; HL = 4.5‒6.0 mm.

HEAD ( Fig. 2 View Fig A‒B). Head dark brown; two ocelli pale; compound eyes dark and protruded; antennae slender and dark brown, much longer than body length; mouthparts brown.

THORAX ( Fig. 2 View Fig A‒B). Brown. Pronotum brown, with dark rugosities, corners angulate; anterior margin arcuate, posterior margin concave. Legs pale brown, joints of each segment darker.

WINGS ( Fig. 2 View Fig A‒B). Macropterous, wing membrane subhyaline, veins brown; margins of wings fringed with short bristles.

ABDOMEN ( Figs 2‒4 View Fig View Fig View Fig ). Abdominal segments generally pale brown; abdominal terga with an obscure longitudinal stripe. Posterior margin of tergum 9 with a row of long bristles. Tergum 10 with a membranous median area anterior of median area, with two small lateral patches of sensilla basiconica; posterior margin of tergum 10 with two sclerotized coniform lobes. Cerci prolonged and upcurved, covered by dense long hairs; inner part membranous, subapically with a stout inner spine; outer surface of cerci sclerotized, outer sclerite kidney-shaped, subapically with a small back-curved spine.

GENITALIA ( Figs 2 View Fig C‒E, 3‒4). Dorsal sclerite of epiproct with two elbow-shaped, dark lateral sclerites; inner apex of each lateral sclerite forked; apex of epiproct with a prolonged median sclerite covered by membrane; ventral sclerite with a C-shaped base and two sinuous lateral sclerites, which project forwards and form two apically dentate arms, the arms each with three or four apical teeth. Vesicle of sternum 9 mostly membranous, claviform and slightly constricted basally; hypoproct broad and elliptical, apex extended backwards, with a long triangular sclerite. Paraprocts bilobed; inner lobe weakly sclerotized, finger-shaped with a blunt tip, near half as long as outer lobe; outer lobe strongly sclerotized, broad basally, posteromedial margin forming a long triangular sclerite, inner margin with a projected basal hump covering half of inner lobe. The accidently extruded aedeagus in a paratype cylindrical, mostly membranous, apex with one or two obscure small lobes.

Female

Similar to males in body coloration ( Fig. 5A View Fig ).

MEASUREMENTS. BL = 4.5‒5.2 mm; FL = 7.0‒ 8.5 mm; HL = 6.0‒ 7.5 mm.

GENITALIA ( Fig. 5 View Fig B–C). Pregenital plate of sternum 7 rounded and sclerotized, reaching half-length of sternum 8. Sternum 8 with two oval-shaped, dark brown lateral spots. Paraprocts near trapezoidal and fused basally.

Distribution

China: western Sichuan Province ( Fig. 1 View Fig ).

Remarks

This species was collected in the afternoon of 5 Oct. 2019, when the adults were emerging massively. The habitat, a very small unnamed stream flows down from a dried mountain ( Fig. 7 View Fig ), geographically isolated from other known water systems. An undescribed new genus of Elmidae (Coleoptera) was simultaneously collected in this unique stream, but no mayflies or caddisflies or other aquatic insects were found at that time.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Plecoptera

Family

Nemouridae

Genus

Nemoura

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF