Rhyacophila asymmetra, Sun, Changhai, 2016

Sun, Changhai, 2016, Notes on the Rhyacophila angulata Species Group with descriptions of two new species (Insecta, Trichoptera, Rhyacophilidae), Zootaxa 4150 (2), pp. 193-200 : 194-196

publication ID	https://doi.org/ 10.11646/zootaxa.4150.2.7
publication LSID	lsid:zoobank.org:pub:58191E8B-9209-45C5-99AA-84D33D259D5F
DOI	https://doi.org/10.5281/zenodo.6090391
persistent identifier	https://treatment.plazi.org/id/039787B3-1E05-FFDF-6789-F9D8D127A34A
treatment provided by	Plazi
scientific name	Rhyacophila asymmetra
status	sp. nov.

Treatment

Rhyacophila asymmetra n. sp.

( Figs 1 View FIGURE 1 , 2 View FIGURE 2 A–2E)

Diagnosis. The new species can be diagnosed easily from other members of the R. angulata Species Group by the apicodorsal lobe of segment IX which is abruptly narrowed in its apical one-third in lateral view and deeply incised apicomesally in dorsal view, and by the asymmetrical parameres in which the left paramere is about 2 times as wide as the right one and both parameres bear strong apical spines.

Description. Length of each forewing of male 7.5–8.5 mm (n = 4), of female 8.0–10.0 mm (n = 14); length of body of male 6.0– 7.5 mm (n = 4), of female 7.0–8.0 mm (n = 14). Body (in alcohol) yellowish brown. Head yellowish brown; antennae and palpi yellow; eyes black, ocelli white. Prothorax yellow; pterothorax yellowish brown dorsally and yellow laterally and ventrally; legs yellowish brown; forewings pale brown, with irregular dark brown patches ( Fig. 1 View FIGURE 1 ), hind wings pale brown. Abdomen dark brown dorsally and yellowish brown ventrally.

Male genitalia ( Fig. 2 View FIGURE 2 ): Segment IX (IX) in lateral view with anterior margin sinuate, in dorsal view anterior margin with broad incision; apicodorsal lobe (ad.l.) large, in lateral view its basal two-thirds somewhat triangular, the apical one-third narrowed abruptly and curved downwards with apex acute ( Fig. 2 View FIGURE 2 A); in dorsal view apicodorsal lobe with lateral margins parallel, apex divided into two hook-like lobes directed mesad ( Fig. 2 View FIGURE 2 B). Segment X (X) oblique in lateral view, with posteroventral margin straight and anteroventral margin convex; in caudal view apex with broad incision ( Fig. 2 View FIGURE 2 E). Anal sclerites (as.) irregular, without root; in caudal view with base fused but apices separated ( Fig. 2 View FIGURE 2 E). Phallotheca (pht.) in lateral view irregular, in ventral view elongaterectangular; aedeagus (aed.) tubular, gradually tapered from base to distal end in both lateral and ventral views ( Fig. 2 View FIGURE 2 A, 2D); parameres (par.) paired but asymmetrical: left one about 2 time as wide as right one, distal end thickened when viewed ventrally, with 3 strong apical spines; right paramere slender, distal end not thickened, with 3 strong apical spines ( Fig. 2 View FIGURE 2 D). Basal segment of each inferior appendages (bia.) slender, extending beyond apex of apicodorsal lobe of segment IX in lateral view, its base in lateral view slightly enlarged, then narrowed to truncate apex, in ventral view slender, slightly curved mesad. Apical segment (aia.) about one-fourth as long as basal segment, in lateral view subrectangular with apex narrowed and obliquely truncate, in ventral view somewhat triangular with acute apex ( Fig. 2 View FIGURE 2 C).

Holotype male. CHINA: Guang-dong Province , Ru-yuan County, Nan-ling National Nature Preserve , Laopeng-keng at cascading tributary, Route X 327, marker 22.5 km, 24.934°N, 113.009°E, elev. 1110 m, 18–19 May 2004, by collected John C. MORSE, Xiaoli TONG, Xin ZHOU GoogleMaps . Paratypes. Same collection data as holotype—4 males, 14 females.

Etymology. The species name comes from the Latin word “ asymmetrum,” meaning “asymmetrical,” in reference to the asymmetrical parameres.

Distribution. China (Guang-dong).