Notes on the Rhyacophila angulata Species Group with descriptions of two new species (Insecta, Trichoptera, Rhyacophilidae) Author Sun, Changhai text Zootaxa 2016 4150 2 193 200 journal article 10.11646/zootaxa.4150.2.7 d07a3d54-e095-4dc4-a6da-fd0e94307eb1 1175-5326 263768 58191E8B-9209-45C5-99AA-84D33D259D5F Rhyacophila asymmetra n. sp. ( Figs 1 , 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 ), hind wings pale brown. Abdomen dark brown dorsally and yellowish brown ventrally. FIGURE 1. Forewing of Rhyacophila asymmetra n. sp. Scale bar: 1.0 mm. FIGURE 2. Male genitalia of Rhyacophila asymmetra n. sp. 2A, left lateral; 2B, segment IX, dorsal; 2C, ventral; 2D, phallic apparatus, dorsal; 2E, segment X and anal sclerites, caudal. Scale bar: 0.5 mm. Abbreviations: ad.l. = apicodorsal lobe of segment IX; aed. = aedeagus; aia. = apical segment of one of a pair of inferior appendages; as. = anal sclerites; bia. = basal segment of one of a pair of inferior appendages; end. = endotheca; IX = segment IX; par. = parameres; pht. = phallotheca; tb. = tergal band; X = segment X. Male genitalia ( Fig. 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 A); in dorsal view apicodorsal lobe with lateral margins parallel, apex divided into two hook-like lobes directed mesad ( Fig. 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 E). Anal sclerites (as.) irregular, without root; in caudal view with base fused but apices separated ( Fig. 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 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 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 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 . 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).