Rhyacophila bisbifida, Sun, Chang-Hai, 2016

Sun, Chang-Hai, 2016, New species, new records, and new collection data of Rhyacophila from China (Trichoptera: Rhyacophilidae), Zootaxa 4189 (1), pp. 134-144 : 139

Rhyacophila bisbifida n. sp.

( Fig. 4 A–4E)

Diagnosis. This new species can be diagnosed easily from other species of the R. wangpo Species Group by the large anal sclerites which, with their roots, are almost as long as the height of segment X in lateral view, and by the paired style-like processes beneath the ventral plate of the aedeagus which are absent in other members.

Description. Length of each forewing: 7.5 mm (n = 1). Body (in alcohol) brown. Head brown; antennae yellow, each flagellar joint with brown ring at middle; palpi pale. Prothorax yellowish brown, pterothorax dark brown dorsally, brown laterally and ventrally; legs brown, with dark brown spurs; wings brown. Abdomen dark brown dorsally and brown ventrally.

Male genitalia. Segment IX (IX) in lateral view with anterior margin straight, posterior margin sinuate, deeply incised on ventral half; in dorsal view rectangular. Segment X small, in lateral view somewhat Γ-shaped (gammashaped), with horizontal part (h.p.X) short and vertical part (v.p.X) oblique; in dorsal view both horizontal and vertical parts incised apicomesally. Anal sclerites (a.s.) large, roots long, elliptical in caudal view. Apical band (u.) with semicircular bottom and two oblique arms; tergal band (t.b.) strong. Inferior appendages strong; in lateral view each with basal segment (b.i.a.) subrectangular and its apex rounded, in ventral view trapezoidal; apical segment about as long as basal segment, in lateral view somewhat in shape of upside-down boot, in ventral view knife-like. Tendons (tend.) of inferior appendages large. Phallic apparatus complicated: phallotheca (pht.) rectangular both in lateral and ventral views; tenons (ten.) slender; aedeagus (aed.) tubular in lateral view, its ventral plate (v.p.a.) in lateral view slender, about 1.5 times as long as aedeagus, in dorsal view with narrow and incised base, gradually widened to subapex, and with apex incised mesally; parameres (par.) each slightly longer than ventral plate of aedeagus, in dorsal view each with lateral margins of basal 2/3 parallel to each other, distal 1/ 3 narrowed abruptly, with apex acute. Pair of style-like processes (s.l.p.) occurring basally beneath ventral plate of aedeagus.

Holotype male. P.R. CHINA: Si-chuan Province , Bao-xing County, unnamed tributary of Bao-xing River, Route S 210 at 240.3 km marker, 30.652°N, 102.765°E, elev. 1985 m, 27 June 2005, collected by Xin ZHOU and John C . MORSE.

Etymology. The species is named Rhyacophila bisbifida from the Latin adjective bisbifidus, -a, -um, meaning “twice cut,” in reference to segment X of the new species incised mesally at the apices of both the horizontal part and the vertical part.

Distribution. China (Si-chuan).

Remarks. The R. wangpo Species Group was established by SCHMID (1970) to include 2 species from Sikkim ( R. wangpo SCHMID 1970 and R. tashepa SCHMID 1970). Afterwards, a species was recognized from Yun-nan, China ( R. complanata TIAN & LI 1986). Rhyacophila brachyblasta MALICKY & SUN 2002 has been reported from Yun-nan, but was placed in the R. annulicornis Species Group. According to the overall shape of the male genitalia, I treat R. brachyblasta as a member of the R. wangpo Species Group. Rhyacophila fernandi ARMITAGE & AREFINA 2003 was reported from Vietnam, but is very similar to R. brachyblasta in male genitalia. MALICKY (2013) doubted they are synonymous. Here I treat R. fernandi as a synonym of R. brachyblasta . Rhyacophila serug Malicky 2012 from Si-chuan was reported to be similar to R. brachyblasta , and should be ascribed to the group. With R. bisbifida n. sp., the group now contains 6 species, of which 4 species occur in China .

Figures

FIGURE 4. Rhyacophila bisbifida n. sp., male genitalia. 4 A, left lateral; 4 B, dorsal; 4 C, ventral; 4 D, segment X and anal sclerites and apical band, caudal; 4 E, phallic apparatus, dorsal. Abbreviations: aed. = aedeagus; a. i. a = apical segment of an inferior appendage (paired); a. s. = anal sclerites; b. i. a. = basal segment of an inferior appendage (paired); h. p. X = horizontal part of segment X; IX = segment IX; par. = paramere (paired); pht. = phallotheca; s. l. p. = style-like process (paired); t. b. = tergal band; ten. = tenons of phallotheca; tend. = tendons of inferior appendages; u. = apical band; v. p. a. = ventral plate of aedeagus; v. p. X = vertical part of segment X.