Rhyacophila voluta, Sun, 2017

Sun, Changhai, 2017, Two new species of the Rhyacophila nigrocephala species group from China (Insecta, Trichoptera, Rhyacophilidae), European Journal of Taxonomy 300, pp. 1-10 : 6-7

Rhyacophila voluta sp. nov.

urn:lsid:zoobank.org:act:DF10323C-1202-4D75-8CB2-9C2C5B87A026

Fig. 2

Diagnosis

The new species belongs to the R. nigrocephala sub-group, and is similar to R. pentagona Malicky & Sun, 2002 from Yunnan, China, in the male genitalia, but differs in: (1) the inferior appendages of about the same length as the complex of the preanal appendages and the apicodorsal lobe of segment IX (obviously shorter than the complex in R. pentagona ); (2) the basal segments of the inferior appendages in lateral view are somewhat rectangular and in ventral view with their bases fused (pentagonal in R. pentagona , and their bases not fused obviously); (3) the apical segments of the inferior appendages with each distal margin slightly concave (straight in R. pentagona ).

Etymology

The species epithet comes from the Latin word “ volutus ”, meaning “having been curled”, in reference to the subapical margin of the complex of the preanal appendages and the apicodorsal lobe of segment X extending upward into a curled lamella.

Type material

Holotype

CHINA: ♂, in alcohol, collected in Guangdong Province, Ruyuan County, Nanling National Nature Preserve, Lao-peng Keng at cascading tributary, Route X 327, marker 22.5 km, 113.01° E, 24.93° N, 1110 m, 18–19 May 2004, John C. Morse, Xiaoli Tong and Xin Zhou leg. ( NJAU).

Paratypes

CHINA: 4 ♂♂, in alcohol, collected at the same locality along with the holotype, except marker 17.45 km, 113.03° E, 24.91° N, 935 m, 21–22 May 2004, John C. Morse and Changhai Sun ( NJAU).

Description

Male

BODY. Length 5.0 mm (n = 3), length of each forewing 6.0–7.0 mm (n = 5). Body (in alcohol) brown. Head dark brown; antennae brown; palpi light brown, eyes black. Thorax brown dorsally, yellow laterally and ventrally; wings dark brown; legs with coxae, trochanters and femora yellow, remainder parts dark brown, spurs dark brown. Abdomen dark brown dorsally and yellowish brown ventrally.

MALE GENITALIA ( Fig. 2 A–C). Segment IX (IX) in lateral view with middle portion of each anterior margin (about half the height of segment IX) straight and slightly projecting anteriad, each posterior margin almost straight, with posteroventral angle slightly projecting posteriad, dorsal and ventral margins straight; in dorsal view, anterior margin incised in V-shaped, posterior margin slightly concave; in ventral view anterior margin with broad shallow incision and posterior margin convex slightly. Apicodorsal lobe of segment IX and preanal appendages fused into complex (com.), in lateral view it curved downward at middle, with broad base and thin apex, subapex with dorsal margin extended upward to form lamella; in dorsal view complex with the two lateral margins parallel to each other, and apex triangular, the lamella curled. Anal sclerites (as.) large, with base fused into complex of apicodorsal lobe and preanal appendages, in lateral view somewhat triangular, in dorsal view its apex incised. Apical band (ab.) membranous. Sagittal appendage (sag.) in lateral view style-like. Basal segment of each inferior appendage (bia.) in lateral view somewhat rectangular, base slightly broader than apex in lateral view, in ventral view bases fused mesally; apical segment of each inferior appendage (aia.) in lateral view trapezoidal, with distal margin shallowly concave, in ventral view somewhat triangular. Phallic apparatus simple: phallotheca (pht.) tubular in lateral view and trapezoidal in ventral view, endotheca (end.) membranous, aedeagus (aed.) tubular, with apex narrowed suddenly.

Female

Unknown.

Distribution

China (Guangdong).

Figures

Fig. 2. Rhyacophila voluta sp. nov., male genitalia. A. Lateral view. B. Dorsal view. C. Segment IX and inferior appendages, ventral view. D. Phallic apparatus, ventral view. Scale bar: 0.5 mm.