Neoperla minuta Du & Chen

Chen, Zhi-Teng & Du, Yu-Zhou, 2016, Contribution to the knowledge of Neoperla (Plecoptera: Perlidae) from Hainan Province of China, Zootaxa 4144 (2), pp. 243-252 : 245

Neoperla minuta Du & Chen , sp. nov.

Figs. 1–4 .

Adult habitus. General color yellow patterned with brown. Head slightly wider than pronotum, with a pale brown stigma on anterior frons and a median pale brown quadrate area covering ocelli; paired ocelli with dark margins; compound eyes dark and antennae pale brown ( Fig. 1 ). Pronotum disc yellow with brownish median stripe and brown margins ( Fig. 1 ). Wing membrane subhyaline, veins brown. Legs pale; cerci pale brown.

Male ( Figs. 1–4 ). Forewing length 10.5–10.8 mm, hindwing length 8.8–9.2 mm. The posterior margin of tergum 7 with a subtriangular median process; the process broad at base, sclerotized and apically with paired, small, lateral spines. Tergum 8 with an upraised, rounded process bearing small sensilla basiconica patch medially; the process with a dark sclerite at posterior margin ( Fig. 2 ). Tergum 9 with mesal and lateral sensilla basiconica patches on three humped areas. Hemitergal processes of tergum 10 straight, pointing to the subtriangular process on tergum 7 ( Fig. 2 ). Aedeagal tube weakly sclerotized, basoventrally with a membranous area near the basal rectangular sclerite. Aedeagal sac curved and gradually tapering to near tip, forming a U-shape in lateral aspect; apical half of ventral sac with two parallel rows of spines; dorsal sac with a continuous patch of spinules from base to near midlength, then constricted to one row of spines ( Figs. 3–4 ).

Female. General color and pattern similar to males. Subgenital plate small and subtriangular, originating from posteromedial margin of tergum 8.

Type material. Holotype: male, China: Hainan Province, Nada, 30 April, 1954, Kai-ling Xia . Paratypes: 3 males, same data as holotype. (Insect Collection of Yangzhou University , China) .

Distribution. China (Hainan).

Etymology. The species epithet refers to the small body size of the male.

Diagnosis. The aedeagal sac of this species curved and gradually tapering, forming a U-shape in lateral aspect. The sac has two parallel rows of spines on ventroapical half, and dorsally has a continuous patch of spinules from base to near midlength before narrowing to one row of spines.

Remarks. The new species was originally studied by the second author in 1999 (unpublished data). A female was associated with the type material listed above. However, the female specimen has been apparently lost and the above description is taken from unpublished notes of the second author. The aedeagal tube and sac of the new species is similar to that of N. hubeiensis Li & Wang, 2012 , N. cavalerieri Navás, 1922 and N. leptacantha Stark & Sivec, 2008 (see figs. 5, 13– 14 in Li et al. 2012 and fig. 9 in Stark & Sivec 2008). Neoperla minuta can be distinguished from members of the N. cavalerieri complex the by aedeagal sac forming a U-shape with distinct arrangement of spines, length of aedeagal tube and sac, details of processes on terga 7–8, and by the distinct head pattern.

Figures

FIGURES 1 – 4. Neoperla minuta, sp. nov. 1. Male head and pronotum, dorsal view; 2. Male terminalia, dorsal view; 3 – 4. Aedeagus, lateral view.