Neoperla minor Chu, 1929

Zeng, Liang-Liang, Huo, Qing-Bo & Du, Yu-Zhou, 2024, Revision of Neoperla minor Chu with a new synonym and a new species of Neoperla Needham (Plecoptera: Perlidae), Zootaxa 5493 (1), pp. 79-90 : 80-83

Neoperla minor Chu, 1929

Neoperla minor Chu, 1929: 90 .

Neoperla minor : Wu, 1938: 116 (misidentification).

Neoperla yao Stark, 1987: 47 . syn. nov.

Neoperla minor : Mo et al., 2020: 372 (misidentification).

Supplementary description. Head mostly yellow but with a dark spot over ocelli and a second small spot anteromesally on frons ( Fig. 2 ); head slightly wider than prothorax; two ocelli, 2 diameters apart from each other; pronotum yellowish, faintly rugose, darkened along the sides of the median longitudinal line; mesonotum and metanotum with brownish areas; ventral surface of thorax yellow; ventral surface of head brownish; pronotum rectangular, slightly narrowed behind, front angles acute, hind angles more or less rounded ( Fig. 2 ).

Male. Forewing length 10–13 mm, hindwing length 8–9 mm, body length 8 mm ( Fig. 2 ). The posteromedial portion of the 7 th tergum elevated into a broad, round prominence, slightly produced rearward, with a varied quantity and density of sensilla basiconica scattered over the process ( Fig. 2 ). Medial tongue-like process of the 8 th tergum slender, erect, recurved, and with apical teeth. Hemitergal lobes short and finger-like, apex pointed.

Aedeagal tube lightly sclerotized, bearing a ventral Y-shaped membranous lobe and a small ventroapical patch of spines ( Fig. 3A ); arms of Y-lobe longer than stalk. Endophallus shorter than tube and covered with spines; large dorsobasal spines are present basally and dorsally, extending nearly to tip, which is beak-shaped and with smaller spines present dorsally. Small spines are present ventrally and across entire circumference immediately prior to tip ( Figs. 3B–C ).

Female. Head mostly yellow but with a dark spot over ocelli and a second small spot anteromesally on frons; spot over ocelli usually acute on anterior margin; pronotum pale brown, disc becoming paler near lateral margins; rugosities obscure. Forewing length 11–14 mm, hindwing length 10–11 mm, body length 9 mm. (n = 4) The 8 th sternite produced rearward into a small, tongue-like, bilobed subgenital plate which is broadly notched at the tip. Subgenital plate produced as a narrow tab, with a median sclerotized area, slightly expanded at apex and broadly U‐shaped posteriorly ( Fig. 4B ).

Egg and nymph. Unknown.

Material examined. Neotype male ( ICYZU), China, Zhejiang Province, Hangzhou City, Mt. Tianmushan (ca. 30.3377N, 119.4507E), specimen No. 1706, 22.VII.2019; 4 males, 1 female ( ICYZU), the same data as the neotype; 2 males ( ICYZU), China, Guangdong Province, Guangzhou City , Liuxi River (ca. 23.7521N, 113.7496E), 24.VI.2002.

Distribution. China (Guangdong, Guangxi, Zhejiang); Vietnam.

Remarks. The shape of the adult male 7 th tergal process, the hemitergite processes, and fully extruded aedeagus of the male specimens, as well as the shape of the subgenital plate of the female are consistent with the description of N. minor by Chu (1929). The size of the adult male and female appear consistent with Wu’s (1929) description of this species as “small”, which is aligns with the etymological nature of the species name “minor ”.

The information for the types of N. minor are as follows: holotype male, allotype female, co-type 2 males and 2 females: Yuan Sie [= Yun Qi, 云%, spelled as Yün Ch’ee in Wu (1938); ca. 30.1929N, 120.0882E]; July 5 1928; Chu’s Plecoptera Collection. Other specimens: 4 males, 13 females, Loong-tsin [= Longjing or Dragon Well, AE井, locality unclear, ca. 30.1929N, 120.0882E or 30.1763N, 119.1341E], July 5 1928; 4 females, Hangchow College Hangchow College Campus, July 10 1928; 1 male, Mao Kya Bu [= Maojiabu, ẓẋệ; ca. 30.2459N, 120.1321E], July 4 1928. The collection time and location of our specimens are similar to the original records. Therefore, we believe that this species collected from Tianmu Mountain is the true N. minor .

We also found that the description and illustrations of N. yao ( Stark 1987; Wang et al. 2013) from Vietnam (Da Lat, Gia Lai) and China (Guangdong, Guangxi) are consistent with our morphological redescription of N. minor from Zhejiang for both male and female adults. In addition to this, we collected specimens of N. yao in Guangdong and found that its aedeagal structure is consistent with that of N. minor . Therefore, we consider N. yao as a synonym of N. minor in this paper.

Figures

FIGURE 2. Neoperla minor Chu, 1929 from Zhejiang, males. A, C, E. Head and pronotum, dorsal; B, D, F. Abdominal terminalia, dorsal.

FIGURE 3. Neoperla minor Chu, 1929 from Zhejiang, neotype, aedeagus.A: everted endophallus, full length, lateral (neotype); B: Y-lobe, lateral; C: Y-lobe, ventral.

FIGURE 4. Neoperla minor Chu, 1929 from Zhejiang, female. A: head and pronotum; B: terminalia (subgenital plate), ventral.