Caroperla brevihamata Mo, Wang & Li, 2020

Mo, Raorao, Liu, Hong, Liao, Debao, Wang, Guoquan & Li, Weihai, 2020, Caroperla brevihamata (Plecoptera: Perlidae), a new stonefly species from Guangxi Zhuang Autonomous Region of southern China, Zootaxa 4869 (3), pp. 430-436 : 431-436

Caroperla brevihamata Mo, Wang & Li , sp. nov.

( Figs. 1–5 )

Adult habitus ( Figs. 1 a–1b). General color brown. Head brown, with a large subtrapezoidal dark brown marking, covering ocelli and extending forward to frons; triocellate, anterior ocellus smaller, head slightly wider than pronotum. Pronotum darker than head, rectangular, covered with dark brown markings, corners rounded. Wings brownish, veins darker. Legs brown.

Male ( Figs. 1a, 1b , 2 , 3 , 4 a–4c). Forewing length ca. 8.0 mm, hindwing length ca. 6.7 mm. Epiproct upcurved, anterior margin distinctly sclerotized, posterior margin membranous, upturned apex seemingly semicircular in dorsal views ( Figs. 2 a–2b, 4a, 4c). Paraprocts strongly bent and upturned, apical half cambered, semicircular in outline, subtriangular in caudal view, with vestige of a triangular gill laterally ( Figs. 2 a–2b, 4a–4c). Cerci short, with 6 segments. Basal cercal segment about 5X as long as apical wide of the segment ( Figs. 2c , 3c , 4a, 4c ); segment 1 of cerci distinctly sclerotized, curved upward, and gradually tapering to the tip, with a short hooked process, a long and large seta and two shorter thinner setae at tip; segments 2–6 covered by short dense thin setae with apical whorls. The apical whorl is a set of strong, acute setae. Abdominal tergum 10 with a large dark brown to brown inverted triangular mesal sclerite; terga 4–9 with mesal patches of thickened setae, also medially interrupted by a broad to narrow membranous patch. Abdominal terga and sterna with setal brushes on posterior edge; those on lateral margins of sterna 7–9 conspicuous. The posteromedian margin of the sternum 8 slightly produced forming a small triangular process with a blunt tip ( Figs. 3 a–3b, 4a). Sternum 9 sclerotized, inverted subtrapezoidal ( Figs. 3 a–3b).

Female ( Figs. 1c , 4d , 5 ). Forewing length 8.2 mm, hindwing length 7.2 mm. Habitus generally similar to male. Sternum 8 with large elliptical subgenital plate, extending over abdomen, with a shallow triangular posteromedian notch; posterior margin fringed with a row of long setae ( Fig. 5 ). Posterior margin of sternum 9 constricted medially forming a shallow incision. Cerci short, with 7 segments ( Fig. 4d ). Basal cercal segment about 2 times long as wide; segments armed with normal fine long setae and with apical whorls of strong and acute setae.

Larva and egg. Unknown.

Type material. Holotype male ( HIST): CHINA: Guangxi Zhuang Autonomous Region, Guilin City, Multinational Autonomous County of Longsheng , Huaping National Nature Reserve , 25°37’ 37’’ N, 109°54’42” E, 731.6 m, 2020.VI.15, light trap, Raorao Mo, Yan Lai et al . Paratype: 1 female ( HIST), same location and collectors as holotype, 2020.VI.17, light trap .

Etymology. Latin “brev” means short; Latin “hamatus” means hooked. The specific epithet refers to the short hooked apical process of basal cercal segment.

Distribution. China (Guangxi Zhuang Autonomous Region).

Remarks. The male of new species is characterized by the inverted triangular mesal sclerite of tergum 10, the semicircular epiproct, the semicircular paraprocts with a small vestige of a triangular gill laterally, the tip of cercal segment 1 with a short hooked process and a long and large seta, and sternum 8 with a small triangular posteromedian process. The dorsolateral paraproct of the male has a vestige of a gill in both the new species and Japanese C. pacifica Kohno, 1946 , but the basal cercal segment of the latter species has a large and long sclerotized hook, distinguishing it from C. brevihamata . Both the new species and C. longilobata Mo, Wang & Li, 2019 , another species known from Guangxi Zhuang Autonomous Region, share a similar long, large and outcurved seta on tip of cercal segment 1, but C. longilobata is easily separated from the new species by having the larger semicircular mid-posterior plate of sternum 9.

In addition, usually the females of other Caroperla species have a large subgenital plate with a row of long setae at posterior margin lacking an apical notch. In C. brevihamata , the large elliptical subgenital plate that extends beyond posterior margin of sternum 10 with a small triangular posteromedian notch, distinguishes the female of it from all known species of Caroperla .

Figures

FIGURE 1. Caroperla brevihamata Mo, Wang & Li, sp. nov. a. Male adult habitus, dorsal view. b. Male head and pronotum, dorsal view. c. Female head and pronotum, dorsal view.

FIGURE 2. Caroperla brevihamata Mo, Wang & Li, sp. nov. (male). a. Abdomen, dorsal view. b. Terminalia after being cleared, dorsal view. c. Cerci, dorsal view. (vestige of gill in blue line)

FIGURE 3. Caroperla brevihamata Mo, Wang & Li, sp. nov. (male). a. Abdomen, ventral view. b. Terminalia after being cleared, ventral view. c. Cerci, ventral view.

FIGURE 4. Caroperla brevihamata Mo, Wang & Li, sp. nov. a. Male abdomen, lateral view b. Male paraproct, caudal view. c. Male terminalia after being cleared, oblique dorsal view. d. Female cerci, ventral view. (epiproct in red line; paraproct in yellow line; vestige of gill in blue line)

FIGURE 5. Caroperla brevihamata Mo, Wang & Li, sp. nov. (female). a. Terminalia, ventral view. c. Terminalia, lateral view.