Claassenia magna Wu, 1948

Xiang, Ya-Nan, Huo, Qing-Bo & Du, Yu-Zhou, 2022, A discussion of morphological differences within Claassenia qingzanga Xiang, Huo & Du, 2022 (Plecoptera: Perlidae) based on molecular data and a redescription of C. magna Wu, 1948, Zootaxa 5141 (3), pp. 287-294 : 288-292

Claassenia magna Wu, 1948

Figs. 1–7

Wu, 1948:146; Illies, 1966:328; Sivec et al., 1988:14; Du et al., 1999:60; Yang et al., 2018:24.

Adult habitus. General color yellowish brown, head mostly light yellowish brown; triocellate, ocelli white, black surrounded the inner base of the circles, light brown bands connected the mid-ocellus and two posterior ocelli, anterior ocellus smaller, posterior ocelli closer to each other than to the eyes; antennae dark brown; palpi yellow brown ( Fig. 1 ). Pronotum elliptical, middle longitudinal line were dark brown, surface rugose ( Fig. 2 ). Legs yellow brown, femorotibial joint darker. Wings translucent, veins dark brown ( Fig. 1 ).

Male. Forewing length 30.5 – 32.2 mm, hindwing length 27.3 – 29.3mm, body length 27.8 – 29.2 mm (n = 21). Terga 1 – 7 simple, tergum 8 with a small round group of scattered papillae near the middle of posterior margin; mesal area of tergum 9 slightly raised, with a larger oval patch of sensilla basiconica transversally arranged ( Figs. 3A–3B ); tergum 10 cleft into two parts, hemitergal lobes thick and finger-shaped, rounded apically, extending to 1/3 of tergum 9 ( Fig. 3C ), hemitergal lobes scattered tiny sensilla basiconica ( Fig. 3B ). Sternum 9 transformed into broad subgenital plate with a round hammer in the middle of the posterior margin, the posterior margin of sternum 9 sclerotized and covered with long hairs ( Fig. 3D ).

Aedeagus membranous, without any conspicuous lobes or spines, long cylinder, the base is simple, ventrally middle of aedeagus inflated to slightly spherical, both dorsally and ventrally the end slender and pointed ( Figs. 4A‒4B ).

Female. Forewing length 39.6 mm, hindwing length 36.4 mm, body length 41.8 mm (n = 1), general body color darker than males but pattern similar to males ( Fig. 5 ). Pronotum is similar in shape to males, margins and middle longitudinal line dark brown ( Fig. 6A ). Terga 9 – 10 dark brown, tergum 10 with triangular posterior projection ( Fig. 6B ). Sternum 8 with slight extension, subgenital plate broad and slightly protruded posteromedially, dense hairs on sternum 8, sternum 9 humped medially, the internode membrane of sterna 9 and 10 with a dense band of hairs, sternum 10 mostly pale, posterolateral margins brown ( Fig. 6C ).

Egg. Length ca. 0.51 mm, width ca. 0.38 mm (n = 1). Spindle-shaped, collar wide. Chorion covered with shallow pits and without ridges ( Fig. 7 ).

Material examined. 8 males, 1 female, China: Fujian Province, Nanping City, Wuyi Mountains , 240 m, N 27.73512, E 117.68541, 15-V-2021, leg. Huo Qing-Bo and Zhao Meng-Yuan; 11 males, China: Guangdong Province, Shaoguan City, Nanling National Forest Park, 1010 m, N 24.92694, E 113.02167, 20-V-2021, leg. Xiang Ya-Nan ; 2 males, China: Hunan Province, Chenzhou City, Mangshan National Forest Park, 500 m, N 24.98148, E 112.89213, 22-V-2021, leg. Xiang Ya-Nan.

Distribution. China (Fujian, Guangxi, Guangdong, and Hunan Province).

Remarks. The specimens that were collected at the type locality (Wuyi Mountain, Fujian Province) and the male described above are identical to the holotype of C. magna , all with a small group of sensilla basiconica on tergum 8 and a larger oval patch of sensilla basiconica on tergum 9 ( Figs. 3A‒3B ). Du (1999) redescribed the males based on specimens collected from Guangxi Zhuang Autonomous Region. In this study, we also examined a series from Nanling National Forest Park and Mangshan National Forest Park, which is close to Guangxi, and the morphological characteristics are consistent with C. magna .

Figures

FIGURE 1. Claassenia magna Wu, 1948. Male adult, dorsal view.

FIGURE 2. Claassenia magna Wu, 1948. Male head and pronotum, dorsal view.

FIGURE 3. Claassenia magna Wu, 1948. A. Male terminalia, dorsal view; B. Male tergum 8-10, details; C. Male hemitergum and cercal base, lateral view; D. Male terminalia, ventral view.

FIGURE 4. Claassenia magna Wu, 1948. A. Aedeagus, dorsal view; B. Aedeagus, ventral view.

FIGURE 5. Claassenia magna Wu, 1948. Female adult, dorsal view.

FIGURE 6. Claassenia magna Wu, 1948. A. Female head and pronotum, dorsal view; B. Female terminalia, dorsal view; C. Female terminalia, ventral view.

FIGURE 7. Claassenia magna Wu, 1948. A. Egg and collar, lateral view; B. Egg, surface details.