Capniella gibba Hwang, Li & Murányi, 2021

Cao, Zhishan, Yang, Ding & Li, Weihai, 2021, The first records of Capniella (Plecoptera: Capniidae) from northeast China, Ecologica Montenegrina 48, pp. 49-61 : 50-52

Capniella gibba Hwang, Li & Murányi, 2021

( Figs. 1–7 )

Capniella gibba Hwang, Li & Murányi, 2021 — Hwang et al. 2021: 44 .

Adult habitus ( Figs. 1–2 ): Body generally dark brown; wings slightly brachypterous, hyaline with brown veins. Forewing: one crossvein between the C and Sc veins, R1 vein strongly curved, A1 vein straight, cubital cell triangular. Hindwing similar to forewing, but anal field bigger. Head wider than pronotum, with three pale and small ocelli, compound eyes round and dark. Antennae and palpi brownish. Pronotum trapezoid with dark rugosities, as wide as long, corners rounded. Legs brown to dark brown. Cerci with 17 segments; distal portion of each segments enlarged.

Male ( Figs. 1a–b , 3–5 ): Body length 3.6–3.7 mm, forewing length 2.6–2.7 mm, hindwing length 2.1–2.2 mm. Tergum 6 with a long finger-shaped posteromedial process, darkly sclerotized, and extend more than the length of tergum 7. The process is slightly elevated, surface covered with very small tubercles and a few setae. Tergum 7 with a conical posteromedial process, darkly sclerotized, apex inverted heart-shaped and bearing big sensilla basiconica. In lateral view, the process on tergum 6 is more elevated and longer than the process on tergum 7. Sternum 9 elliptical with sclerotized margins, vesicle absent. The paraprocts are medium long, apically tapering. The main epiproct sclerite is strongly cleft laterally into a lower and an upper portion, the upper portion is further divided into left and right parts. Each parts of the upper portion are long and triangular, but basally narrow; the opening between them is nearly as wide as the width of each parts. Base of the upper portion dark, median and apical section semitransparent and forming eversible crest on both parts, their apices are pointed and bear few, small sensillae. Lower portion sclerotized and broad basally, medially narrowing, apex ventrally with two sickle-shaped sclerites on both sides and one finger-like sclerite in the middle ( Fig. 4b ); in the lateral view, apex of the lower portion is rabbit-shaped ( Fig. 4d ).

Female ( Figs. 1c–d , 6 ): Body length 5.2–6.3 mm, forewing length 3.9–4.0 mm, hindwing length 3.6–3.7 mm. Terga 1–8 full divided by median membranous area. Sterna 1–7 with quadrate posterior sclerite. The subgenital plate on sternum 8 is rectangular, twice wider than long, corners strongly obtuse, anterior margin slightly concaved medially; darkly sclerotized basally, lateral margins lighter. The subgenital plate covers only half length of sternum 8, slightly raised in lateral view; posterolaterally connected to large, triangular lateral sclerites.

Material examined: China: Liaoning Province, Dandong City, Kuandian Manchu Autonomous County, Tianhuashan Mountains , 41°4'N, 124°35'E, 4.III.2011, leg. J.C. Wang & W.H. Li: 9 males and 10 females .

Distribution: Known from South Korea and Liaoning Province of northeast China. The Chinese specimens were found along a stream draining Tianhuashan Mountains, located in the eastern part of Liaoning Province, an area of dense coniferous and broad-leaved mixed forest ( Fig. 7 ). The species seems scarce, but adults were easily located walking on the fresh snow fell on the last day of our collecting trip to the Tianhuashan Mountains. Specimens were collected together with type specimens of two wingless Limoniidae species: Chionea sphaerae Zhang, Wang & Yang, 2012 and C. tianhuashana Zhang, Wang & Yang, 2012 ( Zhang et al. 2012).

Remarks: The four species of this genus are all having processes on male terga 6–7, but the processes are obviously different. Male of C. gibba is having single process on both terga, C. nodosa is having single process on tergum 6 and two processes on tergum 7, while C. endemica and C. ghilarovi are having two processes on both terga (compare figs. 1182–1185, 1190–1194 in Teslenko & Zhiltzova 2009). The shape of the processes are also distinctive: the process on tergum 6 of C. gibba is finger-shaped and extending over tergum 7, but of the other species the processes are not extending beyond tergum 7 and are more rounded. Main epiproct sclerite of the four species are also different in shape. In C. nodosa and C. gibba , the upper portion of the main epiproct sclerites are longitudinally divided, but those of C. endemic and C. ghilarovi are divided only in the apex (compare figs. 1182–1184, 1190–1193 in Teslenko & Zhiltzova 2009). The parts of the upper portion is widely separated in C. gibba but narrowly separated in C. nodosa , meanwhile the eversible crest on the upper portion is much bigger in C. nodosa . In C. gibba , the apex of the lower portion is branched, while the other three species are having lower portion with beak-like apex. The females of the four species can be distinguished on the basis of their subgenital plate. The rectangular subgenital plate of C. gibba covers only half length of the sternum 8, while that of the other three species covers more than three fourths of length. In addition, the subgenital plate of C. nodosa is butterfly-shaped, of C. nodosa is trapezoid, and of C. ghilarovi is semicircular (compare figs. 1185, 1195 in Teslenko & Zhiltzova 2009).

Figures

Figure 1. Capniella gibba Hwang, Li & Murányi, 2021 — a–b: male habitus, dorsal view; c–d: female habitus, dorsal view — scale 1 mm.

Figure 2. Capniella gibba Hwang, Li & Murányi, 2021 (male) — a: forewing; b: hindwing — scale 0.1 mm.

Figure 3. Capniella gibba Hwang, Li & Murányi, 2021 (male) — a: terminalia, dorsal view; b: terminalia, lateral view; c: terminalia, ventral view — scale 0.1 mm.

Figure 4. Capniella gibba Hwang, Li & Murányi, 2021 (male terminalia after 10% NaOH treatment) — a: terminalia, dorsal view; b: epiproct, dorsal view; c: terminalia, lateral view; d: epiproct, lateral view — scale 0.1 mm.

Figure 5. Capniella gibba Hwang, Li & Murányi, 2021 (male) — a: terminalia, dorsal view; b: terminalia, lateral view; c: processes of terga 6 & 7, dorsal view; d: apex of the main epiproct sclerite, dorsal view; e: apex of the main epiproct sclerite, lateral view.

Figure 6. Capniella gibba Hwang, Li & Murányi, 2021 (female) — a: terminalia, dorsal view; b: terminalia, ventral view; c: terminalia, lateral view — scale 0.1 mm.

Figure 7. Capniella gibba Hwang, Li & Murányi, 2021 habitat: Tianhuashan Mountain, in east of Liaoning Province, an area of coniferous and broad-leaved mixed forest (Photo by Weihai Li).