Capnia s. lat. bispina Cao & Li sp. nov.

urn:lsid:zoobank.org:act: B54BC6B4-681D-4ECA-833B-192955B1B8C7

Figs 1–8, 11A–B, 12A–C, 13–14

Diagnosis

The male of this new species differs markedly from that of most other members of the C. cordata species group by its caudally projecting posteromedial process of tergum IX ending in two acute spines.

Etymology

The specific epithet ‘ bispina ’ is derived from Latin ‘ bi ’ (meaning ‘two’ or ‘double’) and ‘ spina ’ (meaning ‘spine’ or ‘thorn’) in reference to the two apical spines of the posteromedial process of male tergum IX. Use as a noun, gender feminine.

Type material

Holotype

CHINA • ♂; Qinghai Province, Xining City, Datong County, Niangniang Mountain; 36°54′56.81″ N, 101°36′10.51″ E; 2864 m a.s.l.; 17 Mar. 2021; Wei-Hai Li and Fan-Bin Kong leg.; HIST.

Paratypes

CHINA • 9 ♂♂, 5 ♀♀; same data as for holotype; HIST .

Description

Male

ADULT HABITUS (Fig. 2). Body generally dark brown. Body length 9.1–9.3 mm. Forewing length 8.8– 9.0 mm, hindwing length 7.0– 7.2 mm (N = 10). Macropterous. Wing venation typical for species group. Forewing mottled, dark band in distal third, light band basal to it, other clouds of pigmentation. Head slightly wider than pronotum, with three ocelli, M-line and tentorial callosities dark brown. Antennae and palpi brown to dark brown. Pronotum trapezoid with dark rugosities, corner obtuse. Legs brown; tibiae lighter. Cerci with 17–18 slightly clubbed segments, each with apical whorl of long hairs.

ABDOMEN (Figs 2A, 4–7, 11A–B, 12A–B). Tergum I medially divided, terga II–IV subdivided by anteromedial membranous portion; antecosta medially divided on terga III and X, medially indent but entire on terga VI–IX (Fig. 11B). Terga IV–IX laterally with paired longitudinal patch and pair of spots. Tergum IX strongly sclerotized, posterior edge indenting laterad to posteromedial process, process slightly raised and extending to anterior margins of tergum X, 1 /5 × as wide as segment, falciform in shape and bilobed apically. Tergum X subdivided by evenly rounded anteromedial indentation (Figs 4–5). Sternum I entire and unmodified; sternum II with posterior sclerite not fused with anterior and lateral sclerites, sternum III with posterior sclerite not fused with anterior sclerites; sterna IV–VIII with anterior and lateral sclerites fused with posterior sclerite. Sternum IX fused with tergum IX anterolaterally (Fig. 11B); subgenital plate divided from other sclerites and tongue-shaped, with darkly sclerotized lateral margins; vesicle very large and covered with dense long hairs, rounded and wider than long. Short basal stalk, extending over ½ of subgenital plate (Fig. 4B). Paraprocts with long and wide apex, fusion plate long and narrow (Fig. 5B). Epiproct consist of large basal sclerite fused with relatively large, triangular basolateral sclerites; main epiproct sclerite 0.35 mm in length, long and widely triangular in dorsal view, dorsal edge convex while ventral edge convex in lateral view but apical third slightly dilated then abruptly narrowed into sharp, slightly downcurved apex. Dorsal division of main epiproct sclerite straight and narrow, only slightly opens after NaOH treatment; basal portion slightly darker, with delicate keel laterobasally; basal fork relatively large, fused with laterobasal sclerites; apex sharply pointed in both lateral and dorsal aspects (Figs 5, 12A–B); sclerite covered with dense setae on its dorsal and lateral surface, setae slightly shorter on basal portion and not similar to caudal setae of other Capniidae, sensillae occur on apex; inner sclerite long but thin and indistinct (Figs 6–7).

Female

ADULT HABITUS (Fig. 2B). Body length 10.5–10.6 mm. Forewing length 9.2–9.3 mm, hindwing length 8.2–8.3 mm. Habitus generally similar to male.

ABDOMEN (Figs 8, 11A, 12C). Terga I–VIII divided by wide median membranous area, each marked with pair of small dark spots; tergum IX with pair of anterior indentations, tergum X entire. Sternum I entire and unmodified; sterna II–VI with anterior sclerites not fused with posterior sclerite and lateral sclerites lacking, sternum VII with anterior sclerites not fused with posterior sclerite but small lateral sclerites present and fused (Figs 8A, C, 11A). Anterior sclerites of sternum VIII quadrangular, fused with subgenital plate. Subgenital plate wide trapezoidal, covering most of sternum (Fig. 12C), flat in lateral view; evenly sclerotized, setation lacking from medial portion and posterior lobe; posterior lobe less wide than ⅓ of subgenital plate width, not further lobed but expanded laterad with sharp, triangular portions. Lateral sclerites bean-shaped and bald, not fused with subgenital plate nor with tergum VIII. Postgenital plate and inner vaginal sclerite lacking. Sternum IX with wavy anterior edge, not fused with tergum IX; paraprocts triangular (Fig. 8B).

Distribution

China: Qinghai Province, Datong County. Adults were collected in mid-March, emerging from a slow to moderately fast flowing, small headwater tributary of the Datong River, its streambed consisting of large boulders and gravel (Fig. 13).

Remarks

Only C. s. lat. bilobata Chen & Song, 2019 and C. s. lat. badakhshanica Zhiltzova, 1974 share a similar tergum IX process, but in C. s. lat. bilobata, it is wider and bilobed without apical spines and in C. s. lat. badakhshanica, it is shorter and smaller. The entirely setose main epiproct sclerite is unique in the species group, also easily distinguishing the male. The female of C. s. lat. bispina Cao & Li sp. nov. appears the closest to C. s. lat. qilianshana Li & Yang, 2009 and C. s. lat. yunnana Li & Yang, 2011, sharing a similar narrow posterior lobe of the subgenital plate that is expanded lateral with triangular portions. However, the evenly sclerotized subgenital plate easily distinguishes the female from those two species.