Neoperla delphina, Li & Mo & Wang, 2020

Li, Weihai, Mo, Raorao & Wang, Guoquan, 2020, Two new species of Neoperla montivaga group (Plecoptera: Perlidae) from Guangxi Zhuang Autonomous Region of southern China, Zootaxa 4718 (4), pp. 573-583 : 574-577

Neoperla delphina sp. nov.

( Figs. 1–5 )

Adult habitus ( Figs. 1–2 ). Body color brown. Head dark brown, mouthparts brown, palpi light brown, antennae dark brown; biocellate, the distance between ocelli slightly wider than the diameter of the ocellus, ocelli triangle with yellow brown spots, brown patch on the anterior ocelli, two posterior ocelli covered by bat-like dark brown marking; head slightly wider than pronotum. Pronotum trapezoidal, anterior corners sharp, posterior corners round- ed. Wings brown and transparent, veins dark brown; legs brown and banded, but in some teneral or long preserved specimens the bands are obscure: forelegs: the apical third of femora, basal and apical fourth of tibiae dark brown, tarsi brown, remainder pale brown, the bands of midlegs and hindlegs narrower; cerci light brown, apex darker.

Male ( Figs. 2–3 ). Forewing length 16.1–19.2 mm. Hindwing length 13.2–16.3 mm. Tergum 7 process semicircular and extending backward, covered by dense sensilla basiconica; Tergum 8 with protuberance medially, covered by many sensilla basiconica apically. Tergum 9 without long hairs or lobes. Hemitergal processes of tergum10 up-curved, extending backward to the central process of the tergum 8, with a blunt tip. Aedeagal tube with ossified dorsal surface and with a Y-shaped ventral lobe subapically. The forks of the Y-lobe curved backward, and nearly contacting. The aedeagal sac slightly longer than the aedeagal tube and plump for its most length. The apex of the aedeagal sac shrinking into a finger-like shape that remind of the head of a dolphin; many spinules distributed in the distal half.

Female ( Fig. 4 ). Forewing length 19.2–23.3 mm. Hindwing length 16.2–20.1 mm. Sternum 7 extends backwards to form a triangular subgenital plate, the plate with long hairs and an emargination at the posteromedial edge; the subgenital plate reaching the midlength of sternum 8. The vagina basally subquadrate with obvious dark ossified foldings, spermathecal stalk short and slender, spermatheca sausage-shaped and basally curved; a single accessory gland occurs at distal one third; apex with a small tubular hook.

Egg ( Fig. 5 ). Length 0.34–0.39 mm, width 0.21–0.22 mm (N=5). Five mature eggs were dissected from female abdominal terminalia. Chorion brown. Hatching line inconspicuous. Outline oval shape with 70–78 outer striae reaching collar and lid; striae set closely without sulci between them. Micropyles sessile, dispersed between striae. Collar bigger than lid, both of them without distinct flange and FCIs, but with fine distinct punctations; anchor not studied.

Type Material. Holotype: male ( HIST), China: Guangxi, Laibing City, Jinxiu County, Dayao Mountain , Yinshan Station , 2016.V.22, G.Q. Wang . Paratypes: 2 males 1 female ( HIST), same locality and date as holotype ; 1 male ( HIST), Guangxi, Guilin City, Multinational Autonomous County of Longsheng, Huaping Nature Reserve , 2008. V.1, W.Z. Cai ; 43 males 15 females ( HIST), same locality as holotype, 2016. V.22, light trap, G.Q. Wang ; 50 males 8 females, Guangxi, Laibing City, Jinxiu County, Dayao Mountain , Yinshan Park , 1150m, 2016. V.21, light trap, F.Y. Liang ; 1 male 2 females ( NMP), Guangxi, Guilin City, Multinational Autonomous County of Longsheng, Hot Spring, Forested river valley, wet rocks, N 25°53.6’, E 110°12.4’, 360m, 2013 IV.11–14, M. Fikáček, J. Hájek & J. Růžička ; 1 male, Guangxi, Laibing City, Jinxiu County, Dayao Mountain , Yinshan Park, N 24°16’133’’, E 110°36’924’’, 1210 m, 2016.VIII.17, light trap, G.Q. Wang, W.H. Li & R. R. Mo .

Etymology. The term “delphina” refers to the dolphin-like apex of the male’s aedeagal sac.

Distribution. China (Guangxi Zhuang Autonomous Region).

Remarks. This species is similar to the species in diehli subgroup including N. han Stark, 1987 , N. furcostyla Li & Qin, 2013 , N. forcipata Yang & Yang, 1992 , N. mesostyla Li & Wang, 2013 , N. mnong Stark, 1987 , N. yao Stark, 1987 .. However, in Neoperla delphina sp. nov., the forks of the Y-shaped lobe are curved backward, while the bifurcations of other species extend forward.

Figures

FIGURE 1. Neoperla delphina sp. nov. (male). a. Adult habitus, dorsal view. b. Foreleg, lateral view.

FIGURE 2. Neoperla delphina sp. nov. (male). a. Head and pronotum, dorsal view. b. Terminalia, dorsal view. c. Terminalia, lateral view. d. Terminalia, oblique lateral view.

FIGURE 3. Neoperla delphina sp. nov. (male). a. Aedeagus, lateral view. b. Lobes of aedeagus, lateral view. c. Ventral lobes of aedeagus, oblique ventral view. d. Apical part of aedeagal sac, lateral view.

FIGURE 4. Neoperla delphina sp. nov. (female). a. Terminalia, ventral view. b. Vaginal complex, cleared, dorsal view.

FIGURE 5. Neoperla delphina sp. nov. (eggs). a. Eggs, lateral view. b. Entire egg, lateral view. c. Collar end, oblique apical view. d. Collar end, oblique apical view. e. Lid, lateral view. f. Micropyles (indicated by arrows).