Neoperlops triangulatus, Mo & Wang & Li & Murányi, 2020

Mo, Raorao, Wang, Guoquan, Li, Weihai & Murányi, Dávid, 2020, Review of the Oriental genus Neoperlops Banks, 1939 (Plecoptera: Perlidae), Zootaxa 4763 (3), pp. 405-418 : 409-417

publication ID	https://doi.org/ 10.11646/zootaxa.4763.3.5
publication LSID	urn:lsid:zoobank.org:pub:CE6E98DB-0D3A-4709-ADA0-9BA1378390F0
DOI	https://doi.org/10.5281/zenodo.3805313
persistent identifier	https://treatment.plazi.org/id/03BC8436-FFD4-C820-FF5A-F8D3E5ADFD81
treatment provided by	Carolina
scientific name	Neoperlops triangulatus
status	sp. nov.

Treatment

Neoperlops triangulatus View in CoL sp. nov.

( Figs. 3–8 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 )

Adult habitus. General color brown. Head brown with a large dark brown trapezoidal marking, covering ocellar area and extending forward to pale M-line; tentorial callosities slender with curved tips, included in the dark brown patch ( Figs. 3a View FIGURE 3 , 5a View FIGURE 5 ). Biocellate, distance between ocelli about twice as wide as diameter of the ocellus, tentorial cal- losities set close to ocelli. Palpi brown; antennae dark brown, scape paler. Pronotum brown and elongate oval, with a pair of pale brown areas at lateral surfaces; lateral and posterior margins dark brown; rugosities large but obscure except two darker and distinct rugosities present on mediolateral surfaces; slightly narrower than head with eyes ( Figs. 3a View FIGURE 3 , 5a View FIGURE 5 ). Meso- and metathorax ventrally pale, dorsally with brown to dark brown pattern; metathorax with anteromedial brush, being much sparser on the female. Wings membrane brownish with darker veins. Legs pale brown but distal one fourth of femora to tarsi dark brown ( Fig. 4a View FIGURE 4 ). Abdomen pale, sterna 5–7 with medial brush; cerci brown, relatively long.

Male ( Figs. 3–4 View FIGURE 3 View FIGURE 4 ). Forewing length 16.0– 17.5 mm; hindwing length 15.0–16.0 mm. Terga 7–9 bear prominent mesal patches of sensilla basiconica, among them, the patch of sensilla basiconica of tergum 9 is interrupted by a narrow bare band ( Figs. 3 View FIGURE 3 b–d). Hemitergal anterior processes short and flat, spatula shaped in lateral aspect, lacking strong setae; inner basal surface of hemiterga inflated, cushion-like and covered with minute sensilla basiconica ( Figs. 3 View FIGURE 3 b–d).

Aedeagus ( Figs. 4 View FIGURE 4 b–e) mostly membranous but weak sclerotization occurs in basal half; slightly constricted medially and strongly curved ventrally, shape like a “hair dryer;” apical half distinctly enlarged. Basal portion with dorsal field of small scales, a large patch of fine triangular spines covers most of the enlarged apical half but is interrupted by the triangular membranous lobe on the dorsum; apex membranous, bare.

Female. Forewing length 27.0– 28.5 mm; hindwing length 22.0–23.0 mm. abdominal sterna generally pale, but sterna 5–7 medially darker around poorly developed brush. Sternum 8 with small, brown and triangular subgenital plate, forming a distinct bump in lateral view ( Figs. 5 View FIGURE 5 c–d). Sternum 9 with mediolateral pair of brown spots, sternum 10 unmodified, paraproct pale and blunt. Vagina simple, membranous.

Egg ( Fig. 5b View FIGURE 5 ). Length 0.32–0.40 mm, width 0.28–0.36 mm (N=8). Outline oval, nearly globular, chorion dark brown. Opercular line is at one fourth to opercular end. Chorion smooth, micropyles indistinct. Collar short but distinctly flanged, collar rim sinuous. Anchor consists of tentacle-like fibers.

Larva. Body length of female larvae 21.0– 22.5 mm, male exuviae 14.0– 16.5 mm, female exuviae 21.0–23.0 mm. General color brown, with dark brown pattern on head and thorax, and reddish terminal terga and cerci ( Fig. 8a View FIGURE 8 ); ventral surface generally pale ( Figs. 6 View FIGURE 6 e–f). Head mostly dark brown but with pale occiput, tentorial callosities, a transverse patch anterior to M-line, and smaller anteromedial patch on frons; occipital area not elongated, eyes normal sized. Biocellate, distance between ocelli about twice as wide as diameter of one ocellus, tentorial callosities longitudinally elongated and set close to ocelli. Occipital ridge distinct, row of occipital setae complete, setae rather long around eyes; remainder of the head covered by fine, black clothing hairs ( Fig. 6a View FIGURE 6 ). Antenna brown, palpi pale brown ( Fig. 6c View FIGURE 6 ). Postmentum undivided, glossa and paraglossa usual for the family ( Fig. 6e View FIGURE 6 ). Lacinia bidentate, apical tooth longer than subapical tooth, marginal fringe consists of 6–8 strong setae and several thin hairs; galea as long as apical tooth of lacinia, bears only apical setae ( Fig. 7f View FIGURE 7 ). Mandible wide, having two molar and two or three incisors, molar brush dense and relatively long ( Fig. 7e View FIGURE 7 ). Pronotum with rounded corners, less than twice wider than long, marginal row of setae complete, moderately long; the disc is brown to pale brown but submarginal edges dark brown, rugosities numerous but not distinct ( Fig. 6b View FIGURE 6 ). Meso- and metanotum similar in coloration, all thoracic segments covered by fine, black clothing hairs. Mesosternum with long furcasternal pit, furcasternal arms also long ( Fig. 6e View FIGURE 6 ). Thoracic gills moderately long and with dense branches ( Fig. 6e View FIGURE 6 ). Proventricular teeth denser on the basal section of folds ( Fig. 7b View FIGURE 7 ). Legs long, dorsal row of swimming hairs dense, long and distinct on femora, similar on tibiae; surface setation consists of black clothing hairs and regularly placed, short brown setae ( Figs. 6c View FIGURE 6 , 7a View FIGURE 7 , 8b View FIGURE 8 ). Abdominal terga lack distinct pattern, but gradually darkened towards terminalia, with a reddish hint ( Fig. 8b View FIGURE 8 ). All terga bear dense apical row of setae with equal length, about of one fourth of segment length; most of the surface is covered with fine, black clothing hairs, and short setae similar to those on femora; medial silky hairs incomplete, scarce ( Figs. 6d View FIGURE 6 , 7a, 7c View FIGURE 7 ). Clothing hairs pale on sterna, stout brown setae present on lateral areas; the apical row medially widely interrupted on sterna 2–5, complete on sterna 6–10 in case of males while on female sternum 8 it is narrowly interrupted by the shallow genital notch ( Fig. 6f View FIGURE 6 ). Paraproct simple, bears a long and dense anal gill ( Figs. 6f View FIGURE 6 , 7 View FIGURE 7 c–d). Cercus as long as the body, reddish, lacks swimming hairs; apical row consists of short but erect, brown setae, intercalary hairs long and pale, fit tight ( Figs. 7 View FIGURE 7 c–d).

Type material. Holotype male ( HIST): CHINA, Guangxi Zhuang Autonomous Region, Shangsi County, Shiwanda Mts , Wanggui Village , Pinglong River at the village, 21°52.411' N, 107°49.996' E, 260m, 2015.iii.28, J. Kontschán, W.H. Li, D. Murányi, G.Q. Wang GoogleMaps . Paratypes: same data as holotype: 3 males 1 female ( HIST), 2 males, 1 female with its exuviae, 3 male and 3 female exuviae ( HNHM); Guangxi Zhuang Autonomous Region, Shangsi County, Shiwandashan National Forest Park GoogleMaps , Minan River GoogleMaps , 21°51.869' N, 107°50.712' E, 300m, 2015.iii.28, J. Kontschán, W.H. Li, D. Murányi, G.Q. Wang: 1 female larva ( HIST), 1 female larva ( HNHM); Guangxi Zhuang Autonomous Region GoogleMaps , Shangsi County GoogleMaps , Shiwandashan National Forest GoogleMaps Park, Pearl River GoogleMaps below tourist route bridge, 21°54.122' N, 107°54.292' E, 315m, 2015.iii.29, J. Kontschán, J.N. Li, S. Li, W.H. Li, D. Murányi, G.Q. Wang: 1 female larva, 1 male exuviae ( HNHM).

Etymology. The specific name is composed of the Latin words “tri” (three) and “angulus” (angle) and refers to the shape of the triangular lobe in dorsum of aedeagus.

Distribution and ecology. China, Guangxi Zhuang Autonomous Region, Shiwandashan Mountains. Larvae and exuviae were found at three nearby small stony rivers. Adults were emerging only at the Pinglong River ( Fig. 8a View FIGURE 8 ). No adults were attracted to light. The species was found at the Pinglong River with several other Perlidae , a few Nemouridae and Leuctridae species; exuviae of a Chloroperlidae species was found.

Remarks. The female of the new species is similar to the types of N. obscuripennis in coloration but differs with nearly globular eggs differing from elongated oval eggs of the types. As mentioned above, Vietnamese specimens reported by Stark & Sivec (2008) as N. obscuripennis , clearly belong to two species. The illustrated Vietnamese adults differ from the new species by small dark pattern on head, undivided sensilla basiconica patch on male tergum 9, presence of spines on the apex of male hemiterga, much more scales on the basal half of the aedeagus, and nearly erect shape of the aedeagus ( Stark & Sivec 2008, figs. 2–4). Neoperlops vietnamellus , the third species of the obscuripennis group, differs from the new species by partly divided sensilla basiconica patch on tergum 9, fingerlike apex of the male hemiterga, and more dense surface structures of the aedeagus ( Cao & Bae 2008, figs. 4–7). The larva can be distinguished from N. vietnamellus and the Vietnamese specimens illustrated by Stark & Sivec (2008) based on different head pattern, in addition, from N. vietnamellus by complete marginal row of setae on pronotum, and scarce medial silky hairs on the abdomen.