Nemoura tripotini Zwick 2010

Teslenko, Valentina A., 2016, New records of the East-Asian Nemoura species (Plecoptera: Nemouridae) for South of the Russian Far East with description of the larvae, Zootaxa 4085 (4), pp. 575-588 : 584-586

Nemoura tripotini Zwick 2010

( Figs. 24−32 )

Zwick 2010. Illiesia, 6(9):86 (original description of the male including epiproct, cercus and paraproct). Female unknown.

Material examined. Russian Far East , Primorskyi Region: 1 mature larva of male, Vladivostok, Rybachyi Sett., Meortvaya Pad Stream, N 42°080.417’ E132°021.346’, 23.07.2015, coll. Gorovaya E .; 1 male, 1 female, the same place, 28.07.2015, coll. Teslenko V.

Description. Female ( Figs. 24, 25 ). Light brown, no pattern. Forewings 8.9 mm long. Sterna 1−6 are membranous. Sternum 7 extended medially and forms relatively small and narrow weakly sclerotized pregenital plate that covers the middle of sternum 8 completely ( Fig. 24 ). Posterior margin of the pregenital plate is slightly arcuate, lateral margins straight, anterior edge triangular elongated and poorly defined ( Figs. 24, 25 ). Sternum 8 shortened, a pair of triangular slightly sclerotized sclerites on the posterior margin arranges the paragenital plate. Sternum 9 extended medially due to rounded triangular projection on the anterior margin. In cleared slide mounted genitalia ( Fig. 25 ), two vaginal unpigmented lobes (S) with curved posterior edges are faintly visible. Subgenital plate consists of a narrow transversal weakly sclerotized sclerite (T) connected with a short tear-shaped, heavily sclerotized sclerite. A pair of rounded internally sclerotized rough pockets (Rp) inside of the pouch may be visible by transparency. Pouch (P) large, bean-shaped; its dorsal face anteriorly with a small rounded collar-like shield (Sh) and oviduct (O). Below small collar-like shield (Sh) an additional shield with large shawl collar (Co) and wavy margins are visible. A shawl collar of the pouch rounds laterally a pair of cap-shaped vaginal sclerites (C) strongly sclerotized dorsally ( Fig 25 ). Additional details of the internal folds and vaginal sclerites are presented in Fig. 25 .

Mature larva ( Figs. 26−32), preliminary description. Body relatively slender, the male body length is 6.8 mm. Color brown with no conspicuous pattern. Head with dark-brown tentorial callosities, the interocellar area without spot, occiput is darker ( Fig. 26). Pronotum lacking a pattern; rectangular with rounded corners, approximately 1.5 X wider than long. Mesonotum and metanotum brown with U-shaped dark brown band connected scutellum area and base of the wing pads. Legs mainly pale, femora pale, tibia darkened on ⅔ of the length. The fore femur is 2.6 X longer than wide, and the hind femur 3.3 X longer than wide. Abdomen relatively slender, terga brownish, without a distinct pattern.

Chaetotaxy distinct. Dorsally, chaetotaxy of the head and antennal segments similar to N. jejudoensis and N. jilinensis except numerous tiny cylindrical setae of various sizes with blunt apexes. Setal fringe around the pronotum wavy, consisting of occasional long hairs, slender cylindrical bristles of the different length that are slightly narrowed to the apex, apex irregularly notched ( Figs. 27, 28 ). Long, irregularly notched bristles observe on the anterior and posterior pronotal corners, the length of the longest bristles long reach 8% of the pronotal width. The pronotal disc with occasional long hairs and tiny cylindrical setae of various lengths with blunt apexes ( Figs. 27, 28 ); most of the head surface covered in the same kind of setae. The outer wing pad margin covered with slender irregularly notched bristles ( Fig. 29 ), tiny oval setae in the lines on the wing-pads; on the inner wing-pad edge are blunt. All femora with fine procumbent setae, short and long slender blunt bristles. Setal fringe on the outer femur margin begins from the second ½ of the length on the fore leg ( Fig. 30 ) and from the base of the length on the hind leg; setal fringe includes a few thin, long hairs; the longest, slender irregularly notched bristles occur in the apical ½ in an irregular arrangement. The longest slender irregularly notched bristles reach approximately 67% of the femur’s width on the fore leg and 50% on the hind leg. Chaetotaxy of tibia and tarsi very similar with N. jejudoensis and N. jilinensis , including the length of the spine-like bristles along outer and inner edges, except the hind leg, where setal fringe along the outer tibia’s edge includes spine-like bristles with length equals the tibia width. Terga covered with slender irregularly notched bristles of variable lengths ( Fig. 31 ). The posterior tergal margins feature slender irregularly notched bristles that are mostly short, there is one conspicuous pair of long, slightly curved, and slender irregularly notched bristles reaching 50% of the length of segment on the posterior margin of terga 5−6 ( Figs. 31, 32 ).

Diagnosis. Pronotal setal fringe irregular comprising slender cylindrical bristles slightly narrowed and irregularly notched at the apex; the longest bristles at the posterior corners longer than in the other species reaching 8% of the pronotal width. On the leg, the long, slender irregularly notched bristles in an irregular arrangement, also longer than in other species, and reach approximately 67% of the femur’s width on the fore leg and 50% of the length on the hind leg. Paired long slender irregularly notched bristles on terga 5−6 margins reach 50% of length of the segment, other bristles short, innumerous and sparsely placed.

Distribution. This species was known only from the type locality streams on Jirisan Mountain in the southern South Korea and were collected by a Malaise trap at alt. 400-700 m from June to August ( Zwick 2010). The RFE specimens of N. tripotini were collected from a forested stream with moderately fast flow and stony substrate mixed with sandy patches. At this site, N. tripotini was sympatric with N. jejudoensis and N. jilinensis . Nemoura tripotini was not common in the urban Meortvaya Pad Stream. Repeated surveys failed to collect additional material.

Figures

FIGURES 24 – 25. Female of Nemoura tripotini. 24. Abdominal tip, cleared, ventral. 25. Vaginal complex, cleared, dorsal. Ccap-shaped vaginal sclerite, Co—shawl collar with wavy margins; O—oviduct, P—bean-shaped pouch, Pl—pregenital plate, Rp—rounded roughened pocket, S—vaginal lobe, Sh—collar-like shield, T—transverse vaginal sclerite of subgenital plate. Scale (mm): 24 = 0.3; 25 = 0.1.

FIGURES 27 – 30. Larva of Nemoura tripotini. 27. Cylindrical irregularly notched bristles near midline on anterior margin of pronotum. 28. Chaetotaxy on disc and irregular setal fringe of right anterior pronotal corner. 29. Cylindrical irregularly notched bristles on outer margin and rows of tiny oval setae on wing pad. 30. Right fore leg. Scale (mm): 27 – 29 = 0.1; 30 = 0.3.

FIGURES 31 – 32. Larva of Nemoura tripotini. 31. Chaetotaxy of terga 5 – 6. 32. The longest slender irregularly notched bristles on posterior margin of terga 5 – 6. Scale (mm): 31 = 0.3; 32 = 0.1.