Nemoura jilinensis Zhu & Yang 2003

(Figs. 13−25)

Zhu & Yang 2003. Acta Zootaxon. Sin., 28(3): 474 (original description of male and female); Zwick 2010. Illiesia, 6(9): 83 (supplementary description of the epiproct and the male cerci; Yang et al. 2014:363.

Material examined. Russian Far East, Khabarovskyi Region: 3 males , 3 females, Ussuri River Basin, unnamed creek on the right side of the Khor River near Srednekhorskyi Sett., N 47°40.572’ E 136°155.595’, 13.06.1995, coll. Tiunova T .; Primorskyi Region: 3 males, “ Kedovaya Pad ” Reserve, 19.08.1975, on light, coll. Klestov N .; 1 male, “ Kedovaya Pad ” Reserve, Kaskadnyi stream, tributary of the Kedrovaya R., 11.07.1977, coll. Nikolajeva E .; 2 males, Far Eastern Marine Biosphere Reserve, Gorshkova Bay, small unnamed stream, N 42°400.727’ E 131°124.833’, 1.07.1997, coll. Vshivkova T .; 2 males, 2 females, 2 nymphs,, creek Serebryannyi, near road to Slavyanka Sett., N 42°530.078’ E 131°183.857’, 29.05.2015, coll. Drozdov G .; 4 males, 4 females, 17 male larvae, 13 female larvae, 4 exuviae, Vladivostok, Kirova street, small urban forested stream, N 43°110.956’ E 131°544.300’, 18.04.–1.06.2015, rearing, coll. Teslenko V; 1 male, 3 females, the same place, 1.05.2015, sweeping, coll. Teslenko V.; 1male, 2 female larvae, Vladivostok, Rybachyi Sett., Meortvaya Pad Stream, N 42°080.417’ E 132°021.346’, 28.07.2015, coll. Teslenko V .; 1 female larvae the same place, 16.08.2015, coll. Teslenko V.

Mature larva (Figs. 13−23). Body stoUt, the male body length 7.4–8.2 mm; 7.8–9.5 mm in females. Body redbrown with no conspicuous pattern. Head stout with narrow red-brown stripes anteriorly on the tentorial callosities connected with a triangular red-brown spot in the interocellar area (Figs. 13, 14). Interocellar triangular spot with a short, longitudinal, narrow dark mark backward anterior ocellus. Epicranial arms and stem pale; a triangular, oblique red-brown patch near each compound eye and vertex forming a triangular patch directed toward the lateral ocellus. Occiput brown and slightly red-brown at the base. Antenna and pronotum as in N. jejudoensis . Pronotum approximately 1.6 X wider than long. Pattern on the pronotum indistinct, with small red-brown spots that form a figure with a butterfly-like-shaped contour; a pair of triangular red-brown patches medially close to the posterior margin, and the anterior and posterior margins are medially darkened (Figs. 13, 14). Mesonotum and metanotum with V-shaped dark brown patches anteromedially, and a pattern not pronounced (Fig. 14). Legs pale. Femora lack an apical dark ring and a semi-oval pale patch close to inner edge basally (Fig. 14). The fore femur 1.9 X longer than wide (Fig. 18), and the hind femur 2.6 X longer than wide. Abdomen relatively slender, integument light and dull. Terga brown, posterior margins darkened, a pair of medial rounded pale spots on terga 1−8 forms a mesal longitudinal band, and no lateral bands lacking (Figs 13, 14). Ventral surface of the body pale with brown patches. Cerci pale with 22-24 segments (Fig. 20); the cerci length eqUals 56−60% of body length; laterally segments of basal and middle subparallel, apical cercal segments club-like (Fig. 23).

Chaetotaxy of the head dorsally and antennal segments almost similar to N. jejudoensis . Setal pronotal fringe relatively regular, consists of oval bristles slightly narrowed and rounded at the apex; short oval bristles present on the anterior and posterior margins medially (Fig. 15). Long, oval bristles occupy the anterior corners and lateral margins, where arranged close to each other and form an almost regular line (Fig. 16). Few longest bristles occasionally at the posterior corners, the length of the longest cylindrical bristles equals 4.2% of pronotum width. The pronotum disc with occasional long hairs; patchy, tiny procumbent setae; and short, thin oval setae of various lengths and acute at the apexes (Figs. 15, 16). The outer wing pad margin with long sharp bristles (Fig. 17). Tiny setae in the sutures on the wing-pads and at the inner wing-pad margins small and pointed (Fig. 17). All femora have almost the same types of setae as in N. jejudoensis, except long, spine-like bristles in a regular arrangement forming a narrow, semi-ring near the apical ⅓ of the femUr on the foreleg (Fig. 18); the middle leg and hind leg have long spine bristles in an irregular arrangement. The longest spine-like bristles reach 36% of femur width on the fore leg and 26% on the hind legs (Fig. 18). Chaetotaxy of tibia and tarsi similar with N. jejudoensis . Terga are covered with numerous, densely placed acute bristles at variable lengths and a few fine, procumbent setae. The posterior terga margins feature acute bristles that are mostly short with one conspicuous lateral pair of relatively long, slightly curved, spine-like bristles that reach 35% of the segment’s length on the posterior margin terga 5−6 (Fig. 19). Cercal segments have an apical whorl of bristles and apparent long, intercalary setae (Figs. 20, 22, 23). The apical whorl as in N. jejudoensis except number of long acute bristles, reaching 11 in the basal and middle cercal segments (Figs. 21, 22). The longest bristles reach 72% of the segment’s length at cercal segments 14−16 (Fig. 22). Thin intercalary hairs increase in size from the basal to the middle portion of the cerci and then decrease at the distal cercal segments. The longest intercalary hairs reach 52% of the segment’s length at cercal segments 13−19, where their number is approximately 10 (Fig. 22). Setal ring of apical cercal segments sparse, intercalary hairs noticeable (Fig. 23).

Diagnosis. Pronotal fringe relatively regular, not irregularly notched, oval bristles, narrowed and rounded at the apex with different lengths, the length of the longest cylindrical bristles at the posterior corners shorter than in N. jejudoensis, not exceeding 4.2% of pronotum width. On the foreleg, the long, spine-like bristles in a regular arrangement; the medium and hind legs have long, spine-like bristles in an irregular arrangement. The longest spine-like bristles reach approximately 36% of the femur’s width on the fore and 26.0% on the hind leg. Paired spine-like bristles on terga 5−6 margins reach 35% the length of segment, other bristles short and densely placed. Cercal segments with conspicuous long intercalary thin hairs, the longest intercalary hairs reach 52% of the segment’s length on cercal segments 13−19, where their number is approximately 10. In apical whorl the long acute bristles reach 72% of the segment’s length at cercal segments 14−16, the number equals 11.

Distribution. The species was described from northeastern China. Type locality is Jilin, Hunjiang District (Zhu & Yang 2003). Nemoura jilinensis is also known from South Korea (Kangwondo) (Zwick 2010). Both of the above sites are in the Changbai Shan Mountains. The extreme northeastern spurs of the Changbai Shan Mountains form elevated areas of the Black Mountains Range on the South of the Russian Far East where the “Kedrovaya Pad” Reserve is located. My new record for N. jilinensis in the “Kedrovaya Pad” Reserve streams near small forested creeks near Slavayanka Sett. in the Far Eastern Marine Reserve in the urban vicinity of Vladivostok seems predictable. Additional collections of N. jilinensis from the Khor River indicate that this taxon is distributed in streams flowing from the western slopes of the Sikhote-Alin Mountain Range into the Amur River Basin. Mature nymphs were found in May-July, suggesting a flight period that extends to August in the Russian Far East. Specimens were collected from forested streams and springs, both with fast or slow discharge with a substrate of stones or gravel mixed with allochthonous material.