Filchneria wusuensis Chen, 2019,

Teslenko, Valentina A. & Palatov, Dmitry M., 2021, A poorly known species and new records of Plecoptera from the Eastern Tien Shan, Xinjiang Uygur Autonomous Region, China, Zootaxa 4950 (1), pp. 123-136: 129-133

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Filchneria wusuensis Chen, 2019


Filchneria wusuensis Chen, 2019 

Figs. 13–30View FIGURES 13–15View FIGURES 16–22View FIGURES 23–26View FIGURES 27–30

Chen, 2019:512, figs. 1–7.

Material examined. China, the Xinjiang Uygur Autonomous Region, Eastern Tien Shan   : 1 male, 1 female, 1 nymph, Bogdo-Ula Range, Urumqi city, Dabancheng District , Zienzan stream in the headwaters of the Malu River , an altitude 2,443 m above sea level. 09.VII.2017, N 43°49.738’, E 88°10.351’, leg. D.M. PGoogleMaps  .; 2 males, 1 female, Bogdo-Ula Range, Urumqi city, Dabancheng District , Sangecha Stream , 35 km N of Dabancheng, an altitude 2,356 m above sea level, 13.VII.2017, N 43°40.583’, E 88°17.006’, leg. D.M. PGoogleMaps  .; 6 males, 1 female, Karlyktag Range, Hami city, Ayar-Gol Stream , 60 km NE of Hami, an altitude 2,426 m above sea level, 21.VII.2017, N 43°12.225’, E 94°07.128’, leg. D.M. PGoogleMaps  .

Supplementary description. Adult habitus. The head is brown, with an indistinct M-line, tentorial callosities on the clypeus pale, a pair of narrow transverse, and yellow marks above the lateral ocelli and small black spots inside ( Figs. 13View FIGURES 13–15, 23View FIGURES 23–26). The interocellar area has a large, tire-shaped yellow spot that widens anteriorly and is open posteriorly, an almost square, pale-brown spot is present anterior to the median ocellus and a vague M-line. The occipital area bears a transverse yellow band that extends along the epicranial suture ( Figs. 13View FIGURES 13–15, 23View FIGURES 23–26). The submental gills are short. The pronotum is brown, with a large median yellow band that occasionally includes a thin brown stripe along the median pronotal line and two thin incomplete brown stripes laterally ( Fig. 13View FIGURES 13–15). The lateral arms of the mesofurcasternum reach the posterior corners of the furcal pits, with dark beak-like spots at the inner edges of each furcal pit, a dark brown transverse suture occurs on the mesosternum that is unclear and incomplete anteromedially. The abdomen is covered with colorless clothing hairs ( Figs. 13, 14View FIGURES 13–15), and segments 1–3 are divided by a pleural membrane laterally. The pleural folds on segment 4 are vague, and the other segments are undivided. The legs are yellow with brown bands ( Fig. 13View FIGURES 13–15). Dorsally, the femur has a dark brown band that widens basally closer to the inner margin, while the outer margin is pale. The tibia has a dark brown band in the basal quarter ( Fig. 13View FIGURES 13–15). The cerci are bicolored, each segment with a narrow yellow band basally and a wide brown band distally ( Fig. 13View FIGURES 13–15). The color pattern of the female is similar to that of the male, with the exception that the interocellar spot is nearly closed posteriorly while the pronotal median band is narrower and widest posteriorly ( Fig. 23View FIGURES 23–26).

Male. The body is 15.2–19.7 mm in length (n=9). The male is brachypterous, wings not exceeding tergum 6 ( Figs. 13, 14View FIGURES 13–15). Abdominal terga 6–8 are humped laterally; medial indistinct pale spots expand anteriorly and are divided by a longitudinal, dark brown median band ( Fig. 14View FIGURES 13–15). Tergum 8 bears two submedial swellings densely covered by short sensilla basiconica and long colorless hairs posterolaterally. Tergum 9 has an anteromedial arrowshaped membranous area that may be almost hidden under tergum 8 ( Figs. 14, 15View FIGURES 13–15). Similar but smaller posteromedial swellings occur on tergum 9 and are covered by thick sensilla basiconica and colorless hairs posterolaterally ( Fig. 15View FIGURES 13–15). The sensilla basiconica appear much less frequently than on tergum 8 and their bases are clearly outlined with pale brown pigments. In the lateral view, posterior margin of tergum 10 is strongly raised, obtusely angled, and directed forward and upward. In the dorsal view, tergum 10 is rounded posteriorly and is mostly pale with small round membranous marks anteromedially and a pair of diffuse paramedial brown spots ( Figs. 15View FIGURES 13–15, 22View FIGURES 16–22). Short sensilla basiconica are distributed radially from the posterior margin to two-thirds of the tergite length in the middle ( Fig. 15View FIGURES 13–15).

At rest, the paraprocts are triangular with convex dorsomedial edges ( Fig. 16View FIGURES 16–22). The paraproct sclerite is triangular, wide, heavily sclerotized basally, and narrowed distally with a pointed tip that is occasionally truncated and slightly sclerotized ( Figs. 14View FIGURES 13–15, 19View FIGURES 16–22). In the caudal view, the paraproct sclerite surrounds a gray oval paraproct lobe covered with dense, tiny, dark brown sensory spines and sparse fine sensory hairs ( Figs. 16–20View FIGURES 16–22). The naturally everted eversible paraproct lobe (EPL) enlarges into a cylindrical membranous lobe with a small papilla atop, and is covered dorsally by sparse fine sensory hairs ( Figs. 18, 19View FIGURES 16–22). In the caudal view, the EPL margin close to the base bears a small, rounded swelling directed inside that is covered with dense, tiny, dark brown sensory spines and sparse fine sensory hairs ( Fig. 19View FIGURES 16–22). The naturally everted aedeagus is variable in shape, membranous, short and wide, and bears unpaired anterodorsal and posterodorsal lobes, and has two pairs of lateral lobes ( Figs. 21, 22View FIGURES 16–22). The anterodorsal lobe looks like a low, wide, and round arch that emerges above the aedeagus with paired small round cuticular swellings laterally ( Fig. 21View FIGURES 16–22). Each anterolateral lobe is smaller than the posterolateral lobe, with small, round, or papilla cuticular swellings at the apex ( Fig. 21View FIGURES 16–22). Each posterolateral lobe is extended and rounded laterally, occasionally with round cuticular swellings at the apex directed upward. The posterodorsal lobe is wide at the base with a triangular top reaching the bases of the lateral cuticular swellings of the anterodorsal lobe ( Fig. 21View FIGURES 16–22).

Female. The body is 23.5 mm in length, macropterous, and has a forewing length of 14.0 mm and a wingspan of 31.0 mm. The forewing is brownish, while the hind wing is paler ( Figs. 25, 26View FIGURES 23–26). The venation includes an irregular net near the apex comprising three rows of cells. The forewing has three cross-veins between C and Sc and five apical veins between Sc and R 1 ( Fig. 25View FIGURES 23–26). Rs bears three apical branches. There are seven apical veins between М and Cu 2, and three anal veins. The hind wing has a large anal area, and A 2, A 3 and A 5 are forked.

Sternum 8 is brown in the anteromedian half, and a pair of oblique dark brown lateral sclerites surrounds a pale subgenital plate anterolaterally ( Fig. 24View FIGURES 23–26). The subgenital plate is bilobed, large, extending almost half the length of sternum 9. The posterior margin has an U-shaped notch that separates two large lobes with almost straight inner angles. Sparse, tiny, dark setae form a field at the base of the U-shaped notch ( Fig. 24View FIGURES 23–26).

Egg. This is large, rather circular than trilateral in cross-section (the last feature is typical for Filchneria  ) with dimensions of 715×475 μm. The longitudinal ridges are not specially marked ( Figs. 27–29View FIGURES 27–30). The collar is short and formed by weak, barely noticeable extensions of the three longitudinal ridges, and the inner edges of the collar are slightly curved ( Figs. 28, 29View FIGURES 27–30). The sides of the collar bear short longitudinal carinae ( Fig. 28View FIGURES 27–30). The margin of the shoulder transitions smoothly to the egg chorion surface ( Fig. 28View FIGURES 27–30). A transverse row of two to seven micropyles is subequatorial; micropyles have a small, short lipped orifice ( Fig. 30View FIGURES 27–30). The anchor is mushroom-shaped, with single globular bodies on the anchor plate ( Fig. 27View FIGURES 27–30). The margin of the anchor covers the collar completely ( Fig. 27View FIGURES 27–30). The chorionic surface is rough with small, light tubercles ( Fig. 28View FIGURES 27–30).

Note. In our material that was collected at an altitude of 2,300 –2,400 m, F. wusuensis  males had a darker, more contrasting body color pattern, especially on the pronotum, than the holotype. This may be due to the maturity of the adults as well as differences in environmental conditions (increased ultraviolet radiation, decreased temperature, etc.) compared with the type locality at 1,700 m above sea level. On the other hand, the male described in our material is identical to the holotype of F. wusuensis  in its pale color pattern on tergum 10, location of the sensilla basiconica on terga 8–10, cylindrical shape of the naturally everted EPL, and small papilla at the tip of EPL ( Fig. 19View FIGURES 16–22). In general, the penial armature is similar, but in the male described from our material, the aedeagus is turned out more than in the holotype; therefore, the membranous lobes are more distinct. Females from fresh material were similar to Chen’s (2019) paratype. They had a similar color pattern on the head, pronotum, and shape of the notch on the bilobed subgenital plate, with almost straight inner angles as in the paratype ( Fig. 24View FIGURES 23–26). The collar on the egg in the paratype appeared to be present but was poorly visible due to use of a low magnification and lack of scanning electronic imaging, making it impossible to compare the features of the сhorion structure.

Distribution and ecology. The distribution of F. wusuensis  is limited to the Eastern Tien Shan and was first described in China, in the Xinjiang Uygur Autonomous Region, Wusu City, and Bayingou River located in the Eastern Tien Shan. Our specimens were collected in the streams of the neighboring locality, in Bogdo-Ula and Karlyktag Ridges. Filchneria wusuensis  inhabited mountain streams at altitudes of 2,300–2450 m above sea level, including those fed by glaciers ( Figs. 35–37View FIGURES 33–37). Adults were found in July.


Departamento de Geologia, Universidad de Chile