Protonemura sp.

Murányi, Dávid, Manko, Peter, Kovács, Tibor, Vinçon, Gilles, Žiak, Matej, Kerimova, Ilhama G., Snegovaya, Nataly Yurievna & Oboňa, Jozef, 2021, Review and contribution to the stonefly (Insecta: Plecoptera) fauna of Azerbaijan, Zootaxa 4975 (1), pp. 58-80 : 70-73

Protonemura sp. AZE-1 (temporary name)

Lənkəran region: 12: 5♀ adults , 1♂ 1♀ larvae (HNHM).

Description of the female. Medium sized species, macropterous, forewing length 9.0– 10.8 mm. Head brown with indistinct pattern, antenna brown, palpi yellowish. Thorax brown, pronotum pale brown and trapezoid with slightly rounded corners, wider than long, rugosities dark brown and distinct. Cervical gills off white and moderately long, bear fine setation, without subterminal constriction, shorter than forecoxa. Legs pale brown, but outer edge of tibiae and all tarsi are dark; wing membranes pale brown to brown, venation brown. Pilosity short and indistinct.

Female abdomen ( Figs. 18–19 ): Terga 1–8 light brown, full membranous; tergum 9 weakly sclerotized in apical third, tergum 10 full sclerotized and brown with pale pattern; epiproct lightly sclerotized. Sterna 1–8 light brown, membranous with paired small, anterolateral sclerites lacking distal to sternum 3. Sternum 7 with weakly developed, pale pregenital plate that is rounded and slightly overhangs sternum 8 anterior portion. Subgenital plate moderately large, its width is about two thirds of the segment width; lateral sides strongly diverging, posterior edge widely rounded, medial portion weakly depressed; colour of the plate pale brown, with paired darker patches; posterior portion slightly rounded in lateral view. Vaginal lobes large, rounded and pale, stretching about halfway between subgenital plate lateral edge and segment edges. Sterna 9–10 brown, with mediolateral dark patches on sternum 9. Paraprocts brown, apex rounded; cerci short and simple. Inner genitalia: a wide, bulbous and weakly sclerotized structure originates between the subgenital plate and vaginal lobes, genital opening is free; the structure is darker on basolateral portions where attached to basal part of vaginal lobes; apex of the structure joins to the spermathecal ductus with membranous folds, bearing paired, dark drop-like sclerites.

Description of the matured larva ( Figs. 20 , 22–27 ). Body relatively slender, body length without antennae and cerci 6.2–7.0 mm. General colour light brown, with distinct and characteristic dark dorsal pattern: head mostly pale but with transverse dark pattern connecting ocelli and M-line, and brown patches on occiput; antennae and palpi light brown; pronotum dark brown with indistinct rugosities but with six pale spots; meso-, metanotum and wing pads mostly pale with brown, linear patches; legs pale, apex of femora and base of tibiae darker; abdominal terga mostly pale, but with dark lateral sides, and apical terga with a medial dark patch increasing in size towards tergum 10; cerci pale. Ventral aspect of the body entirely pale. Setation sparse but dark and distinct. Legs moderately long, width of hind femora about one-third of their length; tarsi with shortened basitarsus, as long as one third of the length of metatarsus; claws large. The pronotum is rounded trapezoidal, distinctly wider than long, as wide as the head. Cervical gills long and slightly curved, without subterminal constriction, about as long as forecoxa. Wing pads more than twice as long as the corresponding segments. Abdomen relatively long, integument light matt brown, first 6 abdominal segments fully divided by pleura. Posterior margin of sternum 9 of the male larva short triangular, with nipple-like apex; sternum 8 of the female larva widely incised. Paraproct elongated triangular, with blunt apex in both sexes. Cerci moderately long, with 25–30 slightly clubbed segments; length of the 15th segment is equal to its width.

Setation of the larva: Head, antennae and palpi with short setae, postocular setae stronger. Pronotum covered with short setae; marginal setae distinct and acute, row laterally discontinuous, corners have setae as long as 1/12th of pronotum width. Setae on meso- and metanotum with marginal setae slightly shorter than longest marginal setae on pronotum; wing pads with short, blunt setae. Legs with sparse but distinct setae, all tibiae bear sparse swimming hairs shorter than the tibia width. Longest acute setae of mid- and hind femora are about as long as one third of the femur width, those on the fore femur reach half of the femur width; not arranged in line but restricted to apical half. Tergal segments sparsely covered with short setae; posterior margin with row of 14–16 acute and erect setae, of various length, no paired setae can be distinguished; longest reaches less than half of segment length. Cercal segments bald besides the apical whorl; apical whorl of setae consists of 10–14 acute and pale setae, about of equal length on the given segment; setae on cercomeres 14–16 are about as long as segment length.

Remarks. Despite that the terminalia of the female is not so distinctive, it does not agree with any of the species known from the Caucasian region, Anatolia, Iran or the Levant. It can be either a new species, or the unknown female and larva of the Alborz endemic Protonemura waliabadi Aubert, 1964 , the sole regional Protonemura of which the female sex remained undescribed. The larva is distinctive by its exceptional, contrasting color pattern and sparse setation. However, larvae of most of the regional Protonemura remained unknown ( Zhiltzova et al. 2012). The species probably has true autumnal emergence, since last instars but not yet pharate larvae were present by the end of September. The larvae were collected from vertical hygropetric habitats in the splash zone of a waterfall, a habitat rarely occupied by West Palaearctic stoneflies ( Fig. 21 ).

Figures

FIGURES 18–21. Protonemura sp. AZE-1 from the Talysh Mts—18: female terminalia, ventral view; 19: female inner genitalia, dorsal view; 20: habitus of matured male larva, dorsal view; 21: habitat (site 12)—scale 0.5 mm for Figs. 18–19, 1 mm for Fig. 20.

FIGURES 22–27. Larval characters of Protonemura sp.AZE-1 from the Talysh Mts—22: pronotum, dorsal view; 23: terga 4–7, dorsal view; 24: hind femur and tibia, lateral view; 25: cercus and hind tarsus, lateral view; 26: male terminalia, ventral view; 27: female terminalia, ventral view.