Perlodidae Klapálek, 1909

Teslenko, Valentina A. & Palatov, Dmitry M., 2019, A new micropterous winter species of Leuctra (Plecoptera: Leuctridae) and little known endemic stoneflies from the Greater Caucasus, Zootaxa 4613 (2), pp. 342-354 : 349-352

Perlodidae Klapálek, 1909

Bulgaroperla mirabilis caucasica Zhiltzova 1973

Material examined. 3♂, 1♀, 1 larva. Russia. Krasnodarky Region , Novorossiysk urban District , Abrau-Dyur- so Distric , Abrau River, 2 km above the Abrau settlement, 155 m above sea level, 44°43.546 N 37°35.498 E, 18.0 4.2018, coll. D. Palatov.

Mature larva. The association of the mature larva with the adult was established from preemergent male larva collected with adults. Body length of the male mature larva 14 mm. Preserved specimen brown-yellowish with pale markings and pale legs ( Fig. 24 ). Dorsum of head brown with pale pattern ( Figs. 24, 25 ); a pale diffuse patch anterior to median ocellus; lateral frontoclypeal corners brown ( Fig. 25 ); thin lateral branches of M-line and tentorial callosities are pale. А pale trident-shaped spot arranged in interocellar and epicranial areas, with short neck in the part of transverse setal row across occiput widely interrupted medially. Occiput brown, a thin pale band around each eye ( Figs. 24, 25 ). Antennae pale, scape medium brown. Mandible with 6 pointed teeth and a deep cleft between apical and subapical teeth ( Fig. 28 ). The upper edge of lower mandibular tooth weakly serrate ( Fig. 29 ). Lacinia bidentate, triangular ( Fig. 27 ), row of setae along inner edge sparse, discontinuous medially, begins with four thin hairs arranged near apical and subapical teeth, two hairs very long, reach the apex of subapical tooth; two strong marginal setae below subapical tooth; the marginal scattered setae at lacinial base thinner and shorter than beneath the subapical tooth ( Fig. 27 ). The length of galea does not exceed the length of the three basal palpus segments ( Fig. 27 ), with thin short setae along outer edge. Setal fringe along inner edge of galea consists of 7 thin hairs in basal half, and longer than on inner margin of lacinia ( Fig. 27 ).

Pronotum oval with rounded corners, 1.8Χ as long, brown with dark brown posterior and anterior pronotal margins mesally, lateral margins with pale band; median pronotal line and spots forming a X–shaped pale pattern diffused medially ( Figs 24, 25 ). Meso- and metanota with pale median line and complex color pattern ( Fig. 24 ). Abdominal terga pale, each tergum with one median and two lateral pale spots surrounded with dark brown patches, forming longitudinal rows ( Fig. 26 ). Paraprocts and cerci pale; paraprocts blunt ( Fig. 30 ). Ventral surface of abdomen pale. On mesosternum, branches of Y—ridge meet posterior corners of furcal pits. Only first 2 abdominal segments divided into terga and sterna, others ring-shaped.

Setation. Fine black pilosity (or clothing hairs) appressed to body surface closely and cover mainly pronotum and legs ( Fig. 24 ). Transverse setal row across occiput medially widely interrupted, plurilinear setation presents only behind eyes, medially turning into an irregular single row ending far from middle ( Fig. 25 ). Marginal setae on pronotum and abdominal terga relatively short, inconspicuous. Setal fringe around pronotum relatively regular and sparse, a few bristles on posterior pronotal corners much longer than on anterior ones, length of the longest bristles at the posterior pronotal corners attains 3.2% of pronotal width ( Fig. 25 ). Dark pigmented spots with short setae seen on all abdominal terga ( Fig. 26 ). Swimming hairs on the legs present ( Fig. 24 ). Apical whorl of cercal segments basally and in the middle part contains short bristles; dorsal fringe of fine hairs lacking ( Figs. 30, 31 ). Apical whorl of cerci in apical half packed with tenuous dorsal fringe of scattered silky hairs, length of hairs not exceeding length of the corresponding segment ( Fig. 31 ). Additionally, the apical whorl in apical half of cerci bears one long dorsal and ventral setae ( Fig. 31 ).

Remark. The West Palaearctic genus Bulgaroperla Raušer 1966 includes a single species B. mirabilis Raušer, 1966 with three subspecies B. mirabilis mirabilis Raušer, 1966 , B. mirabilis nigrita Zwick, 1978 , and B. mirabilis caucasica . The adults and larvae of these subspecies differ in body size and color patterns (Braash & Joost 1971, Zhiltzova 1973, Zwick 1978). Bulgaroperla mirabilis caucasica can be distinguished by the smaller body size and lighter color pattern from the other two recognized subspecies.

Distribution. Endemic of the Western Caucasus, occurs in lowland streams (900–1000 m), adults emerge in May—beginning of June.

Figures

FIGURES 24–26. Larva of Bulgaroperla mirabilis caucasica. 24. Habitus, dorsolateral. 25. Head and pronotum, dorsal. 26. Terga V–VIII, pigmented spots with short setae.

FIGURES 27–31. Larva of Bulgaroperla mirabilis caucasica. 27. Right lacinia, ventral. Galea with long setae along inner edge. 28. Right mandible, ventral. 29. Arrow shows a weak serration on outer cusp of lower mandibular tooth, ventral. 30. Left cercus, basal segments, ventral. 31. Left cercus, apical segments, ventral.