Perla kiritshenkoi Zhiltzova, 1961

Teslenko, Valentina A., Palatov, Dmitry M. & Semenchenko, Alexander A., 2024, Overview of the Caucasian Perla Geoffroy, 1762 (Plecoptera: Perlidae) based on morphological and molecular data with description of two new species, Zootaxa 5507 (1), pp. 1-56 : 17-22

Perla kiritshenkoi Zhiltzova, 1961

Figs. 50‒68

Zhiltzova, 1961:874‒876, figs. 1‒5 (originally description);

Zwick, 1975: 392 (first record for Iran);

Kazanci, 1983: 90 (first record for Turkey);

Sivec & Stark, 2002:16, figs. 28‒30 (egg illustration);

Teslenko & Zhiltzova, 2009: 56, figs. 306‒310 (key with illustrations copied from Zhiltzova 1961); Darilmaz et al., 2016: 52 (distribution, Turkey, map);

Murányi et al., 2021: 74 (distribution, Azerbaijan).

Diagnosis. Perla kiritshenkoi is one of the darkest-colored species of Caucasian Perla . The male is distinguished by the long mesal field, which is widened and rounded posteriorly; the length does not exceed its width; and the longitudinal serrated ridges (7−8) are concentrated in the middle ( Figs. 55, 57 ). The hemitergal hooks are strongly swollen in the place of the bend, forming a noticeable rounded protrusion, and the apexes are bluntly rounded ( Figs. 54−57 ). An artificially everted penis bears the bulbous, membranous sac with a narrow apical brush ending in triangles of spines ventrally and dorsally; the membranous sac is rough, covered with dense tiny setae, clearly visible near the folds of the lobes ( Figs. 58 , D). The egg is spindle-shaped, tapering evenly to each pole ( Fig. 62 ). The collar is short, but the rim is thick and rough ( Fig. 64 ). The chorion is rough and punctuate throughout; punctations are mostly uniform, but small punctations are also present near the micropylar row located near the equator; micropylar orifices with a raised thin edge are placed laterally on the pit wall; inside the pit there may be additional 1−2 small orifices ( Figs. 62, 65−68 ).

Complimentary description—adult habitus. Males and females are macropterous ( Figs. 50 , 59 ). The M-line on the head is rufous, smooth, and clearly defined ( Fig. 53 ). The interocellar area has a dark brown spot extending upward to the M-line and down to the lateral ocelli, with the lateral branches of this spot reaching the lateral edges of the head above tentorial pits; the lateral edges of the clypeus are also dark brown; and paired rufous spots are located behind the compound eyes ( Figs. 53 , 59–60 ). Along the anterior margin of the clypeus, paired patches between the lateral ocelli and compound eyes, as well as paired patches on the occiput, are yellow ( Figs. 53 , 59−60 ). Tentorial pits above lateral ocelli are clearly defined, bean-shaped, yellow, and have a small, dark spot inside ( Figs. 53 , 60 ). Pronotum with a dark medial band noticeably widening towards the anterior margin; band surrounded by pale rugosities of an X-shaped pattern; lateral fields the same color as the medial band ( Figs. 53 , 59–60 ). Legs are brown ( Figs. 50, 52 ). Femur darkened distally with a thin yellow band along the outer edge ( Fig. 59 ); dark closing hairs and scattered brown bristles along the inner and outer edges; a medial band without hairs and bristles with a small oval pale spot distally. Tibia has a thin yellow band along the outer edge; the base darkened ( Figs. 50 , 59 ); there is a small dark band distally.

Male. Tergum 8 medially has a membranous furrow and posterolateral humps covered with dense, thick, and long setae. Tergum 9 has a depressed, sclerotized mesal field slightly widened posteriorly, and the length does not exceed its width. On the mesal plate, the longitudinal serrated ridges (7–8) are heavily sclerotized and concentrated mesally and do not reach the posterior edge, which is smooth and rounded with a weak notch in the middle ( Figs. 55, 57 ). Tergum 10 has hemitergites that are curved at an obtuse angle and directed obliquely upward; each hook is strongly swollen in place of the bend on the outer and dorsal sides, forming a noticeable rounded protrusion covered with long setae; the same setae cover the outer edge of the hook ( Figs. 54‒57 ). The apex of the hook is rounded (on a cleared specimen, the hook apex is rectangular-rounded) and covered with sensilla basiconica, which is extended at the tip to the front and outer edges ( Figs. 56‒57 ). An artificially everted penis has a tube covered dorsally with densely arranged longitudinal rows of serrate sclerites, turning into scales sometimes with small spines; the shape of sclerites and rows in different parts of the tube is different; the tube is membranous basally with paired patches of rounded spine bases laterally ( Figs. 58 , A‒B). The sac is bulbous and membranous, with thin pointed brown spines, forming a narrow apical brush ending in triangles of spines ventrally and dorsally ( Figs. 58 , C). The membranous sac is rough, covered with dense, tiny setae, clearly visible near the folds of the lobes ( Figs. 58 , D).

Female. Subgenital plate occupies ⅔ of the width of sternum 8 with bilobed projection posteromedially ( Fig. 61 ); lobes are small, narrow, pointed, and covered with small, reddish setae ( Fig. 61 ). The cerci are long, projecting far beyond the end of the wings; the basal cercal segments are brown; and the distal cercal segments are bicolored, yellowish at the base and brown distally ( Fig. 59 ).

Egg. The type material egg is spindle-shaped, tapering evenly to each pole ( Figs. 62–63 ), with mean dimensions of 428 x 242 µm (n = 3; length without anchor). The collar is short, and the rim is thick and rough, with a series of small pits around the base ( Figs. 63–64 ). Chorion is rough and punctuate throughout ( Figs. 62, 65–68 ); punctations are large, deep, and mostly uniform, but small punctations are also present, especially near the micropylar row, which is located almost at the equator ( Fig. 62 ); micropylar orifices with a slightly raised thin edge are located not on the bottom but laterally on the pit wall ( Fig. 67 ); inside the pit there may be an additional 1–2 small orifices ( Fig. 68 ).

Larva. Unknown.

Material examined. Paratypes: male, Azerbaijan, Lelyakoran , Lenkoran. u. (u.=uezd, is an administrative unit of the Russian Empire, author’s note) 15.V.1909, Kirichenko ; 1♂, Armenia, Dshelal-ogly, Kamenka River Gorge, 16. V.22, Shelkovnikov ; 1♂, Armenia, Kaukasus, Dshelal-ogly (now Stepanavan), 29.V.1924, collector unknown .

Additional material. 1♀, Armenia, st. 439, coll. 574, Kamenka River , vicinity of Stepanovan, 27. VI.1956, coll. Zhiltzova LA ; 2♀ (damaged), Jalal-ogly (now Stepanavan), the Kamenka River Gorge, 16. V.1922, coll. Shelkovnikov ; 1♂ (alcohol), Azerbaijan, River Divachach , Tsasharuchey; 5. V.1933 , F. Lukyanovich.

Distribution. Сaucasus: Armenia, Azerbaijan (Talysh). Iran (Alborz), Turkey (eastern Pontius) ( Zhiltzova 1961; Zwick 1975; Kazanci 1983; Sivec & Stark 2002; Darilmaz et al. 2016) ( Fig. 159 ). Adults emerge from the second half of May through the first half of July. Adults were found in Armenia at altitudes of 1440–1850 m along the banks of fast streams and small mountain rivers in the forest zone on cereals and other herbaceous plants. In the Talysh, P. kirischenkoi was found at approximately 1500 m above sea level at the upper border of the forest zone and higher in small, fast-flowing forested streams ( Zhiltzova 1961) and mountain rivers ( Muranyi et al. 2021).

Figures

FIGURE 159. The map of the Perla species distribution in Caucasus according to our data. Perla caicasica—pink, P. persica— green, P. kiritshenkoi—blue, P. schapsugica sp. nov.—white, P. pallida—yellow, and P. palatovi sp. nov.—red.

FIGURES 50‒53. Perla kiritshenkoi Zhiltzova, 1961.Caucasus:Armenia, Stepanavan, Kamenka River;Azerbaijan,Lelyakoran. Paratypes. Males. 50. Habitus, dorsal. 51. Abdominal tip, dorsal. 52. Habitus, dorsal. 53. Head and pronotum, dorsal.

FIGURES 54‒58. Perla kiritshenkoi Zhiltzova, 1961. Caucasus, Armenia. Male. 54. Paratype male, abdominal tip, dorsal. 55. Mesal plate and hemitergites, dorsal, alcohol. 56. Hemitergal hook swollen in the place of the bend, dorsocaudally, alcohol. 57. Mesal plate, dorsal, and hemitergites, lateral, cleared. 58. Chaetotaxy of artificially everted penis, dorsal, cleared. A. Leafshaped scales with small spines. B. Densely arranged longitudinal rows of heavy sclerotized serrate sclerites. C. Pointed brown spines in the apical brush. D. Tiny setae covered the sac lobes.

FIGURES 59‒61. Perla kiritshenkoi Zhiltzova, 1961. Caucasus, Armenia, Stepanavan, Kamenka River. Female. 59. Habitus, dorsal. 60. Head and pronotum, dorsal. 61. Abdominal tip, ventral.

FIGURES 62‒68. Perla kiritshenkoi Zhiltzova, 1961.Caucasus:Armenia, Kamenka River.Egg. 62.Appearance with micropylar row, lateral. 63. Same, dorsolateral. 64. Collar rim, and small pits around the base, lateral. 65−66. Chorion structure with deep punctations. 67. Micropyle with a slightly raised, thin edge. 68. Micropyle on the pit wall with the addition small orifices.