Lectra adjariae Teslenko, 2019

Teslenko, Valentina A., Palatov, Dmitry M. & Semenchenko, Alexander A., 2019, Description of new apterous winter species of Leuctra (Plecoptera: Leuctridae) based morphology and DNA barcoding and further records to stonefly fauna of the Caucasus, Georgia, Zootaxa 4585 (3), pp. 546-560 : 548-552

Lectra adjariae Teslenko sp. n.

( Figs 1–13 )

urn:lsid:zoobank.org:act:711EAB15-5DB4-4F36-ADFA-F588D1B2B3A8

Material examined. Holotype male. Georgia. Adjaria. Kintrishi River , 16 km upstream from Kobuleti and 4 km upstream from Tchakhati Village, 41°47.192 N 41°57.390 E, 0 6.02.2017, coll. D. Palatov ( FSC EATB FEB RAS) . Paratypes: 2 males (one mounted), 3 females (one mounted), same locality and date, coll. D. Palatov ( FSC EATB FEB RAS) .

Description. Body length of males 3.5–4.0 mm, females 4.0–5.0 mm. Apterous species in both sexes. General color brown, sclerotization heavily, body covered with pilosity, visible mainly in lateral view ( Fig. 4 ). Palpi, head, pronotum, meso-, metanotum and legs uniformly brown, dark brown rugosities on the occiput and pronotum ( Fig. 2 ). Head bears two small, barely visible lateral ocelli, the median ocellus indistinct, difficult to distinguish.

Prothoracic sternum of male with diamond-shaped basisternum (b 1), furcasternum (f 1) is a pair of diverging bars, postfurcasternum (p 1)—a large elliptical and medially subdivided sclerite, spinasternum (s 1) obscure, appears as a small round sclerite surrounded by pleurae, ( Fig. 3 ). Mesothoracic sternum bears basisternum (b 2) much wider than that on the prothoracic sternum, with two triangular anterolateral processes; furcasternum (f 2) separated from the basisternum by distinct arms; postfurkasternum (p 2) as a pair of sclerotized rounded triangle sclerites laterally to furkasternum arms (f 2) not fused to furcasternum; spinasternum (s 2) narrow elongated ( Fig. 3 ).

Male. Terga I-VII simple, each tergum with heavily sclerotized anterior margin and semicircular paramedian membranous area, increased in size posteriorly to tergum VIII and covered by dense, long black setae ( Fig. 5 ). Tergum VIII bears indistinct weakly sclerotized anteromedial process looking like a pair of short slightly pigmented fan-shaped spots, closely separated, directed backward and covered by long black setae ( Fig. 5 ). Tergum IX mostly membranous with distinct antecosta, divided medially for more than ¼ of segment width; posteromedial sclerite consists of paired small prolonged pigmented spots covered with long, black setae ( Figs. 5, 6 ). Posterior margin of tergum X with wide and deep median notch, each lobe bears pointed process at posterior inner margin, directed inward and oblique backward in dorsal view and risen in lateral view ( Figs. 4–7 ). Epiproct rounded, mushroom-shaped, membranous with pigmented stalk ( Fig. 7 ). Cerci are very specific, each cercus large, wide, scoop-shaped, gently bent inward and upward, hardly sclerotized on outer edge; the inner part membranous, covered with long black setae, denser than on the outer edge; apex wide, with slight depression on edge ( Figs. 4–6, 8 ). Paraprocts stout ( Figs. 4 , 9 ), styles 2.25X shorter than specilla ( Fig. 9 ). Styles with wide base; narrowed and curved sideward near the apex, and ending in rounded tip ( Figs 5–7, 9 ). Specilla long gently bent inward apically in dorsal view, narrowed to the apex and ending in a sharp point ( Figs. 5, 6, 8, 9 ). In lateral view the apex of specilla pointed and directed upward (but downward as shown in Fig. 4 since the abdomen curved, in mating position). Sternum IX with U-shaped unsclerotized area, no ventral vesicle ( Fig. 2 ).

Female. Terga II-VI with dorsal sclerite and pair of unsclerotized paramedian bands, the size of dorsal sclerite increasing to tergum VI; terga VII-X completely sclerotized. Sternum VII convex, very large and strongly sclerotized, almost trapezoidal with truncated anterolateral margins, anterior margin slightly concave, posterior margin broadly rounded, overlapping the anterior margin of sternum VIII and partly hiding the base of subgenital plate ( Fig. 10 ). Subgenital plate triangular, prolonged, reaches anterior margin of sternum IX: a wide, triangular, unpigmented base delimited by a pair of small sclerotized sports anterolaterally, the second pair of small pigmented spots supports the plate laterally in the first ¼ of its length; further to the subgenital plate narrowing, ending in a pair of sclerotized finger-shaped prolonged posterior lobes, shortly bifurcated at the apex and directed slightly sideward; apex with membranous area mesoposteriorly ( Fig. 10 ). Subgenital plate covered with long setae especially in less pigmented part between sclerotized finger-shaped lobes, along inner edges of the lateral sclerites and on posterior margin ( Fig. 11 ). Sternum IX has two pairs of small triangular, membranous spots and one pair of sclerotized rounded spots between distal tops of each pair of membranous spots, below the subgenital plate ( Fig. 10 ). Seminal receptacle spheroid enclosing spermathecal ring-shaped slightly sclerotized sclerite with pair of lateral pointed arms ( Figs. 12, 13 ).

Diagnosis. Apterous in both sexes. Terga of male I-VII simple, with heavily sclerotized anterior margin and semicircular paramedian membranous area, increased in size posteriorly to tergum VIII. Tergum VIII bears a pair of anteromedial, short, slightly pigmented fan-shaped spots, covered by long black setae. Tergum IX with distinct antecosta, posteromedial sclerite consists of paired small prolonged pigmented spots covered with long, black setae. Tergum X with wide and deep median notch, each lobe bears very specific pointed process at posterior inner margin. Epiproct large, rounded, mushroom-shaped, membranous with pigmented stalk. Cerci large, wide, scoopshaped, bent inward and upward, apex wide, with slight depression. Paraprocts strong, styles shorter than specilla, narrowed and curved sideward near the apex. Specilla long, narrowed to the apex, ending in a sharp point. Ventral vesicle is absent. Female subgenital plate also conspicuous: a triangular, prolonged, reaches anterior margin of sternum IX, with a wide, triangular, unpigmented base delimited by two pairs of small sclerotized sports anterolaterally and laterally, with a pair of sclerotized finger-shaped prolonged lateral lobes shortly bifurcated at the apex.

Affinities: According to the shape of processes and pigmented spots on the male abdominal terga, the structure of male epiproct and paraprocts, L. adjariae appears to belong to the hippopus species group ( Ravizza & Vinçon 1998, Ravizza 2002). However, the indistinct, short, fan-shaped processes on tergum VIII, paired pointed process at posterior inner margin of tergum X and other features mentioned in diagnosis, readily distinguish L. adjariae males from all congeners. No closely related species are indicated based on external morphology. In the male, a pair of pointed processes of tergum X are unique and they only resemble those of male of Alpine-Carpathian L. autumnalis Aubert, 1948 . The short styles of the paraprocts of L. adjariae are also unusual in the hippopus group, that are only shared with L. tarnogradski and L. dispinata , both species with short styles ( Zhiltzova 2003). The triangular, prolonged subgenital plate of female is not similar to other Leuctra species and only remotely resembles members of the brevipennis sub-group, hippopus group, e.g. L. vinconi aubertorum Ravizza & Ravizza Dematteis, 1994 or L. vinconi vinconi Ravizza & Ravizza Dematteis, 1993 , found in the western Alps of Switzerland and Italy ( Ravizza, 2002) and another apterous species L. kumanskii Braasch & Joost 1977 from the Balkan Mountains, Bulgaria.

Distribution. Leuctra adjariae was collected at a single locality along the Kintrishi River near the town of Kobulety in Adjaria, in southwestern Georgia. The Autonomous Republic Adjaria, a historical, geographic and political-administrative region of Georgia, borders Turkey to the south and the eastern edge of the Black Sea ( Fig. 25 ). The Kintrishi River drains the western slopes of Meskheti Range (Lesser Caucasus) into the Black Sea. At the type locality, where the altitude does not exceed 180-190 m a.s.l, the Kintrishi River flows through a canyon, with a width 5- 6 m. The water level increased 0.3 m during flooding, but was clear, flowing at 0.3-0.9 m /s ( Figs. 27, 28 ). Adults of L. adjariae were walking on the snow ( Fig. 26 ).

Etymology. This species is named after Adjaria, region of Georgia, where it occurs.

Figures

FIGURE 1. Maximum Likelihood (ML) tree (-Ln likelihood = 1785.88) of Leuctra adjariae sp. n., Leuctra georgiae sp. n. and outgroup inferred from the cytochrome c oxidase I (COI) nucleotide sequence data (658 bp). Numbers are bootstrap support of 500 replicates. Specimens obtained in this study are in BOLD.

FIGURES 2–4. Male of Leuctra adjariae sp. n. 2. Habitus, dorsal view. 3. Pro- meso- and methatorax. Prothorax: b 1 —basisternum, f 1 —furcasternum p 1 —postfurcasternum, s 1 —spinasternum; b 2, f 2, p 2, s 2 —the same on the mesothorax. 4. Abdominal tip, lateral.

FIGURES 5–9. Male of Leuctra adjariae sp. n. 5. Abdominal tip, VII-X terga, dorsal. 6. Abdominal tip, IX-X terga, dorsal. 7. Epiproct, and styles, dorsal. 8. Abdominal tip, IX-X terga, ventral. 9. Styles and specilla, ventral.

FIGURES 10–13. Female of Leuctra adjariae sp. n. 10. Abdominal tip, subgenital plate, ventral. 11. Subgenital plate, cleared, mounted, ventral. 12. Spermatheca, cleared, mounted ventral. 13. Spermatheca, cleared, mounted, ventrolateral.

FIGURES 25–28. 25. Collecting place of Plecoptera in Adjaria, Georgia (black dot). Square shows the nearest collecting site of Capnioneura gouanerae in Artvin, Turkey. 26. Female of Leuctra adjariae sp. n. on the snow. 27 & 28. The Kintrishi River, Meskheti Range, the type locality of Leuctra adjariae sp. n. and Leuctra georgiae sp. n. Photo by D. Palatov.