Morphological description and DNA barcoding of Diamesa achipseensis sp. nov. (Diptera: Chironomidae: Diamesinae) from Southwestern Caucasus Author Makarchenko, Eugenyi A. Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, 100 let Vladivostoku 159, 690022 Vladivostok, Russia. Author Semenchenko, Alexander A. Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, 100 let Vladivostoku 159, 690022 Vladivostok, Russia. Author Palatov, Dmitry M. 0000-0002-8826-9316 triops@yandex.ru text Zootaxa 2024 2024-07-18 5481 4 477 482 http://dx.doi.org/10.11646/zootaxa.5481.4.6 journal article 300017 10.11646/zootaxa.5481.4.6 602eebbd-9229-4ff4-9207-fada3b4331a0 1175-5326 12780354 D2208B87-090C-46DB-B2DB-FF4F743B515C Diamesa achipseensis Makarchenko, Semenchenko et Palatov , sp. nov. http://zoobank.org/NomenclaturalActs/ 6EE16603-172D-4F5A-BABD-49380AC31B55 ( Figs. 1–11 ) Type material. Holotype , adult male, RUSSIA : Caucasus , Krasnodar Region , Adler District , Sochi urban district, Sochi National Park , Achipse River , 3 km North of the Estosadok Village , altitude 600 m above sea level , 12.IV.2024 , 43°42'25.9"N 40°15'46.18"E , leg. D. Palatov. Derivatio nominis. The species is named as achipseensis after the type locality in the Achipse River of the Southwestern Caucasus. Description Adult male (n = 1). Total length 3.2 mm . Total length/wing length 0.83. Coloration. Dark brown. Head, thorax and abdomen with hypopygium dark brown, antenna grey. Legs brown. Wings greyish. Head. Eyes reniform, bare. Temporal setae including 6–7 preoculars, 6 inner verticals, 8 outer verticals and 8–10 postorbitals. Clypeus with 10 setae. Antenna with 13 flagellomeres and slightly reduced plume of setae; maximal length of these setae on flagellomeres 770 μm; terminal flagellomere with 1 subapical seta, 40 μm long; pedicel with 3 setae, 60–70 μm long; AR 0.70–0.74. Palpomere length (μm): 48, 100, 160, 176, 252. Palpomere 3 in distal part with sensilla capitata with diameter 12 μm. Head width/palpal length 1.02. Thorax. Antepronotum with 6–7 ventrolateral setae. Dorsocentrals 14–15, 116–148 μm long; prealars 11–12, 120–152 μm long. Scutellum with 34 setae, 160–180 μm long. Wing. Length 3.84 mm , width 1.12 mm . Costal extension 82 μm long. Anal lobe outline rounded. Squama with 34 setae. R and R 1 with 28 setae, R 4+5 with 3 setae in subapical part. RM/MCu 2.2. Legs. Spur of front tibia 84 µm long. Spurs of mid tibia 60 µm and 64 µm long. Spurs of hind tibia 84 µm and 56 µm long. Hind tibial comb with 18 setae. Length (μm) and proportions of leg segments are as in Table 1 . TABLE 1. Lengths (in µm) and proportions of leg segments of Diamesa achipseensis sp. nov. , male (n=1)
fe ti ta1 ta2 ta3 ta4 ta 5 LR BV SV BR
P 1 1440 1800 1200 590 361 115 148 0.67 3.66 2.70 1.7
P2 1591 1591 754 470 246 115 148 0.47 4.28 4.22 1.5
P3 1800 1880 1240 574 377 115 148 0.66 4.05 2.97 2.1
Hypopygium ( Figs. 1–10 ). Tergite IX narrow, with 16–18 setae from one side, 48–60 μm long and with anal point, 40 µm long, which bends under tergite IX, dark brown in basal 2/3 and light grey in distal 1/3, with rounded apex ( Figs. 1–3 ). Laterosternite IX with 8–11 setae. Transverse sternopodeme (TSA) wide rectangular with rounded outer angles ( Fig. 8 ), 56 µm high, 156 µm wide; TSA height/TSA width 0.36. Aedeagal lobe knife-shaped, 180 μm long and 48 μm wide, weakly chitinized; phallapodeme sclerotized, 120–128 μm long. Gonocoxite 476 µm long, without inferior volsellae, basally with superior volsellae consisted of ventral and dorsal parts ( Figs. 6, 9–10 ); ventral part located on stalk 130–132 µm long and in subapical part with 18–20 needle-shaped setae, 40–44 μm long; dorsal part rounded, with some long setae ( Figs. 9–10 ). Gonostylus 410 µm long, narrow crescent-shaped, slightly expanded basally, its surface with short setae, ca 8 μm long, along the inner edge with thin setae, 40–48 μm long; apex with short macroseta, 12 µm long ( Figs. 1, 4, 7 ). HR 1.16. FIGURES 1–10. Adult male of Diamesa achipseensis sp. nov. 1–2, part of hypopygium in dorsal view with invisible bent gonostylus; 3, part of tergite IX in ventral view with anal point; 4, dorsally curved gonostylus; 5, part of hypopygium from ventral side; 6, endoskeleton; 7, gonostylus; 8, transverse sternapodeme; 9–10, superior volsellae. Scale bar: 50 μm. Pupa and larva unknown. Diagnosis. Total length 3.2 mm . Eyes bare. Antenna with 13 flagellomeres and slightly reduced plume of setae; AR 0.70–0.74. LR 1 0.67, BV 1 3.66, SV 1 2.70. Tergite IX narrow, with short anal point, which bends under tergite IX, dark brown in basal 2/3 and light grey in distal 1/3, with rounded apex. Transverse sternopodeme wide rectangular with rounded outer angles. Gonocoxite without inferior volaellae, basally with superior volsellae consisted of ventral and dorsal parts; ventral part located on long stalk and in subapical part with 18–20 needle-shaped setae; dorsal part rounded, with some long setae. Gonostylus narrow crescent-shaped, slightly expanded basally, its surface with short setae, along inner edge with thin setae; apex with short macroseta. HR 1.16. The new species belongs to the latitarsis group and most closely related to D. caucasica Kownacki et Kownacka , from which it is well distinguished by structures of gonostylus and superior volsellae as well as some other characters given in Table 2 . TABLE 2. Comparison of adult males characters of Diamesa achipseensis sp. nov. and D. caucasica Kownacki et Kownacka
Characters D. achipseensis sp. nov. (n=1) D. caucasica Kownacki et Kownacka (n=7), Kownacki & Kownacka 1973 ; Makarchenko et al. 2022a
Total length, mm 3.2 2.97–3.5, 5–6*
Wing length, mm 4.1 3.4–3.6, 3.5*
TL/WL 0.83 0.82–0.92
Antenna With slightly reduced plume of setae With developed plume of setae
AR 0.70–0.74 1.0–1.22, 0.91*
Clypeals 10 7–10
Dorsocentrals 14–15 7–12
Prealars 11–12 4–6
Scutellars 34 19–29
Squamal setae 34 21–26
LR1 0.67 0.66–0.68
BV1 3.66 3.45–3.52
SV1 2.70 2,63–2.80
Tergite IX, number of setae 16–18 14–39
Anal point length, ìm 40 40–49
Superior volsellae Ventral part located on stalk 130–132 µm long and in subapical part with 18–20 needle-shaped setae; dorsal part rounded, with some long setae. Ventral and dorsal parts without stalk, rounded, or elongated- rounded, almost same size, covered with long setae.
Gonostylus Gonostylus narrow crescent- shaped, slightly expanded basally, without any appendages. Gonostylus in basal third or half widened along inner margin and with wedge-shaped appendage directed at angle backwards.
HR 1.16 0.90–1.02
Note. Data from Kownacki & Kownacka (1973) are marked with an asterisk Ecology and distribution. Adult male was collected near mountain large Achipse River ( Fig. 11 ) in a wide beech-fir valley. The bottom of this river is large stones and boulders, flow rate of 0.7–1 m /s, located at an altitude of 600 m a.s.l. Known only from the type locality in Achipse River of the Southernwest Caucasus.