Chaetocladius (Amblycladius) franzjosephiensis Krasheninnikov

Krasheninnikov, Andrey B. & Przhiboro, Andrey A., 2022, On taxonomy of the subgenus Amblycladius of the genus Chaetocladius (Diptera, Chironomidae), Zootaxa 5168 (4), pp. 494-500 : 498

Chaetocladius (Amblycladius) franzjosephiensis Krasheninnikov

Chaetocladius (Amblycladius) franzjosephiensis Krasheninnikov, 2013 in Krasheninnikov, Gavrilo, 2013: 158–159.

Material examined. Holotype: adult male, Russia, Franz Josef Land Archipelago , Alger Island, Cape Podgornyy, 80°22’54.66”N 55°46’12.79”E, 10 m, sea terrace in 200 m from seashore, slowly flowing puddle in boggy moss carpet under slope with scree and snowfields, 17.VIII.2012, M. V. Gavrilo leg. ( ZIN).

Redescription of holotype ( Figs 8, 12, 16 )

Adult male. Total length 3.8 mm. Wing length 1.74 mm. Ratio of total length to wing length 2.18. Head, thorax, abdomen and legs brown.

Head. Head width 441 µm. Eye bare, reniform. Temporal setae including 9 inner and 5 outer verticals and 1 postorbital. Clypeus with 8 setae.

Antenna with partly reduced plume; AR 0.82. Total length of flagellomeres (13) 833 μm; flagellomere 13 length 350 μm. Longest seta of flagellomere 13 ca. 230 μm; ratio of flagellomere 13 length to its longest seta length 1.54. Apex of flagellomere 13 with 2 setae 39, 37 (45, 37) μm in length. Flagellomeres 2 and 3 each with 1 sensillum chaeticum in apical part, flagellomere 13 with 11–13 sensilla chaetica and 4 sensilla coeloconica (all in apical part).

Maxillary palp: total length ca. 375 μm; length of palpomeres (in μm): ca. 40: ca. 50: 100: 73: ca. 110. Palpomere 3 with 5–7 sensilla capitata. Ratio of head width to maxillary palp length ca. 1.18.

Thorax. Lateral antepronotals 12; dorsocentrals 21–25; acrostichals 24, beginning close to antepronotum; prealars 10, supraalar 1. Scutellum with 18 setae.

Wing. R with 14, R 1 with 6, R 4+5 with 5 setae. Costa extending to apex of R 4+5 for 40 μm. R 4+5 ending distal to end of M 3+4. Cu 1 slightly sinuate in apical part. Anal lobe well-developed. Squama with 14 setae.

Legs. Fore tibia with spur 65–70 μm long; mid tibia with two spurs 30 μm and 22 μm long; hind tibia with two spurs ca. 56 μm and ca. 36 μm long. Hind tibial comb consisting of 14 setae. Pulvilli reduced, empodium present. Length (in μm) and proportions of legs as in Table 3 .

Hypopygium. Tergite IX with ca. 80 setae. Laterosternite IX with 10 setae.Anal point 60 µm long, without macrotrichia; microtrichia present only at its base, apex of anal point bare, hyaline. Virga consisting of 3 setae ca. 20–25 µm long. Transverse sternapodeme 170 μm long; phallapodeme 150 μm long. Gonocoxite 275 μm long. Superior volsella brown, short, covered with micro- and macrotrichia. Inferior volsella light, rounded, covered with micro- and macrotrichia. Gonostylus 176 μm long; additional lobe of gonostylus 251 μm long, its apex and middle part densely covered with microtrichia, its base with an angular protrusion covered with macrotrichia. Main lobe of gonostylus with apical part, rectangular, not tapered, rounded at outer margin near apex. Megaseta well-developed, 20 μm long. HR 1.56.

Comments. The holotype of Ch. franzjosephiensis is slide-mounted in sandarac balsam under two coverslips ( Fig. 16 ). The original label written with ink (mostly in Russian; translation in brackets) is as follows: “C146/1, 17.08.2012, Zemlya Frantsa Iosifa, o. Aldzhera, mys Podgornyy, golotip [Franz Josef Land, Alger Island, Cape Podgornyy, holotype], Chaetocladius (Amb.) franzjosephi”. A label “ holotype ” on red paper was added by Przhiboro .

Some measurements of the holotype of Ch. franzjosephiensis markedly differ from those given in the original description, i.e. the number of sensilla chaetica on flagellomere 2, the number of supraalar setae and the length of spur on fore tibia.

Figures

FIGURE 8–16. Holotypes (adult males):Arctosmittia biserovi Zelentsov, syn. nov. (9, 10, 13, 15), Chaetocladius (Amblycladius) franzjosephiensis Krasheninnikov (8, 12, 16), Chaetocladius (A.) subplumosus (Kieffer) (11, 14). 8–9, anal point; 10–12, gonostylus; 13–14, tibial spur of hind tibia; 15–16, general view of slides with holotypes.