Arctodiamesa appendiculata (Lundström), Makarchenko, 1983

Krasheninnikov, Andrey B., Makarchenko, Eugenyi A., Semenchenko, Alexander A., Gavrilo, Maria V. & Vshivkova, Kristina A., 2020, Morphological description and DNA barcoding of some Diamesinae (Diptera Chironomidae) from the Severnaya Zemlya Archipelago and the Vaigach Island (Russian Arctic), Zootaxa 4802 (3), pp. 587-600 : 594-595

Arctodiamesa appendiculata (Lundström)

( Figs. 13–15 )

Diamesa appendiculata Lundström, 1915: 23 ; Goetghebuer 1939: 11; Makarchenko 1978: 56.

Arctodiamesa appendiculata (Lundström) Makarchenko 1983: 264, 1984: 96 , 1985: 54, 2006: 259, 471, 610; Ashe &O’Connor 2009: 263.

Material examined. 2 adult males, RUSSIA: Severnaya Zemlya Archipelago , Bolshevik Island, estuary of the nameless river, 27.VII.2018, leg. A. Loginov.

Adult male (n=2). Wing length 3.3–3.4 mm.

Colouration. Total colour brown to dark brown, wings greyish.

Head. Eyes hairy. Temporal setae including 9 outer verticals and 3–4 postorbitals. Clypeus with 10–11 setae. Antenna with 13 flagellomeres and well-developed plume; terminal flagellomere with 1–2 subapical setae 27–39 µm long; AR 1.2–1.4. Palpomeres lengths (in μm): 47–51; 82–90; 133; 106–110; 149–161; palpomere 3 without sensilla capitata. Head width/palp length 1.04.

Thorax. Antepronotum with 8 ventrolateral setae. Dorsocentrals 7–10, prealars 6–8, scutellars ca 20.

Wing. R with 8–11 setae, R 1 with 7 setae, R 2+3 with 4 pores, R 4+5 with 1–2 setae. Anal lobe well developed. Costa extention 62–78 μm. Squama with 35 setae.

Legs. Spur of fore tibia 67–71 μm long; spurs of mid tibia 55–59 μm and 39–43 μm long; of hind tibia 71–78 μm and 47 μm long. Hind tibial comb with 14 setae. Lengths and proportions of leg segments as in Table 4.

Hypopygium ( Figs. 13–15 ). Laterosternite IX with 5–13 setae. Tergite IX with 42–49 setae. Anal point 51 μm long, with 2 setae 27–35 μm long on apex. Transverse sternapodeme 176–184 μm long; distal part of phallapodeme 165–180 μm long; basimedial part 60 μm long. Medial aedeagal lobe strong sclerotized, with large apical spines. Gonocoxite 353–361 μm long; medial field broad and flat, covered with short setae. Gonostylus bifurcate, 157–176 μm long, outer branch 125–137 μm long, in 1.6–2.1 times longer than inner branch; inner branch with broad and serrated megaseta 10–12 μm long. HR 2.0–2.3.

Comments. The adult males of A. appendiculata from Severnaya Zemlya Archipelago fits into the description of the species from other regions of the Arctic and Subarctic ( Makarchenko 1984, 2006). Specimens of all popula- tions of this species are characterized by a slight variability in the ratio of the length of the inner branch to the length of the outer branch of the gonostylus. So, for males from the Wrangel Island, Chaun Bay, the Chukchi Peninsula and the Severnaya Zemlya Archipelago this ratio is respectively 1.34–1.50, 2.03, 1.82, 1.6–2.1.

Distribution. Holarctic arcto-alpine species, known from the upper stream of Kolyma River, Arctic regions of Eurasia and Alaska ( Ashe & O’Connor 2009).

Figures

FIGURES 13–15. Arctodiamesa appendiculata (Lundström), male. 13, hypopygium in dorsal view; 14, inner structures of hypopygium; 15, distal part of gonostylus.