Cheilosia (Cheilosia) nebulosa Verrall, 1871 Fig. 48 Chilosia nebulosa Verrall, 1871: 201. Differential diagnosis Cheilosia nebulosa has the combination of a pilose eye, bare face, posterior margin of scutellum without bristles and legs bicoloured. Distinguished from most other species of Cheilosia possessing the same characters by having the ventral and dorsal pile patches on the katepisternum not connected (connected in, e.g., the otherwise similar C. albitarsis). The wing is brown and infuscate, but this can be indistinct. Best separated from C. megaclama sp. nov. by having basal tarsomeres of protarsus dorsally orange (protarsus black in C. megaclama) and from C. flavipes and C. brunnipennis by orange base of arista (black in the other two taxa). Material examined Cheilosia nebulosa was not collected in 2018, but collected in 2023. GEORGIA – Mtskheta-Mtianeti • 8 ♂♂; Lutkhubi; 42.3797° N, 44.7969° E; 1463 m a.s.l.; 6 May 2023; S. Bot leg.; SBA, SB.002507 = ZFMK-TIS-8027984, SB.002508 = ZFMK-TIS-8027985, SB.002509 to SB.002513 • 1 ♂; same data as for preceding; ZFMK, SB.002505 • 5 ♀♀; same data as for preceding; SBA, SB.002515 to SB.002519 • 2 ♀♀; same data as for preceding; ZFMK, ZFMK-TIS-8027976, SB.002506 • 3 ♂♂; Lutkhubi; 42.3951° N, 44.7847° E; 2138 m a.s.l.; 6 May 2023; F. Van de Meutter leg.; FMT • 27 ♂♂, 9 ♀♀; Lutkhubi; 42.3867° N, 44.79° E; 1580 m a.s.l.; 6 May 2023; F. Van de Meutter leg.; FMT • 1 ♀; same data as for preceding; ZFMK • 7 ♂♂; Lutkhubi; 42.3930° N, 44.7929° E; 1700 m a.s.l.; 6 May 2023; W. Opdekamp leg.; WOR, A003, A010, A013, A016, A018, A020, A025 • 4 ♀♀; same data as for preceding; WOR, A005, A006, A021, A024 • 1 ♂; Lutkhubi; 42.3989° N, 44.7995° E; 2100 m a.s.l.; 6 May 2023; W. Opdekamp leg.; WOR, B005 • 2 ♀♀; same data as for preceding; WOR, B002, B004 • 1 ♂; Lutkhubi; 42.3984° N, 44.7866° E; 2180 m a.s.l.; 6 May 2023; W. Opdekamp leg.; WOR, C002 • 9 ♂♂; Lutkhubi; 42.3823° N, 44.7856° E; 1500 m a.s.l.; 6 May 2023; W. Opdekamp leg.; WOR, D003, D007, D016, D017, D022, D028, D033, D036, D037 • 2 ♂♂; Lutkhubi; 42.3938° N, 44.7857° E; 2120 m a.s.l.; 6 May 2023; W. Opdekamp leg.; WOR, E012, E018 • 5 ♂♂; Lutkhubi; 42.3984° N, 44.7996° E; 2068 m a.s.l.; 8 May 2023; S. Bot leg.; SBA, SB.002500 to SB.002504 • 2 ♀♀; same data as for preceding; SBA, SB.002521, SB.002522 • 9 ♂♂, 1 ♀; Lutkhubi; 42.3936° N, 44.7923° E; 1760 m a.s.l.; 8 May 2023; F. Van de Meutter leg.; FMT • 1 ♂; same data as for preceding; ZFMK • 9 ♂♂; Lutkhubi; 42.3930° N, 44.7929° E; 1734 m a.s.l.; 8 May 2023; W. Opdekamp leg.; WOR, C001, C002, C012, C014, C016, C024, C031, C034, C035 • 1 ♀; same data as for preceding; WOR, C020 • 1 ♀; Tbilisi N.P.; 41.8787° N, 45.0288° E; 1316 m a.s.l.; 9 May 2023; S. Bot leg.; SBA, SB.002520. Genetics DNA sequences for European and Caucasian specimens of C. nebulosa cluster together with high support (BS = 100%). Remarks Reported from the Caucasus for the first time. Biology During our expeditions, collected between 6 May and 9 May at an altitude between 1316 and 2180 m a.s.l. Locally abundant with several hundreds seen on alpine meadows, feeding on Salix sp. and males hovering at hilltops. Distribution Europe, Caucasus, eastward to West and Central Siberia.

Published as part of Bot, Sander, Mengual, Ximo, Meutter, Frank Van de & Skevington, Jeffrey H., 2025, Review of the genus Cheilosia Meigen, 1822 (Diptera: Syrphidae) from the Caucasus, with the description of 14 new species, pp. 1-181 in European Journal of Taxonomy 1023 on pages 95-96, DOI: 10.5852/ejt.2025.1023.3097, http://zenodo.org/record/17442595