Cheilosia vernalis is a Palearctic hoverfly.
Description For terms see Morphology of Diptera The upper margin of the facial tubercle is smooth. The eyes have short black hairs. The post-alar calli and the margin of the scutellum have only short bristles. The normal length wings are usually hyaline. The wing length is 4 ·5-6·75 mm., body length is 5.0 to 7.0mm.A very variable species. See references for determination.Bei-Bienko, G.Y. & Steyskal, G.C. (1988a) Keys to the Insects of the European Part of the USSR, Volume V: Diptera and Siphonaptera, Part I. Amerind Publishing Co., New Delhi. .Van Veen, M. (2004) Hoverflies of Northwest Europe: identification keys to the Syrphidae. 256pp. KNNV Publishing, Utrecht.addendumVan der Goot, V.S. (1981) De zweefvliegen van Noordwest - Europa en Europees Rusland, in het bijzonder van de Benelux. KNNV, Uitgave no.32: 275pp. Amsterdam.Coe, R.L. (1953) Diptera: Syrphidae. Handbks.ident.Br.insects, 10(1): 1-98. R.ent.Soc.London. pdf
Distribution Scandinavia south to the Iberian Peninsula and from Ireland eastwards through central and southern Europe to Turkey', European parts of Russia, Russian Far East and Siberia. Fauna EuropaeaPeck, L.V. (1988) Syrphidae. In: Soos, A. & Papp, L. (eds.) Catalogue of Palaearctic Diptera, 8: 11-230. Akad.Kiado, Budapest.
Habitat Very varied. Forest, pasture, montane grassland, alpine grassland, fen and dune systems.
Biology It is low-flying over ground vegetation; males hover at 1-3m in small clearings. Flowers visited include Caltha, Cirsium arvense, Leontodon, Leucanthemum, Menyanthes, Prunus spinosa, Ranunculus, Salix, Senecio, and Taraxacum. It flies from April to October. The larva feeds in the stems of Achillea, Matricaria and Sonchus oleraceus and in the involucre of Tragopogon.
References