Hypodermatidae Rondani, 1856

The morphology of warble flies is strongly influenced by their parasitic mode of life. Medium-sized to large, rather thickset or oblong flies, 10.0-22.0 mm in length, with a dark or grey body with a dense covering of fine coloured hairs that gives them the appearance of bumble-bees, or with only very short bristles and a small number of longer thick bristles. A characteristic feature of the adults is the entirely rudimentary mouth-parts. Ocelli always developed. Wings well-developed, with vein M1+2 bent towards front vein of the wing. Females with a long projecting ovipositor.

The larval body is cylindrical or even barrel-shaped. The larva is acephalic, with the sclerotized parts of the head reduced to sclerites of the oral organs. The body consists of the head drawn back into the thorax, three thoracal and eight abdominal segments which are armed with transverse bands of sclerotized spines. The posterior respiratory plates have the peritremes oval with numerous respiratory pores.

Warble flies are specific parasites of mammals (Rodentia, Lagomorpha and Arctiodactyla). Females lay eggs on the hairs of their hosts. First instar larvae penetrate the skin of the host and migrate into the host's body. Second and third instar larvae live as parasites under the skin in characteristic warbles with a breathing hole. Mature larvae drop from the skin and pupate in the soil. Adults fly on sunny summer days, but do not feed and are short-lived. There is only one generation per year. The number of larvae parasitizing one host is regulated by an internal regulatory system in the parasite and in the host populations (Breev & Minář 1981, Minář 1993). Warble flies cause serious economic damage in cattle, goats and deer (Grunin 1962, Minář 1993, 2000).

About 30 species are known in the Palaearctic region (Soos & Minář 1986), and there are three endemic species in the Afrotropical region. Altogether eight species of warble flies are known in Europe, five of which are recorded from the Czech Republic and Slovakia (Minář 1980, 1997). Data on the systematics, morphology and biology of warble flies can be found in several monographs (Grunin 1962, Zumpt 1965, Minář 1980, 2000, Papp & Szappanos 1992). Some authors classify the family Hypodermatidae as a subfamily of the family Oestridae (Zumpt 1965, Pape 2007), but most European authors maintain the Hypodermatidae as a separate family.