Oestridae Leach, 1815

Flies of medium to large size, thickset, body length 10.0-18.0 mm, covered with dense hairs or mostly bare with only sparse hairs, without macrochaetae. Oral organs rudimentary. Ocelli developed. Wing vein M1 curved towards anterior edge of wing, and a separate prolongation of M2 developed in some genera. Thoracal scales large. Female ovipositor short, non-projecting.

The larval body in all instars is elongated, and flat on the ventral side. Larvae are acephalic, and oral hooks are present in all three larval instars. Sclerotized spines are present on the anterior edges of the body segments, arranged mostly in perpendicular rows. The posterior peritremes are oval with numerous respiratory pores.

These warble flies are specific parasites of mammals of the orders Marsupialia, Proboscidea, Perissodactyla and Arctiodactyla, and they cause important economic damage in sheep, deer, horses and camels (Grunin 1957, Zumpt 1965). The viviparous females lay first instar larvae in the nostrils of their hosts. The larvae live as parasites in the head cavities or in the throat, where they survive the winter period. In spring they moult twice, having three instars. Full-grown larvae are sneezed out through the nose cavity and pupate in the soil. The growth and the expulsion of the larvae are successive processes. Adults do not feed and have a brief life in summer. Males hilltop during the mating period. Warble flies have one generation in the temperate zone and two generations in the subtropics.

The family contains some 35 species, mostly in the Afrotropical and Palaearctic regions, and ten species are known in Europe. Five of these are recorded from the Czech Republic and Slovakia, where they are the subject of a monograph (Minář 1980, 1997). Data on the systematics, morphology and biology of warble flies can be found in several monographs (Grunin 1957, Minář 1980, 2000, Papp & Szappanos 1992, Soós & Minář 1986,  Zumpt 1965).