British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Including Gasterophilidae.

Warble-flies, Bot-flies.

Life style parasitic; on mammals other than humans (sheep, deer, cattle, horses, etc.).

Adult insects. Small to large. Antennae 2–6 segmented; ‘modified’; aristate; the arista dorsal. The second antennal segment distinctly grooved above, or not grooved (Gasterophilinae). Ptilinal suture clearly defined. Ocelli present; 3. Mouthparts non-functional (atrophied). The maxillary palps 1 segmented; porrect. Thorax with the dorsal suture continuous across the middle; with well defined posterior calli. Wings with a discal cell, or without a discal cell (Gasterophilinae); with a subapical cell (when vein 4 bent), or without a sub-apical cell (Gasterophilinae); with a closed anal cell, or without a closed anal cell. The anal cell if present, short. The costa unbroken. Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins markedly stronger than the rest, or not noticeably stronger than the rest. Wings exhibiting a sharp bend in vein 4 (Hypodermatinae, Oestrinae, Cephenemyiinae), or without a sharp bend in vein 4 (Gasterophilinae). Wing vein 6 present; reaching the wing margin (Gasterophilinae), or falling short of the wing margin. Wings with a well developed lower calypter; patterned (in at least some Gasterophilinae), or unpatterned. Hind tibiae without strong bristles in the basal 4/5. Neither parasitic nor predatory (i.e., non-feeding, being without functional mouthparts).

Larvae and pupae. The larvae parasitic; endoparasitic (in mammals); acephalic. The pupae enclosed within a puparium.

Comments. Mostly large, furry or hairy, bee-like flies. Interestingly, livestock are much more noticeably alarmed by the attentions of these adults, which do not bite and are intent only on depositing eggs or larvae, than by those of the severely biting Tabanids.

Classification. Suborder Brachycera; Division Muscomorpha Schizophora Calyptratae; Superfamily Oestroidea.

British representation. 11 species in Britain. Genera 5; Cephenemyia, Gasterophilus, Hypoderma, Oestrus, Pharyngomyia.

Illustrations. • Gasterophilus, Hypoderma, and Oestrus: Walker. • Pharyngomyia picta (Original generic description. Deer Bot- or Warble-fly: B. Ent. 106). • Pharyngomyia picta (detail: B. Ent. 106). • Pharyngomyia picta (dissections: B. Ent. 106). • Pharyngomyia picta (legend+text: B. Ent. 106). • Pharyngomyia picta (text, cont.: B. Ent. 106). • Gasterophilus nasalis (Healthful Bot- or Warble-fly: B. Ent. 146). • Gasterophilus nasalis: B. Ent. 146, legend+text. • Gasterophilus nasalis: B. Ent. 146, text cont.. • Gasterophilus nasalis, female (as G. salutiferus): Stephens 1846.

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Diptera. Version: 1st January 2012.’.