British Insects: the Families of Diptera
British Insects: the Families of Diptera |
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Non-parasitic.
Adult insects. Small; slender-bodied to robustly-built; not stilt-legged. Antennae 2 segmented, or 3 segmented; ‘modified’. Antennae aristate; the bristle dorsal (not plumed). The second antennal segment not grooved. Ptilinal suture clearly defined. Ocelli present; 3. Eyes not meeting. Lower orbital bristles present, or absent; when present, curved forward. Post-vertical orbital bristles present; divergent. Mouthparts functional. The maxillary palps 1 segmented (vestigial); porrect. Vibrissae present, or absent. Thorax without a continuous dorsal suture; without well defined posterior calli. Wings with a discal cell; with a subapical cell (or almost closed), or without a sub-apical cell; with a closed anal cell. The anal cell short. The costa unbroken. Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins not noticeably stronger than the rest. Vein 6 present; falling short of the wing margin (short and straight). Vein 7 absent. Wings with the lower calypter much reduced or absent; unpatterned (but sometimes with a dark apical spot). Tibiae with a dorsal pre-apical bristle (e.g., Sepsis punctum), or without a dorsal pre-apical bristle. Hind tibiae without strong bristles in the basal 4/5. Abdomen constricted basally (often, lending an ant-like appearance), or not constricted basally.
Larvae and pupae. Larvae terrestrial; saprophagous, or coprophagous (in mammal faeces and vertebrate carcasses); acephalic. Pupa enclosed within a puparium.
Comments. Small black or brownish flies, sometimes metallic and shining. Always with one or more bristles across the posterior spiracle, just below and in front of the haltere.
Classification. Suborder Brachycera; Division Muscomorpha Schizophora Acalyptratae; Superfamily Scyomyzoidea.
British representation. 27 species in Britain. Genera 6; Meroplius, Nemopoda, Orygma, Saltella, Sepsis, Themira.
Illustrations. • Nemopoda, Orygma, Saltella, Sepsis, Themira (from Walker). • Themira annulipes (Ring-footed Fly: B. Ent. 245). • Themira annulipes (detail, dissections: B. Ent. 245). • Themira annulipes: B. Ent. 245, legend+text. • Themira annulipes: B. Ent. 245, text cont..
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: 28th August 2009. http://delta-intkey.com’.
