| | Insects of Britain and Ireland: the families of Diptera |
Excluding Ocydromiinae and Tachydromiinae
Dancing-flies.
Adult insects. Very small to medium-sized; slender-bodied to robustly-built; stilt-legged, or not stilt-legged. Antennae 3 segmented (third segment not annulated); ‘modified’; with a non-annulated terminal segment; aristate, or not aristate; the arista when present, apical (but sometimes downwardly directed). Ptilinal suture absent or weakly defined. Ocelli present; 3. Eyes rounded, well separated (and usually nicked in the inner margin, near the bases of the antennae). Mouthparts functional (proboscis usually rigid, sometimes very long); adapted for piercing. The maxillary palps 1 segmented, or 2 segmented; porrect. Wings usually with a discal cell; without a sub-apical cell; with a closed anal cell, or without a closed anal cell. The anal cell when present, relatively long (but falling well short of the margin), or short. The costa not extending around the entire wing. Sub-costa apparent; reaching the costa independently of vein 1 (e.g., Clinocera, Phyllodromia), or terminating blind (e.g., Rhamphomyia). The leading edge veins not noticeably stronger than the rest. Wing vein 3 distally forked. Wing vein 6 present, or absent; reaching the wing margin, or falling short of the wing margin. Wing vein 7 present; falling short of the wing margin. Wings with the lower calypter much reduced or absent; patterned, or unpatterned. Feet with a triple pad beneath the tarsal claws (occasionally), or without a triple pad. The hind tarsi normal. Predatory (on other, smaller arthropods, mainly Diptera).
Larvae and pupae. The larvae aquatic, or terrestrial; saprophagous, or predatory; hemicephalic. The pupae without a puparium.
Comments. Small to medium sized, mostly bristly flies, folding the wings over the abdomen at rest. Not metallic. Sometimes dancing in swarms, cf. chironomids.
Classification. Suborder Brachycera; Division Asilomorpha; Superfamily Empidoidea.
British representation. 208 species in Britain. Genera 17; Chelifera, Chelipoda, Clinocera, Dolichocephala, Dryodromya, Empis, Gloma, Heleodromia, Heterodromyia, Hilara, Hormopeza, Iteaphila, Kowarzia, Phyllodromia, Ragas, Rhamphomyia, Trichoopeza, Wiedemannia.
Illustrations. • Clinocera, Dolichocephala, Empis, Heleodromia, Hilaria, Ragas, Wiedemannia (from Walker). 1a-c, Empis livida: details of head, with antennae and parts of proboscis extended (1a); antenna (1b); and extremity of tarsus (1c). 1d, antenna of Empis "borealis" (= ?). 2a and 2b, Hilaria curtisi: side view of head, and tarsus of fore leg of male. 3, Ragas unica: 3a-3g, female, showing details of head in side view (3a), antenna (3b), proboscis from the side (3c) and same enlarged (3d), labrum (3f), and a palp (3g); 3h, outline of male head from below, showing the small proboscis, and (3i) the latter with palps in situ and detached. 5a and 5b, Dolichocephala irrorata: head in side view, and antenna. 6, Clinocera stagnalis: with details of antenna (6a), proboscis and a palp (6b), labrum (6c), labrum with a palp (6d), tongue with a portion of epistoma adhering (6e), and base of wing (6f, the asterisk indicating a supernumerary transverse vein). 7, Wiedemannia lota (this specimen with a minute triangular cell in the disc of each wing); with details of head (7a and 7b), proboscis with tongue and a palp removed (7c), lingua with its abruptly enlarged base and a blunt tooth on each side (7d), labrum with membranous edge and notched tip, (7e), antenna (7f), and extremity of tarsus in oblique view (7g). From Walker (1851, Plate III), with approximate lengths (front of head to abdominal tip) added. • Chelifera, Heleodromia, Hemerodromia, Phyllodromia, Rhamphomyia (from Walker). 1, Heleodromia immaculata, male: with details of labium and a palp (1a), maxilla and detached palp (1b), labrum (1c), lingua (1d), and lingua from beneath (1e). 1f-1k, Heleodromia immaculata, female: abdomen in side view (1f), extremity of the latter (1g), and views of the detached vagina (1h-1k). 2a and 2b, head and wing of Rhamphomyia sulcata. 2c, hind leg of male Rhamphomyia barbata; 2d, ditto of the female. 7, Phyllodromia melanocephala, with head in side view (7a). 8a-8f, Chelifera precatoria: head in side view (8a), proboscis from the side (the labium shorter than the labrum, 8b), ditto with the organs separated (8c), a maxilla and its palp (8d), the lingua from above (8e), and a wing (8f). 8g, a wing of Hemerodromia oratoria. From Walker (1851, Plates IV and V), with approximate lengths (front of head to abdominal tip) added. • Wiedemannia bistigma Curtis (Tachydromiinae: Stigma-spotted Heleodromia: B. Ent. 513). • Wiedemannia bistigma (detail: B. Ent. 513). • Wiedemannia bistigma (dissections: B. Ent. 513). • Wiedemannia bistigma (B. Ent. 513, legend+text). Curtis's species is now referred to Wiedemannia, as W. bistigma (Curtis). • Wiedemannia bistigma (B. Ent. 513, text cont.). • Empis borealis (Northern Empis: B. Ent. 018). • Empis borealis (detail: B. Ent. 018). • Empis borealis (dissections: B. Ent. 018). • Empis borealis: B. Ent. 018, legend+text. • Empis borealis: B. Ent. 018, text cont.. • Hilara curtisi (Fan-footed Empida: B. Ent. 130). • Hilara curtisi (B. Ent. 130, legend+text). • Hilara curtisi (B. Ent. 130, text cont.). • Rhamphomyia barbata (Feather-legged Dancing Fly: B. Ent. 517). • Rhamphomyia barbata: B. Ent. 517, legend+text. • Rhamphomyia barbata: B. Ent. 517, text cont.. • Hemerodromia monostigma: Stephens 1846.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the families of Diptera. Version: 14th April 2022. delta-intkey.com’.
