British Insects: the Families of Hymenoptera
Adults small to large; 4–18 mm long. Solitary insects.
Head. Eyes emarginate (Ceropales), or ovate and not emarginate (usually). Antennal segments (10–)12 (females), or (10–)13 (males). Antennae not geniculate (curling after death). Tongue shorter than the prementum; not pointed (bifid).
Thorax. Thorax black, orange, or black-and-yellow. Pronotum deeply indented or emarginate at the back; long, extending back to the tegulae. Mesopleuron with an oblique suture. Cenchri absent. Wings present; not folding longitudinally. Fore-wings with a conspicuous pterostigma; with the venation well developed. Closed fore-wing cells 6–10. Submarginal cells 2 (rarely), or 3. Discoidal cells 2. Hind-wings with closed cells. Hind femur without a well defined trochantellus. Hind tibiae with spurs specialised for a cleaning rôle.
Abdomen. The abdomen with a marked basal constriction; long petiolate to short-waisted. The waist simple. Visible abdominal segments 6 (females), or 7 (males). The gaster concolorous, or colour-patterned; when concolorous, orange, black or grey; when patterned, black-and-orange or -reddish orange, or black-and-yellow. Ovipositor of females not visibly protruding; modified as a retractable sting.
Larvae. Larvae legless or the legs vestigial; predacious, or feeding on prey collected and stored by the adults (specializing on spiders, which are generally paralysed and dragged along the ground to the nest. Some species induce only temporary paralysis, the larvae then parasitizing the living spider).
British representation. Species in Britain about 40; Agenioideus, Arachnospila, Anoplius, Aporus, Auplopus, Caliadurgus, Ceropales, Cryptocheilus, Dipogon, Episyron, Evagetes, Homonotus, Pompilus, Priocnemis (with most of the species in Anoplius, Arachnospila, Dipogon or Priocnemis).
Classification. Suborder Apocrita; Series Aculeata; Superfamily Pompiloidea.
Illustrations. • Episyron rufipes (B. Ent. 238). • Episyron rufipes (detail: B. Ent. 238). • Episyron rufipes (dissections: B. Ent. 238). • Episyron rufipes (B. Ent. 238, legend+text). • Episyron rufipes (text, cont.: B. Ent. 238). • Ceropales variegata: B. Ent. 756. • Ceropales variegata: B. Ent. 756, legend+text. • Ceropales variegata: B. Ent. 756, text cont.. • Aporus, Agenioideus, Anoplius, Episyron, Pompilus (Saunders VIII). • Cryptocheilus, Anoplius, Arachnospila, Priocnemis (Saunders IX). • Auplopus, Dipogon, Priocnemis (Saunders X). • Ceropales maculatus and C. variegatus (Saunders XI). • Evagetes dubius, Cryptocheilus notatus, Sphex flavipennis: 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 Hymenoptera. Version: 1st January 2012. http://delta-intkey.com’.