Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz



Adults small to medium sized; 5–11 mm long.

Head. Antennal segments 3 (with the third very long, and forked in some males). Antennae with a very elongated third segment.

Thorax. Pronotum deeply indented or emarginate at the back. Mesoscutellum not separated from the scutum laterally, axillae not defined. Cenchri present. Fore-wings with a conspicuous pterostigma; with the venation well developed. Hind tibiae without specialised spurs.

Abdomen. The abdomen broadly sessile at its base, without a marked constriction. Ovipositor of females not visibly protruding; adapted as a saw.

Larvae. Larvae with segmented legs, or legless or the legs vestigial (in leag miners); phytophagous.

General comments. Robust-looking sawflies, with distictive 3-segmented antennae (the third segment in male Aprosthema and Sterictiphora forked); flying in sunshine, and often visiting flowers of Umbelliferae.

British representation. Species in Britain 15 (with twelve Arge species); Arge, Aprosthema, and Sterictiphora.

Classification. Suborder Symphyta; Superfamily Tenthredinoidea.

Illustrations. • Arge (10 species: Cameron III, i). • Arge pagana subsp. stephensii (Stephensian Hylotoma: B. Ent. 65). • Arge pagana subsp. stephensii (detail: B. Ent. 65). • Arge pagana subsp. stephensii (dissections: B. Ent. 65). • Arge pagana subsp. stephensii: B. Ent. 65, legend+text. • Arge pagana subsp. stephensii: B. Ent. 65, text cont.. • Arge ustulata (Cameron II, v). female. 7a, antenna; 7b, labium; 7c, maxilla. • Sterictiphora furcata (Cameron II, v). male. 9a, female antenna; 9b, male antenna. • Sterictiphora geminata (Pale-legged Cryptus): B. Ent. 058. • Sterictiphora geminata: B. Ent. 058, legend+text. • Sterictiphora geminata: B. Ent. 058, text cont.. • Sterictiphora geminata (Cameron III). Sterictiphora geminata (Gmel.), male. From Cameron (1890). • Larvae: Arge gracilicornis, A. ustulata (Cameron II, x). 3. Arge ustulata. 3a, head; 3b, cocoon. 4. Arge gracilicornis. 4a, dorsal view of segment. • Larvae: Arge ochropus (Cameron II, xi). Arge ochropus.

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. Insects of Britain and Ireland: the families of Hymenoptera. Version: 16th May 2016.’.