Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz



Adults small to large; 6–21 mm long; conspicuously bearing a spherical head on an elongated ‘neck’.

Head. Sub-antennal grooves present. Antennal segments 13–19.

Thorax. Pronotum deeply indented or emarginate at the back. Mesoscutellum completely separated from the scutum laterally by defined axillae. Cenchri present. Fore-wings with a conspicuous pterostigma; with the venation well developed. Hind-wings with closed cells. Hind tibiae without specialised spurs.

Abdomen. The abdomen broadly sessile at its base, without a marked constriction. The gaster concolorous, or colour-patterned (red-girdled, in X. prolongata only). Ovipositor of females visibly protruding (without the abdominal ‘horn’ of Siricidae); adapted for boring.

Larvae. Larvae legless or the legs vestigial (or the legs vestigial); phytophagous (boring in angiosperm wood).

General comments. Adults characterised by the spherical head on a stalked ‘neck’, and the pronotum viewed from above is cap-shaped by contrast with that of Siricidae (q.v.).

British representation. Species in Britain 2, or 3; Xiphydra.

Classification. Suborder Symphyta; Superfamily Siricoidea.

Illustrations. • Xiphydria prolongata (Cameron II, vii). 4, Xiphydria prolongata. 4a, ovipositor (1, hypopygium; 2, sheath; 3, borer; 4,triangular plate); 4b, labium; 4c, maxilla; 4d, head, from front; 4e, mandible. female.

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.’.