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Insects of Britain and Ireland: the families of Hymenoptera

L. Watson and M.J. Dallwitz

Xyelidae

Sawflies.

Adults minute to small; 2.4–4.5 mm long.

Head. Antennal segments 11–20 (with three ‘normal’ basal segments, followed by a slender filament with nine or more). Antennae with a very elongated third segment.

Thorax. Pronotum more or less straight at the back. Cenchri present. Wings not folding longitudinally. Fore-wings with a conspicuous pterostigma; with the venation well developed. Hind-wings with the venation relatively well developed; with closed cells. Hind tibiae without specialised spurs. Tarsi 5 segmented.

Abdomen. The abdomen broadly sessile at its base, without a marked constriction. Ovipositor of females visibly protruding.

Larvae. Larvae with segmented legs (and with prolegs on all abdomimal segments); phytophagous (in male pine cones).

General comments. Adults black with yellow markings.

British representation. Species in Britain 2; Xyela.

Classification. Suborder Symphyta; Superfamily Xyeloidea.

Illustrations. • Xyela pusilla Dalman, = X. julii (Small Xyela: B. Ent. 030). • Xyela pusilla (detail: B. Ent. 030). • Xyela pusilla (dissections: B. Ent. 030). • Xyela pusilla (B. Ent. 030, legend+text). • Xyela pusilla (text, cont.: B. Ent. 30). • Xyela julii (Cameron II, vi). X. julii (male). 11a, antenna. 11b, ovipositor - a, saw, b, sheath, c, triangular plate. 11c, mandibles. 11d, palpus.


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 Hymenoptera. Version: 14th April 2022. delta-intkey.com’.

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