Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz


Gall Wasps.

Adults small to large (to 15 mm - among the largest Cynapoidea).

Head. Antennal segments 13 (female), or 15 (male). Antennae not geniculate.

Thorax. Thorax black. Pronotum long, extending back to the tegulae; not vertically grooved for reception of the fore femur. The spiracle cover lobe of the pronotum not margined with close fine hairs. Cenchri absent. Fore-wings without a pterostigma; with the venation well developed (the radial cell at least 9 times as long as broad). Closed fore-wing cells 3–5. Submarginal cells 3. Hind femur with a clear trochantellus. Hind tibiae without specialised spurs.

Abdomen. The abdomen with a marked basal constriction; short-waisted (short-petiolate); very laterally compressed and knife-like. Visible abdominal segments 6 (male), or 5 (female). The gaster concolorous; reddish brown. Ovipositor of females visibly protruding, or not visibly protruding (usually); adapted for piercing.

Larvae. Larvae with segmented legs; parasitic on hosts selected by the mother (the British representative on Sirex larvae).

General comments. The hind basitarsus twice as long as segments 2–5 combined.

British representation. Species in Britain 1; Ibalia.

Classification. Suborder Apocrita; Series Parasitica; Superfamily Cynipoidea.

Illustrations. • Ibalia leucospoides (Knife-shaped Ibalia): B. Ent. 22. • Ibalia leucospoides (detail: B. Ent. 22). • Ibalia leucospoides (dissections: B. Ent. 22). • Ibalia leucospoides: B. Ent. 22, legend+text. • Ibalia leucospoides: B. Ent. 22, text cont..

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.’.