Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz

Orussidae

Adults medium sized to large; 9–15 mm long.

Head. Eyes hairy, a unique or very unusual feature in the Symphyta. Sub-antennal grooves present. Antennal segments 10 (females), or 11 (males). Antennae inserted below the eyes.

Thorax. Thorax black. Mesoscutellum completely separated from the scutum laterally by defined axillae. Cenchri present. Fore-wings without a pterostigma; with the venation well developed. Hind-wings without closed cells. Hind tibiae without specialised spurs.

Abdomen. The abdomen broadly sessile at its base, without a marked constriction (or with a slight constriction only). The gaster colour-patterned; white flecked and red girdled. Ovipositor of females not visibly protruding (the long ovipositor being stored coiled within the body).

Larvae. Larvae legless or the legs vestigial (and lacking abdominal prolegs); phytophagous and predacious (in wood, predacious in the later instars on wood-boring beetle larvae).

General comments. Further distinguished from other sawflies by lacking a closed anal cell in the fore-wings.

British representation. Species in Britain 1; Orussus abietinus (Scop.): not recorded in Britain since the 19th Century.

Classification. Suborder Symphyta; Superfamily Orussoidea.

Illustrations. • “Orussus coronatus Fab.” (Coronetted Oryssus: = O. abietinus. B. Ent. 460). • "Orussus coronatus” (detail: B. Ent. 460). • "Orussus coronatus” (dissections: B. Ent. 460). • "Orussus coronatus” (B. Ent. 460, legend+text). • "Orussus coronatus” (text, cont.: B. Ent. 460).


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. delta-intkey.com’.

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