Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz



Adults minute; 0.7–1.5 mm long. Insects mainly associated with plant galls.

Head. Antennal segments (8–)10. Antennae geniculate (doubly so, forming a Z).

Thorax. Pronotum long, extending back to the tegulae; vertically grooved to receive the fore femur. The spiracle cover lobe of the pronotum not margined with close fine hairs. Cenchri absent. Wings present, or absent (some females). Fore-wings without a pterostigma; with very reduced venation (venation absent, or reduced to a submarginal vein that is often slightly knobbed at its apex); not combining greatly reduced venation with conspicuous stigmal vein; not combining greatly reduced venation with a conspicuous radial cell. Closed fore-wing cells 0. Submarginal cells 0. Discoidal cells 0. Hind-wings without closed cells. Mid and hind tibiae with one spur only. Mid tibiae with one spur. Hind femur without a well defined trochantellus. Hind tibiae without specialised spurs.

Abdomen. The abdomen with a marked basal constriction. The ‘waist’ simple. Ovipositor of females visibly protruding, or not visibly protruding; adapted for piercing.

Larvae. Larvae legless or the legs vestigial; parasitic on hosts selected by the mother, or parasitic on hosts selected by the mother and predacious; parasitic on other gall occupants, or predacious on other gall occupants (mainly on gall-inducing Cecidomyidae).

British representation. Species in Britain about 130; Acerotella, Allotropa, Amblyaspis, Inostemma, Iphitrachelus, Isocybus, Isostasius, Leptacis, Metaclisis, Metanopedias, Piestopleura, Platygaster, Platystasius,Synopeas, Trichacis.

Classification. Suborder Apocrita; Series Parasitica; Superfamily Proctotrupoidea.

Illustrations. • Inostemma boscii (B. Ent. 309). • Inostemma boscii (detail: B. Ent. 309). • Inostemma boscii (dissections: B. Ent. 309). • Inostemma boscii (B. Ent. 309, legend+text). • Inostemma boscii (text, cont.: B. Ent. 309).

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.’.