Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz


Adults minute to small; 0.7–6.5 mm long.

Head. Antennal segments 7–8, or 11–12. Antennae geniculate.

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 (e.g., Trimorus procris). Fore-wings when present, without a pterostigma; with very reduced venation (with distinct, though sometimes short, marginal and stigmal veins); combining greatly reduced venation with a conspicuous, blind-ending stigmal vein (though this is sometimes short). Closed fore-wing cells 0, or 1 (the costal). 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 not visibly protruding; adapted for piercing.

Larvae. Larvae legless or the legs vestigial; parasitic on hosts selected by the mother (on eggs of Lepidoptera, Hemiptera, Orthoptera and occasionally Arachnids).

British representation. Species in Britain about 110; Allophanurus, Baeus, Gryon, Opisthacantha, Plesiobaeus, Scelio, Sparasion, Teleas, Telenomus, Thoron, Trimorus, Trisacantha, Trissolcus, Xenomerus (with numerous species in Telenomus and Trimorus).

Classification. Suborder Apocrita; Series Parasitica; Superfamily Proctotrupoidea.

Illustrations. • Sparasion frontalis (B. Ent. 317). • Sparasion frontalis (detail: B. Ent. 317). • Sparasion frontalis (dissections: B. Ent. 317). • Sparasion frontalis: B. Ent. 317, legend+text. • Sparasion frontalis: B. Ent. 317, text cont.. • Scelio rugulosus: B. Ent. 325. • Scelio rugulosus: B. Ent. 325, legend+text. • Scelio rugulosus: B. Ent. 325, text cont.. • Trimorus elatior: B. Ent. 333. • Trimorus elatior: B. Ent. 333, legend+text. • Trimorus elatior: B. Ent. 333, text cont.. • Trimorus procris (apterus): as Teleas procris, Stephens 1846.

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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.’.