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| Insects of Britain and Ireland: the families of Hymenoptera |
Including Elasmidae, Tetracampidae
Chalcid Wasps.
Adults minute to small; (0.6–)1–3(–4) mm long. Insects associated with plant galls, or not associated with galls.
Head. Antennae geniculate.
Thorax. Pronotum short, not extending back to the tegulae. Cenchri absent. Wings not folding longitudinally. Fore-wings without a pterostigma; with very reduced venation (reduced to a proximal submarginal vein, which becomes marginal distally before giving off the stigmal vein); combining greatly reduced venation with a conspicuous, blind-ending stigmal vein. Closed fore-wing cells 0. Submarginal cells 0. Discoidal cells 0. Hind-wings without closed cells. Fore tibiae with a straight spur. Hind femur not toothed below; with a clear trochantellus. Hind tibiae not curved around the femora; without specialised spurs. Tarsi 4 segmented.
Abdomen. The abdomen with a marked basal constriction. Ovipositor of females visibly protruding; adapted for piercing.
Larvae. Larvae legless or the legs vestigial; phytophagous, or parasitic on hosts selected by the mother (including some hyper-parasites on other hymenoptera); when associated with galls, primary inducers of galls, or parasitic on other gall occupants, or predacious on other gall occupants.
General comments. Spur of fore tibia short and straight, and the basitarsus with the strigil characteristically modified into an oblique medial comb at the base.
British representation. Species in Britain about 380; about 60 genera, with Cirrospilus, Elachertus, Entedon, Sympiesis, etc., well represented, and Chrysocharis, Omphale, Pediobius and Tetrastichus especially so.
Classification. Suborder Apocrita; Series Parasitica; Superfamily Chalcidoidea.
Illustrations. • Eulophus larvarum (Kirbian Eulophus: B. Ent. 133). • Eulophus larvarum (detail: B. Ent. 133). • Eulophus larvarum (dissections: B. Ent. 133). • Eulophus larvarum: B. Ent. 133, legend+text. • Eulophus larvarum: B. Ent. 133, text cont.. • Hemiptarsenus unguicellus (male) and Cirrospilus diallus: as Eulophus cinctipes and C. walkeri, Ste. EULOPHIDAE. 1, Hemiptarsenus unguicellus, male (as Eulophus cinctipes). 3, Cirrospilus diallus (as C. walkeri). From Stephens, 1846.
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’.
