Insects of Britain and Ireland: the families of Hymenoptera

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L. Watson and M. J. Dallwitz


Including Aphidiidae.


Adults small to large. Insects associated with plant galls, or not associated with galls.

Head. Antennal segments 13–30 (or more, often multi-segmented, but sometimes short with as few as 13 segments in the females of small species). Antennae not 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 (usually), or absent (females, sometimes). Fore-wings with a conspicuous pterostigma; with the venation well developed (usually), or with very reduced venation; not combining greatly reduced venation with conspicuous stigmal vein; never exhibiting the linking cross-vein ‘distal 2m cu’. Hind-wings with closed cells, or without closed cells; when cells present, with the median cell terminating short of the base of the marginal vein (see illustration, exemplifying the difference from Ichneumonidae). Hind femur with a clear trochantellus. Hind tibiae without specialised spurs.

Abdomen. The abdomen broadly sessile at its base, without a marked constriction to with a marked basal constriction; when waisted, long petiolate, or short-waisted. The gaster concolorous (mostly), or colour-patterned; when concolorous, mostly black or orange-red; when patterned, black-and-orange, black-and-reddish or black-and-yellow; attached low on the propodeum. Ovipositor of females visibly protruding; adapted for piercing.

Larvae. Larvae with segmented legs; parasitic on hosts selected by the mother (ecto- and endo-parasites victimising a great diversity of insect hosts, commonly on Lepidoptera, the Aphidiinae specialising on aphids); when gall-associated, parasitic on other gall occupants.

General comments. Apterous forms of Braconidae and Ichneumonidae may be morphologically indistinguishable via family desriptions.

British representation. Species in Britain over 700; about 130 genera, with numerous species of Apanteles, Aspilota, Bracon, Chorebus, Dacnusa, Meteorus, Microgaster, Opius, etc.

Classification. Suborder Apocrita; Series Parasitica; Superfamily Ichneumonoidea.

Illustrations. • Wings of Ichneumonidae and Braconidae: exemplifying different venation patterns. • Coelinius anceps (Curtis) (Yellow-bodied Ichneumon): B. Ent. 289. • Coelinius anceps (B. Ent. 289, legend+text). • Coelinius anceps: B. Ent. 289, text cont.. • Microdus calculator (Beautiful Bassus: B. Ent. 73). • Microdus calculator (detail: B. Ent. 73). • Microdus calculator (dissections: B. Ent. 73). • Microdus calculator: B. Ent. 73, legend+text. • Microdus calculator: B. Ent. 73, text cont.. • Protomicroplitis alvearius (Pretty Microgaster): B. Ent. 321. • Protomicroplitis alvearius: B. Ent. 321, legend+text. • Protomicroplitis alvearius: B. Ent. 321, text cont.. • Rogas balteatus Hal. mss (Red-and-black Rhogas), cf. Aleiodes signatus Nees. (B. Ent. 512). • Rogas balteatus Hal. mss: B. Ent. 512, legend+text. • Rogas balteatus Hal. mss: B. Ent. 512, text cont.. • Aphidius matricariae (Thistle-aphis Destroyer): B. Ent. 383. • Aphidius matricariae: B. Ent. 383, legend+text. • Aphidius matricariae: B. Ent. 383, text cont.. • Hecabolus sulcatus Curtis (4-stigmared Ichneumon: B. Ent. 507). • B. Ent. 507: Hecabolus sulcatus Curtis, legend+text. • B. Ent. 507, Hecabolus sulcatus Curtis legend+text, cont.. • Chelonus wesmaŽlii Curtis: B. Ent. 672. • Chelonus wesmaŽlii Curtis: B. Ent. 672, legend+text. • Chelonus wesmaŽlii Curtis: B. Ent. 672, text cont.. • Dapsilarthra apii Curtis (Celery-feeding Alysia): B. Ent. 141. • Dapsilarthra apii Curtis: B. Ent. 141, legend+text. • Dapsilarthra apii Curtis: B. Ent. 141, text cont.. • Atanycolus denigrator (Smokey-winged Bracon: B. Ent. 069). • Atanycolus denigrator: B. Ent. 069, legend+text. • Atanycolus denigrator: B. Ent. 069, text cont.. • Zemiotes albiditarsus (Curtis): B. Ent. 415. • Zemiotes albiditarsus (B. Ent. 415, legend+text). • Zemiotes albiditarsus (B. Ent. 415, text cont.). • Leiophron apicalis Haliday in Curtis: B. Ent. 476. • Leiophron apicalis (B. Ent. 476, legend+text). • Leiophron apicalis (B. Ent. 476, text cont.). • cf. Chelonus basalis Curtis: as Microgaster basalis(?), Stephens 1846. • Cotesia tibialis (Curtis): as Microgaster tibialis, Stephens 1846. • Homolobus annulicornis: as Helcon annulicornis, Stephens 1846.

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.’.