Subfamily Pimplinae. The insects in this subfamily range are all elongate and range from robust, heavily-sculptured ichneumons to slender, smooth-bodied ones. In addition to insects with the 'normal' parasitoid life-cycle (eggs laid in or on the host larvae, feeding on the hosts' fat bodies until they are full-grown and then killing and consuming the hosts) there are some variations within this subfamily. Some species search in leaf litter for prepupae -fully-grown larvae which are preparing to pupate -which they parasitise and lay one or more eggs on it. The ichneumon grubs feed on this store of meat, acting more like predators than parasitoids. Other pimplines attack very dangerous hosts -they parasitise spiders! Some are solitary ectoparasitoids and their grubs can be seen wrapped around the cehalothorax of immature spiders with their mouthparts embedded in the hosts, sucking nutriment from them. Others lay their eggs in spider egg-cocoons, which involves taking on the mother spiders first. Their grubs eat the eggs and developing spiderlings and often the paralysed females. 

Pimplines can be identified by reference to:

Fitton, M.G., Shaw, M.R. & Gauld, I.D. (1988) “Pimpline Ichneumon-flies.” Handbooks for the Identification of British Insects Vol 7, Part 1.

Shaw, M.R. (2006) "Notes on British Pimplinae and Poemeniinae (Hymenoptera, Ichneumonidae), with additions to the British List." British Journal of Entomology & Natural History 19, p217-38

Information on Pimpline ichneumons in Yorkshire is:

Ely, W.A. (1987) “The Pimplinae (Hymenoptera, Ichneumonidae) of Askham Bog.” YNU Bulletin 8, p23-5

Ely, W.A. (1992) “The Ichneumons of South Yorkshire. 1. Pimplinae.” Sorby Record 28, p7-13

Ely, W.A. (2000) “Ichneumons of the Sorby Area: Update on Pimplinae."Sorby Record p44-48

Mayhew, P.J., Dytham, C., Shaw, M.R. & Fraser, S.E.M. (2009) "Collections of ichneumonid wasps (subfamilies Diacritinae, Diplazontinae, Pimplinae and Poemeniinae) from woodlands near York and their implications for conservation planning." Naturalist 134, p 3-24 

Until recently the subfamily Poeminiinae was included within the Pimplinae. Identification and Yorkshire occurrences are included in the references above.

Until recently the subfamily Rhyssinae was included within the Pimplinae. Identification and Yorkshire occurrences are included in the references above.

Until recently the subfamily Diacritinae was included within the Pimplinae. Identification and Yorkshire occurrences are included in the references above.

The single British species has been found in Yorkshire.

The subfamily Tryphoninae are ectoparasitoids whose eggs are anchored into the skin of the host larvae but do not hatch until those larvae pupate, and the ichneumon grubs feed on the developing pupae. The larvae of sawflies and moths are attacked. One method by which the hosts attempt to prevent parasitism is for the caterpillars to hide under leaves during the day and emerge to feed at night. A number of ichneumonoids, spread through several subfamilies of both ichneumons and braconids, exploit this resource by hunting at night. Most ichneumonoids are blackish, which makes them less obvious to predators, but colour is not important in the dark and many of these nocturnal ones have lost the melanin that provides the dark colour, so they are pale orange. The genus Netelia in the Tryphoninae has developed the large-eyed, yellowish-orange appearance typical of these nocturnal hunters and individuals are often attracted to light.

Most recent research on this subfamily has been carried out in Russia, led by D.R.Kasparyan and there is little identification literature in English:

Fitton, M.G. (1978) “A Review of the British Species of Tryphon Fallen.” Entomologist’s Monthly Magazine 110, p153-71

Fitton, M.G. & Ficken, L (1990) "British ichneumon-flies of the tribe Oedomopsini (Hymenoptera: Ichneumonidae)." The Entomologist 109 (4), p200-214

Kasparyan, D. R. 1973 [Fauna of the USSR Hymenoptera Vol.III Number 1. Ichneumonidae (Subfamily Tryphoninae) Tribe Tryphonini.] Leningrad: Nauka Publishers [in Russian, English translation published by Amerind Publishing Co. Ltd., New Delhi, 1981

Kerrich, G.J. (1952) A Review, and a Revision in Greater Part, of the Cteniscini of the Old World.Bulletin of the British Museum (Natural History). Entomology II, 6

Ichneumons in the subfamily Adelognathinae are small insects with short antennae with only 12 or 13 segments. They are ectoparasitoids of sawfly larvae.

Identification is difficult as the most recent British publication has been superceded by research in Russia:

Fitton, M.G., Gauld, I.D. & Shaw, M.R. (1982) "The taxonomy and biology of the British Adelognathinae (Hymenoptera: Ichneumonidae)." Journal of Natural History 16, p275-83

The subfamily Xoridinae contains insects which are ectoparasitoids of the larvae of wood-boring beetles. They can be identified by reference to:

Gauld, I.D. & Fitton, M.G. (1981) "Keys to the British Xoridine parasitoids of wood-boring beetles (Hymenoptera: Ichneumonidae)." Entomologist's Gazette 32, p259-67

 The subfamily Agriotypinae is parasitic on caddis-fly larvae.

The single British species is described in:

Perkins, J.F.(1960) Hymenoptera Ichneumonoidea Ichneumonidae, subfamilies Ichneumoninae II, Alomyinae, Agriotypinae and Lycorininae." Handbooks for the Identification of British Insects Vol VII, 2 (aii)

It has been found in Yorkshire.

The subfamily Cryptinae is one of the larger groups and much of the recent research has been carried out in Germany and Scandinavia. The following key (to the world fauna!) allows us to sort specimens into their tribes, subtribes and genera. It has been the stimulus to much recent research and large parts of the generic keys have been replaced by European ones:

Townes, H. K. (1969) "The genera of Ichneumonidae, Part 2." Memoirs of the American Entomological Institute 12, 1-537.

Scandinavian authors often publish in English and recent studies include:

Jussila, R. (1979) "A revision of the genus Atractodes (Hymenoptera, Ichneumonidae) in the Western Palaearctic region." Acta Entomologica Fennica 34, 1-44.

Jussila, R. (1983) "Addition to the revision of the genus Atractodes (Hymenoptera: Ichneumonidae) of the Western Palearctic region I." Contributions of the American Entomological Institute 20, 201-204.

Jussila, R. (1987) "Revision of the genus Stilpnus (Hymenoptera, Ichneumonidae) of the western Palaearctic Region." Annales Entomologici Fennici 53, 1-16.

Jussila, R. (1994) "Additions to the revision of the genus Atractodes (Hymenoptera, Ichneumonidae) of the Western Palaearctic region. II." Entomologica Fennica 5: 129-134.

Jussila, R. (1999) "Additions to the revisions of the genus Stilpnus (Hymenoptera, Ichneumonidae) of the Palaearctic Region. I." Entomologica Fennica 10, 107-112.

Jussila, R. (2001) "Additions to the revision of the genus Atractodes (Hymenoptera: Ichneumonidae) of the Palaearctic Region. III." Entomologica Fennica 12, 193-216.

Sawoniewicz, J. (1980) "Revision of European species of the genus Bathythrix Foerster (Hymenoptera, Ichneumonidae)." Annales Zoologici 35, 1-47.

Sawoniewicz, J. (1985) "Revision of European species of the subtribe Endaseina (Hymenoptera, Ichneumonidae), I." Annales Zoologici 39, 131-145.

Sawoniewicz, J. & Luhman, J. C. (1992) "Revision of European species of the subtribe Endaseina, III genus: Endasys Foerster, 1868." Entomofauna 13, 1-94.

The subfamily Stilbopinae is very small and British spec ies can be recognized by reference to:

Fitton, M.G. (1984) “A Review of the British Collyrinae, Eucerotinae, Stilbopinae and Neorhacodinae.” Entomologist’s Gazette 35, p185-95

The subfamily Banchinae consists of medium-sized ichneumons. Much of the recent work has ben carried out in France and Russia but a Royal Entomological Society handbook dealing with the British fauna is in preparation.

They can be identified by reference to:

Aubert, J.F. (1978) "Les ichneumonides ouest-palearctiques et leurs hes 2. Banchinae et Suppl. aux Pimplinae." Laboratoire d'Evolution des Etres Organises, Paris & EDIFAT-OPIDA, Echauffour.

Fitton, M.G. (1985) "The ichneumon-fly genus Banchus (Hymenoptera) in the old world." Bull. Br. Mus. nat. Hist. (Ent.) 51, 1-60

The subfamily Ctenopelmatinae has been very little studied in Yorkshire recently.

The single species in the Subfamily Lycorininae is described in:

Perkins, J.F.(1960) Hymenoptera Ichneumonoidea Ichneumonidae, subfamilies Ichneumoninae II, Alomyinae, Agriotypinae and Lycorininae." Handbooks for the Identification of British Insects Vol VII, 2 (aii)

It has been found in Yorkshire.

The subfamily Campopleginae has not been studied in Yorkshire in recent years. The following species have been found in Yorkshire.

The subfamily Cremastinae is a very small group of insects which superficially resemble the previous subfamily. They can be identified by reference to:

Fitton, M. G. & Gauld, I. D. (1980) "A review of the British Cremastinae (Hymenoptera: Ichneumonidae), with keys to the species." Entomologist's Gazette 31, 63-71.

The subfamily Tersilochinae contains small insects which are parasitoids of beetles. The European fauna can be identified through:

Horstmann, K. (1971) "Revision der europaischen Tersilochinen 1 (Hymenoptera: Ichneumonidae)." Verfentlichungen der Zoologischen Staatsammlung (Munchen) 15, 47-138.

Horstmann, K. (1981) "Revision der europaischen Tersilochinen II (Hymenoptera, Ichneumonidae)." Spixiana Supplement 4 (1980), 1-76.

Insects in the subfamily Phrudinae are very small and compact. They can be identified by reference to:

Vikberg, V. & Koponen, M. (2000) "On the taxonomy of Seleucus Holmgren and the European species of Phrudinae (Hymenoptera: Ichneumonidae)." Entomologica Fennica 11(4), 195-228

The subfamily Ophioninae is that of the archetypal 'yellow ichneumon', though several others contain similarly-coloured species. They can be identified by reference to:

Brock, J. P. (1982) "A systematic study of the genus Ophion in Britain (Hymenoptera, Ichneumonidae)." Tijdschrift voor Entomologie 125, 57-97.

Gauld, I. D. (1973) "Notes on the British Ophionini (Hym., Ichneumonidae) including a provisional key to species." Entomologist's Gazette 24, 55-65.

Gauld, I. D. (1974) "Further notes on the British Ophionini (Hym., Ichneumonidae)." Entomologist's Gazette 25, 147-148.

Ichneumons of the subfamily Mesochorinae are typified by a diamond-shaped areolet in the forewing, a long ovipositor in the female and long, rod-like claspers in the male. The following literature will sort out the genera and some species:

Lawton, F.D. (1981) "An introduction to the Mesochorinae (Hymenoptera, Ichneumonidae)." Proc Trabns Br. Ent Nat Soc. 14, 93-97

Fitton, M. G. (1985) "The British species of Cidaphus (Hymenoptera: Ichneumonidae)." Entomologist's Gazette 36, 293-297

The subfamily Metopiinae is characterised by a smooth, convex face and very strongly developed limbs. There is no current British literature on them and there are very few reliable records:

Ichneumons in the subfamily Cylloceriinae are small and slender. There is no current British literature on them and there are very few reliable records:

The subfamily Anomaloninae contains very elongate icgneumons. The females use their long, flexible 'abdomen' to reach their hosts, which are leaf-rolling moth caterpillars.

They can be identified by reference to:

Gauld, I.D. (1977) "Ichneumonidae Orthopematinae & Anomaloninae." Handbooks for the Identification of British Insects Vol 7, Part 2(b)

There is no modern literature on the subfamily Oxytorinae and it has not been studied in Yorkshire recently.

Recent research on the subfamily Orthocentrinae has been in France and there is no current British literature.

The tiny subfamily Orthopelmatinae parasitises the gall wasp that causes Robin's Pincushion galls on rose leaves. They can be identified by reference to:

Gauld, I.D. (1977) "Ichneumonidae Orthopematinae & Anomaloninae." Handbooks for the Identification of British Insects Vol 7, Part 2(b)

The two British species in the subfamily Collyriinae are parasitoids of stem-mining sawflies. The British species can be recognized by reference to:

Fitton, M.G. (1984) “A Review of the British Collyrinae, Eucerotinae, Stilbopinae and Neorhacodinae.” Entomologist’s Gazette 35, p185-95

Information on Collyriine ichneumons in Yorkshire is:

Ely, W.A. (2001) The Collyrinae (Hymenoptera, Ichneumonidae) of Yorkshire. Naturalist 126, p185-7

Both British species have been found in Yorkshire.

The subfamily Diplazontinae parastises hoverfly larvae and is characterised by having the upper mandible divided into two teeth. The following will allow most of them to be identified:

Beirne, B.P. (1941) "British species of Diplazontini (Bassini auctt.) with a study of the genital and postabdominal segments of the male (Hym.: Ichneum.)." Transactions of the Royal Entomological Society of London 91 (13)

Fitton, M. G. & Rotheray, G. E. (1982) A key to the European genera of diplazontine ichneumon-flies, with notes on the British fauna. Systematic Entomology 7, 311-320.

Fitton, M. G. & Boston, M. (1988) The British species of Phthorima (Hymenoptera: Ichneumonidae). Entomologist's Gazette 39, 165-170

Information on Diplozontine ichneumons in Yorkshire is:

Mayhew, P.J., Dytham, C., Shaw, M.R. & Fraser, S.E.M. (2009) "Collections of ichneumonid wasps (subfamilies Diacritinae, Diplazontinae, Pimplinae and Poemeniinae) from woodlands near York and their implications for conservation planning." Naturalist 134, p 3-24

 The Ichneumoninae is a large subfamily of insects with a 5-sided areolet in each wing and a distinctly petiolate gaster (the apparent 'abdomen'). Identication is by the following though, as much research has been carried out in Europe over the last half century, the comments about additional species are particularly relevant:

Perkins, J.F.(1959) Hymenoptera Ichneumonoidea Ichneumonidae, key to subfamilies and Ichneumoninae - I." Handbooks for the Identification of British Insects Vol VII, 2 (ai)

Perkins, J.F.(1960) Hymenoptera Ichneumonoidea Ichneumonidae, subfamilies Ichneumoninae II, Alomyinae, Agriotypinae and Lycorininae." Handbooks for the Identification of British Insects Vol VII, 2 (aii)

The two British species of Alomyinae can be identified by reference to:

Perkins, J.F.(1960) Hymenoptera Ichneumonoidea Ichneumonidae, subfamilies Ichneumoninae II, Alomyinae, Agriotypinae and Lycorininae." Handbooks for the Identification of British Insects Vol VII, 2 (aii)

Both species have been found in Yorkshire.