Ichneumonids are notoriously difficult to identify. Traditional advice has been that they are a group that only specialists can attempt. This is because so many of them share virtually identical body shapes and markings. There are also lots of them, about 2,500 species in Britain. The usual procedure is to take specimens and using a microscope and complex identification keys, work through an identification from subfamily through to species that is, if keys exist for that group. Few people specialise at this level and as a consequence there are few recording schemes and little is known about ichneumonid distributions in the UK. With the advent of digital photography and social media, however, it is possible for experts to skip the keying and identify a few species from good-quality photos. With this in mind, the Natural History Museum, London has worked with Dr Gavin Broad, lead curator of ichneumonid wasps at the NHM to produce this free guide (50 page pdf, lots of colour photos). The guide combines photographs taken in the wild of living ichneumonids with photographs of pinned specimens from the NHM collections. The pinned material points out small features that show the features that must be visible in their photos to make an identification.
Beginner's guide to identifying British ichneumonids