still the most comprehensive guide to the butterfly and moth caterpillars of the UK I think.
has good photos of usually only one larval stage - I would have liked more stages described/shown.
photos are accompanied by short text on the facing page. has useful information about food plants, including substitutes if rearing the caterpillars in captivity for release.
A very useful book, the descriptions and image plates are ideal in helping to identify caterpillars, even for those with little experience in this area.