Book Review

Abstract

The Adult Trichoptera (caddisflies) of Britain and Ireland (Handbooks for the Identification of British Insects volume 1, part 17) by Peter Barnard and Emma Ross . 2012 . Royal Entomological Society, St. Albans, U.K. 192 pp. with line drawings and colour photographs . ISBN 9780901546944 , paperback, £29.50. Adult Trichoptera are at times dismissed as being too drab to be of interest. Although less colourful than many in their sister group the Lepidoptera (moths and butterflies), many species do have striking wing patterns. Appearances aside, caddisflies have interesting life histories and are important inhabitants of freshwater habitats, both ecologically and as indicator species. For those not put off by the potentially drab cover of trichopterans, good identification resources are critical to identify what you have caught. Prior to the recent publication of The Adult Trichoptera (caddisflies) of Britain and Ireland, the best resource was Thomas Macan's (1973)A Key to the Adults of the British Trichoptera. While Macan's book provided usable keys, it also required a certain level of determination, and was very unlikely to appeal to those not already with a serious interest in Trichoptera. In contrast to this, The Adult Trichoptera (caddisflies) of Britain and Ireland is much better organized, and includes colour photos which allow some of the more striking species to be identified from general appearance alone. The book provides keys to all 199 known species of caddisflies in the British Isles and contains several informative introductory chapters. The actual introduction covers earlier works, provides references for the identification of British caddisfly larvae and a description of the geographical area covered by the keys. The introduction also mentions the very useful online Trichoptera World Checklist (http://entweb.clemson.edu/database/trichopt) which includes references for both original descriptions and later taxonomic changes. Chapters on life history, morphology, and collecting and preserving adult caddisflies follow, all with further references. The technical chapter includes photos illustrating the difference in appearance of in situ genitalia of dry and alcohol-preserved specimens, as well as cleared genitalia. A short chapter on the pros and cons of dichotomous keys, some notes on species accounts, a higher classification of the Trichoptera families found in Britain and a checklist of British species are also part of the introductory section. The main part of the book is dedicated to identification of the British caddisflies to species. While the authors discuss the question to key or not to key, they end up using fairly traditional keys at the higher levels (families and genera). Within genera the authors have decided not to use keys, but instead rely on extensive illustrations. Unfortunately the authors seem to be unaware of the innovative approach by Steven Marshall (2006) in his recent book: Insects: Their Natural History and Diversity. Marshall used graphical keys, creating bifurcating identification trees which make it easy to trace both forward and backward in the key. However, the keys in the present book are well organized and illustrated, and the authors have completely avoided the use of the potentially confusing term ‘not as above’. Key and diagnostic characters are clearly indicated in the drawings, facilitating use by people not familiar with the nomenclature of wing venation or Trichoptera genitalia. In the family key (not every key as stated by the authors), the authors provide the number of the preceding couplet after the couplet number, e.g. 14(11) indicates that couplet 14 was reached via couplet 11, to facilitate back tracking. The first key is to families, after which follows keys for the different families, starting with the spicipalpian families followed by the annulipalpian and integripalpian families. Within each family, the species are grouped by genus and the genera are arranged phylogenetically. This contrasts with the checklist in which the genera within each family/subfamily/tribe are arranged alphabetically. Once through the keys, the reader is directed to a (number of) species account(s) with information on common name (if any), size and general appearance, abundance, distribution and habitat as well as flight period. The species accounts include illustrations of male and female genitalia, generally illustrations of wing venation, and in most cases, colour photos of the wings/and or a live specimen. The many colour photographs and the uncluttered drawings of genitalia are a definite asset for this book. The book is a considerable improvement on its predecessor, Macan's A Key to the Adults of the British Trichoptera, and I would warmly recommend it to anyone wanting to identify adult British Trichoptera. Marie Djernaes 1