• Adult caddis
  • Adult caddis
  • Adult caddis

Adult caddis (Trichoptera)

of Britain and Ireland: a practical guide

Adult caddis AIDGAP is a photo-based identification guide for naturalists and enthusiasts, including moth-trappers.

There are approximately 200 species of caddis in Britain and Ireland. A good range of species occur in even the most mundane habitats such as suburban gardens. Adult caddis are common and sometimes abundant in light traps and around freshwaters.

Neverthless many naturalists ignore these insects. Unfortunately caddis have a reputation for being difficult to identify. Many keys require examination of the wing venation and genitalia of dead specimens. And unlike moths and butterflies, there are no identification guides where comparison with pictures of whole insects is the norm. It frustrates many recorders that they cannot easily name many conspicuous caddis.

This new guide aims to solve this problem. It uses the visual appearance of the whole living insect. Where possible, it takes the identification of adult caddis in Britain and Ireland to species. To begin with an initial visual key places a caddis into one of four major groups.  After that similar-looking caddis are arranged into sub-groups and sections. Both wing markings and genitalia can be examined on living specimens. All you need is a x10 hand lens.

As well as keys, the guide includes species accounts with photographs and text. Each account covers flight period, distribution and diagnostic characters. Additionally there is guidance on techniques for collecting adult caddis, as well as making records and voucher specimens.

This guide is part of the FSC’s AIDGAP series (Aids to Identification in Difficult Groups of Animals and Plants). Our AIDGAP guides are accessible identification keys, suitable for non-specialists from age 16+. As with all guides in the series, the Adult caddis AIDGAP underwent extensive testing before publication, by beginners and specialists alike.