Caddisflies

Caddisflies or Trichoptera, (meaning, from the Greek trichos a hair and pteron a wing; hairy-wings)

Recorder: Sharon Flint

This is one of the few insect groups where, at least in so far as the British fauna is concerned, the majority of the larvae are known and both adults and larvae can be identified to species. Careful manipulation of both larval and adult specimens, under the microscope, is required in order to see characters clearly. In the larvae, some important characters are the form and position of gills, hairs on various parts of the body and legs and the shape, position and colour of sclerotized plates on body segments, along with head patterns. In the adults, examination of the wing venation (front and hind wings) and genitalia, as well as spur formula are among the characters used to determine a species identification. Though some characters can be difficult to assess, the identification of the order, in both its life stages is relatively straight forward, using the excellent keys (listed below). These volumes also provide much interesting information on their ecology as well as instructions on collection and preservation. The majority of the larvae make, and live in, portable cases, but a considerable number of them do not. All the species in any particular family are either case bearing or caseless. This is not; however; as straight forward a division as it might seem, as some case-bearing larvae wait until their final instar before constructing a case and some flowing water species are known to abandon their cases from time to time to drift with the current. Caseless larvae construct a fixed shelter when they are ready to pupate.

Keys to adults:-

Macan T.T.(1973.) A Key to the Adults of the British Trichoptera. Scientific publications of the Freshwater Biological Association, No.28.

Barnard and Ross (2012). The Adult Trichoptera (caddisflies) of Britain and Ireland. Handbooks for the identification of British Insects. Vol.1 Part 17.

Keys to the larvae:-

Edington, J.M. and Hildrew, A.G.(1995). A revised key to the caseless caddis larvae of the British Isles with notes on their ecology. Scientific publications of the Freshwater Biological Association, No. 53.

Wallace, I.D., Wallace, B. and Philipson, G.N. (2003) Keys to the case-bearing Caddis larvae of Britain and Ireland. Scienfitic Publications of the Freshwater Biological Association, No.61.

You can send records to the Trichoptera Recording Scheme via:

https://www.brc.ac.uk/schemes/RRS/trichoptera.htm

I am happy to receive members specimens for identification and have been receiving specimens from members to identify,usually from moth trap catches. Members have also been very accomodating about me taking Caddisflies from their moths traps when we are out in the field recording moths. When the specimens are identified,  the records are submitted to Dr Ian Wallace or entered into the NBN database.

Adult Caddisflies can be humanely euthanised by putting them into a domestic freezer for a few hours. Each sample can then be put into an envelope and sent direct to me. I often receive specimens from members when they see me at field meetings, conference or other YNU meetings and events. I have received specimens that have been put into 70% alcohol in specimen jars. Some Caddisflies can be identified reliably from good quality photographs, but most are difficult to reliably identify this way unless a high quality image of the genilalia and wing venation is provided. Please provide the following data with your specimens; date of capture, six figure grid reference, catch method, habitat, name of collector. Please write this in pencil on a piece of paper, this is especially important if you are putting the label into alcoholed specimen jars.

Thankyou