Halesus digitatus (Shrank, 1781)

Halesus digitatus is one of 40 members of the Family Limnephilidae found in Ireland, and one of two members of the genus Halesus. It is a species whose larvae can be found in streams and rivers. Its substratum preference is for particulate organic matter and woody debris, in slow-flowing and standing water. Halesus digitatus has a case that is made of plant fragments and may incorporate long sticks. The larvae have a preference for neutral to alkaline water.

The feeding ecology of the larvae of Halesus digitatus is predominantly shredding, with some predation and grazing.

Characteristic features of the larva of Halesus digitatus include a prosternal horn, dorsal protuberance on the 1st abdominal segment, antenna midway between the eye and the anterior head margin, gills with only single filaments, two anterior-median sclerites on the metadorsum, mandibles with teeth along the edges and setae proximal to the large primary seta on at least one femur of the 2nd and 3rd legs. Separation from Halesus radiatus is based on a range of features and may not always be possible.

Adults of Halesus digitatus can be found on the wing from September to November.

For details of distribution records of Halesus digitatus in Ireland available through the National Biodiversity Data Centre mapping system, click here.

References

Barnard, P. and Ross, E. (2012) The Adult Trichoptera (Caddisflies) of Britain and Ireland. RES Handbook Volume 1, Part 17.

Graf, W., Murphy, J., Dahl, J., Zamora-Muñoz, C. and López-Rodríguez, M.J. (2008) Distribution and Ecological Preferences of European Freshwater Species. Volume 1: Trichoptera. Astrid Schmidt-Kloiber & Daniel Hering (eds). Pensoft, Sofia-Moscow.

O’Connor, J.P. (2015) A Catalogue and Atlas of the Caddisflies (Trichoptera) of Ireland. Occasional Publication of the Irish Biogeographical Society, No. 11.

Wallace, I.D., Wallace, B. and Philipson, G.N. (2003) Keys to the Case-bearing Caddis Larvae of Britain and Ireland. Scientific Publication of the Freshwater Biological Association No. 61.

Last updated: 07/12/2017

Advertisements