Species profile: Wormaldia mediana

August 7, 2016

Wormaldia mediana McLachlan, 1878

Wormaldia mediana is one of five members of the Family Philopotamidae found in Ireland, and one of three Irish representatives of the genus along with Wormaldia occipitalis and Wormaldia subnigra. This species can be found in fast-flowing streams. The substratum preference ranges from coarse gravel to boulders and bedrock. Wormaldia mediana has a preference for neutral to alkaline waters (pH ≥ 7) and is a filter-feeder, building long, tubular nets attached to rocks; feeding on organic particulate matter. The species lives for over one year.

The larvae of the Family Philopotomidae can be readily separated from those of other families by the fact that they possess a white membranous labrum, with a brush-like anterior margin, as opposed to a sclerotized labrum. The larvae of Wormaldia spp. are separated from the other genre in the family by the smooth curve of the anterior margin of the frontoclypeus. Separation from Wormaldia occipitalis, and Wormaldia subnigra in particular, is difficult and adults are likely to be needed to identify to species.

Adults of Wormaldia mediana can be found on the wing from July to August.

Records of Wormaldia mediana on the National Biodiversity Data Centre mapping system can be found here.

Wormaldia mediana


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

Edington, J.M. (1968) Habitat preferences in net-spinning caddis larvae with special reference to the influence of water velocity. Journal of Animal Ecology 37(3): 675-692.

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. Freshwater Biological Association Special Publication No. 53.

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.

Last updated 15/03/2018


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