© 2009-11 Pontardawe and Swansea Angling Society Ltd

There are 51 species of upwinged flies in the UK.  We have found 20 on the Tawe and its tributaries.

The life cycle is egg, nymph (or larva), dun (or sub-imago) and spinner (or imago).  Most of their life is spent in the nymphal stage and the final stages of dun and spinner last a very short time - from just hours in the case of the smallest species to a day or two in the case of the largest.

Depending on species, some nymphs live in weeds or gravel, some burrow in silt, some are free-swimming and some cling to stones.

To hatch from the nymph stage into the dun stage, they either swim to the surface or crawl out of the water, shedding their skin in the process. The duns then fly off and take refuge before shedding their skin again and becoming spinners. Duns tend to be rather drab whereas spinners are bright and shiny with longer legs and tails.

Nymphs of all species have 3 tails but duns and spinners have 2 tails or 3, according to the species.

Most species have a yearly cycle but a few of the largest species have a two-year cycle and some of the smaller species may have more than one cycle in a year.

Mating takes place during the spinner stage and eggs are laid by the female spinner either on the surface or below the surface, where they are either deposited on weeds or sink to the bottom, where they remain until the tiny nymphs hatch.

In the table below click on a picture to see a full-size image of the naturals or click on the name of a pattern to see a full-size picture of an artificial.

Unless otherwise indicated, all pictures are taken and all artificials are tied by Ray Lockyer.

10 Feb 2009