River Fly Surveys

The Cressbrook & Litton Flyfishers’ Adult Upwing and Stonefly Records 2019


This is the fifth and final year of this project. But, please don’t worry; I have another idea up my sleeve that may interest some of the more entomologically minded members of the Cressbrook and Litton Flyfishers Club…more of that later.

For the past five years in each of the fishing huts there have been sample packs available for members to pick up. Each sample pack consisted of a small zip-lock bag inside of which was a screw top sample tube and an information slip. Members were invited to take along a sample pack when they went fishing and if they came across any upwing flies or stoneflies, they could be caught and put into the screw topped sample tube. On returning to the fishing huts the sample tube was filled with some preserving alcohol and the information slip completed with the members name along with the date and the beat number where the sample was caught. All was then put back in the zip-lock bag and placed in a box where I could pick them up for analysis.

The term “upwing flies” relates to the insects in the order Ephemeroptera, this includes some very familiar insects as far as the anglers are concerned such as the blue winged olives, mayflies and iron blues. The name “stoneflies” relates to the insects in the order Plecoptera, these are less well known, and like caddisflies (that I also study in detail), tend to be overlooked by the anglers yet they are often taken eagerly by fish the anglers are trying to catch.

I only required the adult stages of these insects for this project. This was so I could see flight period data. Most flyfishers are aware that upwings are peculiar in that all our UK species have two adult stages. Anglers know these as duns and spinners. I needed both because some species are easier to identify (to the full species level) as duns while others can only be positively identified at the spinner stage.

I hope you find this final report interesting as it highlights the richness of this wonderful river which I just hope no one ever takes for granted because it is a rare and very special place.

Stuart M Crofts, February 2020

Download the PDF of The Cressbrook & Litton Flyfishers Club – Adult upwing and stonefly report for 2019