This pattern works well to imitate pale wateries, spurwings and pale coloured olives. Mostly useful in April, May, June and July. It will take trout feeding on the above mentioned flies that are emerging or are returning to the water to lay their eggs.
Originally designed to imitate a drowning beetle which it imitates well but it also does a great job of imitating a whole range of insects including terrestrial flies and even emerging sedges. Very useful to have in a range of sizes.