Yellow Sally (Isoperla grammatica)
In the late spring and early summer this is one of the most important stoneflies. It is widespread and abundant in most of the clear and cold rivers of Europe.
Adult female of Yellow Sally is often in the trout’s diet, because it swarms above the riffles and dips abdomen into the water to lay eggs.
It’s middle-sized stonefly with body length about 1 cm.