Stone-fly

Stone-fly (Perla), a genus of insects typical of the order Plecoptera. The hind-wings are broader than the fore-wings, and folded at the inner edge. The body is elongated, narrow, and flattened; the wings fold close to the body, which generally bears two terminal bristles. The larvæ are aquatic, and much resemble the perfect insect, except in the absence of wings. A number of species—e.g. P. bicaudata—are common in Britain, and are well known to anglers as an attractive lure for fishes.