Anonyme, Pond & Aquarium, n°9, Caddis-Fly and Larvae, W. D. & H. O. Wills, Branch of the Imperial Tobacco, 1935.
Sheltered by stones on the bottom of ponds and streams you may often find in early spring the small tubular cases made by Caddis-« worms »- really the larvae of Caddis-flies, one of which, magnified (actual span of wings approx. ¾ inch.), is shown in our picture. As soon as it is hatched each larva sets to work to build a protective case of small pebbles, sand, twigs or leaves, snail-shells or similar materials. Some larvae moor their cases to stones, but others drag their cases with them. A few of these Caddis-cases make an interesting addition to a fish-pond or aquarium.