Anonyme, Pond Life, Pochette de diapositives, Teachers note, Studley ( Warwickshire), Philip Green Educational, circa 1980.
Larva of Caddis Fly crawling along the bottom of the pond. The larva defends itself by building a movable home. First it spins a loose silk coat and then sticks on whatever covering is available-in this case, shells and small pebbles. When it is ready to tum onto an adult, it bites its way out and swims to the surface. The adult, or imago, Caddis fly (Trichoptera) is a medium sized moth-like insect.