SPONGILLAFLY

any insect of the parasitic neuropteran family Sisyridae. The adult, a smoky brown insect, deposits clusters of eggs under a silky web near or on the water. The larva lives as a parasite on a freshwater sponge. It leaves the water when fully grown and spins a double-walled, lacelike cocoon in which it passes the pupal stage. Spongillaflies are found throughout the world wherever there are freshwater sponges.