CADDIS-FLY. A neurupteroid insect of the order Trichopterag the larva: of which, usually aquatic, are eommonly known as ease-worms. Caddis-flies show inneh resemblance to small moths, on account of their long antenna-, moth like wings, and nocturnal flight. The body and wings are hairy. and some species possess scales. Four wings are generally present, but Ti:wastes has only the anterior pair, while in Anamalop teryx there is a curious dimorphism. the wings being quite short in the male, but of normal length in the female. They are seen mainly about streams and ponds, hut a are marine, and the genus Onoicyla is terrestrial. eggs are laid in a double mass, which is gelatinous and usually green in color. They are usually at tached to the surface of some water plant. . . . The lame are all aquatic, . . . and they arc nearly all protected by a ease of some sort." These larv:c are long and cylindrical, with a hard head and thoracic) seg ments. but soft ab domen, to cover which the worm forms a tubular shelter. composed of bits of sticks. moss. leaves, sand, or small stones, bound together with silk; and this is dragged about, or may be attached to some submerged object, preferably a stone at the bottom of rapidly running but shallow water. These eases are very diverse, from simple tubes to spirals vary closely resembling snail-shells. Since they open behind, a current of water is allowed to pass through. and thus the respira tory filaments on the abdomen are aerated. The case-vvorm retains its hold in the tube by means of a pair of claws located at the apex of the abdomen. These larva) are largely vegetable feed
ers, but will occasionally eat insects, and such species snin near the mouth of the tube a net of silk which is eup-shaped when drawn out by the water-current, and catches prey. The caddis worms ('cad-bait' of anglers) live several months in this condition, and sonic regularly through the winter. "When ready to transform to pupa," says Howard, "both ends of the or tube are protected by a silk netting spun by the larva, which transforms in security, well drawn back from either orifice. When ready to trans form to the adult stage, the pupa works its way through the guarded orifice, swims to the sur face of the water, and crawls out." These insects have been but little studied in America; yet about one hundred and fifty species are known. They may be studied to advantage by placing the larvw in a wire cage in their na tive stream, the cage extending above the water, so that the insect may emerge, but not escape. The most prominent family is Phryganeida., which contains the species of largest size. Con sult McLachlan. Nonograph of the Trichoptera (London, 1874-S0), the authority for European forms. A list of species and key for genera, IT N. Banks, may be found in Transactions of the American Entomological Society (Philadelphia, 18921: also a paper by Needham and Retten in the Neu: l'ork State Museum Bulletin No. )7 (Albany, 1902).