. Elementary entomology . to both the neuropterous insects and the Lepidoptera. The mouth- parts of the adults are quite rudimentary. The hind-wings are often somewhat larger than the fore-W'ings and are then folded under them in repose, the fore-wings being held like a roof over the back. The antennas are usually very long and slender. The lar- vae are aquatic and form an important item of fish food. Some of them build most interesting little cases from grains of gravel, small shells, bits of twigs, pine needles, or whatever rubbish may be at hand, lined within with silk, which they carr}' ar
. Elementary entomology . to both the neuropterous insects and the Lepidoptera. The mouth- parts of the adults are quite rudimentary. The hind-wings are often somewhat larger than the fore-W'ings and are then folded under them in repose, the fore-wings being held like a roof over the back. The antennas are usually very long and slender. The lar- vae are aquatic and form an important item of fish food. Some of them build most interesting little cases from grains of gravel, small shells, bits of twigs, pine needles, or whatever rubbish may be at hand, lined within with silk, which they carr}' around with them, the head and thorax projecting out as they move or feed. Every small pool or brook harbors some of these interesting case bearers, which will hardly be distinguished except by closely watching the bottom until they are seen in motion. Most of these larvae are herbivorous, feeding on whatever vegetable matter is available, and look like small caterpillars. The caddis-worms of one group construct silken nets across small rapids, between stones, or upon the brink of little water- falls, which are doubtless of serv- ice in catching the tiny insects which float downstream, as the lar- vae which make them are known to be carnivorous. When ready to change to a pupa, the caddis- worm closes up the entrance to its case, but leaves an opening for the water to flow through so that the pupa can breathe, sometimes making a simple grating of silk over the entrance. Upon trans- forming to the adult the caddis-fly secures almost immediate use Fig. I20. Caddis-fly larval cases. (Enlarged) (After Furneaux)
Size: 2130px × 2346px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912
