284 INSECTS. 
tapering and delicate ; their wings, four, almost transpa- 
rent and marked with net-like veins. They keep in 
continual motion for the purpose of catching smaller 
insects, on which they mainly feed, and generally deposit 
their eggs in the water, where the grubs live from one to 
two years on plants or other insects. 
That most fearful looking, but really harmless and bene- 
ficent creature, the devil's darning-needle, or dragon-fly, 
Itbellula^ is a remarkable specimen of this family. They 
are called demoiselles by the French, wasserju7ifern,wsiter- 
virgins by the Germans; but, in spite of these pretty 
appellations, are the tyrants of the surface of the ponds ; 
they seize and tear to pieces all other insects, including 
butterflies and mosquitoes, and will clear a house of the 
common fly. They are cruel, rapacious and insatiable, 
and I do not know of their ever being used as bait for 
trout. 
The phryganea^ or water-moth, is one of the favorites 
of the fly-fisher. Its grubs surround themselves with a 
case formed of wood or grass, and are used by him as 
bait under the name of caddis-worms. They are the 
favorite food of the trout in early spring. But the 
ejphemeridcB include most of the specimens imitated by 
the fisherman. The larvae of these live in the water, for 
one or more years, and then, swimming to the surface, 
suddenly change into winged insects, delicate and beau- 
tiful. They sometimes appear in myriads, their dead 
bodies covering the water. A few make a second change 
after fiying about for a time, and crawl out of their skins 
once more, leaving their old clothes, to all appearance 
perfect, sticking to a tree or fence. On their first appear- 
