AQ) MISC. PUBLICATION 318, U. 8. DEPT. OF AGRICULTURE 
of oatmeal, white arsenic, sugar, salt, and water is the best method 
of control. 
Caddisflies.—Along streams where the water flows rather swiftly, 
one finds small mothlike insects of pale-brown color with wings folded 
rooflike over their backs. These are the caddisflies. Unlike those of 
the moths, the two pairs of wings are 
scaleless and usually more or less 
clothed with long, silky hairs. The 
adults take very little food, but many 
accept sweet fluids to a certain extent. 
They fly readily. The larvae crawl or 
swim in water and feed on water forms 
of either plant or animal life. They 
winter as larvae, usually in streams. - 
Their life changes are complete. The 
caddisfly shown here is about three-fourths of an inch long with a 
wing expanse of about 144 inches. A sketch of the caddisfly, ap- 
pearing in the section on collections and identification, order Tri- 
choptera, part IIT of this manual, gives an idea of the position of the 
wings when at rest. The scientific name of this insect 1s Platyphylax 
subfasciatus. 
Stone flies——There is another group of insects that lives around 
rapid streams and wave-washed, rocky shores. This is the stone fly 
group, which belongs to the order Plecoptera. 
These insects range from 34 to 114 inches in 
length, are pale brown, and the wings are 
folded flat over the back. They have chewing 
mouth parts, but the adults feed very little: 
the nymphs feed mainly on insects in the fast- 
flowing streams. The adults fly readily, but = = oN 
the nymphs crawl and swim in the water.  ricure 102—Stone fiy. 
The stone fly winters as a nymph in water 
leading to large rivers. The life changes are incomplete. The 
nymphs may serve as fish food. The species shown here is Acro- 
neuria abnormis. 
FicurE 101.—Caddisfly. 
