502 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



margin so that it forms a distinct spot, and this outer band is seen 

 on the hind-wings, though it is less distinct. The females are a 

 uniform, ash-gray without markings, and with longer antennae 

 than those of the other species, the segments of which are about 

 as broad as long, and are bare of hairs. 



Control. In old sod orchards where the pest is always worst, 

 thorough cultivation will largely destroy the pupae during the sum- 

 mer. The caterpillars may be quickly de- 

 stroyed by spraying with arsenate of lead, 

 3 pounds per barrel. The first spray- 

 ing should be applied as soon as the 

 foliage is fairly expanded and before the 

 trees bloom, and the second should be 

 given as soon as the blossoms drop. 

 The first is the more important and one 

 thorough spraying will usually suffice, as 

 the young caterpillars are much more 

 easily killed. Where for any reason spray- 

 ing is not feasible, the females may be 

 prevented from ascending the trees by 

 encircling the trunks with bands of tangle- 

 foot or someother sticky substance which 

 they cannot cross. These bands should 

 be applied in early October and late 

 March, according to the species preva- 

 lent. The tanglefoot may be applied 

 directly to the bark of the tree, making 

 a band two inches wide by one-quarter 

 inch thick. Printer's ink, bodlime, and 

 caterpillar-lime are often used, but should 

 not be placed on the bark. A narrow 

 band of cotton batting should be run around the tree and cov- 

 ered with a strip of building paper 4 to 6 inches wide, on the 

 center of which the sticky band should be placed, thus preventing 

 any injury to the bark by the material. Where spraying and cul- 

 tivation are customary canker worms rarely become troublesome, 

 but they are likely to be the worst insect pest of street-trees and 

 wood-lots in the Middle- west. 



FIG. 428. Wingless 

 male moth and 



fe- 



g 



eg 



mass, and winged male 

 moth of the fall canker 

 worm twice natural 

 size. ( A f t e r W. E. 

 Britton.) 



