. Dandelions, hawkweeds, ginseng, canker worms. CANKER WORMS. 123 have a broad, dark stripe along the back, as opposed to the narrow markings of the other species. The eggs, which are slightly larger than in the previous species, somewhat resemble small flower pots and are attached to the bark, in exposed situ- ations, in masses of from 60 to 200, placed side by side as seen in figure 40, 壉 . The eggs highly magnified, are shown in figure 40 a and 40 d. The eggs are deposited in fall or early winter (sometimes in mild winters as late as March). They hatch about the same time as those of the
. Dandelions, hawkweeds, ginseng, canker worms. CANKER WORMS. 123 have a broad, dark stripe along the back, as opposed to the narrow markings of the other species. The eggs, which are slightly larger than in the previous species, somewhat resemble small flower pots and are attached to the bark, in exposed situ- ations, in masses of from 60 to 200, placed side by side as seen in figure 40, 壉 . The eggs highly magnified, are shown in figure 40 a and 40 d. The eggs are deposited in fall or early winter (sometimes in mild winters as late as March). They hatch about the same time as those of the other species and the larvx" act in a similar manner, entering the ground about the same time. Instead of forming a cell lined with silk, however, this species spins a tough cocoon, and the moths come forth and begin laying eggs in October and Figure 40 -Fall canker worm; a. and eggs, enlarged; c. segment of larva enlarged; <?. egg cluster;/, full grown larva. HOW TO FIGHT CANKER-WORMS. The natural enemies of the canker-worms, including Ichneumon, Tachina and Chalcid flies, certain wasps and beetles, and various kinds of birds, are so numerous as to prevent serious damage save in exceptional years. In the absence of these natural enemies, however, or when the weather conditions are specially favorable to the increase of the worms, active measures must be taken to save the trees. One of the surest preventive measures is to place a band of tarred paper about the tree in March and smear it with printers' ink, thus preventing the ascent of the female moths and the deposit of eggs. In case the bark is very rough, it should be scraped smooth to prevent the insects from crawling up behind the paper. The ink must be renewed often enough to prevent hardening, or it will be of no use. If the fall canker-worm is present, of course the treatment must begin in October. If the trees are already attacked, jarring the limbs will cause many of the worms to spin a thread an
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