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worms reach their full growth and are slender measuring worms, 

 about an inch and a half long, figure 42 a. When first hatched 

 the head is glossy black and the body dark green or olive ; but 

 during successive molts the color grows lighter, the head is not 

 uniformly colored, but spotted. Along the body there are eight 

 more or less distinct lines or bands of a lighter color than the rest 

 of the body, as shown in the magnified section of the back, figure 

 42 d.^ and of the side, figure 42 c, but the markings are far from 

 constant, different specimens showing great variation. When 

 mature the worms creep, or very often low'er themselves from the 

 trees by a filament of silk. I have seen trees from which during 

 the last week in June the worms were hanging by hundreds and 

 dropping to the ground. Having reached the ground the worms 

 burrow a few inches, then the}' turn and work themselves about 

 until a sort of cell is formed and in this they change to pupai, and 

 remain through the winter, for the most part emerging, as we have 

 seen, the next spring. It is obvious to any one that any method 

 which can be devised to prevent the female from ascending the 

 trees and placing her eggs near the leafbuds will effectually check 

 the increase of the insect, since the young must perish unless they 

 speedily find proper food at hand when they hatch, and most of 

 the remedies which have been proposed have sought to accomplish 

 this. Various appliances have been tried, but none seem more 

 satisfactory than simple bands covered with some stick}' substance 

 that will remain sticky in all weather. Probably that recommend- 

 ed by Dr. Packard, cheap printer's ink, is as good as anything and 

 better than most ; coarse molasses or tar and oil are good. Mr. 

 Saunders says that if the worms are found on a tree they may be 

 removed by jarring them off' in the same manner as that used to 

 get rid of curculias. Spraying with poisonous liquids would de- 

 stroy many, and when once established on a tree, this method 

 would probably be better than any other. Various parasites at- 

 tack the canker worm. One, figure 43 which shows it greatly mag- 

 nified, has often proved most helpful in this respect, so than I have 

 known seasons in which the trees were 

 very seriously affected, to be followed by 

 one in which there w'as scarcely one to 

 be seen, and the chief agent of destruc- 

 tion was this little parasite, which is one 

 Fignre 43. ^^ ^'^^ tiniest of insets. It lays its eggs, 



Egg Parasite of Canker Worm, one in each of the eggs of the canker 



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