INSECT INJURIES TO SHADE TREES. 335 



may often be gathered by the quart. Many, however, crawl 

 into crevices of the rough bark of the trunk and larger branches 

 and there undergo this change. In from six to ten days the 

 adult beetle comes forth, feeds for a time upon the leaves and 

 then retires to winter quarters in some building or almost any 

 sheltered place. In New Haven some of the beetles lay eggs 

 for a second brood, but usually there is but one complete genera- 

 tion in a season. 



The full grown larva or grub is about one-half inch long, 

 with a broad black band along each side of the body and 

 is covered with short tubercles bearing hairs. The pupa is 

 about one-quarter inch long, naked and light yellow. The 

 adult beetle is about one-quarter inch long, with head, chest and 

 margins of the wing-covers, brownish yellow. Each wing- 

 cover is also marked lengthwise with a more or less obscure 

 black stripe. Plate XVI, fig. 17, shows this insect in its various 

 forms. 



Canker Worms. Fall Canker Worm, Anisopteryx pometaria, 

 Harr. Spring Canker Worm, Paleacrita vernata, Peck. 



Both these species injure elms in New Haven by eating the 

 leaves during May and June. The eggs are laid on the bark 

 of the trunk or branches by the wingless females ; those of the 

 fall species during warm days in November and December, 

 those of the spring species in March and April. 



The adult males are grey moths, having a wing expanse of 

 about an inch, while the females are wingless and must creep 

 up the trunks of the tree to lay their eggs in them. See Plate 

 XVI, fig. 16. 



The larva or caterpillar becomes full grown in about four 

 weeks after hatching, and is then about an inch long, of a dark 

 brown color, with lighter stripes running lengthwise of the 

 body. The color, however, varies considerably. The cater- 

 pillars "loop" in crawling, and when disturbed "spin down" 

 from the branches on a fine thread by means of which they 

 afterwards ascend. 



They pupate in the ground. Much of the damage done by 

 canker worms in the city has been wrongly attributed to the 

 elm leaf-beetle ; but the work of the two insects may be readily 

 distinguished. The adult elm leaf-beetle makes "shot-holes" 

 through the leaf and its larva or grub eats away the under 



