56 BULLETIN 286 



FOOD PLANTS 



The larvae infest a great variety of forest-trees, apparently some- 

 what preferring beech and maple. They have been found on elm, 

 linden, chestnut, hickory, ash, apple, birch, and others. 



V 



THE LIFE HISTORY AND HABITS OF THE INSECT 



This insect requires nearly a year to pass through its life history. 

 It is said that in Georgia the eggs were laid on the leaves as though 

 there might be a second brood or generation in a season. It would 

 seem from a study of the insect in New York that this must have been 

 due to the carelessness of the female moths and can hardly be taken 

 as an evidence of a second brood. At any rate, there is only one brood 

 in New York State each year; and this is fortunate. If this pest could 

 pass through its life history and produce a generation every two or 

 three months, our forests would surely be doomed to destruction. 



The eggs of the female moth are laid on the under sides of the branches 

 as often on the upper branches of the smaller trees, at least, as on the 

 lower. In a rather hasty search, the writer found the eggs laid on the 

 beech only. However, a correspondent at Arena, N. Y., has sent many 

 eggs deposited on maple. The eggs are always deposited at an oblique 

 angle to the surface of the bark and lean against each other like a pile 

 of leaning bricks. They are laid in masses of 20 to 100 or even more, 

 and are stuck so securely to the branch that in 1909 the writer found 

 still adhering to the trees the empty shells of quite as many old egg 

 masses of 1908 as there were new ones of 1909. The eggs are deposited 

 on the branches in the latter part of June and first part of July, and 

 remain unaffected by snow, rain, or extremes of temperature until the 

 following April and May, nearly a year after deposition. 



The eggs are about one twenty- fifth of an inch in length, barrel shaped, 

 often more or less flattened on the sides, light olive when first deposited 

 but later becoming darker in color, with a conspicuous ring at the free 

 extremity. They occur in irregular masses, long and narrow if the 

 branch is small but spread out if the surface is large (Fig. 55). 



Eggs brought from Cooks Falls in August, 1909, were placed out- 

 doors under natural conditions and began to hatch May 2nd, 1910. 

 Eggs sent from Cooks Falls on May nth, 1910, had not hatched, and 

 the writer found that the caterpillars on the mountain at Cooks Falls 

 had appeared two to three weeks later than at Ithaca or at Arena, 

 N. Y., the difference probably being due to the higher altitude and 

 lower temperature. Eggs at Arena, N. Y., brought into the house in 



