12 NEW YORK STATE MUSEUM 



their eating the softer under part, leaving the upper epidermis 

 and the veins. The result of their feeding is so characteristic 

 that it is easy to detect their presence by the semitransparent 

 places in partly eaten leaves and by the skeletonized appearance 

 of the foliage which has been more severely attacked. 



The larvae complete their growth in from 15 to 20 days in 

 summer (in cooler weather the time is extended), become rest- 

 less, forsake the leaves and descend the limbs and trunks of the 

 tree to a greater or less extent, seeking proper shelter for pupa- 

 tion. In warm July weather seven days are passed in this state, 

 in September the time is extended to 12 days and in October to 

 24. The descent of the larvae of the first brood usually occurs 

 in Albany the latter part of June, — in 1896 some were observed 

 descending May 19, and beetles of the second brood were taken 

 May 30. The oviposition of the second brood of beetles begins 

 about the middle of July. From that date until late in the 

 autumn, it is possible to find the eggs of this insect most of the 

 time in some part of the city. The beetles are naturally more 

 attracted by a fresh growth of foliage and it is on the trees 

 throwing out a second or third crop of leaves that the eggs of the 

 later generations are found most abundantly. Most of the 

 second brood of larvae complete their growth about the middle 

 of August, transforming to adults the latter part of the month. 

 If there is an abundant food supply a third generation is pro- 

 duced. In 1896 numerous eggs were found on elms in Troy the 

 first part of September, and the same was probably true in 

 Albany, as indicated b}^ the large numbers of full grown larvae 

 descending certain Scotch elms, which had been practically un- 

 injured in the early part of the season, near the middle of Octo- 

 ber. 



This latter occurrence shows most conclusively, that the larvae 

 must be able to develop on old leaves. The persistent breeding 

 of this insect late in the autumn is shown by the presence of full 

 grown larvae on trunks of elms October 31 and the finding of 

 living pupae November 7, 1896, and on the still later date of 

 November 16, 1897. 



