14 NEW YORK STATE MUSEUM 



are found most abundantly. Most of the second brood of larvae 

 complete their growth about the middle of August, becoming 

 adults the latter part of the month. If there is an abundant 

 food supply a partial third generation may be produced. In 1896 

 numerous eggs were found on elms in Troy the first part of Sep- 

 tember. This was probably the case in Albany also, as indicated 

 by the large numbers of full grown larvae descending near the 

 middle of October certain Scotch elms which had been practi- 

 cally uninjured in the early part of the season. 



This latter occurrence shows most conclusively that the larvae 

 are able to develop on old leaves. The persistent breeding of 

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

 grown larvae on elm trunks October 31 and by the finding of 

 living pupae on November 7 in 1896, and in 1897 on the still later 

 date, November 16. 



Number of generations. The detailed observations of 1896 to 

 1898 have established beyond question the possibility of two 

 well marked generations annually and the occurrence under 

 favorable conditions of an incomplete third brood at both 

 Albany and Troy. In these two cities the insect has continued 

 breeding as long as the elms afforded sustenance. There is every 

 reason for believing the same to be true in adjacent cities and 

 villages. This is the more remarkable since Dr Smith records 

 but one brood a j'ear, or one and a partial second, at New Bruns- 

 wick N. J., about 150 miles to the south. As is well known, 

 most insects are more destructive soon after their introduction 

 than in later years. This may be accounted for by the fact that 

 in time native parasites, diseases and other natural checks 

 gradually assert their power on new comers. An insect's free- 

 dom from natural enemies might have some effect on its prolifi- 

 cacy, and possibly on the number of generations. It will not 

 only be of interest but of great practical importance to ascer- 

 tain by observations whether this beetle continues to produce 

 two or three generations yearly in this latitude. 



Habits of beetles and larvae. A knowledge of certain habits of 

 this insect are of. great value in controlling it. Its hibernation 



