14 NEW YORK STATE MUSEUM 



since they are liable to desert the tree even when slightly underfed 

 and complete their transformations, rather than to eat distasteful 

 foliage. 



The full grown larvae crawl down the trunks in great numbers 

 and the golden yellow pupae may be found in abundance in crevices 

 in the bark and on the ground about the tree. A great proportion 

 of the insects can be forced to take refuge on the ground by scrap- 

 ing off the rough bark, thus depriving them of shelters upon the 

 tree. Large numbers can then be killed when assembled about the 

 base of the tree by spraying them with a contact insecticide such as 

 kerosene emulsion, whale oil soap solution or even by pouring boil- 

 ing water on them. The grubs should be destroyed in the manner 

 indicated every five days so long as the pests are seen in numbers, 

 in order to secure the best results. This method of fighting the pest 

 is advisable only when it is impossible to employ the more satisfac- 

 tory arsenical sprays. Bands of tar, sticky fly paper, cotton batting 

 etc., while they do no harm, can not be considered of much value in 

 keeping the elm leaf beetle under control. The relatively few grubs 

 caught on a sticky band are but a drop in the bucket compared with 

 the masses which complete their transformations either above or 

 below. It is worse than useless to attempt to control this or any 

 other insect by boring a hole in the trunk of a tree and inserting 

 therein compounds of any nature. The tree is weakened and unless 

 the chemical be powerful enough to kill it, the insects are not 

 affected. 



