INJURIOUS INSECTS, FUNGOUS DISEASES, ETC. 173 



Ordinarily there are two broods of this insect during a 

 year. The beetles take to the leaves, feed on them and 

 deposit their eggs. The larvae of the second brood go 

 through the same cycle of feeding on the under side of the 

 leaves, changing to pupae and transforming to adult beetles. 

 In the latter part of August, the development of the second 

 brood of beetles is complete. They hibernate during the 

 winter in the adult form and begin to feed on the developing 

 elm-leaves the following spring. 



This insect is confined in its attacks to the elms, and pre 

 fers the European to the American variety. It has been a 

 most serious pest in many States. The defoliation of a tree 

 in midsummer is a serious injury, and if this occurs for suc 

 cessive years, the early death of the elm may be expected. 

 Such has been the record of the elm-leaf beetle in a great 

 many cities. 



The only way to control the elm-leaf beetle is by spray 

 ing the foliage with arsenate of lead. The time to spray is 

 just when the leaves develop and the adults begin to feed. 

 A thorough spray at this time is very important, because if 

 the beetles can be killed before they lay eggs, there will be 

 no larvae to deal with later. 



If early spraying is neglected or has not been effective, 

 an application of arsenate of lead is necessary when the 

 larvae begin to feed. It is important in this case to reach 

 the under side of the leaves. The beetles eat the entire 

 leaf tissue and it makes no difference whether the poison 

 is on the under or upper surface. The larvae eat only 

 the lower layer of cells, and even if the upper surface be 

 fully covered with arsenical poison they may not get even 

 a particle. 



When the full grown larvae crawl down the trunks to 



