24 BULLETIN 352^ U. S. DEPAETMEXT OF AGEICULTUEE. - 



strengths of arsenate of lead would be likely to cause severe injury to 

 peach foliage. The addition of 2 pounds of soft soap or 1 pound of 

 hard soap to 50 gallons of the mixture has been generally found to 

 increase the effectiveness of the nicotine sulphate. 



Sweetened arsenate of lead is recommended for cherry trees because 

 of its eificiency in killmg the beetles and because its effect is con- 

 tinuous in favorable weather. Rain destroys the effectiveness of 

 this spray. The combination found most useful is 5 pounds of arse- 

 nate of lead, H gallons of molasses, and 50 gallons of water. 



If the beetle migration should occur during a rainy period, the 

 unsweetened arsenate of lead might be most useful. 



In applying a poison spra}^ care must be taken to cover the under- 

 side of the leaves where the beetles feed. In some instances it may 

 be necessary to spray only young cherry trees or older trees of the 

 thin-leaved varieties. In large orchards into which the beetles are 

 migrating in great numbers it is advisable to spray first the trees 

 most susceptible to attack, for during the season of 1915 the maxi- 

 mum injury occurred immediately after the first arrival of the beetles. 

 In no case should the sweetened arsenate of lead be used with Bor- 

 deaux mixture as a combination spray, for burning of foliage is 

 likely to result. 



