166 Bulletin 190. 



application just before the blossoms open in the spring might be 

 desirable and profitable. Usually, however, the pest will not be 

 discovered until later, and the spraying should then be delayed until 

 after the fruit is picked. AVe believe that one or two thorough 

 applications of a poison in July or early September would greatly 

 reduce the numbers of the caterpillars and thus prove profitable ; 

 we would spray with the arsenate of lead or a carefully made 

 arsenite of lime or soda. (See Spray Calendar, Bulletin 188, for 

 formula.) 



Probably the most effective method of combatting this pest will 

 be to mow the infested strawberry patch soon after the fruit is 

 picked. Allow the mown leaves to dry a few days, then burn over 

 the patch, using a little of the mulching or dry straw if necessary 

 to make it burn well. This fire will destroy the caterpillars and 

 pupse which happen to be on the leaves, and rarely will it injure 

 the plants in the least. This is a cheap, practicable method and 

 has been found to be very effective against other strawberry leaf- 

 rollers. It must be remembered, however, that this burning over 

 process cannot help the crop for that year, but it will greatly reduce 

 the horde of caterpillars which might otherwise develop to ruin the 

 crop the next year. 



The ploughing under of infested plants would, of course, effectu- 

 ally check the pest ; it is often best to treat old strawberry beds in 

 this way. 



