23 



In this test, and in others which we have seen, the chief difficulty 

 with an early seasonal application of arsenicals to the expanding foliage 

 is that when the leaves are unfolding and growing rapidly the weevils 

 can select trees which are free from arsenic. This is particularly true if 

 the beetles are abroad in abundance when the leaf buds are just breaking, 

 and here an additional difficulty is encountered in that there is not 

 enough leaf surface on which the poison can be lodged and held. 



Pig. 14. Invei'U-d doth cone suspt^nded from trees .sprayed 

 with arsenicals to tegt the effectiveness of the several 

 poisons tritd. 



The residual effect of summer spraying 7i.nl li arsenicals. — One of 

 two adjoining orchards, both badly infested, was treated the second week 

 in June with an upshoot ,>^])ray of arsenate of lead without a fungicide, 

 at a time to poison the weevils as they left their summer mines and 

 began to feed. The foliage of both orchards at this time was so badly 



