ISTew York Agricultural Experiment Station. 357 



Fig 



29. Con- 

 dition of 

 blossom buds 

 during the 



spraying for 

 the " flies." 



1. Spraying for hibernating or winter flies. — Especial pains should 

 be taken to destroy the pest in this stage, as effective 

 work greatly reduces the number of eggs deposited on the 

 trees and simplifies subsequent spraying operations. The 

 best means of killing the " flies " is spraying during 

 a period of warm weather, preferably in November or 

 December, or during March or early April. A rise 

 in temperature induces the insects to emerge from 

 their hiding quarters and creep to the portions of the 

 trees exposed to the warm rays of the sun and protected 

 from a cold wind. While the insects are able to crawl 

 they are very sluggish in their movements and do not 

 fly. This habit makes them very vulnerable to treat- 

 ment and the grower should take full advantage of it 

 by so spraying that none of the insects be allowed to escape. 



To kill the flies it 

 is essential to wet 

 thoroughly all por- 

 tions of the trees, 

 and especial pains 

 should be taken 

 to force the liquid 

 under loose bark 

 and into all cracks 

 and crevices in 

 the bark. The 

 experiments by 

 this Station have 

 also shown the 

 wisdom of spray- 

 ing one tree thor- 

 oughly before 

 proceeding to 

 another. In balmy 

 weather the flies, 

 like squirrels, may 

 dodge quickly to 

 the opposite side 

 of the tree. By 

 spraying the en- 

 tire tree they are 

 unable to avoid 

 wetting by the 

 spraying mixture. 

 Treatment late in 

 the fall or early winter is especially recommended as the influence 



Fi£. 30. Conditions of trunk and larger limbs which attract winter " f ies." 



