New York Agricultural Experiment Station. 449 



Formula 3. Miscible Oil. 



Miscible oil 7-8 gate. 



Water 100 gals. 



This is a rather dangerous spray and should be used only in the 



spring as buds are swelling and never after buds begin to show green 



at the tips. 



Formula 4. Lime-Sulphur Mixture. 



Lime-sulphur solution (32°-34° B.) 1 gal. 



Water 8 to 9 gals. 



To be applied just as the blossom cluster-buds separate at the tips 

 to destroy psylla eggs a! out to hatch and newly-emerged nymphs. 



DIRECTIONS FOR STAYING FOR THE WINTER " FLIES " AND EGGS 



Ol' THE PEAR PSYLLA. 



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 in April. A 



rise in temperature induces the insects to emerge 

 from their hiding quarters and creep to the por- 

 tions 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 slug- 

 gish in their movements and do not fly. This 

 habit makes them very vulnerable to treatment 

 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 essen- 

 tial to wet thoroughly all portions of the trees, 

 and especial pains should be taken to force the 

 liquid under the loose bark and into all the 



Fig. 24.— Too Early cracks and crevices in the bark. The experi- 

 for Most Effective , , ., . , » 



Psylla Control. ments have shown the wisdom of spraying 



one tree thoroughly before proceeding to 



another. In balmy weather the " flies " may dodge quickly to the 



opposite side of the tree. By spraying the entire tree they are unable 



to avoid wetting by the spraying mixture. Treatment late in the 



fall or winter is especially recommended, as the influence of steadily 



29 



