ISTew York Agricultural Experiment Station. 945 



control as there is an intermingling of all stages of the insect, 

 and some of them are resistant to any spraying mixtures which 



can safely be used on foliage. 



Moreover the leaves, especially 



i}i§k *$$&- ^ tne S rowt h i s heavy, seriously 



f|f |I ; t\ ^JnT interfere with thorough treatment, 



^'■■'Pslll f^ an< ^ there is also danger that 



it^plif M$fe$? foliage injured by the psylla may 



be further damaged by the appli- 

 cations of the sprays. 



Frequent and thorough spray- 



^M f ing with the tobacco extract 



*plF" ^^^a^^lillk. (Formula 1), on the first dis- 



W 4^3d^U^ covery of injurious numbers of 



Sk. the insects is the most satis- 

 factory means of affording pro- 



H,t- ^ C ° ndltlons f of bloS n° m dus u ers tection to the trees, 

 during the spraying for psylla nymphs. 



SPRAYING MIXTURES AND FORMULAS. 



Formula 1. Tobacco Extract. 



Tobacco extract (40 per ct. nicotine) f pt. 



Water 100 gals. 



Soap 3 to 5 lbs. 



Formula 2. Fish-oil Soap. 



Fish-oil soap 20 lbs. 



Water 100 gals. 



These are recommended for fall or spring spraying to destroy the 

 " flies." 



Formula 3. Miscible Oil. 



Miscible oil 7-8 gals. 



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 

 ar 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 about to hatch and newly-emerged nymphs. 



60 



