370 Report of the Department of Entomology of the 



Late summer spraying. — The grower should endeavor to combat 

 the pests by the preceding measures and thus avoid, if possible, 

 the necessity of later applications. If earlier treatments have pre- 

 served the leaves and checked the development of the insects, later 

 sprayings may be advisable to avoid injuries from the late summer 

 broods. Frequent and thorough spraying with nicotine extract 

 (Formula 1) is the most satisfactory means of affording protection 

 to the trees and should insure against late attacks of the lice. 



For the woolly aphis a spraying of the infested portions of the 

 limbs is usually sufficient to reduce the insects to unimportant 

 numbers. Either Black Leaf 40 (Formula 1) or kerosene emulsion 

 (Formula 2) is a suitable summer spray for this purpose. 



SPRAYING MIXTURES AND FORMULAS. 



Formula 1, Nicotine Extract. 



Nicotine extract 40 per ct. (Black Leaf 40) f pt. 



Water 100 gals. 



Soap 3 to 5 lbs. 



Formula 2, Kerosene Emulsion. 



Kerosene 2 gals. 



Whale-oil or fish-oil soap 2 lb- 

 Soft water 1 gal- 



Directions for making kerosene emulsion are as follows: 

 Dissolve the soap, which has been finely divided, in one gallon 

 of boiling water. Remove the vessel from the stove and add the 

 oil. Then agitate the mixture violently for from three to five minutes 

 by pumping into itself under high pressure until a creamy mass is 

 formed, from which the oil does not separate. Fruit-growers are 

 advised not to employ an emulsion which shows a separation of 

 the oil as application of such preparations may cause injuries to 

 the trees. This is used with success by some growers for summer 

 spraying against the lice at a dilution of one gallon of the emulsion 

 to eight gallons of water. 



failures to control plant lice. 



Efforts to protect bearing apple orchards from plant lice are, as 

 a rule, failures. These are due mostly to the manner of spraying 

 and the lateness of making the applications. Most orchardists do 

 not spray until the insects are abundant and the leaves are curled. 

 Little benefit is derived from treatments under such circumstances 

 as not many of the lice are destroyed, and besides there is always 

 great danger that the most of the injury by the insects is done. 

 The foliage on which the lice have been feeding becomes weakened 

 and may prove susceptible to further injuries from spraying mixtures. 



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