Insect and Disease Control 283 



favorably in cost with other contact sprays. Nicotine is 

 extracted from refuse tobacco, principally stems, by different 

 commercial concerns, and is put on the market in several 

 grades and strengths. The 40 per cent nicotine sulfate is 

 the solution principally used, although weaker grades of 

 nicotine may be employed provided care is taken that the 

 spray be made so as to contain not less than 0.05 or 0.06 

 per cent of actual nicotine. 



"Nicotine may be added either to the winter-strength 

 lime-sulfur solution for the San Jose scale or to the dilute 

 lime-sulfur solution and arsenate of lead spray employed 

 in the control of insects and diseases of fruit and foliage. 

 It may also be used in bordeaux mixture and arsenate of 

 lead spray without interfering with its effectiveness, or in 

 an arsenate of lead, milk of lime, and water spray. In 

 orchard spraying the 40 per cent nicotine sulfate is used 

 at the rate of about f pint to 100 gallons of water, lime- 

 sulfur solution, or bordeaux mixture. When used in water 

 the addition of soap at the rate of 4 or 5 pounds to 100 

 gallons adds much to its spreading power and efficiency. 

 Soap should not be used with lime-sulfur solution, but 

 may be used in bordeaux mixture. Where only a small 

 quantity of spray is required, the nicotine sulfate may be 

 used at the rate of 1 teaspoonful to a gallon, or 1 ounce to 

 8 gallons of soapy w^ater." 



Linseed oil emulsion. 



This preparation is reported by Simanton ^ as being one 

 of the most effective of a considerable number tested in 

 controlling the terrapin-scale or peach-lecanium. It is 

 composed as follows : 



1 U. S. Dept. of Agr. Bull. 351. 



