INJURIOUS INSECTS OF 1903. 113 



without danger. (W. Va. Bui. 78, 1902.) Under no cir- 

 cumstances, however, is pure kerosene recommended to 

 be used on plant Hfe of any kind. It has been used undi- 

 luted on plants dormant and in foliage (apple trees and 

 others) without apparent injury, but there are too many 

 uncertainties attending its use to warrant its application. 



For sprays always purchase the 150 degree fire test 

 kerosene. 



For Cockroaches — With an atomizer spray into the 

 cracks, etc., where the roaches are located. 



We have kept roaches within bounds by having an 

 atomizer handy containing kerosene, and spraying a roach 

 whenever seen. See p. 162. F. L. W. 



31. Kerosene Emulsion — 



This, probably, is the best form into which kerosene 

 can be put in order to obtain the best results. When the 

 kerosene is in an emulsion the proportion of kerosene is 

 known to a certainty, while with the Kero-water sprays 

 the proportion is not always just what one expects. 



A stock emulsion is made as follows : 



Hubbard Formula: 



Hard soap, shaved fine, ^ pound ; 

 Kerosene, 2 gallons ; 

 Water, i gallon. 

 Dissolve the soap in boiling water ; remove from the 

 stove and add the kerosene while the water is still boiling 

 hot ; churn with a spray-pump until it gets to a soft, but- 

 ter-like mas6. 



For Plant Lice use i part of the stock to 10 parts of 

 water. Some insects will require a much stronger mix- 

 ture. 



32. Kerosene Milk Emulsion — 



When small quantities of emulsion are wanted it is 

 often less trouble to make it with milk than with the soap 

 and water. 



