Insect Pests and Plant Diseases. 187 



(For use without Bordeaux mixture). Sal soda, i lb., water, 



Arsenite i gal- white arsenic, i lb., quick lime, 2 lbs. Dissolve the 



of lime. white arsenic with the water and sal soda as above and 



use this solution while hot to slake the 2 lbs. of lime. Add 



enough water to make 2 gallons. Use 2 quarts of this stock solution in 50 



gallons of water. 



For wet application, use fresh white hellebore, i oz., water, 2 

 Hellebore. or 3 gals. For dry application, use hellebore, i lb., flour or air- 

 slaked lime, 5 lbs. This is a white, yellowish powder made 

 from the roots of the white hellebore plant. It loses its strength after a time 

 and should be used fresh. It is used as a substitute for the arsenical poisons on 

 plants or fruits soon to be eaten. 



Hard, soft or whale-oil soap, ^ lb., water, i gal, kerosene, 



Kerosene 2 gals. Dissolve the soap in hot water; remove from the fire 



emulsion. while still hot .nnd add the kerosene. Pump the liquid back 



into itself for five or ten minutes or until it becomes a creamy 



mass. If properly made the oil will not separate out on cooling. 



For use on dormant trees, dilute with from 5 to 7 parts of water. For killing 

 plant-lice on foliage dilute with from 10 to 15 parts of water. Crude oil emulsion 

 is made in the same way by substituting crude oil in place of kerosene. The 

 strength of oil emulsions are frequently indicated by the percentage of oil in the 

 diluted liquid : 



For a 10% emulsion add 17 gals, of water to 3 gals, stock emulsion. 



For a 15% emulsion add loi gals, of water to 3 gals, stock emulsion. 



For a 20% emulsion add 7 gals, of water to 3 gals, stock emulsion. 



For a 25% emulsion add 5 gals, of water to 3 gals, stock emulsion. 



Soap, I lb. ; water, i gal. ; crude carbolic acid, i pint. Dissolve 

 Carbolic acid the soap in hot water, add the carbolic acid and agitate into an 

 emulsion. emulsion. For use against root-maggots, dilute with 30 parts 

 of water. 



This is a valuable insecticide and is used in several forms. As 



Tobacco. a dast it is used extensively in greenhouses for plant-lice, and in 



nurseries and about apple trees for the woolly aphis. Tobacco 



decoction is made by steeping or soaking the stems in water. It is often used as 



a spray against plant-lice. Tobacco in the form of extracts, punks and poi^'ders is 



sold under various trade names for use in fumigating greenhouses. 



An effective insecticide for plant-lice is zvhalc-oil soap. Dis- 



„ solve in hot water and dilute so as to obtain one pound of soap 



" ■ to every five or seven gallons of water. This strength is 



effective against plant-lice. It should be applied in stronger 



.solutions, however, for scale insects. Home-made soaps and good laundry soaps, 



L..e ivory soap, are often as effective as whale-oil soap. 



There are now on the market a number of preparations of 



,_. ., , ., petroleum and other oils intended primarily for use against the 



Miscible oils, o T ' 1 T-! • j-1 .n T 1 * I 



San Jose scale. They mix readny with cold water and are im- 

 mediately ready for use. While quickly prepared, easily applied 

 and generally effective, they cost considerably more than lime-sulfur wash. They 

 are, however, less corrosive to the pumps and more ageeable to use. They are 

 especially valuable to the man with only a few trees or shrubs who would not care 



