The Control of Insect Pests and Plant Diseases. 597 



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

 For a 15% emulsion add 10 J 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 dust 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. There are now on the market several concentrated 

 tobacco extracts which have been found effective against plant-lice, pear psylla 

 and similar insects. Use them according to directions. Tobacco in the form of 

 extracts, punks and powders is sold under various trade names for use in fumigating 

 greenhouses. 



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

 Soaps. olve 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, like Ivory soap, are often as 

 effective as whale-oil soap. 



There are now on the market a number of preparations of petro- 

 Miscible oils, leum and other oils intended primarily for use against the San 



Jos6 scale. They mix readily with cold water and are immedi- 

 ately ready for use. While quickly prepared, easily applied and generally effect- 

 ive, they cost considerably more than lime-sulfur wash. They are, however, 

 less corrosive to the pumps and more agreeable to use. They are especially 

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

 to the trouble and expense to make up the lime-sulfur wash. They should be 

 diluted with not more than 10 or 12 parts of water. Use only on dormant trees. 

 , Quicklime, 20 lbs. 

 Home-made g^jf^^. ^^^^^ ^^ flowers), 15 lbs. 



^ea^d Water, 50 gals. 

 SUltur wasn. ^^^ y^^^ ^^^ sulfur must be thoroughly boiled. An iron kettle 

 is often convenient for the work. Proceed as follows: Place the lime in the 

 kettle. Add hot water gradually in sufficient quantity to produce the most 

 rapid slaking of the lime. When the lime begins to slake, add the sulfur and 

 stir together. If convenient keep the mixture covered with burlap to save 

 the heat. After slaking has ceased, add more water and boil the mixture one hour. 

 As the sulfur goes into solution, a rich orange red or dark green color will appear. 

 After boiling sufficiently, add water to the required amount and strain into the 

 spray tank. The wash is most effective when applied warm, but may be applied 

 cold. If one has access to a steam boiler, boiling with steam is more convenient 

 and satisfactory. Barrels may be used for holding the mixture, and the steam 

 applied by running a pipe or rubber hose into the mixture. Proceed in the same 

 manner as for boiling in the kettle until the lime is slaked, when the steam may be 

 turned on. Continue boiling for 45 minutes to an hour, or more if necessary to get 

 the sulfur well dissolved. 



