424 CONTROLLING INSECTS AND PLANT DISEASES 



Persian insect powder is made from the blossom of the pyre- 

 thrum plant. This is used as a dust and smothers the insects. As 

 it is not poisonous to human beings, it may be used in windows or 

 other places where flies collect in great numbers. Like hellebore, 

 it deteriorates with age, and so becomes ineffectual. When com- 

 bined with water as a spray, one ounce of pyrethrum is mixed 

 with two gallons of water. This should be boiled a few minutes 

 before using. The fumes of burning pyrethrum powder will 

 destroy flie^ and mosquitoes, if the fumes are confined in a closed 

 room. 



Kerosene emulsion is made of one-half pound of hard soap, one 

 gallon of water and two gallons of kerosene. Dissolve the soap 

 in the water made boiling hot. Then remove from the fire and 

 add the kerosene. This should be mixed vigorously for ten minutes. 

 A good way is to use a small spray pump and turn the nozzle back 

 into the mixture. It will become a creamy mass when all of the 

 oil is thoroughly emulsified. This mixture may be kept in bottles 

 any length of time desired. It is to be diluted when used with ten 

 to fifteen parts of water for summer use against plant lice and 

 soft insects. As a winter spray, only three or four parts of water 

 to one part of the stock solution are used. This is one of the oldest 

 and one of the best remedies for use in the garden and greenhouse 

 against any form of sucking insects. 



This emulsion is modified by substituting crude petroleum 

 for the kerosene, or some petroleum distillates are sometimes used. 



Crude Oil. For mange on horses and cattle and for lice on 

 hogs, poultry and other animals, nothing is better than crude 

 petroleum. This is rubbed on the coat of the animal, or sprayed 

 among the feathers of poultry with an air blower. If light appli- 

 cations are made, little or no injury results, but the parasites are 

 destroyed and the eggs when hatched are killed by the residue of 

 oil yet remaining in the hair or feathers. Light weight crude oil 

 is preferred for these purposes. 



Pure sulfur is used against the red spider in grain houses, and 

 is dusted on infested plants and trees such as citrus fruits in 

 warm climates. 



Carbon bisulfide is used in destroying grain moths, weevils 

 and other pests in stored seeds, stored grain, and other fruits in 

 the pantry. Bins of wheat or other grain may be covered tightly 

 with canvas and the liquid placed in a dish above the grain under 

 the cloth. The liquid evaporates and the fumes penetrate through- 



