228 WAR ON FIELD AND GARDEN PESTS 



in about a week, hence if the plants are promptly sprayed 

 with poison the young will be killed and the pest reduced 

 or destroyed altogether. 



Paris green at the rate of one pound to the acre in 

 twenty-five to forty gallons of water is a common remedy. 

 It is also used in connection with bordeaux mixture, the 

 latter killing the blight. Lime should be used with the 

 paris green. Perhaps a better insecticide for potatoes is 

 arsenate of lead, applied at the rate of five or six pounds 

 to the acre in about fifty gallons of water or bordeaux 

 mixture. 



The cottony maple scale is one of the best-known in- 

 sects because it heavily infests several common shade 

 trees, and because the cottony masses beneath the body 

 of the adult female in summer make it a conspicuous 

 object. These large white masses are a deposit of waxy 

 threads within which are the minute, oval, pale yellowish 

 eggs. The soft maple is the tree most generally infested 

 by this insect. The boxelder is also subject to injury, and 

 next to this, perhaps, the linden or basswood. 



Among the other trees and woody plants often more 

 or less injured are the elm, honey locust, black locust, 

 walnut, sumac, willow, poplar, beech, hawthorn, bitter- 

 sweet, grapevine and Virginia creeper. The common 

 kerosene emulsion, made by mixing kerosene with one- 

 third of its volume of strong soapsuds, is a satisfactory 

 spray and should be applied twice in the summer. Where 

 caterpillars are usually numerous apply arsenate of lead 

 freely. 



The government has shown that insect pests cause a 

 loss of about ten per cent on nearly all crops. The an- 

 nual damage is placed at $420,000,000. The cinch bug 

 wheat pest sometimes costs us $20,000,000 a year. 



The boll weevil costs the cotton planters $20,000,000 a 

 year. 



