148 MANUAL OF VEGETABLE-GARDEN INSECTS 



diseases. From 8 ounces to 1 pound should be added to each 

 50 gallons, depending on the thoroughness of the application. 

 Arsenate of lead, 3 or 4 pounds of the paste to 50 gallons, has 

 also been found satisfactory. It adheres to the foliage better 

 than paris green but does not kill the insects so quickly. It 

 may be used either in water or in bordeaux mixture. Arsenate 

 of lead may also be applied in the dry or powdered form diluted 

 with sulfur, gypsum or hydrated lime. Experiments in New 

 Jersey, however, have shown that, on the whole, this treatment 

 does liot give as good results in yield as are obtained by spray- 

 ing with bordeaux and arsenate of lead. When expense is an 

 important item, sodium arsenite may be used instead of paris 

 green or arsenate of lead with satisfactory results, at the rate 

 of 1 quart of the stock solution to 50 gallons of bordeaux mix- 

 ture. For the preparation of sodium arsenite see page 369. 



The first application for the potato beetle should be made 

 about the time the eggs are hatching. The larvae are much 

 harder to kill when nearly full-grown and they have then 

 caused the greater part of the damage. It sometimes happens 

 that the eggs are deposited in patches in the field so that the 

 infestation is not general. In such cases it is a good plan to 

 treat these areas early and not wait till the whole field can be 

 sprayed. In Virginia, where potatoes are seriously injured 

 by the over-wintered beetles, just as the plants are peeping 

 through the ground, it is recommended that they be dusted 

 with a mixture consisting of 1 pound of paris green and 20 to 

 30 pounds of hydrated lime. This application is intended to 

 protect the plants until they are large enough to be sprayed. 



In the home garden where only a few potatoes are grown, 

 it is practicable to hand-pick the beetles into pans containing 

 a little kerosene oil or the plants may be dusted with paris 

 green or powdered arsenate of lead diluted with land plaster, 

 hydrated lime or some similar substance. 



For the protection of tomato plants, arsenate of lead should 



