The Bulletin. 17 



and that is, being a comparatively new spraying material, it is not 

 as easy to obtain as Paris green. However, it sticks to the foliage 

 longer than Paris green and does not have the same characteristic 

 burning effec^k that is sometimes noticeable after Paris green has 

 been used. F^r this reason arsenate of lead may be used at much 

 greater strength than Paris green. Arsenate of lead costs from 15 to 

 25 cents per pound and may be secured from the larger druggists in 

 the State. Arsenate of lead comes in a thick paste-like form and 

 goes into solution readily when mixed with water. Recently a dry 

 powdered form of arsenate of lead has been placed upon the market. 

 At the present time it is not nearly so available, however, as the 

 paste form and has scarcely any advantages over the paste form 

 when used in a liquid spray except its lesser bulk. In spraying 

 plant-beds for Flea Bugs it may be used at the rate of 8 or 10 pounds 

 to 50 gallons of water. In the field under all conditions it is not 

 safe to use this stronger than 4 pounds to 50 gallons of water. In 

 early spring, before hot weather commences, it may be used safely 

 as strong as 6 pounds to 50 gallons of water; but later, when the 

 days are hot, slight burning may be noticed if it is applied as strong 

 as 5 pounds to 50 gallons of water. It is perhaps advisable to use 

 the stronger solutions in the early spring, for in that way the earlier 

 generations of Flea Bugs and the first Horn Worms will be cut off 

 before they have a chance to do much damage. The number of 

 sprayings' necessary will depend largely upon the condition of the 

 weather. If dry, a fewer number of sprayings will be necessary 

 than if there are long-continued or frequent rains. In our experi- 

 ments decided advantages in favor of the sprayed plats as against 

 the unsprayed plats could be noticed where but a single spraying 

 was given, even when this spraying was followed by a heavy rain 

 the same day the application was made, although it would be better 

 practice to spray oftener than this. Our experiments in which 

 arsenate of lead was used go to show that it would require 20 to 50 

 gallons of mixture per acre, depending upon the size of the plants. 

 Paris Green. — This poison has the advantage of being easier to ob- 

 tain than arsenate of lead, but, as mentioned above, it does not stick 

 to the foliage as well, and there is often danger of burning the leaves. 

 Paris green has another advantage over arsenate of lead, and that is, 

 that it may be applied in the dry form. While this is convenient. 

 because the apparatus for applying the dry mixture is so much lighter 

 and easier to handle than a spray pump, poison in the dry form can- 

 not be applied nearly as uniformly as in a liquid, hence there is 

 usually much greater danger of burning by applying dry Paris green 

 than there is from applying Paris green in the form of a spray. Paris 



