INJURING THE LEAVES. 171 



This oscillation is probably due to the various 

 natural enemies of the insect. 



Remedies. — The standard remedy for this pest is 

 that of spraying or dusting with some form of arsenic, 

 such as London purple, Paris green, Slug Shot, Per- 

 oxide of Silicates, etc. All of these take effect, both 

 upon the larvae and beetles. London purple or Paris 

 green may be dusted or sprayed on with a perforated 

 can or a powder-gun, or spraying machine. If used 

 as a powder, the poison may wpII be diluted with 

 several times its bulk of plaster, finely sifted ashes, 

 or flour. In spraying use six or seven ounces of 

 London purple or Paris green to fifty gallons of 

 water. For this purpose London purple seems prefer- 

 able on account of its cheapness and finely powdered 

 condition. The application should be made as soon 

 as the beetles appear, in order to kill off the first 

 brood, and it must be repeated as often during the 

 season as is necessary to keep the pests in check. 

 By many growers hand-picking of the beetles and 

 eggs, especially early in the season, is resorted to in- 

 stead of the use of poisons. This method is effective 

 if thoroughly carried out. 



The Striped Blister-beetle. 



Epicauta vittata. 



This insect is sometimes called the Old-fashioned 

 Potato-beetle, because it was known as " The Potato- 

 beetle " before the introduction of the more modern, 

 as well as more destructive, Colorado species. It is 



