Blister-beetles 



(e) BLISTER-BEETLES 



(Figs. 8, 9, 12 and 13, Plate VII, Page 23) 



In nearly all lists of insects attacking the sugar beet mention is made 

 of several species of blister-beetles. The economic status of some of our 

 common species is difficult to determine, as the larvae, by destroying 

 grasshopper eggs, render a real service to agriculture, while the adult 

 beetles damage certain crops by feeding upon their leaves. 



A powder made of the dried bodies of the adult beetles is used in 

 the treatment of certain diseases and injuries. When applied to the flesh 

 in a paste form blisters are produced. This led to the beetles being 

 called blister-beetles. The powder made from the dried bodies of a 

 European species is known in the commercial world as Spanish-fly. 



NATURE OF INJURY 



The injury to crops (which is the result of the feeding of the adult) 

 is similar to that caused by other leaf-eating beetles. 



These beetles are strong fliers, often appearing in swarms on sugar 

 beets, potatoes and other crops, where they feed most ravenously for a 

 time. Disappearing as suddenly as they come, they leave only the riddled 

 remains of the crop. 



At such times applications of poisons are of little avail because of 

 the great numbers of beetles and because of their voracity. Only the 

 promptest action and most thorough application of whatever remedies 

 are employed against them will be effective. 



METHODS OF CONTROL 

 Poison 



As already stated, the use of poison is seldom effective. If poison 

 is used, 2 to 2\ pounds of Paris green or 4 to 5 pounds of dry arsenate of 

 lead, or 8 to 10 pounds of arsenate of lead paste, should be used in the 

 quantity of water necessary to spray one acre. This varies from 50 to 

 100 or 125 gallons in the different types of sprayers. 

 Mechanical Measures 



As the beetles are very active and readily put to flight, driving them 

 from a field is often the most effective means of preventing losses. This 

 can be done by several persons, armed with brush or small branches of 

 of trees, driving the beetles ahead of them. Always work in one direc- 

 tion, taking as wide a strip across the field as possible, and going with the 

 wind. 



According to Dr. Chittenden*, a windrow of dry straw or hay placed 

 along one side of the field can be burned after the beetles have been driven 

 onto it, thus destroying them. 



When small areas or gardens are attacked the beetles can sometimes 

 be knocked into pans containing a small quantity of water covered with 

 a thin film of kerosene. This method l is not suited to large fields. 



When the beetles are not very numerous they can be dispersed and 

 serious damage prevented by using the cultivator equipped as suggested 

 for scattering flea-beetles, i. e., with pieces of rope or strips of canvas 

 attached to the frame so as to drag on the plants. 



*"A Brief Account of the Principal Insect Enemies of the Sugar Beet," Bulletin No. 43. Division ot 

 Entomology. U. S. Department of Agriculture (1903). 



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