2B6 



INSECTS INJURIOUS TO STAPLE CROPS. 



swarm, tliey settle in a field and tlioroiiglily riddle the 

 foliage with holes or strip it bare before going to another 

 field. 



One of the most common forms is the Striped Blister- 

 beetle, or ^^old-fashioned potato-bug" (Epicauta vittata), 

 which is shown in the illustration, together with the im- 

 mature stages. The asli-gray Blister-beetle [Meter ohasis 

 unicolor) is also a common form, shown in Fig. 153. 

 Three or four other forms are common throughout the 

 country, but are especially numerous in the West, where 

 grasshoppers are more abundant. The reason for this is 

 apparent when we come to consider the life-history of the 

 pest, for the Blister-beetles are not an unmixed evil. 



Life-liistory. — In a small cavity in the earth the female 

 beetle lays some four or five hundred eggs, these being 



Fig. 152. — Striped Blister-beetle {Epicauta mttata). a, larva; c, d, 

 hibernating stage of larva: adult beetle at right, and pupa at 

 a, b. (After Riley.) 



deposited from July to October. About ten days later the 

 eggs hatch, and from them emerge some small but very 

 active larv», with long legs, large heads, and strong jaws. 

 They at once commence running about in search of the 

 pod-like masses of grasshoppers' eggs, and as soon as one 

 is found the larva enters it and commences a hearty meal. 

 As soon as his appetite has been somewhat satisfied he 

 sheds his skin, and now being surrounded by food and no 



