INSECTS INJURIOUS TO BEETS AND SPINACH 



343 



this machine it should be well adapted for beets and similar 

 crops. 



Blister-beetles * 



Among those insects attacking the young sugar-beets and 

 often doing considerable damage after they have become partly 

 grown, few are more widespread or do more general injury than 

 the blister-beetles. They have been especially destructive 

 in the northern Mississippi Valley, where they are usually worst 

 after a period of unusual abundance of grasshoppers. Coming 

 suddenly in a large swarm, they settle in a field and thoroughly 



FIG. 246. The striped blister-beetle (Epicauta vittatd)'. a, female beetle; 

 6, eggs; c, triungulin larva; d, second or caraboid stage; e, same as / 

 doubled up as in pod; /, scarabseoid stage; g, coarctate larva all except 

 e enlarged. (After Riley and Chittenden, U. S. Dept. Agr.) 



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 vittatd), which is 

 shown in the illustration, together with the immature stages. 

 The ash-gray blister-beetle (Macrobasis unicolor) is also a common 

 form, shown in Fig. 230. 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. 



* Family Meloidoe. 



