172 INSECTS AFFECTING THE POTATO. 



a foe to the farmer only in its adult condition, for as 

 -a larva it feeds upon the eggs of various grasshop- 

 pers, forming one of the most efficient natural checks 

 upon the increase of these pests. The adult blister- 

 beetle (Fig. 88) is a slender-bodied, rather long- 

 legged insect, measuring from one-half to three- 

 fourths of an inch in length, with alternate stripes 

 ■ j of black and yellowish-brown upon the 

 back. It feeds voraciously on the leaves 

 of potatoes and various other vegetables. 

 These beetles are generally gregarious, 

 feeding in good-sized flocks, and when 

 f disturbed take to flight readily. The fe- 

 strFpeci S Biis- ma l es deposit their small eggs in masses 

 tor-beetie. Q f a hundred or more, in the soil just be- 

 low the surface. In about ten days the eggs hatch 

 into curious little larva? that burrow through the 

 earth in search of the eggs of grasshoppers. A large 

 proportion of them probably perish because they can 

 find none, but those that are successful feed upon the 

 eggs and go through a curious series of changes, 

 which have been admirably described by Dr. Riley, 

 finally going into the pupa state and emerging later 

 on as beetles. In the South there are apparently 

 two broods each season. On account of the depend- 

 ence of the larvae upon grasshopper eggs, the beetles 

 are much more likely to be destructively numerous 

 during seasons following those in which grasshoppers 

 have been abundant. 



There are several other species of blister-beetles 

 with habits similar to this one, that are frequently 



