OF THE FARM AND 



given it by the presence upon its body of minute ash-gray ' 

 scales or short hairs, and whenever these are rubbed off, 

 which happens almost as readily as on the wings of a but- 

 terfly, the original black color appears. It attacks not only 

 potato vines, but also Honey-locusts, and especially the 

 English and Windsor bean. In one particular year, we 

 have known them, in conjunction with about equal 

 numbers of the common liose-bug (Macrodactylus sub- 

 spinosus, Linn.), to swarm upon every apple tree in a small 

 orchard in Northern Illinois, not only eating the foliage, 

 but gnawing into the young apples. They were formerly 

 quite common in parts of Illinois, Missouri, Wisconsin, 



Fig. 61. ASH-GRAY (a), AND BLACK-BAT (6) BLISTER-BEETLES. 



and Iowa; and the people there got so habituated to the 

 presence of the Colorado bug, that in many cases they 

 thought it was a fresh invader from the region of the 

 Rocky Mountains: whereas it has existed everywhere in 

 the more northerly parts of the United States from time 

 immemorial. 



THE BLACK-RAT AND BLACK BLISTER-BEETLES. 

 (Lytta murina, Leconte, and L. atrata, Fabr.) 



The first of these, the Black-rat Blister-beetle (fig. 61, 

 b 9 ) is entirely black, and is sometimes found in swarms 

 upon the potato vines in the more Northern States. 

 There is a very similar species, the Black Blister-beetle 



