93 . INJUEIOUS INSECTS 



{Lytta atrata, Fabr.), from wlii^h the Black-rat Blister- 

 beetle is distinguishable only by having four raised lines 

 placed lengthways upon each wing-case, and by the two 

 first joints of the antennae being greatly dilated and 

 lengthened in the males, as above in figure 61, c. The 

 true Black Blister-beetle we have never met with, except 

 quite late in the year, namely about the last of August or 

 tlie fore part of September; usually upon the flowers of the 

 Golden-rod, the Thistle, etc. It sometimes does injury 

 in the potato field, especially when the development of 

 the tubers has been retarded, but generally appears too 

 late in the season to prove very destructive. 



THE MAEGnSTED BLISTER-BEETLE. 

 {Lytta marginata, Fabr.) 



This species (fig. 62,) may be at once recognized by its 

 general black color, and the narrow ash-gray 

 edging to its wing-cases. It usually feeds on 

 certain wild plants; but has been found quite 

 abundant on potatoes in Missouri, Illiuois, 

 and elsewhere. It is a common species in 

 the Mississippi Valley, and prefers most other 

 varieties of the potato to the " Peach Blow." 

 It feeds on many other plants, and especially 

 the Kentucky Co2ee-tree {Gymnocladus). 

 It also attacks the Egg Plant. 



THE THREE-LINED LEAF-BEETLE. 

 {Lema trilineata, Olivier.) 



The first three insects, described and figured above as 

 infesting the potato-plant, attack it only in the larva 

 state. The four next, namely the four Blister-beetles, 

 attack it exclusively in the perfect state. The three that 



