THE STATE ENTOMOLOGIST. 97 



ease. This is the case with the four following beetles which infest the 

 potato. As these four species all agree with one another in living 

 under ground and feeding upon various roots, during the larva state, 

 and in emerging to attack the foliage of the potato, only when in the 

 course of the summer they have passed into the perfect or beetle 

 state ; it will be quite unnecessary to repeat this statement under the 

 head of each of the four. In fact, the four are so closely allied, that 

 they all belong to the same family of beetles, the blister-beetles 

 (Lytta family)— to which also the common imported Spanish-fly or 

 blister-beetle of the druggist appertains — and all of them will raise 

 just as good a blister as that does, and are equally poisonous when 

 taken internally in large doses. In Missouri, these blister-beetles 

 were more numerous and more injurious in 1868 than the dreaded 

 Colorado Potato-beetle. 



The Striped Blister-beetle (Fig. 39) is almost exclusively a south- 

 ern species, occurring in particular years very abundantly 

 on the potato vine in Central and Southern Illinois, and in 

 our own State, though according to Dr. Harris, it is also 

 occasionally found even in New England. In some speci- 

 mens, the broad outer black stripe on the wing-cases is 

 divided lengthways by a slender yellow line, so that instead 

 \ of two there are three black stripes on each wing-case ; and 

 in"the same field all the intermediate grades between the two varie- 

 ties may be met with ; thus proving that the four-striped individuals 

 do not form a distinct species, as was formerly supposed by the Euro- 

 pean entomologist, Fabricius, but are mere varieties of the same 

 species to which the six-striped individuals appertain. 



The late Samuel P. Boardman, of Lincoln, Illinois, discovered 

 that this Striped Blister-beetle, like the Colorado beetle, eats all other 

 potato tops in preference to Peach-blows. (See N. Y. Sem. Tribune, 

 July 13, 1868.) This is certainly a new fact, so far as regards the for- 

 mer species, though it has long been ascertained to be true of the 

 latter, but as I shall presently show, the Margined Blister-beetle has 

 the same tastes. 



THE ASH-GRAY BLISTER-BEETLE*— Lytta cinerea, Fabr. 



This species (Fig. 40 a, male) is the one commonly found in the 

 more northerly parts of the Northern States, where it usually takes 

 the place of the Striped Blister-beetle figured above. It is of a uni- 

 form ash-gray color; but this color is given it by the presence upon 



* In the male of this species, but not in the female, the first two joints of the antennae are 

 greatly elongated and dilated ; which is also the case with the species next to be referred to. (Fig. 

 40 d, represents the male antenna 1 , above ; that of female below.) Hence, in splitting up the extpn- 

 sive and unwieldy old genus (Lytta), these and certain allied species have been very properly placed 

 in a genus by themselves (Macrobasis) ; while the Striped Blister-beetle and the Margined Blister- 

 beetle, not possessing this peculiarity, are grouped together under a distinct genus (Epicauta). 

 Practical men, however, who do not desire to trouble their heads with these niceties, will find it most 

 convenient to class them all together under the old genus (Lytta) ; and this we have accordingly 

 done. 



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