uthern species, occurring in some years
very abundantly on the potato-vines in Southern Illinois, and also in
Missouri, and according to Dr. Harris, it is occasionally found even in
New-England. In some specimens the broad outer black stripe on the
wing-cases is divided lengthwise by a slender yellow line, so that,
instead of _two_, there are _three_ black stripes on each wing-case; and
often in the same field may be noticed all the intermediate grades; thus
proving that the four-striped individuals do not form a distinct
species, as was supposed by the European entomologist Fabricius, but are
mere varieties of the same species to which the sixth-striped individual
appertains.

The striped blister-beetle lives under ground and feeds upon various
roots during the larva state, and emerges to attack the foliage of the
potato only when it has passed into the perfect or beetle state.

This insect, in common with our other blister-beetles, has the same
properties as the imported Spanish fly, and any of them will raise just
as good a blister as that does, and are equally poisonous when taken
internally in large doses. Where the striped blister-beetle is numerous,
it is a great pest and very destructive to the potato crop. It eats the
leaves so full of holes that the plant finally dies from loss of sap and
the want of sufficient leaves to elaborate its juices. In some places
they are driven off the plants (with bushes) on a pile of hay or straw,
and burned. Some have been successful in ridding their fields of them by
placing straw or hay between the rows of potatoes, and then setting it
on fire. The insects, it is said, by this means are nearly all
destroyed, and the straw burning very quickly, does not injure the
vines.

~The Ash-Gray Blister-Beetle~, (_Lytta cinera_, Fabr.)--This species (Fig.
7, 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 before mentioned. It is of a uniform ash-gray color. It
attacks not only the potato-vines but also the honey locusts, and
especially the Windsor bean. In particular years it has been known, in
conjunction with the rose-bug, (_Macrodactylus subspinosus_, Linn.,) to
swarm upon every apple-tree in some orchards in Illinois, not only
eating the foliage, but gnawing into the young apples.

This beetle does considerable damage to the potato crop, especially in
the North-Western States. Lik