Pests and Diseases 187 
the most serious in one locality are not known in others. 
Certain insects, though present in a locality, may do very 
little damage even when serious elsewhere. Such insects 
as the leaf-hopper are greatly affected by geography. 
In some places they have rendered successful beet-culture 
practically impossible, though in other sections the injury 
is but slight. Treatments must, therefore, be applied 
locally. No general description will suit all conditions. 
Blister-beetles (Meloidae). (Plate XXI.) 
These insects sometimes descend in swarms on field 
and garden crops, destroying the foliage and ruining the 
crops. No less than a dozen species of blister-beetles 
work on crops. The insect is a long, narrow beetle with 
a distinct head and “neck.” In color it is black, gray, or 
mottled, with a black or yellow stripe running the length 
of the wings on most species. The grubs, or larvae, of 
the blister-beetle feed on grasshopper eggs, and when the 
grasshoppers are more injurious than the beetles, it may 
pay not to disturb the beetles. The beetles may be kept 
from the leaves by applying bordeaux mixture. When 
this spray is made up with paris green as a constituent, 
it may be beneficial, When the attack is sudden, the 
usual method of control is to drive the insects from the 
field by a number of men swinging branches over the 
crop. The beetles move ahead of such a disturbance and 
do not return quickly after once having been expelled. 
Army-worms. 
The beet army-worm (Caradrina [Laphygma] exigua 
Hbn.) occurs in disastrous abundance on beets at certain 
