INSECT ENEMIES OF EASTERN FORESTS 99 
summer or in the fall, usually in grain stubble, meadows, along ditch- 
banks, fences, and roadsides. In the South the egos may hatch as 
early as February, but in the Northern States hatching usually does 
not occur until May or June. The young erasshopper nymphs re- 
semble the mature insects, except that the wings are not fully devel- 
oped and functional. Although maturity is reached in 40 to 70 days, 
the “hoppers may continue to feed until cold weather. There is 
usually only one generation a year. There are a few species, espe- 
cially in the South, that overwinter in the nymphal or adult stage, but 
these forms never become abundant enough to be destructive. The 
habits are variable. 
Most of the species breed and live in the same general area through- 
out the year and these are called nonmigratory grasshoppers. A few 
of the species, however, which build up in vast numbers, leave their 
breeding grounds when their wings are fully developed and migrate 
in vast swarms, settling on and ‘devastating farm crops, orchards, 
shelterbelts, and shade trees. These are known as migratory grass- 
hoppers. One species, Dendrotettix quercus Pack., is “known to be 
arboreal in habit and occasionally causes some damage to oak in very 
local areas. 
Grasshopper outbreaks in the United States are largely confined 
to the northern Great Plains, Rocky Mountain and Plateau States, 
upper Mississippi Valley, and the Great Lakes region. After crops 
and grasses have been destroyed they frequently eat the leaves and 
green bark of both deciduous and evergreen trees commonly planted 
for shelterbelts and shade trees. One complete defoliation of conifers 
is fatal. The girdling of the bark on young hardwoods is also fatal. 
Although there are a great many species of grasshoppers, five species 
are responsible for 90 percent of all the orasshopper damage to cul- 
tivated crops. The same species kill many shelterbelts and shade trees 
during their epidemics. They are the lesser migratory grasshopper 
(Melanoplus mexicanus (Sauss.)), the differential grasshopper (J/. 
differentialis (Thos.)) the two-striped grasshopper (J/. bivittatus 
(Say)), the red-legged grasshopper (J/. femur-rubrum ( Deg.) ), and 
the clear-winged grasshopper eae pellucida (Scudd. ne For 
a good discussion of these grasshoppers see Parker (329). 
The migratory grass- 
hopper (fig. 15) is about 1 
inch long, reddish brown 
with a distinct patch of 
black on the neck or collar, 
and is a strong flier. It 
is found throughout the 
United States, but is most 
abundant in the northern 
Great Plains. It issimilar 
in most respects to the 
Rocky Mountain locust. or 
grasshopper, which rav- 
Figure 15.—The migratory grasshopper 
aged the Western States (Melanoplus mexicanus), X 2%. 
years ago. 
The differential grasshopper is 114 inches long, yellow with con- 
trasting black markings, has clear glossy hind wings, and hind legs 
