THE GRASSHOPPER PROBLEM AND ALFALFA COLYUSS 3 
DESCRIPTIONS OF THE TWO PRINCIPAL ALFALFA-AFFEC ‘a SPECIES. 
The differential grasshopper (fig. 1) is about 14 inches long, its 
wings expand about 24 inches, and it is of a general bright yellowish- 
green color. There is, however, a nearly black melanic form that does 
not seem to differ otherwise from 
thenormal. The head and thorax 
are olive brown, and the front 
wings are of very much the same 
color, without other markings 
but with a brownish shade at the 
base; the hind wings are tinged 
with green; the hind thighs are Fig. 2.—Two-striped grasshopper ( Melanoplus bivitta- 
. ; tus). Natural size. (After Riley.) 
bright yellow, especially below, 
with four black marks; the hind shanks are yellow, with black spines 
and a ring of the same color near the base. 
The two-striped grasshopper (fig. 2) varies in color from a dull 
green to a dull brown, with a distinct yellow stripe extending on each 
side from the upper part of the eye to the end of the wing. The male 
is about 1} inches long and the female about one-fourth of an inch 
longer. This grasshopper may be so easily 
recognized from the accompanying figure 
that further description is unnecessary. 
The young are very much like those of 
the Rocky Mountain grasshopper, or locust, 
shown in figure 3. 
DISTRIBUTION OF THE TWO SPECIES. 
oe eg Oe BGO Although both these grasshoppers seem 
per or locust ( Melanoplus spretus): : : an 
a, a, Newly hatched larve; b, ful. to be generally distributed over the coun- 
grown larva; ¢, pupa. Naturalsize. try, the differential grasshopper rarely be- 
(After Riley.) : 
comes destructively abundant east of the 
Mississippi River. It is very decidedly so, and with great frequency, 
however, to the west of the Mississippi, while, though extending from 
Maine to California, the two-striped grasshopper is sometimes dis- 
astrously abundant, locally at least, as far east as Ohio. In the red- 
clover-growing sections of the country the two-striped species 1s prob- 
ably very much the more destructive of the two, though even as far 
east as Indiana the differential grasshopper does considerable injury 
to fruit trees by gnawing the bark from the twigs. 
