196 PESTS OF GARDEN AND FIELD CROPS 
abling it to jump quickly and take wing readily. The younger stages 
are similar, but are smaller and wingless. Usually the hoppers 
appear in the beet field suddenly, 
having fed first on some other 
plant, probably species of weeds. 
In hot, dry fields conditions are 
especially favorable to the pest 
and unfavorable to the beets, 
while in fields where the reverse 
conditions prevail the beets are 
able to withstand attack. 
Infested fields may be sprayed 
Fic. 244.— The Beet Leafhopper. ; c mS d 
Enlarged and natural size. Original. With a contact insecticide, making 
the first application just as the 
young nymphs are found in numbers, and repeating. Kerosene 
emulsion may be used, diluting the stock solution with § parts of 
water. It is very difficult, however, to hit all the insects with 
the spray. A drag may be used to turn the leaves over, so as 
to help to make the application more thorough. 
Frames coated with tar dragged through the fields at the first appear- 
ance of the adults will catch many, and will help to check injury. 
The Spring Grain-aphis, or ‘‘ Green Bug’ (Toroptera graminum 
Rond.) 
Occasionally, in recent years, oats, wheat, barley, and sometimes corn 
have been damaged to the extent of millions of dollars by this tiny 
louse. It occurs in both winged and wingless forms. The latter is 
about one twentieth of an inch long, yellowish green, witha faint dark 
line down the middle of its back. Its eyes are quite black. The 
winged form is a little larger, has a dark thorax, but otherwise is of 
the same general appearance. 
Attack comes on suddenly in the spring. Countless billions of the lice 
appear on young grain, sucking the juice of the leaves, stunting the 
growing plants or killing them outright. Reproduction goes on rapidly. 
When the fields in a section attacked are destroyed, or the plants have 
