198 PESTS OF GARDEN AND FIELD CROPS 
The European Grain Aphis (Siphocoryne avene Fab.) 
In summer the leaves, stems, and heads of small grains sometimes are 
literally covered with this species of plant lice. They are rather 
pale green in color, marked with short bands of darker green on the back, 
and for the most part are wingless. Usually their increase is quickly 
followed by a similar increase in parasites, so that serious injury is 
averted, but occasionally they seriously damage young wheat in the 
fall. 
The lice come to the grain fields in the spring from fruit trees, 
where they have passed the winter in an egg stage, and have already 
gone through one or two generations on the fruit buds and foliage. They 
return to the trees in the latter part of summer or the fall. 
No direct measures of control on grain are known. 
The Corn Leaf-aphis (Aphis maidis Fitch) 
In midsummer, corn, or more especially sorghum and broom corn, 
becomes infested with bluish green lice which work on the younger 
leaves, and on the tassel. On broom corn their punctures often are 
followed by a red discoloration due to a bacterial disease. The wingless 
female is usually seen. It has black legs, antennew, and honey tubes, 
and a row of black dots down either side of the back. 
Winged generations are devel- 
oped as the corn matures, but the 
alternate host plants, if any, are 
unknown. No remedial measures 
have been devised. 
The Green Peach Aphis, or Spinach 
Aphis (\fyzus persice Sulz.) 
This plant louse often is known 
as the spinach aphis, or “ green 
fly.” It is the same species as 
Fic. 247.—The Green Peach Aphis. the louse found on the foliage of 
Enlarged. Original. peach trees early in the season, 
