ll ts i ee 
The Green-Bug or Spring Grain-Aphis. 5 
popular publication. There are no less than three distinct forms 
of adult females of the pest. A wingless one, producing its young 
alive (fig. 1); a wingless one, which lays eggs (fig. 3); and a fully 
winged one (fig. 4), producing its young alive. The male is of 
small importance, as ordinarily he is not required in the multiplica- 
tion of the species. 
In the southern latitudes the egg-laying females are not believed 
to exist, but both the other forms of females which produce living 
young are found at certain seasons. The wingless form of this type 
is practically. always present and producing young all the year 
round. The egg-laying females appear in the north only in the 
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Fig, 3.—The spring grain-aphis: Oviparous female, showing eggs within the abdomen. 
Hnlarged ; actual size, 2.25 mm. (Webster and Phillips.) 
fall of the year and the insect may pass the winter either in the egg 
stage or as active nymphs or adults on the lower parts of its food 
plants. 
South of the thirty-fifth parallel this pest (except in high alti- 
tudes) appears to breed continuously throughout the year, and for 
this reason is most dangerous to the wheat and oats crops of these 
warmer regions. 
The egg (fig. 5) of the green-bug is green when freshly laid, but 
soon becomes shiny black, and is to be found attached to the food 
plants of the pest. These eggs are deposited in the fall and do not 
hatch until the following spring. The young bugs (fig. 6), upon 
