$ BULLETIN 112, U. S. DEPARTMENT OE AGRICULTURE. 
aphides in which the author has either failed to describe the insect 
or its habits, or has confused two or more species in his descriptions. 
On the other hand, we have one important reference to injury 
recognizable as that of the true Aphis avence. In Insect Life x Prof. 
F. M. Webster says : 
The wingless viviparous females of this species flock to the fields [of wheat] 
and on these [wheat plants] give birth to their young, which at once make 
their way to the roots, where they continue reproduction, sapping the life 
from the young plants. On very fertile soils this extraction of the sap from 
the roots has no very serious effect, but where the soil is not rich, and especially 
if the weather is dry, this constant drain of vitality soon begins to tell on the 
plants. Though they are seldom killed outright, these infested plants cease to 
grow, and later take on a sickly look * * *. It is very seldom that the 
affected plants fully recover, at least in autumn, and the results must be to 
reduce their productiveness the following year. 
In January, 1891, Mr. Christian Steiffel, of Salem, Ind., reported 
this plant-louse as injuring wheat, causing it to turn yellow and die 
out in spots. 
Prof. Webster received a report from Wooster, Ohio, of serious 
injury to wheat in December, 1898, on land subject to overflow. The 
wheat came up very well and remained green for about a month, 
after which it began to assume a brownish cast, and the warmer the 
weather and the more sunshine the plants got, the browner they 
became. In a letter dated December 4, 1901, to this bureau, Mr. J. D. 
Hummell, of Carroll, Ohio, writes : 
This plant louse seems to have almost completely destroyed one field of 
wheat in which it appeared early in the fall, and is not yet dormant, although 
we have had nights when the temperature was down to 15° F. 
November 12, 1908, Mr. E. O. G. Kelly, of this bureau, reported 
this species abundant on the roots and stems of wheat at Caldwell, 
Kans., and doing considerable and noticeable injury to the early 
sown wheat. 
Mr. A. A. Cooke, in a letter dated August 21. 1910, reported 
damage by this aphis to dwarf broom corn at Dale, Union County, 
X. Mex., the insect covering the plants and causing the foliage to turn 
a reddish color. 
This insect was abundant in western North Carolina in March, 
1913, reports of serious damage to wheat, oats, and rye having been 
received from several parties. 
Numerous reports were received by this bureau from Oklahoma 
and northern Texas in December, 1913, and January, 1911, to the 
effect that the " green bug," which had ravaged the wheat fields in 
these areas in 1907, was again abundant and destructive to oats and 
wheat. Detailed examinations were made by Messrs. W. E. Penning- 
l U. S. Dept. Agi\, Div. Ent., Insect Life, v. 6, no. 2, Dec, 1S93, p. 152. 
