8 BULLETIN 112, IT. S. DEPARTMENT OF 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 elated August 21, 1910, reported 

 damage by this aphis to dwarf broom corn at Dale, Union County, 

 Ni 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, 1914, 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- 



X U. S. Dept. Agr., Div. Ent., Insect Life, v. 6, no. 2, Dec., 1893, p. 152. 



