247 
these reports they usually proved to be Toxoptera. At Lafayette this 
was by far the most abundant species. wintering over in the wheat 
fields, and examinations in April showed them to have survived the 
winter in great numbers. They did not appear to increase rapidly, and 
I had ceased to anticipate trouble from them, when early in June let- 
ters from the southern part of Indiana gave the information that the 
grain Aphis was appearing in the wheat fields precisely as it had done 
the previous year, and was also ravaging the oat fields. <A visit to 
Posey County on the 11th day of June revealed the true state of affairs. 
There were Stphonophora avene on the wheat in considerable abun- 
dance, and many also on the oats, but the number on the latter grain 
was no comparison to those of the Toxoptera. Not only were the 
larger leaves covered with them in many cases, but the tender unfold- 
ing leaves also, while there were myriads of the brown parasitized 
females everywhere on the plant. The oat crop was there a total fail- 
ure, many fields being at that time as brown as though the entire 
growth of plants had been winter-killed. There was no lack of proof 
that the damage, so far as due to insect attack at all, had been done 
by this species. 
From notices appearing in Illinois and Missouri papers, I am 
inclined to the opinion that the Toxoptera was equally abundant in 
portions of these States. In the extreme southern portions of Indiana 
the oat crop was a total failure; in many cases I was at a loss to 
account for this destruction, as its magnitude did not correspond to 
the numbers of the Toxoptera, notwithstanding its numbers were enor- 
mous. A solution of the problem, however, came from an unexpected 
quarter. Prof. Bb. T. Galloway, Chief of the Division of Vegetable 
Pathology, had, during the st*mmer, discovered a bacterial disease in 
the oats plants, of which I had no knowledge, and his paper on a “ New 
Disease of Oats” read at the Indianapolis meeting of the American As- 
sociation for the Advancement of Science,* relieved me from my dilem- 
ma. Whilethe Toxoptera can not be held entirely responsible for the fail- 
ure of the oats crop during that season, as serious damage occurred where 
__ the insects were not sufficiently abundant to be noticeable, yet they cer- 
tainly aggravated the work of destruction in several States, and in 
_ southern Indiana, at least, greatly emphasized the effect of this dis- 
_ ease, showing us clearly that the species may in future prove a serious 
pest to the oats crop. 
_ The young and apterous agamic females may be confused with the 
_ true Grain Aphis, Siphonophora avene, by casual observers, but the 
- winged female has the cubital vein of the wing but once forked, thereby 
distinguishing it from all others of the subfamily Aphidine. These 
_ Toxoptera are great favorites of ants, while I have never yet observed 
an ant in attendance on Siphonophora avene, Prof. A. J. Cook notwith- 
_ standing. 
—— 
*Preliminary notes on a new and destructive oat disease, by B. T. Galloway and 
E. A. Southworth. The Journal of Mycology, yol. v1, no. 2, p. 72, September, 1890. 
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