6 
out the entire summer. In fact, this has been actually cbserved to 
occur in the city of Washington. Mr. Phillips has observed the 
same thing in Indiana, and throughout the northern sections of the 
country where the Toxoptera occurs it is more likely to be found on 
this plant during summer than upon grain, excepting, perhaps, 
during seasons of excessive abundance. Mr. Ainshe also found 
it moderately abundant on beard-grass (Polypogon monspeliensis) 
about Albuquerque, N. Mex. It has been found breeding on yellow 
foxtail or pigeon-grass (lvophorus glaucus) by Mr. Phillips at 
Richmond, Ind., and on green stipa (Stipa viridula) at Las Vegas, 
N. Mex., by Mr. Ainslie. In the latter case the grass was heavily 
infested. As one or more of these grasses will be found to occur 
in almost every portion of the United States, it would appear that 
the nonoccurrence of Toxoptera in any considerable section of coun- 
try can not be due to a lack of uncultivated food plants. Of food 
plants other than grasses we have only the one observation made 
by Mr. Phillips at Kingfisher, Okla., April 23, 1907, where a species 
of ragweed growing up in a badly damaged wheat field was quite 
heavily infested with Toxoptera, at the time breeding freely on this 
plant. 
The outbreak on the grounds of the Department of Agriculture 
was notable in some respects, in that the continued close cutting of 
the blue grass supplied a continual fresh, tender growth as food for 
the “green bug,” thus preventing the development and escape of 
winged females; and especially is it notable in view of the total lack 
of Lysiphlebus tritici, the most important of the natural enemies of 
this aphis. The only natural enemy found in this case feeding upon 
the “ green bug” was the diminutive black and yellow lady-beetle 
(Hyperaspis undulata Say), not previously known in connection with 
this pest. 
When this outbreak became known to Mr. E. M. Byrnes, superin- 
tendent of Experimental Gardens and Grounds, he at once had the 
entire infested block sprayed with a solution of one-half gill of rose- 
leaf nicotine to each gallon of weak soapsuds. The application was, 
however, ineffective. Four days later a strip through this plat was 
thoroughly saturated with a strong solution of barnyard manure, 
made by soaking the manure in water. While there was no evidence 
that this killed any of the “ green bugs,” after nine days the pest was 
notably less on this area than where the application of manure 
solution was not made. 
A series of experiments was then undertaken under the writer’s 
direction by Mr. E. O. G. Kelly, as follows: 
Tobacco dust was applied at rates of one-fourth, one-half, and 1 
pound to each 100 square feet, but after over a week had elapsed 
[Cir. 93] 
