5) 
erass about Washington, D. C., up to the time of publication of this 
circular. Mr. E, O. G. Kelly and the writer found it quite common 
on the underside of the lower leaves of corn at Sharpsburg, Md., 
July 9, and Messrs. Kelly and Hayhurst also found it on corn near 
Washington, D. C. Mr. W. J. Phillips found it breeding on Hor- 
deum pusillum in Oklahoma, and the same food habit was cbserved 
in Kansas by the writer, by Mr. Ainslie, and by Prof. E. A. Popenoe. 
Both Mr. Ainslie and Mr. Phillips observed it breeding on marsh 
foxtail (Alopecurus geniculatus) in Oklahoma, but observations on 
all three of these grasses were made in March, April, and May. Mr. 
Ainslie found it breeding on blue grass (Poa pratensis) at Welling- 
ton, Kans., and Prof. C. P. Gillette mentions this insect as infesting 
this grass in Colorado. Strangely enough, and happily so for our 
investigations, a quite serious outbreak of the * green bug ” is at pres- 
ent (July 25, 1907) in progress on the grounds of this Department 
at Washington, and chiefly on blue grass, though the insect is also 
breeding on crab grass (Syutherisma sanguinalis). 
This outbreak on the grounds of the Department of Agriculture 
is notable in some respects, in that the continued close cutting of the 
blue grass has supplied a continual fresh, tender growth as food for 
the “ green bug,” thus preventing the development of winged females 
to escape; 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 
“ oreen bug” was the diminutive black and yellow lady-beetle (/7y- 
peraspis undulata), 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, 
inade 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 4, $, and 1 pound to each 100 
square feet, but after over a week had elapsed from the date of appli- 
cation no effect was to be observed and no dead insects were found. 
Kerosene emulsion was applied at 8 and 10 per cent strengths. 
There was practically no difference in the effect of these two strengths, 
[Cir. 93] 
