20 
In summing up these field experiments, then, it is found that these 
spots may be treated successfully either by plowing under and har- 
rowing and rolling the surface of the ground, by spreading straw 
over them and burning, or by treating with a 10 per cent solution of 
kerosene emulsion. Except in the southernmost regions infested by 
this pest, however, the greatest difficulty does not arise from these 
isolated colonies, which seem to extend outward day after day, but 
from the fact that, after their food supply has become either largely 
destroyed or the grain too old and tough for them to feed upon, 
immense swarms of winged adults are produced, and these drift, 
in general, northward with the advance of the season and infest the 
grain fields of entire sections of the country much earlier and more 
completely than would be possible from the scanty stock natively 
present. This habit is also seen in the behavior of the pest in its 
original home in Europe. It may therefore prove that the country 
north of the Red River may be more or less protected if the pest can 
be early overcome in northern Texas. 
AGRICULTURAL METHODS OF CONTROL. 
The fact that the “ green bug” in the South originates in spots in 
the grain fields has been alluded to, and also that from these fields 
come the vast swarms of winged females that develop and drift over 
the country, dispersing themselves in uninfested fields. Early sown 
fields or fields overgrown with volunteer grain seem especially to 
invite early attack in the more southern localities. Where these im- 
mense swarms settle down in a section of country, even the best fields 
of grain may succumb to their attacks. But usually, outside of an 
extremely limited area, there is a noticeable difference in intensity of 
attack as between different fields. In Oklahoma and northward, fields 
that have been late sown or that were pastured during the winter 
suffered worst and were the first to be destroyed. It has been fre- 
quently noticed that a field of grain may be totally destroyed, while 
an adjoining field, though seriously injured, will frequently produce 
a partial crop. An investigation of the history of these fields has 
invariably shown that the result in the latter case is due to fertile soil, 
proper cultivation, and seeding at the proper time. It seems to have 
been almost universally true, outside of the lmited area of total 
destruction, that the best farmed fields have suffered the least. This 
does not apply alone to wheat, as the writer observed a field of oats 
near Hutchinson, Kans., that gave promise of a fair yield, where 
almost the entire crop would otherwise have been destroyed. The 
owner of this field, who had been obliged to plow up other fields 
where the cultural methods had been the same, expressed his opinion 
[Cir. 93] 
