88 THE CHINCH BUG. 
was a rapid decline in the growing of this grain in northern Illinois. 
It seems possible thai spring wheal might be more liable to attack 
from chinch bugs than fall wheat, as the former is, at the time when 
chinch bugs seek out their breeding grounds, more tender and inviting 
than the latter. Mr. Walter Young, writing from Galesville, Wis., 
states that his spring wheat was totally destroyed in l s '>7. though 
there had been none sown for ten year- previous on the premises, and 
while the ehineh bugs did not ordinarily do much injury, just a- soon 
a- spring wheat was -own they returned, as it were, and destroyed it. 
If spring wheat is so attractive to chinch bugs in spring as this 
would indicate, might it not be used for baits instead of millet, a- is 
advised further on. in order to draw oft' the females in spring when 
seeking localities for oviposition I 
This was in a country where there was comparatively little timber, 
the only forests, if such they could be called, being along the streams 
of waiter.. The writer is confident that the chinch bug did not sud- 
denly make its appearance in that section, but that with the increase 
of grain growing and the decrease of prairie fires its effects began to 
be more and more marked. Since then Prof. S. A. Forbes has secured 
information of the occurrence of these insects in sufficient numbers 
to attract attention as early as 1823 in southern Illinois, and within 
25 miles of New Harmony. Ind., where Thomas Say resided and did 
the most of his entomological work. 
REASONS FOR THE PRESENT THEORY OF DIFFUSION. 
It seems to the writer that in all of this we have good grounds 
for supposing that the chinch bug occupied the most of the country 
prior to its occupancy by the Avhite man. and that its first depreda- 
tions were caused by its own advance coming in contact with the 
advance of civilization; and the simultaneous cessation of fore>t and 
prairie fires, with the displacement of the native gras>es by large 
areas of wheat, so combined that the points of contact were in Illi- 
nois in the West and Virginia and Xorth Carolina in the East. Xot 
until within the last twenty-four years has the chinch bug been 
known to work serious and widespread injury east of the Allegheny 
Mountains, north of Virginia : and west of these mountains they have 
done scarcely any damage north and east of a line drawn from 
Chicago southeast to Cincinnati. Thousands of farmers in Ohio 
never -aw a chinch bug until within the last thirteen year.-, and there 
are thousands more in northwestern Ohio, southern Michigan, and 
northern Indiana that, even yet. would not be able to recognize one 
were they to see it among their growing grain, or even if in abund- 
ance. I > 1 1 1 in considering this matter the fact must be borne in 
mind that timothy meadows are not burned over annually as were the 
