REMEDIAL AND PREVENTIVE MEASURES. 139 
scarcely to be found, although the dead bugs were to be observed 
almost as abundantly as were the living on the space untreated. 
It must be remembered, however, that these experiments were 
carried out in grass kept closely cropped by frequent use of the 
lawn mower, and such areas can be sprayed much more effectively 
than a wheat field, where the ground would have to be literally 
soaked in order to reach all of the aphidids. 
In the light of these experiments field spraying seems an impracti- 
cal measure, even when small areas are involved. Burning or plow- 
ing would probably be more effective and the recommendations 
would probably be more readily complied with, as the average farmer 
does not usually have spray pumps of any description. 
Lime and sulphur was dusted on the plants in badly infested areas 
with practically no benefits. 
CULTURAL METHODS. 
Examination of a large number of fields infested by Toxoptera, 
extending over a wide range of country, resulted in securing a con- 
siderable mass of information that may be included under the head of 
cultural methods. 
The senior author visited Sumter, S. C, April 17, 1907, driving 
over much of the country in that vicinity. All fields of fall-sown 
oats, the only grain grown, Were infested, there being no perceivable 
difference in severity of attack between fields following cotton, 
those following oats, and those on new ground, thus showing that 
the pest had swept over the country, diffusing itself generally. 
At Winston-Salem, N. C, April 19-20, where both wheat and fall 
oats were grown, the ravages of the pest were much more serious, 
and fall-sown oats were completely ruined. A part of one field 
that had been in oats the previous year had, that fall, thrown up a 
heavy growth of volunteer grain, while the remaining portion was 
free of this growth. Wheat was drilled directly across both these 
areas on November 15, 1906, the whole field having first been pre- 
pared by disking, leaving much of this volunteer grain undisturbed. 
April 20, 1907, when examined by the senior author, the wheat on the 
part that had been overgrown with volunteer oats the previous 
fall was totally ruined, while on the clean part the damage was about 
50 per cent. In wheat fields generally there was a marked difference 
in severity of attack as between those seeded before and those sown 
after about November 1, 1906, the later-sown suffering little while 
that sown earlier, on ground where there was much volunteer wheat 
or oats, was seriously damaged. This indicated that the trouble 
had been aggravated by the volunteer growth at the time of wheat 
seeding the previous autumn. It was very significant that in late- 
sown fields on clean ground the injury was comparatively small. 
In Oklahoma it was observed by both the junior author and Mr. 
C. N. Ainslie that late-sown and pastured fields were destroyed much 
