290 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
from three to four square miles, which is very level, and poorly drained. 
Every year since 1911 this area has been inspected and always has re¬ 
vealed the fly. Also, two miles east of Haysville there is a field consist¬ 
ing of about 25 acres made up of low, sandy soil which retains the moist¬ 
ure much longer than the adjoining fields. This field was first visited 
by Messrs. Kelly and McColloch in 1913, and a careful examination 
showed that about 50 percent of all the plants were heavily infested. 
A small swale at the north end of the field had a still heavier infestation. 
Other fields in the vicinity were not infested. The infested field which 
was planted about Sept. 23rd, following wet weather, had been in wheat 
continuously since 1906 and was badly infested the previous year. 
Fig. 3. Map of Kansas showing areas that have been infested continuously 
with Hessian fly for a period of from 10 to 12 years. + large areas, o small 
areas. 
In order further to test this point, members of the Department of 
Entomology, in November, 1921, made a 60-mile circular trip east of 
Manhattan and examined every field of wheat for Hessian fly. The 
survey did not reveal a single fly, except in one field about 25 miles east 
of Manhattan. This field was so heavily infested that in some in¬ 
stances as many as 400 flaxseed were found in a single clump of wheat. 
The field consisting of low land, bordering on a small stream, had been 
