10 
by this time many were already there. This introduction of para- 
sites was carried out in order to give a decisive test as to whether it 
was possible to aid in protecting fields in this manner along the ad- 
vance line of invasion. The weather was still cold, and if the artifi- 
cial introduction of parasites would, with the return of warmer 
weather, hasten the control of the “ green bug,” the introduction of 
such large numbers would clearly demonstrate this fact. And if 
such introduction on a large scale proved favorable, it would show 
reasonable ground for the more general introduction of parasites in 
lesser numbers. 
There was a minor introduction of Lysiphlebus started at McPher- 
son, Kans., April 18, though this parasite was already found in the 
fields in that vicinity at that time. 
The weather during the whole of April was generally cold with, as 
on May 4, an occasional storm that is known to have killed many of 
the parasites, and though there were brief periods of warm weather 
during which the parasites would increase rapidly, the Lysiphlebus 
did not finally overcome the “ green bug” in southern Kansas until 
about the middle of May. . 
As will be observed, this experiment was made under weather con- 
ditions almost uniformly unfavorable to the parasite and favorable 
to the development of the “green bug.” There is no reason for 
supposing that the weather would affect the introduced parasites 
differently from those already present when the introduction was 
made. 
Mr. Ainslie remained in the vicinity of Wellington, and more 
briefly at McPherson and Sterling, for the purpose of watching 
these experiments, and he was, moreover, in direct communication 
with Mr. Phillips in northern Oklahoma; and the two were therefore 
able to keep under their observation a wide range of country, thus 
eliminating the possibility of oversight or misconception on the part 
of either that might otherwise have occurred. 
It was during this period of generally cold weather in late April 
and early May, interspersed by shorter periods of weather favor- 
able to the parasites, that the latter increased generally throughout 
Kansas and, judging from reports, also in Missouri and Colorado. 
It wanted only the more extended warm spell that came soon after 
to enable them to get the upper hand and subdue the pest, as they 
did throughout the southern Atlantic coast section earlier in the 
season. 
The field in which the two and a half million Lysiphlebus were 
introduced and liberated on April 9 did not, at the time of the over- 
coming of the pest in this and the adjacent country in May, indicate 
any benefit whatever above other fields, near or remote, where no | 
[Cir, 93] 
