13 
periment, however, it was desirable to know just what the conditions 
were under which it was begun. As stated above, one of these oat 
fields was used for the experiment of introducing parasites, while the 
other was kept as a check. The fields were so widely separated that 
the introductions could not have spread from one field to the other. 
Six areas of a square yard each, selected for the examinations in dif- 
ferent parts of each field, were gone over by Mr. Phillips and two of 
Professor Popenoe’s assistants. Examinations of both of these fields, 
made on May 17 and 18, showed that the field in which the parasites 
sent from Wellington by Mr. Ainshe were to be liberated contained 
approximately fifty millions of the unparasitized “ green bugs ” and 
approximately one and three-quarter millions that were undoubtedly 
parasitized ; in other words, approximately 3.5 per cent of the * green 
bugs ” were at that time parasitized. In the check field the parasites 
were even more abundant, about 7.8 per cent being there found, by 
similar counts, to be parasitized. 
On May 18 parasites from 12 packages, each containing about half 
a bushel of wheat plants, were liberated in one of these fields. Now, 
a count similar to that made before the parasites were introduced 
was made on May 23, and this showed that the percentage of para- 
sitism in the field in which the experiment was carried out had in- 
creased only to 5.4 per cent, while in the field in which no parasites 
had been liberated it was 19.3 per cent. On May 27 a similar count 
was made, when the percentage of parasitism in the field where the 
introduction was made was 27.1 per cent, while in the check field it 
was 32.5 per cent. Clearly, under weather conditions favorable for 
their development, an introduction of these parasites to the extent of 
millions, carried out under field conditions, did not indicate enough 
efficiency to afford any encouragement for the use of this measure in 
the protection of the grain fields of the farmer in case of future 
attack. 
With all the artificial introductions of this parasite that were made 
in the grain fields of Kansas and adjacent States and Territories, 
there is no probability that a single bushel of grain was saved thereby 
or that the United States harvested one bushel more of grain than 
it would have harvested had no introductions of parasites been made 
or attempted. In substantiation of this statement it is interesting 
to note the history of the “green bug” during 1907 throughout 
North and South Carolina, upward of a thousand miles from where 
any introduction of parasites had been attempted, excepting two 
that the writer himself conducted. A considerable amount of ma- 
terial was sent from Winston Salem, N. C., on April 20, to a point 
a few miles west of Richmond, Va., where it was introduced into a 
small meadow of orchard grass, with no grain field within 5 miles. 
[Cir. 93] 
