142 THE SPRING GRAIN-APHIS OR " GREEN BUG." 



Over the northern part of the country where the insect passes the 

 winter largely or wholly in the egg state, another measure can be 

 applied to great advantage. The junior author has found that blue 

 grass (Poa) is not only a summer food plant, but that it is very largely 

 upon this grass that the eggs are deposited in the fall, and from 

 which the offspring of the stem mothers make their way to the grain 

 fields in spring. He has observed cases where the portion of a grain 

 field bordered by bluegrass was the most seriously affected part of 

 the entire field. If, then, roadsides, fence corners, and other waste 

 lands were closely grazed in fall, winter, or early spring, these eggs 

 would be largely destroyed and the food supply of the stem mother 

 and her progeny cut off. This can always best be done during mild 

 winters on account of a lack of snow. Where close pasturing is not 

 practicable, burning over during the same season will have a similar 

 if not an even more drastic effect. 



ARTIFICIAL INTRODUCTION OF PARASITES. 



As ApTiidius testaceipes destroyed such hordes of Toxoptera in 

 apparently very short periods of time, after they had once become 

 established, we thought it possible materially to aid in this destruc- 

 tion by introducing the parasites artifically into localities where they 

 were apparently absent. As Mr. C. N. Ainslie was unable to find 

 any evidence of parasitization in the fields about Wellington, Kans., 

 on April 1, 1907, it was decided to begin operations there. Accord- 

 ingly, on April 9, over a bushel of wheat leaves that were almost 

 covered with parasitized Toxoptera were collected at Kingfisher, 

 Okla. Mr. Ainslie took charge of this material, and on April 10, made 

 a careful survey of the fields about Wellington, Kans., to determine 

 the situation relative to Toxoptera infestation, and on the morning 

 of April 1 1 he scattered a portion of this material in one of the most 

 badly infested fields that could be found in that vicinity, the remain- 

 der being left sheltered by the box lids. At this time he could find 

 parasitized Toxoptera already in the fields, both the dead leathery 

 bodies and those showing the characteristic yellow color. The 

 parasites included in this introduction were roughly estimated at 

 2,500,000; this number, however, was probably not a "drop in the 

 bucket " to those already in the field. If there were only one or two para- 

 sitized Toxoptera to a leaf, when a whole field is considered 2,500,000 

 would seem to be a very small number. So far as published records 

 show this was the first artificial introduction of parasites into Kansas. 



April 12 another lot of parasitized material, sent Mr. Ainslie by 

 the junior author from Kingfisher, which was fully as large as the 

 previous consignment, was introduced into another field 2 miles 

 from the first. All of this material, originally intended for one field, 

 was reported as one experiment by the junior author and appeared 

 as one experiment in Circular 93, since Mr. AinshVs notes were not 

 on file in the office at the time. We find, however, that Mr. Ainslie, 



