32 THE SPBING GKAIN-APHIS OR ' l GREEN BUG. ' ' 



day, taking with him more than a bushel of these wheat plants with 

 the parasitized Toxoptera thereon and on the 11th this material was 

 put out in a field near Wellington where the Toxoptera was the most 

 plentiful, in order to determine if it was possible to increase the 

 limited numbers of parasites at the time observable in the field, so 

 as to expedite the work of the latter in overcoming the pest. This 

 was the first artificial introduction of Aphidius into Kansas, six 

 days after which Prof. S. J. Hunter began distributing parasites. 

 The following day a second lot of material sent from Kingfisher by 

 the junior author, some of it carrying as many as 100 parasitized 

 Toxoptera to a single blade of wheat, was distributed in a wheat 

 field, also near Wellington, by Mr. Ainslie, some of it being placed 

 in bunches to protect it from the weather and the remainder scattered 

 over the ground among the growing wheat. The Aphidius already 

 observed in the fields on the 11th appeared to be on the increase, as 

 many as 11 parasitized individuals being observed on a single growing 

 leaf, though but few of the adult parasites were observed abroad in 

 the fields. On April IS parasites were sent to McPherson and on 

 May 18 to Manhattan, Aphidius being present in the fields at the time 

 of introduction. These introductions will be taken up in detail 

 farther on in this bulletin. 



On April 12 a letter was received from Mr. J. A. Akers, at Hooker, 

 Beaver County, Okla., stating that the "green bug" was destroying 

 his wheat. The junior author, being notified of the outbreak, pro- 

 ceeded there, arriving on April 24, and found that Mr. Akers's field 

 was the only one in that locality that had been injured, and, in fact, 

 it was outside the zone of destructive infestation in this State. This 

 field comprised 52 acres, over a portion of which oats had been sown 

 the previous year, while cowpeas had been grown upon another and 

 much smaller part. Volunteer oats were plentiful over the first 

 mentioned area. One of the infested spots was located among the 

 wheat and volunteer oats, while the second spot was in the area pre- 

 viously devoted to cowpeas. There were no other injured spots in 

 the whole field, although an occasional Toxoptera could be found 

 here and there over the field, which was also true of other fields in 

 this vicinity. It is a significant fact that young plants of Agropyron 

 occidentale Scrib. were found growing in both of these spots and they 

 were as badly infested as the wheat plants. A few parasitized 

 Toxoptera were found, but the parasites were apparently developing 

 slowly on account of cold weather. 



The junior author went to Indiana the latter part of the first week 

 in May, but was recalled to Kansas and reached Manhattan on thel 8th, 

 where he was met by the senior author, and a final experiment for the 

 artificial introduction of parasites was here planned and begun at 

 this time, the results of which are given farther on in the proper place. 



