THE OUTBREAK OF 1907. 35 



badly infested; outside of these counties the infestation was slight. 

 He received very few if any reports of its occurrence north of the 

 Missouri River. It probably occurred in the northern part of the 

 State also, as the bureau received a report, with specimens, of injury 

 to oats at Weaver, Lee County, Iowa, and Mr. C. N. Ainslie found 

 it occurring in small numbers at several points in northwestern Iowa. 



From reports received by this bureau it seems that Toxoptera, was 

 very abundant in northern Illinois, confining its injuries chiefly to 

 oats. Mr. Edgar McGee, of Sciota, McDonough County, 111., sent us 

 specimens July 5 which proved to be Toxoptera, and in a letter dated 

 July 29 he stated that it was very widespread, that his and adjoining 

 counties were badly infested, and that some fields of oats were so seri- 

 ously injured that the owners had plowed them under and planted 

 other crops. The yield in that locality, from Mr. McGee's report, 

 seems to have been greatly reduced. 



At Sandwich, Dekalb County, 111., there was apparently consider- 

 able damage to oats; no specimens were received; the injury in all 

 probability was, however, due to Toxoptera. To quote from a letter 

 from Mr. Clark Graves, bearing date of July 12: 



I have today mailed to you, under separate cover, a fair sample of the oats of this 

 vicinity, and I think from general appearances that the crop will be shortened half 

 on account of the green bug. The bugs have now disappeared, and it would seem that 

 the late oats have suffered considerably more than the early ones. 



There were no specimens of plant-lice in this material from Mr. 

 Graves. 



A report, with specimens, was received from Manteno, Kankakee 

 County, 111., which stated that that section had suffered considerably 

 from "green-bug" attack. 



We have only one record of serious injury from Indiana in 1907 

 that can without doubt be attributed to Toxoptera. This was in a 

 small field of oats just outside the limits of Indianapolis. The junior 

 author examined this field and found that over an acre had been seri- 

 ously affected, part of it being entirely destroyed. The " green bug" 

 disappeared from the oats before the latter headed out, probably 

 overcome by Aphidius and other enemies. This infestation appar- 

 ently originated from rank bluegrass growing along one side of the 

 field. Later in the season, when the oats had been harvested, Tox- 

 optera could be found along this margin on the bluegrass, where the 

 sexes appeared and eggs were produced. Toxoptera was found at 

 other points in Indiana, but only in small numbers. 



Mr. T. H. Parks, of this bureau, states that in the latter part of 

 June, 1907, the oats on his father's farm in Pickaway County, Ohio, 

 were badly damaged by aphides. He states that parts of some fields 

 in the neighborhood were scarcely worth cutting. Aphides were very 

 abundant on the plants and parasitized aphides were very plentiful 

 also. The oats plants that were badly infested turned brown, and 



