THE OUTBREAK OF 1907. 33 



From here the junior author made a trip into northwestern and north- 

 eastern Kansas and south-central Nebraska to determine the north- 

 ern limit of destructive infestation. The following places were 

 visited: Solomon, Dickinson County, Kans.; Beloit, Mitchell County, 

 Kans. ; Lenora, Norton County, Kans. ; and Kearney, Buffalo County, 

 Nebr. The infestation at all of these places was very slight and no 

 damage was done. At two places only, Solomon and Beloit, , were 

 parasites found. 



The senior author in the meantime proceeded to Great Bend, 

 Barton County; Dodge City, Ford County; Garden City, Finney 

 County; and Syracuse, Hamilton County — all in Kansas. The 

 object of this trip was to see how far Toxoptera had spread to the 

 westward. It was found at all of the above points, doing consid- 

 erable injury; at Syracuse an unirrigated field of oats of 10 acres was 

 found bordering an irrigation ditch. Along this ditch was a ragged 

 border from 10 to 30 or 40 feet in width of vigorously growing oats 

 where the ' 'green bug" had apparently done no injury, while beyond 

 this border, where the moisture from the ditch had not penetrated, 

 the loss was total. In another case in the same locality, a part of the 

 wheat in an unirrigated field came up in the fall and the rest not 

 until the following spring; the former was uninjured by "green 

 bugs," while the latter was killed. From Syracuse the senior author 

 proceeded to Wellington, Kans., to join Mr. Ainslie. 



In a letter dated June 5, 1907, Prof. C. P. Gillette states that he 

 made a trip into the Arkansas valley early in the spring and found 

 Toxoptera doing very serious injury to wheat fields; to such an 

 extent was this the case that he advised some of the farmers to plow 

 up some of their fields and plant other crops. Following this trip 

 there was a heavy snowstorm and the "green bugs" were greatly 

 diminished in numbers, though at the date of his writing (June 5) 

 Toxoptera was abundant in the fields. 



On July 9 Prof. Gillette sent us badly parasitized Toxoptera on 

 blue grass from Fort Collins, Colo., with the statement that the "green 

 bug" had largely disappeared from the grain fields in that locality. 



Mr. Ainslie remained in the vicinity of Wellington, Kans., from the 

 last week of April to the 21st of May, at which date he was joined by 

 the senior author and went south to Kingfisher, Okla. The condi- 

 tions found there were serious in the extreme, most of the grain 

 fields being bare and many had been plowed and displaced by other 

 crops. Between Wellington, Kans., and Kingfisher, Okla., a strip of 

 country was encountered by them about 30 miles in width, beginning 

 above Medford, Okla., with Pond Creek about midway between, 

 and extending almost to Kremlin, Okla., over which the injury from 

 Toxoptera was not nearly so great as in the country both to the 

 26675°— Bull. 110—12 3 



