84 
Under date of May 17, 1907, also at Wellington, Kans., Mr. Ainslie 
made an interesting record as follows: 
Yesterday, the 16th, the air was full of Toxoptera rising on wing, but the breeze 
was light and they had no chance to travel far. If the wind had favored their flight 
they must have carried parasites with them as guests, by the myriad, for many of 
them, probably the major part, were parasitized. [The temperature at Wichita 
ranged from 44° to 82° F.] 
On the same day the senior author, in company with Prof. E. A. 
Popenoe, in driving about the country hi the vicinity of Manhattan, 
Kans., during the afternoon found that they were in the midst of 
swarms of winged Toxoptera; frequently a number of individuals 
might be noted crawling about over their hats and coats and to an 
annoying degree traveling over their faces. Two days later, the 
senior author observed both winged Toxoptera and Aphidius crawl- 
ing about on the inside of the windows of a Pullman car in which he 
was traveling over the Santa Fe, crossing central Kansas. 
At Piano, Tex., June 4, 1909, Mr. Urbahns learned of a most 
interesting migration reported to him as having taken place two 
days before. A farmer, Mr. Foreman, reported to him that "green 
bugs" were observed flying east, probably coming from out of a 
very badly infested wheat field, moving with the evening breeze. 
In this case there was clearly a rapid disappearing of the food supply, 
precipitating a development to winged adults that were probably 
forsaking the fields for some other locality affording them a greater 
abundance of food. It would appear, then, that the influence of 
winds is more or less dependent upon several other phenomena. 
With the natural advance of spring from the South, there would 
be a continually decreasing supply of fresh* tender, succulent food 
in the South, while to the North this condition would be reversed. 
Therefore, with winged viviparous females developing with increas- 
ing abundance along the area of a certain latitude, such winged 
females as were carried south or backward over an area already ren- 
dered barren of food would consequently perish. On the other 
hand, those females that drifted or made their way northward would 
encounter a continually increasing fresh supply of food; therefore 
they might be said to follow along with the advance of the spring 
from the South far into the North, until overtaken b} r their natural 
enemies. Then, too, south winds are associated with a warm tem- 
perature and north winds with the reverse, as will be seen from 
Tables IV- VIII, furnished by the United States Weather Bureau. 
Another factor that must not be lost sight of is that after about the 
latitude of southern Kansas and Missouri is reached wheat ceases 
to be the food plant for Toxoptera in spring, and spring oats takes 
its place in this respect. 
