238 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



During 1911, this species occurred everywhere in the midwest; 

 however, the rains were general, and the species did not become 

 abundant. The volunteer oats which were rather plentiful in 

 August and earh^ September died out later on account of the dry- 

 weather and cultivation, and by November it was very difficult to 

 find Toxoptera at all. 



The insect was not observed during 1912 in the vicinity of Wellington, 

 nor practically any other place in the west. In May, 1913, a few were 

 foimd on young wheat and quite a number on Hordeum juhatum. 

 Wheat and oats were too far advanced, and with warm weather there 

 was no danger from them. None could be found during the late sum- 

 mer and fall of this year. 



1913 went on record as one of the hottest and driest years for the 

 middle west, there being several weeks without rain. The rains came 

 in plenty by mid-September, but none of this species were found on the 

 wheat. Mr. W. E. Pennington made an excursion through northern 

 Texas and southern Oklahoma, during the fall, and found a few indi- 

 viduals here and there on oats. 



Early in April, 1914, reports of the insect came in from southern 

 Oklahoma, investigation indicated that a few could be found on oats and 

 wheat, and by mid-May thej^ were generally distributed over Oklahoma 

 and southern Kansas ; however, the oats were large and wheat heading, 

 so no damage was done. In December they were generally distributed 

 over northern Texas, Oklahoma, and Kansas. The rains had been 

 sufficient during August, September, and October, for growing of crops, 

 but July was a record breaker for heat and drought. 



In the spring of 1915 the aphids were plentiful throughout the west. 

 This being an unusual year, with an abundance of moisture, especially 

 in June, July, August, and September, the wheat and oat plants suck- 

 ered freely, and were followed by an abundance of volunteer small 

 grain, very early in the summer. The oats and wheat being fresh and 

 juicy, naturally gave the insects food for rapid multiplication. In the 

 fall it was not difficult to find good-sized colonies in everj^ wheat field, 

 and especially in fields following oats; by early December there were a 

 number of wheat fields devastated in northern Oklahoma and southern 

 Kansas. The frosts in October and November killed out the volunteer 

 oats, thus precipitating the Toxoptera onto the small wheat, which 

 they severely injured. The area of infestation seemed to be limited to 

 about two counties. Grant county, Oklahoma, and Sumner county, 

 Kansas. However, they were found almost everywhere in scattering 

 numbers, throughout northern Texas, Oklahoma, Kansas, and even in 

 northeastern New Mexico, where they were doing considerable damage 

 to early fall-sown grain. Aphids were collected from points over the 



