24 THE SPRIXG GRAIN-APHIS OR GREEX RUG. 



extreme difficulty in separating its young and its wingless adults 

 from those of other species, it would seem that more or less damage 

 to the oats crop might be with justice accredited to Toxoptera in 

 Butler, Miami, and Clermont counties in extreme southern Ohio. 



THE OUTBREAK OF 1901. 



(Fig. 5, p. 20; Diagram III, p. 25.) 



The outbreak of 1901 was less extensive than that of 1890. Little 

 damage was reported south of Waco, Tex., but from this point 

 northward wheat was more or less injured, and oats were destroyed 

 to the northward into what was at that time Oklahoma and Indian 

 Territories. The farthest point to northeast at which damage was 

 reported, with specimens of the depredator, was Saratoga, in extreme 

 southwestern Missouri. The specimens accompanying correspond- 

 ence from Texas and Oklahoma gave ample proof of the identity 

 of the destroyer, which in Texas alone ruined grain to the extent 

 of several million dollars. In central Texas the ravages of the pest 

 began to attract attention early in March, while the report from 

 Missouri came under date of April 30. It will be noticed that the 

 direction taken by this invasion followed very closely that of 1890 

 (see fig. 5), beginning, however, farther south in Texas, not extending 

 so far to the northeast, and dying out, as it were, earlier in the 

 season. These phenomena will be explained farther on under 

 meteorological influences. 



THE OUTBREAK OF 1903. 



(Fig. 5, p. 20; Diagram IV, p. 26.) 



As foreshadowing the impending outbreak of 1903, as early as 

 Xovember 26, 1902, Mr. J. F. Ordman, writing from Windthorst, 

 Tex., complained to this bureau of the ravages of the green louse, 

 stating that it had destroyed several small areas in his wheat field 

 and that it was reported generally prevalent in his neighborhood. 

 This outbreak was, however, an incipient one and resulted in little 

 injury, the seriously infested areas being confined to northern Texas, 

 exclusive of the ''Panhandle," with possibly the country in the 

 then Oklahoma and Indian Territories bordering the Red River, 

 and in South Carolina. While the outbreak was thus limited in 

 area, the natural enemies of the pest in the West evidently fell far 

 short of completely subjugating it. In March, 1904, Prof. E. D. 

 Sanderson and Mr. E. C. Sanborn found it in Grayson County, Tex., 

 sufficiently abundant to work serious injury in the fields of young 

 wheat and oats, in some cases the destruction of the growing grain 



