THE OUTBREAK OF 1907. 29 



Joaquin. Over this latter area the temperature for the same month 

 was 12° F. above the normal, and within this latter area the pest 

 first began its work of destruction. 



For reasons to be explained later in their proper place, the spread of 

 the pest was much more rapid to the north and northeast from north- 

 central Texas than it was in the opposite direction. In March the 

 pest was found generally present about San Antonio, Kerrville, 

 Menardville, and New Braunfels, of that State, but because of the 

 small acreage of grain grown in that section the damage was not 

 serious. Indeed, the same may be said of the country west of a line 

 drawn from western Wilbarger County to the Brazos River at Round 

 Timber, Baylor County, and west of the Brazos to and except about 

 Waco. East and north of this the damage ranged from serious to 

 total ruin. 



As early as March 6 it was also reported to the bureau as destroying 

 wheat in the vicinity of Summers, northwestern Arkansas. This 

 was probably due to local causes, uninfluenced by invasions of 

 swarms of winged viviparous females that were being continually 

 swept from off the more disastrously affected country to the southwest 

 and drifting toward the northeast. Mr. C. N. Ainslie was instructed 

 to proceed from Washington, D. C, to this part of the country, where 

 he arrived on March 16. On March 15 the Texas Grain Dealers' 

 Association, through its secretary, Mr. H. B. Dorsey, made an appeal 

 to the chief of this bureau for aid in devising means for destroying 

 the pest and curtailing or preventing its ravages. In response to 

 this appeal the junior author was dispatched to Fort Worth, Tex., 

 arriving there on March 26. The situation here was found to be most 

 serious. Hundreds of acres of both wheat and oats had been wiped 

 out of existence; in many cases fields were observed where it was 

 impossible to find a living plant, and as a rule numbers of such fields 

 were being plowed and prepared for other crops. Plate I, figure 1, 

 shows a field entirely destroyed. The weather at this time was hot 

 and dry and Toxoptera appeared to have been entirely overcome by 

 its natural enemies. 



On March 25, 1907, a telegram was received from the Roosevelt 

 Grain Elevator Co., of Hobart, Okla., reporting serious attacks from 

 Toxoptera and appealing to the Secretary of Agriculture for assist- 

 ance. The junior author was at once instructed to proceed to Hobart, 

 where he arrived April 1, remaining until April 5. This point ap- 

 peared to be on the western border of serious injuries by the pest, and 

 the situation was therefore not so grave as in Texas. From the 

 junior author's observations it appeared that much of the damage 

 that was being done was caused by insects which had drifted into the 

 fields and not from individuals originating therein. This was evi- 

 denced by the fact that in wheat fields where a part had been sown 



