42 



CEREAL AND FORAGE INSECTS. 



tion of Professor Newell the investigation of the sorghum midge 

 by the Bureau of Entomology would have been much delayed. 



Acknowledgment is due Prof. C. S. Scofield, of the Bureau of 

 Plant Industry, who rendered valuable assistance to the investigation 

 in Texas by placing the experiment farm near San Antonio, Tex., 

 at the service of the writer for growing varieties of sorghum used 

 in the experiments. 



During 1908, in Louisiana, and 1909, in Texas, the investigation 

 was continued, and the results constitute the basis for this report. 



DISTRIBUTION. 



The distribution of the sorghum midge in the United States, as given 

 under this chapter, does not necessarily include all infested territory. 



Fig. 21. 



-Base map showing present distribution of the sorghum midge, 

 ties. (Original.) 



Dots indicate infested locali 



Through examinations made in person in the fields or through the 

 actual rearing of the midge from heads received from various sections, 

 these data have been collected and will of course be added to from 

 time to time. The sorghum midge is not known to exist west of the 

 one hundredth meridian, and its extreme southern point of distribu- 

 tion in the United States is Brownsville, Tex. The accompanying 

 map (fig. 21) shows the general distribution as known at this writing. 



INVESTIGATIONS CARRIED ON IN LOUISIANA AND TEXAS DURING 



1908 AND 1909. 



During the years 1908 and 1909 the writer pursued the investiga- 

 tion of the sorghum midge in Louisiana and Texas. These investi- 

 gations were in the main confined to the field, although certain labora- 



