Jn one instance the writer," (Mr. W. Harper Dean) "reared 

 a single adult from the common fcxtail grass (Setaria glauca) 

 and Mr. George G. Ainslie has also reared the midge from the 

 "grass Sieglingia sesleroides" ( Ent. Bull. 85, p. 44). 



"In the spring the midge appears with the first Johnson grass 

 and sorghum, and as this grass heads .considerably before the 

 cultivated sorghum, it may be said that by the time the latter 

 has headed, the midge has become sufficiently abundant on 

 the grass to make the first sorghum infestation a neavy one. 

 In the latitude of San Antonio. *Tex., the first midges to be 

 found during the season of 1909, were found actively oviposit- 

 ing in Johnson grass on May 14. At this date the neighboring 

 sorghum had not headed, and it was not until June 19 that 

 the first brood emerged from the sorghum, which puts the date 

 of this first infestation at approximately June 5" (p. 53). 

 "From what has been said previously in regard to the midge 

 in relation to Johnson grass, it is a self-evident fact that this 

 grass furnishes the key to the situation (p. 55). "The de- 

 struction of Johnson grass : s one of the most vital factors in 

 midge control" (p. 58). 



Destroying Johnson grass will not control the midge, be- 

 cause the midge could no doubt breed in a great number of 

 other grasses if it were deprived of its usual food plant early 

 in the season. Take a similar case: The bollweevil from its 

 introduction into the United States in 1892 to 1913, was not 

 known to feed and breed on anything but cotton, but evidently 

 as the result of trying to starve it out bv the early destruction 

 of all of the plants in the fall it was found feeding in 1913 by 



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