THE SORGHUM MIDGE. 



45 



In one instance the writer reared a single adult from the common 

 foxtail grass (Setaria glauca) a and Mr. George G. Ainslie has also 

 reared the midge from the grass Sieglingia seslerioides. b 



In the investigation of this problem many varieties of sweet sor- 

 ghum were observed in their relation to infestation, among which 

 are Early Amber, Gooseneck, Sapling, and Sumac, with some mem- 

 bers of the durra group; and while there is some difference in the 

 degree of infestation of these varieties it has not been observed to 

 be sufficiently great to merit the recommendation of any of them as 



Fig. 24.— The sorghum midge ( Contarinia sorghicola): a, Adult male; b, antenna 

 joints of same; c, head, frontal view, a, Greatly enlarged; b, c, highly mag- 

 nified. (Original.) 



resistant varieties-— all being infested to such an extent that they 

 would have failed to produce a profitable crop of seed. 



DESCRIPTIONS. 

 THE ADULT. 



The following is the original description of the species by Mr. 

 Coquillett: 



Antennse of the male as long as, of the female almost one-half as long as, the body, 

 in both sexes composed of 14 joints; joints 3 to 14 in the female each slightly con- 

 stricted in the middle, each except the last one greatly constricted at the apex into 



"Baton Rouge, La., September 14, 1908. 



&Clemson, S. C, August 15, August 31, November 3, and September 8, 1908. 



