n6 ENTOMOLOGICAL NEWS. [March, '09 



Notes on Contarinia sorghicola. 



By GLENN W. HERRICK. 



(PI. VII.) 



Upon assuming the duties of Entomologist at College Sta- 

 tion, Texas, October ist, 1908, my attention was called to the 

 serious and widespread injury to the seed of Kaffir corn and 

 sorghum. In many localities in Texas a large part of the 

 crop of Kaffir corn seed was destroyed and since this plant, in 

 the drier parts of the state, takes the place of corn quite largely 

 the failure to produce seed becomes a serious problem to the 

 farmers in these regions. The cause of the "blasting" of the 

 seed has been ascribed to various agencies, fungi, insects, un- 

 favorable meteorological conditions, etc. Thinking that the 

 trouble might be due to the work of an insect, I carried many 

 of the heads of sorghum and kaffir corn to the laboratory and 

 was gratified to find many small flies and an abundance of tiny 

 hymenopterous insects issuing. In looking up the literature on 

 sorghum insects I found that Mr. D. W. Coquillett had de- 

 scribed a fly, bred from sorghum heads sent him by Mr. R. H. 

 Price from this College in 1898, as Diplosis sorghicola. On 

 submitting our specimens to Dr. Howard he informed me that 

 Mr. Coquillett determined them as Cecidom\na sorghicola.* 



The blasting is undoubtedly due to the work of this small 

 Cecidomyiid, Contarinia sorghicola. On October 29th we bred 

 many adults, male, and female, from sorghum and kaffir corn 

 heads, together with an abundance of parasites, kindly identi- 

 fied for us by Dr. J. C. Crawford, as Aprostocetus diplosidis 

 Craw. On November 29th I gathered five heads of Kaffir corn 

 from the field and the adults of both species are still emerging. 

 November 19. On the night of November I3th, we had quite a 

 freeze at the College, the thermometer registering 27 deg. Of 

 course, the heads were in the house and were not subjected to 

 so low a temperature as 27 deg. 



On November 2Oth, I brought several Kaffir corn heads into 

 the laboratory to see if the freeze had been hard enough to 

 kill the larvae and pupae. In an examination of the blasted 



*Bull. 18 new series U. S. Bureau of Entomology, page Si. 



