230 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



however, to the farmers, the requisite amount of Paris Gre^n was put 

 in the center of each sack, and the farmer instructed to mix according 

 to directions when he reached home. 



President H. T. Fernald: The next paper will be read by Mr. 

 Wilmon Newell. 



NOTES ON THE INSECT ENEMIES OF SUDAN GRASS 



By Wilmon Xewell, College Station, Texas 



As Sudan grass ^ has, through the pubhcity given it by the Bureau 

 of Plant Industry, U. S. D. A., and the Texas Experiment Station, 

 become a forage crop of much importance in Texas and the Southwest, 

 mention of some of the insects attacking it may be considered timely. 



The insect enemies of this crop thus far observed are not new to 

 entomologists, but are comprised of insects which are already quite 

 well known on account of their ravages on other crops. 



The Sorghum Midge 



First in importance is the sorghum midge, Contarinia (Diplosis) 

 sorghicola Coq., on account of its destruction of the seed before maturity. 

 This Cecidomyid is well known on account of its attacks on sorghum, 

 milo maize and related crops, there being many localities in the South 

 where the midge entirely prevents the maturing of seed. It attacks 

 Sudan grass with equal facility and, while not injuring the crop so far 

 as forage is concerned, it makes the production of seed well-nigh impos- 

 sible in heavily infested sections. Inasmuch as the seed has thus far 

 sold at prices varying from SI. 00 to $1.50 per pound, the monetary 

 loss is very considerable. 



The sorghum midge is essentially an insect of humid sections and 

 in localities of heavy annual rainfall, as in southern Louisiana and 

 Mississippi and in the southeastern portion of Texas, it seems improb- 

 able that Sudan grass seed will ever be produced successfully. 



In Texas the extent of damage appears to vary considerabty with 

 the seasons. The only portion of the state entirely exempt from the 

 midge is the western part where the annual rainfall is usually less than 

 25 inches. 



During the past two years Sudan grass has been grown, not only at 

 the main Experiment Station at College Station, but also at each of 

 the eleven sub-stations and this has given us a good general knowledge 



^ Andropogon sorghum, var. Recently described by Prof. C. V. Piper, of the 

 Bureau of Plant Industry, as variety sudanensis. 



