MINUTE WORMS WORKING IN THE SEED 219 
The Sorghum Midge (Contarinia sorghicola Coq.) 
Heads of sorghum are attacked by the larva of a minute two- 
winged insect or ‘‘ midge,” preventing the formation of seed. If 
infested heads are examined, the seeds will be found shriveled, while 
beside them may be seen a tiny grub. Profitable crops of seed can- 
not be secured where the midge is abundant. 
The first generations of the midge are passed in other plants that 
mature heads earlier, notably Johnson grass. By the time the sor- 
ghum is sufficiently mature the midges are numerous. Eggs are laid 
within the developing seeds. 
Remedial measures include destruction of Johnson grass, and clean 
harvesting in the fall. 
The Clover Flower-midge (Dasyneura leguminicola Lint.) 
The presence of the clover 
flower-midge is recognized by 
the fact that the florets of clover 
bloom fail to develop normally, 
become shrunken, and the whole 
head lacks color. 
The adult insect is a minute, 
gnatlike creature with long legs 
and dusky wings. Eggs are laid 
in the clover head, and the larva 
feeds in the ovaries, preventing 
the normal expansion of the floret 
and the development of seed. 
A pupal stage is passed in the 
ground, followed by a second 
brood at the time of the second 
blooming of clover. Winter is 
assed in the soil. fe ae 
oe is Fic. 272.— Clover head showing irregu- 
In fields containing mostly la BIOOHIe -eatiged Be the<Clover 
clover and little timothy it is Flower-midge. Original. 
