24 
Journal of Agricultural Research 
Vol. IX, No. i 
winter and lay eggs in the spring, since those which emerged were killed 
by a sudden cold snap. While the climate at Arlee is warmer than that 
at Bozeman, the winter there is considerably colder than a September 
cold snap at Bozeman and more liable to be injurious to insect life. 
PARASITES OF THE MINER 
Two hymenopterous parasites were reared from the puparia of C. 
femoralis. The puparia which are parasitized are of a darker color, with 
the segmentations more distinct than in normal puparia. These para¬ 
sites were determined by Mr. A. B. Gahan, of the Bureau of Entomology, 
through the courtesy of Dr. L. O. Howard, to be a new species of Dacnusa 
(Braconidae) and Cyriogaster occidentals (Chalcididae). There were not 
enough of either of these species to be effective agents in control. 
CONTROL 
No control measures have as yet been tried, but a knowledge of the 
seasonal history of the fly leads to suggestions. At the time wheat is cut 
for harvest, the larvae of the second brood are in about the last instar at 
the crown of the plant, or have already pupated. Scattering the straw 
over the field and burning the stubble as well as grass borders surround¬ 
ing the fields would doubtless get rid of a high percentage of the flies. 
Should this insect ever become a very important factor in grain growing, 
it is possible'that it would be desirable to use a header or cut the grain 
very high, either of which would leave the straw on the field where it 
could be burned. However, if burning the stubble is not practicable, 
plowing it under about 6 inches and harrowing just after removing the 
crop or before planting a spring crop would probably bury the pupse 
deep enough to prevent the flies from emerging. 
The late seeding of winter wheat, after a thorough destruction of vol¬ 
unteer grain and grass, would doubtless accomplish much in control. 
The wheat could be sown about the third week in September, and would 
not be up until after the greater number of flies had finished ovipositing. 
This would not only prevent the injury to the wheat itself, but would do 
away with the main source of infestation in the spring. 
As native grasses are probably the natural hosts of the fly, crop rota¬ 
tion would be almost useless. However, the cleaning up of field borders 
and destruction of volunteer stools during the fallowing period would aid 
greatly in the control of this insect. 
LITERATURE CITED 
(1) Macquart, Justin. 
1835. Histoire Naturelle des Insectes Dipt&res. v. 2. Paris. 
(2) Meigen, J. W. 
1838. Systematische Beschreibung der bekannten europaischen zweifliige- 
ligen Insekten. T. 7. Hamm. 
(3) Rondani, Camillo. 
1861. Dipterologise Italicae Prodromus. v. 4. Parmae. 
