20 
PREVENTIVE AND REMEDIAL MEASURES. 
It is practically impossible to save a field once severely attacked by 
this fly, and under such circumstances it is better to plow the wheat 
under deeply and plant to corn or other spring crop. 
In cases of mild infestation the best procedure is the prompt use of 
fertilizers, which may enable the wheat to tiller sufficiently to yield 
a partial crop. Pasturing in fall of early-sown fields is also recom- 
mended, and may do some good by reducing the numbers of the pests. 
Somewhat in line with pasturing of early-sown fields is an interest- 
ing experiment made in the spring of 1900 by Mr. E. P. McCaslin. 
Finding that the flies were ovipositing abundantly on wheat which had 
reached a height of 6 or § inches, he conceived the idea of cutting 
it off closely with a mowing machine as soon as all the eggs of a 
spring brood had been deposited, keeping close watch to determine 
the proper moment. The theory was that the severed tops of the 
wheat with attached eggs would dry up in a day or two, and the larve, 
not being able to move freely except down the green leaf blades, would 
fail to reach the live stubble. Wheat so cut threw out new stalks 
and gave every promise of a good yield, but, unfortunately for the 
success of the experiment, the fly was so extraordinarily abundant 
everywhere in the spring of 1900 that the stubble was reinfested and 
the experiment came to naught. Nevertheless, under a less extraordi- 
nary instance of general fly infestation, some benefit might reasonably 
be expected from the procedure, and it is perhaps worthy of further 
trial. 
By some such means as the above a crop of wheat may be partly 
saved, but in the main the measures of really practical value against 
this insect are, of necessity, chiefly in the direction of preventing 
future injury. These are all in the line of farm methods of control, 
and are arranged in the order of importance as follows: 
Late planting of winter wheat.—As already indicated in the para- 
graphs on habits and life history, late planting of winter wheat is 
undoubtedly the best and most practical means in normal seasons of 
preventing damage in regions where infestation is to be anticipated, 
and this is true in spite of the failure of this means of control during 
the season of 1899-1900. The most that can be advised under this 
head, however, is to give a general statement covering normal years 
and climatic conditions. The actual date after which planting may be 
safely made must necessarily be fixed for each locality separately, and 
be subject to yearly modification to meet varying seasonal conditions. 
In a general way, to avoid fly injury, planting should be made in the 
northern winter-wheat districts after the 15th or 20th of September, 
and in the more southern districts between October 1 and 15. If 
the right time be selected, neither early enough to be attacked by the 
132 
