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6 
NATURAL CHECKS. 
Mr. Criddle found that many of the broken stems of infested 
wheat had bent in such a way as to crush and kill the larva which was 
working at the point where the stem collapsed. Since the stems of 
grasses do not break under the attack, this is a danger which the in- 
sect has incurred by changing to a new food plant. This form of 
accident materially reduces the number of individuals which may 
reach maturity and deposit eggs in the wheat, since from 6 to 75 per 
cent of the infested stems break near the point where the larva is 
working, shortly before the larva retreats toward the roots to pre- 
pare for hibernation. 
Parasites were reared by the junior author from larve collected at 
Minot, N. Dak., belonging to an undescribed species of the Chaleidid 
tribe Entedonini. 
PREVENTIVE MEASURES. 
Mr. Criddle tried burning the stubble in the autumn with the aid 
of straw scattered over it, but found that the larve were not much 
damaged thereby. A remedy which suggests itself and has been 
practiced to some extent is the plowing down of all stubble, either in 
autumn or before June 15,at which time the adults may be expected 
to emerge and deposit eggs. Grass growing near the edges of fields 
should be mowed early in July, while the larvee are small, to prevent 
them from maturing and attacking the crop of the following year. 
Approved : 
James WaALsoN, 
Secretary of Agriculture. 
Wasuineton, D. C., December 24, 1909. 
P@irst17] 
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