31 
f volunteer wheat and, second, destroy this at a time to catch 
le progeny of the earlier breeding flies before they have had 
me to mature. Just what the details of this procedure should 
e, is a question for the farmer rather than for the entomologist; 
ut I suppose that the conditions may best be met by plowing 
le stubble rather early, to give the volunteer wheat a chance to 
:art, and then so timing the planting that this wheat may be 
died by the final preparation of the soil (say with a rotary har- 
)w) just before the grain is sown for the regular crop. In other 
ords, what is wanted to give effect to this idea is a definite in- 
irval between plowing and sowing, and a final treatment of the 
fil such as will kill the volunteer wheat. It is not necessary 
lat either plowing or sowing should be done at any uniform 
me, but only that the proper interval be preserved between them, 
'or more precise indications we must wait until another year has 
iven us an opportunity to verify this season’s results and to re- 
mcile, if possible, some discrepancies between our own observa- 
ons and those of our correspondents; but the interesting fact re- 
iains that the early breeding of the fly in volunteer wheat is a 
eak point in its life history, of which we may reasonably hope 
) take advantage for the overthrow of this great enemy of wheat 
llture in Illinois.* 
If it should prove to be true that a much larger percentage of 
le fly than I have estimated continues in the stubble in midsummer, 
1 e shall then simply have to revive, as an adjunct to the protective 
easure above outlined, a preventive method already often recom- 
euded; viz., that of using every opportunity to burn the stubble 
iter harvest and to destroy the screenings from the thresher, in 
hich such of the puparia will appear as were carried away with 
le straw. By a general practice of these precautions, it is now 
3ry likely that the Hessian fly could be in very great measure 
mtrolled. 
I add two calendars summarizing in tabular form the entire 
Lass of our data respecting the life history of the Hessian fly in 
le southern part of the State.*]* The first of these tables exhibits 
le dates and localities of all our collections and observations of 
tie fly in its various stages, while the second presents an abstract 
f the results obtained by breeding only. The numbers in paren- 
ieses on the second table in,the columns devoted to imagos and 
ggs, refer back simply to the figures at the left of the table, and 
idicate the original lots from which imagos and eggs w T ere bred. 
•Fortunately the measure here recommended against the Hessian fly will be equally effective 
;ainst a companion insect, sometimes scarcely less injurious, viz., the wheat bulb worm, Mero- 
yza americana, since the second brood of this specips occurs in volunteer wheat at substantially 
e same period as the fly. 
i Complete to Dec. 30,1886. The divisions between the broods are indicated by the heavy 
ansverse lines in each column. 
