REMEDIAL AND PREVENTIVE MEASURES. 61 
per cent of the injury from chinch bugs may be prevented, and, in fact, 
with a reasonable degree of watchfulness and prompt action, all injury 
from migrating hordes may be prevented. The use of tarred boards 
set on edge or slightly reclining might, under some circumstances, take 
the place of the ridge or furrow, but these cases will be exceptional, 
and the use of kerosene emulsion will probably be found equally prac- 
tical here, as also will the post holes for collecting the chinch bugs. I 
merely cite this method in order to call attention to its possible use 
where the others are found impractical. The plowing of furrows has 
been in vogue since the first writings of Le Baron and the second report 
of Dr. Fitch, and may be utilized in other ways than those previously 
mentioned. A heavy log dragged back and forth in this furrow will 
pulverize the soil in dry weather, and Forbes has recorded the fact that 
where this has a temperature of 110° to 116° F. it is fatal to the young 
bugs that fall into the furrow, even if they are not killed by the log. 
As 120° is not uncommon in an exposed furrow on a hot summer day, 
it will be observed that there may be cases where this method will be 
found very serviceable, and especially is this likely to prove true in a 
sandy soil with a southern exposure. In sections of the country where 
irrigation is practiced these furrows may be flooded and in this way 
rendered still more effective without the expenditure of either time or 
money to keep them in constant repair. Dr. Riley long ago laid con- 
siderable stress on this measure, believing it of much value, especially 
in the arid regions of the far West. The same writer advised the flood- 
ing of infested fields, wherever it could be done, for a day or so occa- 
sionally during the month of May. It is hardly likely, however, that 
this will often be found feasible, though such occasions might arise. 
NECESSITY FOR PREVENTING CHINCH BUGS FROM BECOMING ESTABLISHED IN FIELDS 
OF WHEAT AND GRASS. 
In the foregoing it will be observed that prevention of migration has 
been the chief end in view either by destroying the chinch bugs in their 
hibernating quarters, and thus preventing the spring migration to the 
breeding places, or by various traps and obstructions to prevent them 
from migrating from such places to others not already infested. The 
great problem remaining to be solved is to prevent their breeding in 
wheat fields at all. As I have shown, it is absolutely impossible, with 
our present inability to forecast the weather months in advance, to be 
able to foretell whether or not an outbreak of chinch bug is likely to take 
place. There may be an abundance of bugs in the fall — enough to cause 
an outbreak over a wide section of country — and these may winter over 
in sufficient numbers to cause some injury in spring, yet a few timely, 
drenching rains will outbalance all of these factors, and our wisest 
prognostications fail of proving true. It is this very factor of uncer- 
tainty that renders the carrying out, over any large area of country. 
any protective measures where, as in this case, the benefit to be derived 
