49 
Howard of progress in experimental work was published in the Year- 
book of the Department for 1901 (pp. 459-170). Unfortunatel}^ the 
spread of these diseases is so contingent upon certain weather condi- 
tions that while uninfected grasshoppers may be inoculated under the 
most favorable circumstances, we can not always obtain or predict 
atmospheric conditions which will operate with the disease in destroy- 
ing the grasshoppers. The conclusion is therefore reached that, owing 
to the inability of man to control the conditions necessary to the 
spreading of the disease, it is far better to employ the bran-arsenic 
mash, hopperdozers, fall plowing, and other remedies which have been 
specified where possible in preference to the fungus; in other words, 
we can not depend absolutely on the fungus, although in some cases it 
is eminentl}^ beneficial, more especially in climates which are unusually 
moist and in w^hich the conditions desired are ordinarily present. The 
principal diseases in question are caused by Mucor ramosus^ Mnpusa 
grylU^ and an undetermined species of the genus Sporotrichum. 
Poisoned horse droj^pings. — During recent years Mr. Norman Griddle 
has used a mixture with great success against locusts in Manitoba. It 
consists of 1 part of Paris green mixed thoroughly in 60 parts of 
fresh horse droppings, 2 pounds of salt to half a barrel of mixture 
being added after being dissolved in water. This is placed in a half 
barrel and drawn on a cart to the edge of the infested field or one likely, 
to be invaded. The mixture is then scattered broadcast along the 
edge of the crop, or wherever needed, by means of a trowel or wooden 
paddle. The locusts are attracted to it and are killed in large num- 
bers by eating the poison.^' Although this mixture is "sure death," 
it sometimes requires from two to five days for it to kill the locusts. 
Hye as a trap) crop. — Manitoba farmers also deal successfull}^ with 
locusts by sowing a strip of rye around the edge of a field of wheat. 
The former grain grows more rapidly and it requires a long time for 
the insects to eat sufiiciently of it to destroy it. The rj^e is poisoned 
with a spra}^ of Paris green. Beet fields might be protected in the 
same manner. 
Burning over and p'lowing. — In some cases it has been possible to 
ascertain the particular breeding places of grasshoppers, some species 
depositing their eggs in pasture lands and among foothills at the bases 
of mountains in the far West in regions in which the tar weed grows. 
Here the ^^^ cases can be destroyed by burning over the ground late 
in the fall after all of the eggs are deposited, or by plowing them in 
to a depth of 6 or 8 inches before the}^ hatch in the spring. 
In case, for any reason, it is not feasible to employ any of these last- 
mentioned remedies, and the place of ^g^ deposit is ascertained, a 
watch should be kept for the young grasshoppers and they should be 
« Fletcher, Kept. Ent. and Bot. Experimental Farms, Canada, for 1902^ 1903, p. 187. 
10697— No. 43—03 4 
