49 



Howard of progress in experimental work was published in the Year- 

 book of the Department for 1901 (pp. 459—1:70). Unfortunatel}^ the 

 spread of these diseases is so contingent upon certain weather condi- 

 tions that while uninfected gi'asshoppers 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 eminently beneficial, more especially in climates which are unusually 

 moist and in which the conditions desired are ordinarily present. The 

 principal diseases in question are caused 1;)y Mucor ramosus^ Empusa 

 grylll^ and an undetermined species of the genus Sporotrichum. 



Poisoned horse droijpings. — During recent years Mr. Norman Criddle 

 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 ;i 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 w^herever 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. 



Rye as a trap crop. — Manitoba farmers also deal successfully 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 sufficiently of it to destroy it. The r3'e is poisoned 

 with a spra}^ of Paris green. Beet fields might be protected in the 

 same manner. 



Biirning over and lylovnng .—\\\ 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 \Yest in regions in which the tar weed grows. 

 Here the ^^^ cases can be destro3'ed 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 they 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 ^^^ deposit is ascertained, a 

 watch should be kept for the 3^oung grasshoppers and they should be 



a Fletcher, Kept. Ent. and Bot. Experimental Farms, Canada, for 1902^ 1903, p. 187. 

 14612— No. 43—03 4 



