9 



only place where its use will prove more or less impracticable will be 

 on hilly or rocky lands or on that not j-et cleared of stumps. 



Poisoned haits. — Here again we have an inexpensive, practical way 

 of dealing with these grasshoj)pers even when, as is frequently the 

 case, they breed in the alfalfa fields and the protection, whatever 

 it may be, must be applied there. What has come to be known as 

 the " Criddle mixture " is giving most satisfactory results on the 

 ranches of both the United States and Canada. The mixture is 

 composed of half a barrel of fresh horse droppings in which is 

 mixed 1 pound each of salt and Paris green. If the horse droppings 

 are not fresh the salt is dissolved in water and mixed with the manure 

 and poison. When this mixture is scattered freely about where the 

 grasshoppers are abundant they seem to be attracted to it, for they 

 devour it readilj^ and are poisoned thereby. Dr. James Fletcher, 

 entomologist for the Dominion of Canada, cites an instance where 



Fig. 8. — " Hopperdozer." A simple coal-oil pan, to be drawn by horse. (After Riley.) 



this mixture had been scattered freely around the edges of a field 

 and states that this particular field stood out as a green patch in a 

 brown plain, as it was situated in the midst of fields where nothing 

 had been done to destroy th6 grasshoppers. This Criddle mixture 

 now seems preferable to the poisoned-bran remedy that has given 

 and still continues to give beneficial results, for it is less expensive 

 than the latter and less likely to poison other animal life. 



COOPERATION. 



Cooperation between farmers or ranchmen is of the utmost im- 

 portance, whether the hopperdozer or poisoned baits be used. On 

 some of the more extensive ranches the owners can protect themselves 

 by reason of the great extent of territory that is under the control of 

 a single individual, but among smaller holdings cooperation is very 

 essential. 



[Cir. 84] 



