CONTROL OF MORMON CRICKET WITH POISONED BAIT 6 



in that method, and it was believed that if a successful bait for the 

 Mormon cricket could be developed it would become equally popular, 

 and that the one bait might control both insects. The use of bait 

 would materially reduce the cost of Mormon cricket control and lower 

 the danger of injury to man and animals. The necessity of special 

 equipment would be eliminated, as the same machines used for mixing 

 and distributing grasshopper bait could be used during outbreaks of 

 the Mormon cricket. 



BAIT-TESTING METHODS 



Prior to 1935 experimental baiting of Mormon crickets consisted of 

 broadcasting the baits over selected areas and estimating the per- 

 centage of kill. This method has several disadvantages, most impor- 



FlGURE l. 



-Series of closed pens used in early bait tests against the Mormon 

 cricket. 



tant of which are the following: (1) Estimates are subject to all types 

 of error in addition to those due merely to chance and require a great 

 many replications to arrive at a true average. (2) The crickets that 

 were on the area at the time the bait was broadcast are likely to have 

 migrated some distance by the time the estimates of results are made. 

 Therefore, it was necessary at the start to develop a method of sam- 

 pling whereby the mortality from various baits could be accurately as- 

 certained. Three methods were used: (1) Baiting in closed pens, 

 (2) baiting in front of wing pens into which the crickets moved after 

 feeding, (3) pan baiting, and (4) baiting of large fields. 



In the first method the crickets were trapped and then placed in 

 pens built of 10-inch galvanized iron strips set on edge to form a 

 circle 9 feet in diameter (fig. 1). The bait was broadcast in the pens. 

 Each day the dead crickets were taken out and counted and on the 

 fourth day a record was made of those still alive. The percentage 



