June, '21) FORD & LARRIMERr EFFICIENCY OF GRASSHOPPER BAITS 299 



This series of experiments shows the variation in kill received from 

 the different poisons for the several dates on which the poison was 

 applied. In order to come to a definite conclusion it is necesFary to 

 combine all tests on each poison tmder one head. This is shown in 

 the following table. 



Table X 



Totals 1715 887 



When Paris green, white arsenic, or crude arsenic are used at their 

 optimum strengths and applied at the optimum rates, it would seem 

 that one is practically as good as the other. In these eight series of 

 experiments there was only 3.5% variation in the percentage of kill. 

 Although rather poor kills were obtained in the experiments shown 

 in Table IX, due to lateness of the season, the comparative results are 

 fairly accurate since all poisons were applied under similar conditions. 



Summary 



1. Black strap molasses gave much better results than any of the 

 other syrups used. 



2. The optimum strengths for the three standard poisons was found 

 to be, Paris green y^ lb., white arsenic ^ lb., and crude arsenic 

 \]/2 lb. per each 25 lbs. of bran. 



3. The optimum rate of applying poison bait was found to be lyi 

 lbs. of the wet mash per acre, however, a general recommendation 

 of from 5 to 10 lbs per acre might well be made. 



4. There was very little difference in the three arsenicals when run 

 under similar conditions at their optimum strengths and rates. 



