282 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



checks along with the poisoned one in each experiment, thus giving 

 the difference in the amount of food eaten by poisoned and unpoisoned 

 hoppers for the same period of time. 



In this work poison mash mixed with Paris green, white arsenic and 

 crude arsenic were used and data obtained on the effect of these differ- 

 ent arsenicals on the feeding capacity of grasshoppers. Also data 

 were obtained on the length of time required for these various poisons 

 to kill, together with the effect of different amoimts of poison mash 

 constmied on the time of death and food eaten after poisoning. 



The following table shows the difference in the amount of com leaf 

 eaten during the same length of time by unpoisoned hoppers and those 

 poisoned by mash containing Paris green. 



The poison mash used in the experiments, the results of which were 

 shown in Table I, was mixed according to the following formula: yi 

 lb. Paris green; 25 lbs. wheat bran, and 2 qts. black strap molasses, 

 no fruit being used. In the four experiments, individual records were 

 kept on 29 poisoned hoppers and 23 check (unpoisoned) hoppers, both 

 groups being allowed to feed for the same length of time. The aver- 

 age period between poisoning and death for the lot was 35.5 hours. 

 During this time the poisoned hoppers ate an average of 0.071 square 

 inches of com leaf each, while the impoisoned hoppers ate an average 

 of 0.944 square inches, showing that the unpoisoned consumed slight- 

 ly over 13 times as much food as the poisoned ones. 



The following table shows the difference in the amoimt of com leaf 

 eaten by unpoisoned hoppers and those poisoned by mash containing 

 white arsenic, during the same period of time. 



Table II 



Expt. No. hoppers No.check Aver.time .\v3r.time . Aver.amt. Aver.amt. 



No. poisoned hoppers between check hop- eaten by eaten by 



poisoning pers were poisoned poisoned 



and death allowed to hoppers hoppers 



feed 



1998 9 9 55 hrs. 55 hrs. 0.295 sq. in. 0.816 sq. in. 



191.56 10 10 33.9 " 33.9 " 0.022 " " 1.26 " " 



Averages 43.9 " 0.151 " ~' 1.049 " ^ 



