294 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 14 



The mixtures containing black strap molasses were noticeably better 

 than the rest, both of these giving better than 90% kiU, there being 

 little difference between the two quart and one quart strengths. All 

 of the other syrups except Orleans molasses at the one quart strength 

 were even poorer than the mixtvire without any syrup. The check 

 (unpoisoned) showed a mortality of 6.1% during the six days of con*- 

 finement. 



Optimum Strength of Arsenicals 



Having determined (to the writers' satisfaction) the best time to 

 apply poison bran mash in the field and the proper sjrrup to obtain the 

 maximum results, experimental work was started on the various ar- 

 senicals used in bran mash. In all of the following experiments black 

 strap molasses was used without fruit flavors, these having been found 

 tmnecessary by another series of experiments. 



First it was decided to determine, if possible, the most efficient strength 

 of arsenicals in poison bran mash, basing this both on percentage of 

 kill and cost to the farmer. A series of experiments was arranged where- 

 by the common arsenicals namely, Paris green, white arsenic (AS2O3) 

 and crude arsenic (crude arsenious oxide) were used at varying strengths, 

 as shown in the following tables. The mash was applied and the re- 

 sulting percentages of kill obtained by the method previously explained. 

 Each series of experiments was performed in duplicate, the following 

 tables giving the combined results. These tables show the poison 

 used, its strength, the total nimiber of hoppers swept, hoppers which 

 died, hoppers remaining alive, and the resulting percentages of kill. 



Table II (Bait applied Aug. 21). 

 Strength of Paris Total No. hoppers No. hoppers dying Hoppers remain- Percentage of kill, 



green swept ing alive 



Totals 



'472 



