6 CIRCULAR 5 7 5, TJ. S. DEPT. OF AGRICULTURE 



These results, while far from conclusive because of the experi- 

 mental method, show that standard bran was the most promising 

 carrier. This has been borne out by tests in subsequent years. 

 Mill-run bran, flour, and shorts, combined with sawdust, although 

 not so effective as standard bran, proved to be better than dried 

 beet pulp or cracked wheat. 



EXPERIMENTS TO DETERMINE THE BEST 

 ATTRACTANTS 



The first series of experiments in 1936 was designed to test the 

 value of common attractants previously used in grasshopper baits, 

 and others thought to be particularly attractive to crickets. The 

 same poison and carrier were used in all tests, namely, 2 quarts of 

 sodium arsenite (4-pound material. 32 percent As 2 3 ) mixed with 100 

 pounds of bran and 12 gallons of water. Each test was replicated 

 seven times. The mortalities obtained by the closed-pen method 

 and listed below are indices of the value of the popular attractants 

 used in grasshopper baits. 



Average 

 kill 

 Attractant {percent) 



Beet molasses, 2 gallons ; aniyl acetate, 3 ounces 94. 4 



Ainyl acetate, 3 ounces 89. 8 



Cane molasses, 2 gallons; amyl acetate, 3 ounces 89. 1 



Beet molasses, 2 gallons; salt, 5 pounds 88. 5 



Cane molasses, 2 gallons 88. 4 



Beet molasses, 2 gallons 87. 



Standard bran 86. 7 



Cane molasses, 2 gallons : salt, 5 pounds 86. 3 



Salt, 5 pounds 85. 8 



Cane molasses, 2 gallons; amyl acetate, 3 ounces; salt, 5 pounds 85. 6 



Beet molasses, 2 gallons; amyl acetate, 3 ounces; salt, 5 pounds 84. 7 



Standard error of any average, 3.58 percent. 



Minimum significant difference, 10.12 percent. 



There was no significant difference between any of the percentages 

 obtained. The bait containing bran, poison, and water was as effec- 

 tive as the baits containing attractants. It may be noted that the 

 average kills were much higher than those obtained in the experiments 

 of 1935. This was probably due to the more active feeding of the 

 crickets which accompanies higher temperatures and lack of moisture. 

 The tests of 1935 had been conducted at a much higher altitude, 

 with greater soil moisture and lower temperature. 



The materials thought to be especially attractive to crickets were 

 then tested. With the exception of the attractant, the same bait 

 formula, the same number of tests, and the same method were used 

 as in the previous test. The mortalities listed below serve as an 

 index of the value of the attractants. 



Average 

 kill 

 Attractant (percent) 



Tankase, 20 pounds 86. 2 



Xone (standard bran, sodium arsenite, and water only) 86. 



Ground onions, 20 pounds 85. 7 



Tankage, 10 pounds 85. 3 



Nicotine sulfate (40-percent) , 3 ounces 83. 7 



Dried orange pulp, 10 pounds 81. 5 



Standard error of any average, 2.85 percent. 

 Minimum significant difference, 8.14 percent. 



