June, '21] LARRIMER GRASSHOPPER AND CRICKET REPELLENTS 261 



on "Observation on the Attractiveness of Materials used in Grasshop- 

 per Baits." Small amounts of wheat bran were treated with the var- 

 ious repellents, these samples were exposed under natural conditions 

 in the field, and the crickets and grasshoppers observed within six inches 

 of the bran or feeding upon it, were recorded. In all cases the vari- 

 ous samples were run in duplicate and interchanged frequently so 

 that any variation of results might not be due to advantage of location. 

 A pair of field glasses was used to make the counts since, by this 

 method, accurate counts could be made with the observer stationed 

 twenty or thirty feet from the bran samples and thus not disturb the 

 crickets or hoppers which were being counted. 



In choosing the following materials as fairly representative of the 

 various groups of the common repellents, the availability and cost was 

 of course an important consideration. Soap, gasoline, sulphur, aloes, 

 creosote oil, furniture polish, nitrobenzine, nicotine sulphate, auto oil, 

 kerosene and copper sulphate were each mixed -with small samples of 

 wheat bran and these exposed in the center of card board discs twelve 

 inches in diameter and cross marked with black lines to facilitate 

 counts. These discs were placed in a tract of uncultivated land grown 

 up to weeds, imiformly but not heavily, infested by grasshoppers and 

 crickets. 



Melanoplus femur-rubrum was by far the predominating species of 

 the grasshoppers present but some M. atlanis, M . diferentialis , Dis- 

 sosteira Carolina, Encoptolophus sordidus, Scudderia furcata, Orchelimum 

 vulgare, and a species of Conocephalus were also taken.. The species 

 of crickets taken in the comits were Gryllus assimilis pennsyhanicus 

 and Nemohius fasciatus. Wet bran was used as a check and since 

 black strap molasses has been found to be one of the best attractive 

 agents, samples of bran treated with the standard strength of this ma- 

 terial were included as an additional basis of comparison. 



The bran samples were moistened with the various materials mixed 

 in the following strengths. The liquid repellents, black leaf 40 except- 

 ed, one part repellent to four parts water; powdered aloes or sulphur, 

 one tablespoonful to one pint water; copper sulphate, a saturated so- 

 lution in water; black leaf 40, one tablespoonful to one pint of water; 

 soap, either Ivory or fish oil, as strong a solution as possible in cold tap 

 water. It was not practical to run all of the materials at one time, 

 but four seres were run on the following inclusive dates Series 1, 

 August 23 to 25; Series 2, August 31 to September 1; Series 3. Septem- 

 ber 21 to 22; Series 4, October 5 to 8. 



In Series 1 , fresh samples were used for August 23 and 24 ^nd those 



