ENTOMOLOGY 



During the past season the writer has considered that grass- 

 hopper control was the most important single problem which could 

 be taken up as a matter of demonstration and direct aid in the con- 

 servation of important crops. The matter of grasshopper control 

 has been disposed of for the most part as an experimental project 

 by numerous investigations which have been conducted in various 

 parts of the country during the i)ast few years. However, there Is 

 a diversity in the details of the recommendations which have been 

 published which show^ that we still lack important information In 

 certain respects concerning the subject. In connection with demon- 

 stration work against grasshoppers in the Salt River Valley during 

 the past season problems were presented which lead to a series of 

 observations and tests which are of considerable local importance. 

 The differential* grasshopper {Melanoplits diftercntialis), the most 

 destructive species in Arizona, is the one which was the subject of 

 the investigation. 



The formula for poisoned bait which is now most generally 

 recommended by entomologists consists in a mixture of 25 pounds 

 of bran, 2 quarts of molasses, 1 pound of Paris green, 3 to 6 finely 

 chopped lemons or oranges and water to make a crumbly mash. 

 The more important experiments conducted by the writer concern 

 the matter of modifications of this formula with the view to reduc- 

 ing its cost and possibly increasing its effectiveness. Miscellaneous 

 observations were made in connection with these experiments. 



In many sections of southern Arizona cull canteloupes can be 

 obtained by farmers without expense and the experiments referred 

 to above have shown that canteloupe can be substituted for the 

 lemons in the usual grasshopper bait formula. One pound of finely 

 ground. canteloupe may be substituted for six lemons. The experi- 

 ments have further shown that with the differential grasshopper in 

 the adult stage the molasses may be omitted without interfering 

 with the results, also that in the place of 25 i)ounds of bran a half 

 and half mixture of bran and sawdust may be substituted. These 

 changes in the grasshopper bait formula represent a substantial 

 decrease in the cost of grasshojiper bait. A long series of experi- 

 ments was first conducted on a small scale and the baits made with 

 the substitutions noted were afterward tried out on tracts of land 



