ENTOMOLOGY 



In continuation of the experiments with grasshopper baits be- 

 gun in 1917, forty combinations were tested in 1918, beginning in 

 the month of May. Definite records were made concerning appli- 

 cations of these combinations to 269 acres of alfalfa and cotton 

 lands. In this work assistance was rendered in various ways by 

 Messrs. O. C. Bartlett, D. C. George, J. L. E. Lauderdale, George 

 Acuff, M. E. Kimscy, and R. H. Armstrong. The work was directed 

 against the same species as in 1917, the differential grasshopper, 

 Melanoplns diffcrcntialis. The tests were all made in the Salt River 

 Valley with the excc])ti()n of one application made by the writer 

 in a len-acre alfalfa field in the Verde \'alley near Camp Verde. 



The movement or drifting of the grasshoppers in the fields 

 both toward and away from poisoned areas tends to confuse the 

 results of experiments with poisoned baits and makes it necessary 

 to repeat the tests many times under various conditions before 

 drawing final conclusions. Tentative conclusions from the work 

 done in 1917 are as follows: 



1. A combination of half and half wheat bran and pine saw- 

 dust is fully equal to wheat bran alone for the bulk of the substance 

 of the bait and is easier to distribute than when all wheat bran is 

 used. 



2. All sawdust is decidedly inferior to all bran or to a half and 

 half bran- sawdust mixture. 



3. For the fruit, oranges are in no degree inferior to lemons 

 and are perhaps slightly better. 



4. Canteloupes are in no degree inferior to lemons but on the 

 contrary are apparently slightly superior as well as cheaper. 



5. Molasses is not only an unnecessary ingredient of poisoned 

 baits but wdien used w^ith citrus fruits the effectiveness of the bait is 

 reduced rather than increased. 



From the experiments conducted in the summer of 1918 the 

 following tentative conclusions are drawn concerning poisoned baits 

 for the differential grasshopper : 



1. Half and half and 60-40 percent wheat bran and sawdust 

 mixtures are fully as good as all bran. 



2. Barley middlings is not entirely satisfactory as a substitute 

 for wheat bran although it usually gives fairly good results when 

 used in half and half mixtures with sawdust. 



3. Dry horse manure is not a satisfactory substitute for wheat 

 bran altho it is not without merit for use in emergencies. 



