Insect Pests of Interest to Cotton Growers 



195 



yard they may consume the equivalent of a ton of hay a day in a 

 forty acre alfalfa field. The number mentioned represents only a 

 moderate infestation. 



The other two species of grasshoppers destructive to cotton in 

 Arizona are closely related (Schistocerca shoshone and S. vega.J 

 They are nearly twice as large as 

 the differential grasshopper. One is 

 brown in color and the other is green. 

 So far they have been excessively 

 numerous in only one instance, where 

 they completely defoliated a small 

 field of cotton. 



Grasshoppers may be destroyed in 

 cotton fields with comparatively slight 

 expense. The method consists in 

 spreading broadcast a poisoned bait. 

 The standard grasshopper bait con- 

 sists of bran, molasses, Paris green, 

 finely chopped lemons or oranges and 

 water. Experiments by the writer 

 during 1917 and 1918 have shown 

 that a half and half mixture of bran 

 and sawdust is as effective as the 

 bran alone. Ground canteloupe (culls) 

 have been found as effective as lemons 

 or oranges. The evidence so far favors 

 the conclusion that the addition of 

 molasses to the bait does not increase 

 its attractiveness to the grasshoppers. The proportions of the ma- 

 terials in a bait successfully used in Arizona are as follows: 



Bran, 12^-15 pounds. 



Sawdust, 12^/2 pounds. 



Paris green, 1 pound. 



Canteloupe, 1 pound. (Use 5 lemons or oranges if canteloupes 

 are not available.) 



Water, enough to make a crumbly mixture. 



The Paris green should be mixed with the dry sawdust and bran. 

 This may be done by placing the bran, sawdust and Paris green in 

 a barrel, tub or special mixing vat, and using a hoe. A wet sponge 

 or a gauze mask should be used to protect the operator against 

 breathing the Paris green dust. The finely ground canteloupe^ 

 lemons or oranges should be mixed with about a gallon of water 



Fig. 22 — The large cotton grass- 

 hopper, Shistocerca shoshone (nat- 

 ural size). 



