Experience with an Outbreak of GrassJioppers. 267 



ther additions to their ranks would be effected just as fast as 

 the young forms attained maturity in the weeds along the 

 bayou, where they abounded in multitudes. The destructive 

 effects of their voracious feeding were seen on nearly all of the 

 wild vegetation, and many of these unfleged insects had ac- 

 tually encroached on the cotton plants standing close to the 

 weedy border. 



Of the two different measures that were being tried out 

 here with the object of thwarting the insects, one consisted in 

 the scattering of poisoned bran along the outer edge of the 

 weeds, next to the field, according to the directions that had 

 first been advised by letter; and the other treatment proved to 

 be nothing more than an application of plaster of Paris to the 

 cotton plants. The idea of using the latter substance had been 

 proposed by the owner and carried out by his instructions. 

 Since no dead grasshoppers could be found around the heaps of 

 poisoned bran, and neither had any of the insects been known 

 to feed on or pay any attention to the mixture, the trial of this 

 preparation was therefore considered to be an absolute failure. 

 But the plants that had been dusted with plaster of Paris, this 

 having been first applied about a week before, presented a 

 nearly perfect condition, though a very slight coating of the 

 piaster* remained on them. Few grasshoppers were seen on 

 plants mCre recently treated with the plaster, but none of 

 them could be detected in the act of feeding. 



Results seemed to show that the latter treatment had some 

 merit by preventing attacks after the application had been 

 made. The plaster merely appeared to deter the insects from 

 eating the coated leaves, as no evidence of any dead or dying 

 hoppers came to notice anywhere. Its application on just a 

 few rows of the plants covering but a short distance into the 

 field was not sufficient to afford a conclusive test, yet the ad- 

 vantage which it gave, while the poisoned bran had proved 

 useless, had to be acknowledged. Being an admirable stick- 

 ing medium, its use might have been made more practical with 

 less quantity per plant, and with the addition of Paris green at 

 the rate of one part to fifteen times the amount of plaster, or in 

 the same proportion as when the poison is used with lime. 

 Either of these mixtures can be applied with safety to field 

 plants. Mention might be made of another benefit rendered 

 by the use of plaster, which is its fertilizing value to the soil 

 after it becomes deposited on the ground. 



