December, '15] BALL: ESTIMATING NUMBER OF GRASSHOPPERS 



527 



considered to be an insignificant swarm as compared to those of 1902, 

 when a total of ten times as many were caught in the county, or 

 two hundred and seventy-four tons. Estimating that five tons were 

 caught from the swarm enumerated above (there was some mixture of 

 swarms) and that they ran about the average catch of eight milhon 

 to the ton, then this catch of forty milhon out of the swarm of three 

 thousand, three hundred and thirty million would show that about 

 one hopper in every eighty-seven was caught by balloons. If the same 

 proportion were caught in 1902, and there were less if anything, San 

 Pete Valley had swarms aggregating somewhere near two hundred 

 billion grasshoppers that year. 



These swarms were caught for bounty by using balloons," catch- 

 ing beginning as soon as a swarm was found large enough to pay, which 

 meant the capture of from four hundred to eight hundred pounds per 

 day per outfit. In this way many swarms were caught while the 

 insects were quite small; others were not found until later when they 

 would be larger. Many swarms contained hoppers of all sizes, and 

 finally, late in the season, some catching was done on the breeding 

 ground where only adults were present, so that the average ''catch" 

 was probably about half grown. The following table gives the number 

 by weight at different ages: 



Approximate Weight of Grasshoppers 





Per Ounce 



Per Pound 



Per Bushel 

 (60 pounds) 



Per Ton 





95,000 



1,500,000 



92,000,000 



3,000,000,000 



One week old 



5,000 



80,000 



5,000,000 



160,000,000 



J to i grown— large enough to catch easily . . 



1,000 



16,000 



1,000,000 



32,000,000 



Average catch — from small to adult 



250 



4,000 



250,000 



8,000,000 





55 



900 



50,000 



1,800,000 



Adult males 



115 



1,850 



110,000 



3,700,000 



SOME DEVELOPMENTS IN GRASSHOPPER CONTROL 



By F, M. Webster, In charge of Cereal and Forage Insect Investigations, Bureau of 



Entomology 



During recent years, first the Criddle mixture and soon afterward 

 the poison bran bait, came rapidly to the front as the most practical 

 and efficient measures that could be applied in protecting the crops of 

 the farmer from attacks of grasshoppers which for many years have, 

 with greater or less frequency, over-run his fields and destroyed his 

 crops. 



