Plant-Diseases and Insects. 



99 



part the work of the entomologist has played in reducing 

 injury or preventing loss, so that we may overcome this diffi- 

 culty and provide legislators and ourselves with data with 

 which to meet this argument. After a careful examination 

 and great effort to obtain data, I have found that there are 

 certain of these large estimates which appear to be reliable. 

 I think better results will follow the publication of a few quite 

 reliable statistics, which may be taken as typical instances, 

 than by accumulating a large number of items which would 

 increase the chance of error and might not be read so care- 

 fully. By way of example 1 will refer to the chinch-bug. I 

 have examined carefully the estimates which have been pub- 

 lished concerning that particular insect, and the following are 

 probably quite reliable and appear to have been made with 

 due regard to all collateral considerations — as the increased 

 value of the saved crop, the cost of remedial measures, and 

 similar subjects. 



" In 1864 Dr. Shimer's estimate, which I find was drawn 

 up with very great care, put the loss in the one state of Illinois 

 to the corn and grain crops at $73,000,000. In Dr. Riley's 

 reports on the injurious insects of Missouri, we find in 1874 

 there was a reliable estimate of the loss to that state by the 

 same insect of $19,000,000. In 1887 Professor Osborne's 

 estimate, founded upon the reports of the correspondence of 

 the State Agricultural Society of Iowa, put the loss in that 

 state on corn and grain at $25,000,000; and lastly, Mr. 

 Howard's estimate, as given in the entomologist's report for 

 1887, for the nine states infested by the chinch-bug in that 

 year, was $60,000,000. Now, gentlemen, I think that these 

 statistics of the injuries to crops by one insect alone are 

 probably as reliable as any we can get, and they give a good 

 argument which we may use as showing the depredations of 

 insects. But it is not sufficient that we can convince people 

 that great injury is going on ; we must show that we are doing 

 something to mitigate this injury. In Professor Comstock's 

 report for 1879 the estimate of the possible loss in years of 

 general prevalence of the cotton-aletia is placed at $30,000,- 

 000 through the cotton states. The injuries by grasshoppers 

 in the different states of the Union and also occasionally 

 through the British North American provinces, have been so 



