VALUE OF BIRDS TO MAN. 37 



the time a most safe and conservative one, was three million, 

 one hundred thousand dollars. Mr. Stockwell also asked 

 Dr. H. T. Fernald and Mr. A. H. Kirkland, both expert 

 economic entomologists, to make, independently, a similar 

 estimate. Their replies follow, showing how they made up 

 their figures. These gentlemen had every facility for obtain- 

 ing knowledge of insect injury in the Commonwealth. It 

 will be seen that their approximations considerably exceeded 

 my own. Dr. H. T. Fernald says : 1 — 



Years ago a number of experts, figuring independently, came to the 

 conclusion that for farm, market-garden and orchard crops the loss by 

 the attacks of insects in an average year would represent one-tenth of 

 the value of the crop, or about two million, six hundred thousand dollars 

 for Massachusetts. Recently, however, prominent entomologists have 

 expressed the opinion that this per cent, is too low. Three factors have 

 caused this change : first, the concentration of crops of the same kind 

 into large contiguous acreage ; second, the introduction of over one 

 hundred pests from foreign countries, which have been here long enough 

 to make their presence seriously felt ; and third, the great reduction in 

 the number of insectivorous birds. 



I believe it will be entirely safe to take fifteen per cent, of the crop 

 valuation of Massachusetts, and that you will be sufficiently conserva- 

 tive in using that amount as representing part of the damage. I have 

 never seen a cherry tree killed by plant lice, yet I have often seen lice 

 so abundant on cherry trees as to much reduce the crop, which is true 

 of a large proportion of our crops ; and it is loss of this kind which is 

 covered by the fifteen per cent, estimate, . . . but how are we to place 

 a money value on the defoliation of an elm tree unless it be repeated 

 year after year until the tree dies ? I would be inclined to add, to the 

 fifteen per cent, estimate already given, two hundred and fifty thousand 

 dollars for labor, apparatus, poison, etc., used in the fight against 

 insects, and another two hundred and fifty thousand dollars to cover 

 damage actually done, but which cannot be reduced to figures, making 

 a total yearly damage of four million, four hundred thousand dollars for 

 Massachusetts. 



Mr. Kirkland says : * — 



The best figures available for estimating the loss caused by pests in 

 this State are those of the 1895 census. From the report of this census 

 I have taken figures giving the value of certain crops notably attacked 



1 Report of Secretary J. W. Stockwell, Annual Report of the Massachusetts 

 State Board of Agriculture, 1901, pp. xiii, xiv. 



