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: !— 
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 toolow. 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 
T 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. 
