The Food of Birds. Ill 



quart of caterpillars counts as the e([uivaleiit of a (juart of 

 blackberries, and, on the otlier hand, as the e(|uivalent, 

 also, of a cjuart of predaceous l)eetles. It is evident, there- 

 fore, that we cannot i;et at any close estimate of the 

 economic values of this species in this indiscriminate 

 way. 



A nearer approximation to the truth may Ije made l)y 

 critically comparinii, the ii'eneral averages for the year 

 found in the vertical column at the right of the table. 

 Here we have the following totals of injurious and benefi- 

 cial species : — Of the first, caterpillars, seventeen parts 

 (including eight parts cutwH)rnis) ; Bibio larva^, fifteen 

 parts; leaf-chafers, three parts; wireworms, two parts; 

 snout-beetles, two parts ; crickets and grasshoppers, four 

 parts. Of the second, predaceous beetles, six parts ; pre- 

 daceous bugs, three parts ; garden fruits, twenty-four parts. 

 Now, the opinions of entomologists would prol)ably be found 

 to dift'er somewhat widely on the question of the relative 

 values of these various elements, and each must form his 

 own opinion from the data given.* My own judgment is 

 that, taking into consideration only the immediate present 

 eft'ect of the robin upon the fruits and insects of the state, 

 ignoring for the moment the important secondary disturl)- 

 ances likely to arise if the number of the species were 

 greatly lessened, and balancing these elements carefully 

 against each other (applying to them, in fact, the opera- 

 tion of cancellation in arithmetic), we can reduce the 

 question finally to about this form : — Will the destruction 

 of seventeen quarts of average caterpillars, including at 

 least eight quarts of cutworms, j)ayfor twenty-four ([uarts 

 of cherries, blackberries, currants and grapes? 



To this question I, for my own part, can only reply that 

 I do not believe that the horticulturalist can sell his small 

 fruits anywhere in the ordinary markets of the world at 

 so high a price as to the robin, provided that he uses prop- 

 er diligence that the little huckster doesn't overreach him 

 in the bargain. In other words, while the l)ird is far too 



*Concerning tlie value of predaceous beetles, the reader is especially 

 requested to examine tlie papers on that subject in the present bulletin. 

 It is probable that their services have been greatly overestimated. 



