4G 



THE PRACTICAL EiNTOMOLOGIST, 



we should be inclined to characterize them as uni- 

 versally beneficial to mankind. Yet on one occa- 

 sion, as I was advancing, net in hand, to capture 

 a large Dragon-fly (^Ana.c Junius), a Bank Swal- 

 low (Hirundo riparia), just as I was only a yard 

 or two from my game, swooped in like a flash of 

 lightning under my very nose and robbed me 

 of my prey. Now I incline to believe that this 

 large insect devours as many Flies, Gnats and Mus- 

 ketoes in the course of a day as the tSwallow could 

 have done; and if so, there was certainly a heavy 

 item to be posted up against the bird on the Debtor 

 side of the account.* 



On the whole — putting any damage done to the 

 Farmer's grain and corn, or to the Orchardist's 

 fruit, out of the question for the present — I do not 

 think that we are entitled to assume that any par- 

 ticular species of bird is a Public Benefactor, un- 

 til we know by the results of numerous experi- 

 ments, not only that it feeds upon insets, but that 

 it destro)'s at the very least thirty times as many 

 Noxious Insects as it does Beneficial Insects. For 

 assuming, what I believe to be very near the truth, 

 that the number of Noxious Species of Insects is 

 to that of Beneficial Species as three to one, we 

 must also take into account the further fact that, on 

 the average. Noxious or Plant-feeding species are 

 very much more numerous in individuals than 

 tliose species which prey on them, just as in most 

 places the Rats and Mice greatly outnumber the 

 Cats. Suppose that, on the average, they are ten 

 times as numerous, which is certainly, I think, 

 much within bounds. Then it will follow that, out 

 of a large lot of individual insects indiscriminately 

 captured, the plant-feeding or injurious individuals 

 will be on the average thirty times as numerous as 

 the individuals that prey on them, the plant-feeding 

 species by the supposition being thrice as numerous, 

 and the individuals of each plant-feeding species on 

 the average ten times as numerous. Hence it re- 

 sults that, unless an insect-devouring bird is found 

 to destroy considerably more than thirty times as 

 many Noxious Insects as it does Beneficial Insects, 

 it is not on the whole useful to man ; and if it 

 destroys considerably less than the above propor- 

 tion, it is decidedly injurious to man. For in the 

 latter case, instead of inclining Nature's scales in 

 favor of the Agriculturist, it inclines them the 

 other way; and if the same process were repeated 

 by other birds to an indefinite extent upon all 

 sides, the final result would be that every Beneficial 

 Insect would be swept away from off the face of 

 the earth, while there would be a large residuum 

 of Noxious Insects to increase and multiply in 



» Mr. Glover, the Entomologist of tlipi Agricultural 

 Bureau, found tlie stomachs both of hummino- binls 

 and of robins to contain spiders. Now spiders a°e uni- 

 versally carnivorous, and, so far as they prey upon 

 no.xious species of insects, beneficial to the Agriculturist. 

 Again, in the stomach of a Red-bellied Woodpecker 

 killed in December he found a species of wasp belondnir 

 to the genus Politics. Now I have mvaelf seen in South 

 Illinois Pohstcs rubiginosua (St. Fargeau) devouring a 

 green caterpillar i inch long, and probablv other species 

 " 38 3'/"^ similar habits. (See Agrk. Rep.MHb, 



future seasons, without any check whatever from 

 their Insect foes. 



3Ir. J. A. Allen, of Massachusetts, has obligingly 

 furnished me with the following list of birds, which 

 he has observed to prey on the Apple-tree Plant-louse 

 during the autumn months and especially in Octo- 

 ber: The Pine Finch (Chrysomitus pinus), the Yel- 

 low-Bird (Chrysomitus tristis), the Purple Finch 

 (Carpodacuspurpureus),theSnow-Bird(Juncohye- 

 malis), the Field Sparrow (Spizella pusilla), the 

 Chipping Sparrow (Sp. socialis), the Tree Sparrow 

 (Sp. monticola), the SongSparrow (Melospiza mclo- 

 dia), and the AVhite-throated Sparrow (Gonotrichia 

 albicollis). As Mr. Allen expressly states, that he 

 found plant-lice in the stomachs of many of these 

 birds on dissection, there can be no doubt of the 

 fact that they eat Plant-lice. But do they not 

 also eat those bitter enemies of the Plant-lice, the 

 larvre of the Ladybirds and of the Lace-wing 

 Flies and of the Syrphns flies ? To refuse a 

 good fat fleshy white Syrplnis magsot, when it 

 lies just under his bill, would, I suspect, require 

 more philanthropic self-control, than mortal Spar- 

 row was ever yet possessed of. And perhaps — if 

 I may be pardoned for such a malignant and slan- 

 derous supposition — some of Mr. Allen's birds took 

 the Syrplius m;iggots exclusively, and refused the 

 Plant-lice, as "too small business" to bother their 

 beaks with. 



A great deal has been said of late, about 

 importing into this country the European House 

 Sparrow to destroy our insect enemies, and 

 according to my venerable friend. Dr. Kirtland, of 

 Ohio, " it is now breeding successfully on Staten 

 Island, N. Y." (iV: Y. Tnb. Feb. 2, 1866.) But 

 I agree with a writer in the Horticulturist. (Nov. 

 LS6G,) that we ought to think twice before we im- 

 port a bird of so doubtful a character. So far as a 

 recollection of thirty years standing goes, the 

 House Sparrow is an unmitigated pest in England 

 in Farmers' Stack-yards, pertinaciously pulling out 

 the straws one by one from a grain-stack, and feed- 

 ing at his leisure upon the grain which he thus 

 secures for his own liquorish chops. It is not, 

 however, the European House Sparrow, as the 

 writer in the Horticulturist suggests, but the Euro- 

 pean ]5ullfinch that feeds upon tender fruit-buds 

 in early spring, before they expand into blossom. 

 Many a time, when I was a schoolboy of eight 

 years old in a Village School in England, have I 

 seen my worthy schoolmaster rise in hot haste 

 from his elevated chair in April and May, to scare 

 away the Bullfinches out of his Gooseberry bushes.* 



There is one fact which has always struck me 

 as adverse to the fashionable theory, that, without 

 the presence of numerous small birds, noxious in- 

 sects cannot effectuallv be checked. Throughouta 



»■' According to Mr. Glover, we have birds in North Ame- 

 rica with the s.ame habits as the Eui'o])can Bullfinch. For 

 the Purple Finch or American Linnet is said by him to 

 feed very largely on tlie fruit-buds of the peach: and ac- 

 cording "to the same writer, "the Ruffed Grouse, or Phea- 

 sant of the middle and western States, and Partridge of 

 the north, sometimes does much damage to orchards by 

 devouring the buds of apple-trees." (Aqr. Bep. 1S65. pp. 

 41, 44.) 



