THE ENGLISH SPAEROW. 235 



ing for this exile of insect-eating birds by destroying some 

 of the smaller gypsy caterpillars and occasionally killing 

 some moths or even eating a few moth eggs; but it was 

 noticeable that wherever the sparrow was most plentiful in 

 the infested region, there also the gypsy moth became most 

 numerous. This was due partly to a distribution of both 

 species along the same highways and partly to the indirect pro- 

 tection extended by the sparrow to the moth in driving away 

 the latter's enemies among native birds. The caterpillars used 

 the bird boxes occupied by the sparrows as a place of retreat, 

 and the female moths deposited their eggs in these boxes. 

 Sparrows and caterpillars formed a sort of happy family in 

 the bird houses, which swarmed with both birds and insects. 

 By driving the native birds away the sparrow became in a 

 measure responsible for the phenomenal increase of the gypsy 

 moth in numbers and its consequent destructiveness in Med- 

 ford. The increase of some other injurious insects has been 

 noticed wherever the sparrow has become so plentiful as to 

 banish native birds.* The trees in Boston and some of the 

 towns in its vicinity have often suffered injury from invasions 

 of the Orgyia leucostigma, or white-marked tussock moth, 

 caused indirectly by this sparrow. The sparrow, having 

 driven away the native birds, fails to make good their loss 

 by destroying the hairy caterpillars. 



The ravages of leaf-feeding beetles ( Chrysomela scalar is) 

 have also become noticeable upon elm trees in localities most 

 frequented by the sparrow. The imported elm-leaf beetle 

 (Galeruca xanthomelcena) has also been most injurious in 

 cities where the sparrow is abundant. 



The Distribution of the Moth by Birds. 

 The dissemination of the moth in woodlands seems to indi- 

 cate that it is distributed more or less by birds. This theory 

 is substantiated by our observations. Isolated colonies of 

 the moth are sometimes found in the vicinity of the nests 

 of the larger land birds, such as crows, jays and robins. 

 Occasionally birds flying to their nests with food for their 



* Second report on the " Injurious and other insects of the State of New York," 

 by J. A. Linter, Albany, 1885, pages 80-82. 



