42 FOOD HABTTS OF THE GROSBEAKS. 



the seeds of vervain (fig. 3) "and dock are occasionally devoured. 

 Milkweed and sunflower are added to this list by other writers. 



MISCELLANEOUS VEGETABLE FOOD. 



The rosebreast feeds upon some vegetable matter which does not 

 fall into any of the previously discussed categories. Seeds of the 

 touch-me-not and blood-root, plants widely known for their flowers, 

 are examples. Each was eaten by 1 individual, and 1 fed upon red- 

 bud seeds also, which constituted 80 per cent of its stomach contents. 

 The spiny, globe-like fruits of the sweet gum {Liquid 'arnbar sti/ra- 

 eiflua) are bitten into occasionally, but the remains found in the 

 stomach so resemble another but unknown substance that it was pos- 

 sible to identify them certainly in only one instance, and then by 

 means of the very characteristic fertile seeds. The pendent sycamore 

 balls are sometimes rifled of their seed, as also are the aments of alder 

 and birch. 



Among the objects most puzzling to classify economically are the 

 curious excrescences of plants, known as galls. These, as is well 

 known, are nurseries for insects, within which the larvas develop. 

 They are eaten by many birds, extensively by some, and in an instance 

 cited by Dr. A. D. Hopkins," turkeys, chickens, and even hogs and 

 cattle fattened on an abundant gall of the black oak, known in Mis- 

 souri and Arkansas as " oak wheat " or " wheat mast." An analysis 

 accompanies this note which leaves no doubt that the nourishing 

 elements of galls are of vegetable, not animal, origin. Although this 

 may not be true of all galls, such as certain thin-walled kinds made by 

 plant lice in which at the proper stage the bulk of the imprisoned 

 insects exceeds that of the shell, yet generally, no doubt, it is safe to 

 classify galls as vegetable food. This has been done in the case of 

 those eaten by grosbeaks. Nine rosebreasts had eaten galls, but in 

 only one instance did they compose as much as half the food. The 

 galls eaten appeared to be similar to the spherical species common on 

 oaks. 



Animal Food. 



Animal food, consisting almost exclusively of insects, composes 52 

 percent of the food of the rose-breasted grosbeak. Nearly 36 per- 

 cent is beetles, 3.82 percent caterpillars, 6.43 percent Hymenoptera, 

 and 2.38 percent scale insects, the remainder (about 3.33 percent) 

 being made up from several other groups of invertebrates. While 

 the rosebreast feeds upon a large number of formidable insect pests, 

 it devours some beneficial species also. The latter are accorded prior 

 consideration. 



a Proc. Ent. Soc. Wash., V, 1903, pp. 151-152. 



