LEAF-BEETLES EATEN BY THE KOSEBKEAST. 



49 



Although the potato beetle is the worst pest in the Chrysomelidse, 

 this family contains other serious enemies of crops. The rosebreast 

 feeds upon several of them, thereby further commending itself to our 

 esteem. Both the small striped and the spotted cucumber beetles (fig. 

 26) , which are abundant and injurious over much of the United States, 

 are consumed. The importance of the bird's inroads upon one of 

 these little black and yellow species, which in the larval stage is the 

 destructive corn root-worm, is emphasized by the fact that no direct 

 method of combating the insect has yet been devised. Twelve gros- 

 beaks fed upon these beetles, as many as 7 being found in a single 

 stomach. Further evidence of the bird's strong preference for them 

 is furnished by Mr. Ridgway, who observed a number of rosebreasts 

 feeding exclusively on spotted cucumber beetles in a locality where 

 the latter were very 

 abundant. 



Ten of the gros- 

 beaks examined 

 had eaten another 

 kind of leaf-beetle 

 (Melasoma lappon- 

 ica), which feeds on 

 willows and pop- 

 lars, sometimes 

 working havoc by 

 defoliating trees, 

 especially in wind- 

 breaks. These 

 beetles appear to 

 be much relished, 

 as from 10 to 27 

 were taken by individual rosebreasts, of whose food they composed 

 from 60 to almcst 100 percent. Two or three other species of Chry- 

 somelidas, injurious to willows, to grapes, and to garden crops, are 

 devoured. Nine birds ate beetles of one of these species {CaUigrapha 

 bigsbyana), which in individual cases constituted 70 per cent of the 

 stomach contents. The rosebreast devours also two Hispid leaf- 

 beetles, one of which causes considerable injury. This is the locust 

 leaf-miner (Odontota dorsalis), which sometimes devastates whole 

 groups of trees, leaving them as if scorched by fire. Eight grosbeaks 

 had eaten leaf-miners, and in one case 8 were consumed by a single 

 bird. 



The long list of beetles of this family that are preyed upon by the 

 rosebreast is completed by the strawberry root-worm {Typophorus 



Fig. 26.— Spotted cucumber-beetle (Diabrotica 12-punctata) 

 (From Riley and Chittenden, Bureau of Entomology.) 



