BIRDS IN" RELATION" TO THE ALFALFA WEEVIL. 49 



Stomachs containing remarkably large numbers of these insects 

 for so small a bird are to be found in this material. One brood of 

 five half-grown young consumed, respectively, 55 larvae and 1 adult; 

 110 larva? and 2 adults ; 95 larvse and 3 adults ; 85 larvse and 4 adults ; 

 and 123 larvae and 1 adult, an average of 93.6 larvae and 2.2 adults for 

 each bird. A brood of three averaged 5f adults and 88 larvae apiece, 

 one of these having eaten 170 larvae and 5 adults, the largest number 

 recorded for a young of this species. Four young collected on 

 June 1, 1912, were still busy with the breeding adults, which were 

 abundant, 272 adults as well as 4 larvae being consumed, an average 

 of 68 adults and 1 larva apiece. Another hatch of 4, about two- 

 thirds grown, had taken a total of 54 larvae and 176 adults, one of 

 these alone having eaten 42 larvae and 50 adults. Another brood of 

 4 were making heavy inroads on the larvae, a total of 218 larvae and 

 26 adults being their record. A single bird of another hatch had 

 destroyed 150 larvae and 14 adults, while another made away with 

 95 larvae and 8 adults. Numerous other cases occurred where indi- 

 vidual nestlings had eaten upward of 50 weevils in one stage or 

 another of development. 



Of the 382 birds examined 5 had eaten more than 100 larvae; 6 

 had taken from 75 to 99; 17, from 50 to 74; and 49, from 25 to 49. 

 The adults were not taken in quite so large numbers, two birds having 

 eaten from 75 to 99 ; 9, from 50 to 74 ; and 46, from 25 to 49. 



The total animal food in this period was 60.81 per cent, of which 

 35.06 was other than weevil. About one-third of this, or 11.3 per 

 cent, consisted of Lepidoptera, principally caterpillars ; 7.15 per cent 

 was ground beetles (Carabidae) ; 5.31 per cent Diptera, mainly Tipu- 

 lidae; while the remainder, 11.3 per cent, was made up of various 

 insects, of which dung beetles (Aphodius) , bugs (Hemiptera), grass- 

 hoppers, spiders, and parasitic Hymenoptera were most important. 



The vegetable food (comprising 39.19 per cent of the contents) is 

 again characterized by the predominance of wheat, with a little other 

 grain and some weed seeds. 



June 16 to June 30. — Most of the first crop of alfalfa has been cut 

 by this time, and in badly infested regions the fields are kept barren 

 by the work of the larvae, which prey on every green shoot of the new 

 crop as it makes its appearance. English sparrows still frequent the 

 fields after food for their young, though the increased percentages of 

 some of the other food items, especially grasshoppers, indicate that 

 the weevil is becoming less abundant. Many insects have pupated, 

 and in that stage are little eaten by birds. Thirty-six stomachs col- 

 lected in this half of the month show a percentage of 18.25 of weevil 

 food. All but three of these contained the insect. Examination 

 revealed a noticeable decrease in the number of these insects taken 

 by young birds at this time — an average of but 4.97 adults and 5.36 



