BIRDS IE" RELATION TO THE ALFALFA WEEVIL. 19 



had consumed 60 larvae, 84 larvae and 1 adult, and 100 larvae and 1 

 adult, respectively. Another hatch of three had averaged 32^ larvae 

 apiece. Several other food items characteristic of these birds ap- 

 peared with such regularity that the actual bulk of weevils in no case 

 amounted to over 50 per cent. 



Caterpillars formed the next most important item, totaling 27.38 

 per cent. Dragon flies (Odonata) and their nymphs, and snails, 

 forming 9.84 and 6.46 per cent, respectively, were secured from the 

 immediate vicinity of the nests. Spiders composed over 15 per cent, 

 and ground beetles, with the genus Amara predominating, a little 

 less than a tenth of the food. The major portion of the remaining 

 animal food was divided about equally between aquatic beetles, bugs, 

 flies, and grasshoppers. The vegetable food (6.84 per cent) was un- 

 important, as over half was rubbish taken accidentally with the food. 



An observation for a period of an hour was made of a female red- 

 wing feeding a brood of four nestlings about three days old. The 

 nest was situated in a clump of cat-tails with alfalfa fields not far 

 distant. The parent bird divided her time between visits to the 

 adjacent marsh and the near-by alfalfa, and made trips to the nest 

 on an average of one every 3| minutes. Though the alfalfa was 

 visited oftener than the marsh, the food of the nestlings was 

 gleaned largely from the latter place, as over one-quarter of it was 

 dragon flies and over half spiders, while the weevil amounted to but 

 7.25 per cent. The parent bird, however, had made good use of her 

 time in the field, as her stomach contained 3 adults and 56 larvae, 

 comprising 45 per cent of the contents. 



Adults. — The early warfare on the weevils by adult redwings is 

 verified by examination of stomach contents, and although the insect 

 formed but a small proportion of the bulk (4.94 per cent), it was 

 present in 27 of the 36 birds used in this computation. Five of seven 

 other stomachs, which were too nearly empty to be of use, also con- 

 tained the insect. Weevils taken in April were breeding adults, and 

 were eaten on an average of 2£ per bird. The highest number eaten 

 by any was 13. 



Of other animal food, caterpillars and fly larvae, mostly aquatic, 

 composed slightly more than 13 per cent each. Aquatic beetles 

 formed nearly 3 per cent and ground beetles nearly 2, while several 

 other items occurred in small quantities, none over 1 per cent. Vege- 

 table matter formed 57.08 per cent of the food, over half of which 

 was grain, while the rest was divided between weed seeds (18.78) 

 and a little rubbish. 



During the month of May adult redwings increased their work 

 on the alfalfa weevil until it comprised about one-sixth of their food, 

 occurring in 23 of the 32 stomachs examined and averaging 4.84 



