26 BULLETIN" 10*7, U. S. DEPARTMENT OF AGRICULTURE. 



Adult blackbirds consume the largest proportion of alfalfa weevils 

 in June, when the insect comprises nearly a third (32.70 per cent) of 

 the food. Among the 99 stomachs examined are to be found records 

 of the most remarkable work done by this bird. Only four had 

 failed to eat the insect. The 99 birds together had made away with 

 580 adults, 68 pupae, and 4,406 larvae, averaging 6.4 adults, 0.7 pupa, 

 and 48.9 larvae, or 56 individuals per bird. Though this bird has 

 a strong liking for insects of larger size, as cutworms and beetles of 

 various kinds, the weevil formed the greater portion of the contents 

 of many stomachs. In 11 cases it amounted to 90 per cent or more 

 of the food. 



A female secured from a post-breeding flock had devoured the 

 largest number of weevils recorded for any individual bird — 374 

 larvae, 65 pupae, and 3 adult weevils, a total of 442 individuals, com- 

 prising 96 per cent of the stomach contents. (See PI. IV.) It also 

 had eaten the larvae of an aquatic beetle, a caterpillar, a dipterous 

 larva, a nymph of a tree hopper (Membracidae), two spiders, and 

 a little rubbish, including a seed of filaree. Three birds had eaten, 

 respectively, 281 larvae, 268 larvae and 6 adults, and 240 larvae and 17 

 adults. In each case the weevil comprised 90 per cent of the food. 

 Another had eaten 212 larvae and 4 adults. In each of 14 other birds 

 the combined number of larvae, pupae, and adults amounted to over 

 100, noteworthy among which was one containing 1 adult and 190 

 larvae; another with 3 adults and 170 larvae: and a third with 14 

 adults and over 140 larvae. 



Besides the weevils eaten during this month (32.7 per cent) the 

 adult birds had taken nearly an equal quantity (27.83 per cent) 

 of caterpillars. In seven stomachs this item made up over 90 per 

 cent, while in one it formed the entire contents, the bird having eaten 

 about 23 of these insects. Carabid beetles, Hemiptera, Orthoptera, 

 and spiders formed the bulk of the remainder. The vegetable food, 

 amounting to but little more than 5 per cent, was unimportant, as 

 much was rubbish. 



In July the depredations of these birds on the weevil are con- 

 fined almost wholly to feeding on the adults of the year, which 

 by this time are out in great numbers, especially in the vicinity of 

 haystacks and along ditch banks, where they early seek places of 

 hibernation. In one favorite resort of these birds about the base of 

 a recently constructed stack, so many adult insects had fallen from 

 the hay while the stack was being built that a brush of the hand in 

 the debris at the base would disclose a squirming mass of hundreds 

 which produced a distinctly audible " whir " in their scramble 

 through the dry hay for new places of shelter. 



During this month the weevil formed 20.26 per cent of the food, 

 taken on an average of 12.45 adults and 1.79 larvae per bird, and it was 



