76 FOOD HABITS OF THE GROSBEAKS. 
tected in great measure by planting here and there suitable decoy 
trees, as mulberries. 
Aside from the fact that ravages by the grosbeak may be pre- 
vented or greatly reduced without destroying the birds, it is evident 
that their general services to agriculture are so valuable that ‘their 
destruction is not to be considered. It is to be noted: First, that. the 
animal food of the blackhead, consisting almost wholly of injurious 
insects, is practically twice the bulk of the vegetable food, or more 
than four times that portion which is pilfered from man. Second, 
that the bird could not possibly select insects more prejudicial to the 
interests of western horticulture than the ones forming its natural 
food. These include the codling moth, cankerworms, flower-beetles, 
and such scale insects as the frosted, apricot, and black olive scales. 
Finally, these formidable fruit destroyers alone, not to mention 20 
percent of other injurious insects, compose two-fifths of the entire 
amount of the black-headed grosbeak’s food from April to September, 
or at least three times as much by actual bulk as the fruit consumed. 
In other words, for every quart of fruit eaten, more than 3 pints of 
black olive scales and more than a quart of flower-beetles, besides a 
generous sprinkling of codling moth pupe and cankerworms fall 
prey to this grosbeak. 
. 
LIST OF SEEDS, FRUITS, AND INVERTEBRATES EATEN BY THE BLACK-HEADED 
GROSBEAK. 
GRAIN. 
Oats (Avena sativa). | Wheat (Triticum vulgare). 
CULTIVATED FRUITS. 
Vig (Ficus carica). Crabapple (Malus prunifolia). 
Mulberry (Jorus sp.). Apricot (Prunus armeniaca). 
Strawberry (Fragaria vesca). Cherry (Prunus cerasus). , 
Blackberry (Rubus sp.). Prune (Prunus domestica). 
WILD FRUITS. 
Juneberry (Amelanchicr sp.). Nightshade (Solanum nigrum). 
Poison oak (Rhus dirersiloba). Elderberry (Sambucus sp.). 
WEEDS. 
Dock (Rumesr sp.). Chickweed (Alsine media). 
Smartweed (Polygonum sp.). Cranesbill (Geranium sp.). 
Pigweed (Amaranthus sp.). Alfilaria (Hrodium sp.). 
Red maids (Calandrinia menziesi). Bur clover (Medicago denticulatum). 
Catchfly (Silene sp.). Milk thistle (Mariana mariniana). 
