26 LEAFHOPPERS AFFECTING CEREALS, ETC. 
only 7 in 1,150; the purple grackle or crow blackbird (Quiscalus 
quiscula) only 10 in 2,384, and these either but a trace or very small 
percentage, and the common meadowlark, a most familiar field resi- 
dent, shows no record at all of eating Jasside, but two birds out of 
1,157 had eaten cercopids to the extent of 5 per cent and 2 per cent, 
The Baltimore oriole (/cterus galbula) gives 1 in 207, but this one con- 
tained 88 per cent jassids. The orchard oriole (Jeterus spurius) 3 in 
153, and the Bullock’s oriole (Icterus bullock) 6 in 293. 
In the sparrow family there are many species which from constant 
occurrence in fields have a distinct interest in this connection. While 
primarily seed feeding, it is known that many of them frequently 
include insects in their diet. None of the stomachs, however, except 
possibly the sharp-tailed sparrow, shows a suflicient amount of jassids 
to indicate that the members of this family are of any consequence 
as a check for these pests. 
The lark sparrow shows only 5 in 257 and very small percentages 
in these five; the sharp-tailed sparrow 4 in 44, and Passerherbulus 
maritimus 2 in 31; the swamp sparrow, 2 in 72; the Lincoln spar- 
row, 4 in 42, and the common song sparrow, 12 in 714; the savanna 
sparrow, 3 in 300; the spotted bunting (Pipilo m. montanus) 2 in 150; 
the vesper sparrow, 2 in 140; the field sparrow 4 in 240, and the tree 
sparrow 2 in 555. The field sparrow shows 4 in 250, but these four 
are high, two being credited with 100 per cent jassids. 
The sharp-tailed sparrow, with 4 birds out of 44, shows percentages 
of 80, 80, 75, and 30, or an average for the four of 662 per cent, or a 
ratio for the 44 birds of 1 to 17, or 6 per cent jassid food, which is 
the highest percentage we have noted for any species and shows no 
records of spiders eaten. 
The next best of these records, 4 in 42 or 1 in every 104 for the 
Lincoln sparrow, with percentages of 4, 15, and 24, applies to one 
of the less common birds, and when the proportion of jassid mate- 
rial is noted gives us only 1 to 100 as the real ratio of leafhopper food 
_to be credited to this bird. : 
Two of the swallows, the violet-green swallow and the bank swallow, 
show considerable numbers, but these are doubtless from eases of 
unusual flight. The good record of the marsh wren is offset by the 
fact that it must be of little service except in swampy places, but the 
Bewick wren, if a more common bird, would make a very good showing. 
One of the nuthatches, Sitta pygmexa, as will be seen by the table, 
has a very striking record of 18 stomachs out of 32 birds with 
several containing 100 per cent of cercopids, but this is a Pacific 
Coast species and the tree-feeding habits of the bird exclude it from 
any probable service in grass or grain fields. 
It is clear, if any conclusions at all are warranted from the mass 
of evidence here available, that it is useless to depend on birds for 
