The Regulative Action of Birds upon Insect Oscillations. 
17 
PERDICIDiE. Quails and Partridges. 
Ortyx virginiana, L. Quail. 
Two quails were shot, among half a dozen seen. All but four 
per cent, of their food consisted of corn and other seeds, chiefly 
those of Compositae. A single chrysomelid, a rhynchophorous 
beetle, and a carabid, were the only insects found. 
Besides the species of birds above mentioned, the following 
were noted rarely in the orchard, but no specimens were secured: 
and ~Vii eo olivaceus , Sturnella magna , Cyanurus cristatus , and 
Chcetura pelasgica. The blue jay was seen eating canker-worms in 
the trees. The total number of species observed in the orchard wa 
therefore forty, and the number of specimens obtained and studied 
was one hundred and forty-one, representing thirty-six of the 
species. Twenty-six of these species had been eating canker- 
worms, which were found in the stomachs of eighty-five speci- 
mens. That is to say, seventy-two per cent, of the species, and 
sixty per cent, of the specimens, had eaten the worms. Taking 
the entire assemblage of one hundred and forty-one birds as one 
group, we find that thirty-five per cent, of their food consisted of 
canker-worms; and if we exclude the species evidently merely 
accidental in the orchard, the average of canker-worms in the 
food of those properly belonging there rises to about forty per 
cent. 
For a correct estimate of the probable effect of the birds 
in limiting the increase of the canker-worm, it is necessary to 
take into account some of the features of its natural history. 
The larval life of the insect lasts about one month, after which it 
enters the ground and pupates, where it remains until the follow- 
ing spring. The imagos, the females of which are wingless, 
emerge about the middle of April. They lay their eggs upon 
the bark of the trees, usually at night, remaining concealed upon 
the ground by day under fallen leaves and other rubbish. The 
eggs remain upon the trees about a month before the worms 
emerge, when the latter crawl up the trunk and commence their 
attacks upon the leaves. The pest is consequently exposed to 
destruction from the time it emerges until it disappears again, the 
adults falling an easy prey to birds which search the ground for 
