314 Report OF THE DEPARTMENT OF ENTOMOLOGY OF THR 
ing stage was reached and one insect succeeded in reaching full 
development. 
General summary.—These experiments are of practical interest 
in indicating the temperature required in a cellar for cold storage 
of trees or fruit to prevent the development of young larve or 
to kill the adult females, which if able to survive the cold would 
probably produce young, as was the case with the adults referred 
to on page 313 very soon after being brought into warmer tem- 
peratures. This is of especial interest in connection with cold 
storage of fruit. It will be noticed that at a temperature of 45° 
I’. development was merely checked and continued when the 
scales were brought into higher temperature, while at 35 F, none 
of the young scales survived. 
MEANS OF LOCAL DISTRIBUTION. 
It is during the active stage that the insect is distributed 
locally. There are three principal agencies which aid in local 
distribution. First, the activity of the larva which enables it 
to migrate from one place to another; second, the wind which 
may carry infested leaves and twigs about; and third, insects, 
birds and similar agencies. The ability of the larva to migrate 
over smooth surfaces has been previously referred to. 
Wind.—To ascertain the probability of the larve being carried 
on foliage by the wind, 200 pear leaves were picked and carefully 
‘examined October 1, and although the larvee were numerous on 
the trees none could be found on the leaves. Ten leaves were 
then placed on the ground and a larva on each. In one hour all 
had gone except two which remained three hours. October 4, 
when the larve were numerous and active on the infested pear 
trees, 1680 green leaves on the trees were carefully examined 
and but 54 larve were found. A larva was then placed on a 
pear leaf which was released from a point about 10 feet from 
the ground. It was carried by a light breeze about 16 feet and 
when examined the larva had disappeared, evidently having been ~ 
blown off by the wind. This was repeated six times, the leaves 
