14 The Colorado Experiment Station. 
The eggs of this aphis hatch very early in the spring. 
E. P. Taylor reports having found them hatching at Grand Junc¬ 
tion, Colorado, on the 16th day of February, 1907. The month of 
February that winter was unusually warm and the extremely early 
hatching of the eggs was due to that fact. However, hatching 
takes place when the buds have scarcely begun to swell, a fact which 
is not generally understood by the fruit grower, and one which is of 
very great importance in its relation to the control of the pest by 
means of a spray. The past spring, eggs were found hatching on 
the 7th of March at Clifton, Colorado, at which time the buds 
seemed perfectly dormant. 
Spring Habits .—When first hatched from the eggs these aphids 
are dark green in color, and may be seen as tiny, dark specks crawl- 
• mg along the twigs, or more often, clinging to the buds. It is prob¬ 
able that they can exist for a number of days after hatching with 
little or no food. What feeding they do takes place on the buds or 
very tender bark into which their beaks are inserted, and from 
which a portion of the early flow of sap is extracted. Plant lice of 
the spring brood, which hatch from eggs that have remained on 
trees over winter, are known to the entomologist as stem-mothers. 
The full grown stem-mothers of this plant louse are of a pinkish 
or salmon color, and before there is a sign of a peach blossom in 
the spring, these stem-mothers have begun reproduction. Their 
progeny are born alive, eggs never being laid except in the fall, and 
( then by an aphis which, though only a different form of the same 
species, might be taken by the orchardist for an entirely different 
kind of plant louse. The generation from the stem-mothers differ 
from the latter in that they are light green in color, with darker 
green, longitudinal markings on the dorsal surface of the abdomen, 
but are never pink like the stem-mothers. Just as soon as the buds 
on infested trees begin to unfold, the stem-mothers, with their 
progeny, are ready to enter within. At first they seem to prefer 
feeding in the blossoms, but after these fall, quite serious injury is 
often done by their feeding on the leaves. Probably the greatest in¬ 
jury to peaches resulting from their attack, consists in the dropping 
of the small fruit which has become devitalized from the loss of 
sap until it can make no growth, hence shrivels and falls to the 
ground. The injury to the peach is practically all done while it is 
yet in the husk or calyx tube. After the peach has cast off this 
calyx tube it is not likely to be molested further by the aphids, and 
unless it has been too much weakened before this time, the proba¬ 
bilities are that it will not drop as the result of aphis attack. 
Summer Habits .—Fortunately this pest cannot, or does not, 
spend its entire existence upon the peach or other trees, but leaves 
them for more succulent vegetation. Shortly after the peaches are 
