38 
THE COTORADO EXPERIMENT STATION 
While this insect is known as the Black Peach Aphis, the 
greater number of the individuals in any colony are always of a 
reddish-yellow or amber color (Plate I,_ Fig. 13). It is only the 
full grown lice that are black, whether winged or wingless, and 
none of the individuals are ever green in color. The fully grown 
wingless lice are deep shining black and highly polished (Plate I, 
Fig. 12. 
The other lice occurring upon the peach attack the foliage 
and blossoms and in some cases the young peaches, but none of 
them attack the year-old bark of the limbs as does this one. 
LIRE HISTORY 
This louse appears very early in the season. Last year it was 
found in Delta County and also in the vicinity of Palisades, early 
in February in considerable numbers, and badly infested twigs were 
received from Paonia that were taken March 18, 1908. These early 
appearing lice confine their attacks to the tender bark of the twigs 
and are nearly always most abundant at first upon small limbs or 
sprouts near the ground. The tender twigs may be literally cov¬ 
ered with the lice before the leaves open at all. When the buds do 
open, exposing the leaves and blossoms, some of the lice migrate 
upon these tender parts. They may kill the little peaches, and if at 
all abundant upon the leaves, the latter curl and protect the lice 
from storms or from the insecticides that may be thrown upon 
the tree by the orchardist. 
The lice that appear upon the trees early in the season are all 
wingless. The winged examples begin to appear in the vicinity of 
Grand Junction about the last of April. By the tenth of May these 
winged lice are usually very abundant, and by the middle of May, 
in our experience, the lice have begun to disappear from the peach 
trees and very few have been found in the orchards after the 
T5th of June. 
It is said that this louse migrates to the roots of the peach trees 
where it spends the fall and winter coming back to the top early in 
the spring. This part of the life history we have been unable to 
verify although we have dug about many peach trees in search of 
the lice. 
That it is the habit of this insect to pass the winter upon the 
roots of trees seems highly probable as we have been unable to 
find any sexual forms or eggs, and we are not aware that any one 
has. 
In the older peach growing sections of the country this aphis 
has been reported as fre-jnently killing peach trees, especially small 
ones in nurseries. 
PREVENTION AND REMEDIES 
It is not very uncommon for horticultural inspectors to find 
