12 
COLORADO EXPERIMENT STATION. 
Other larger larvae were within extensive chambers, extending up and 
down through the wood, sometimes an inch beneath the bark. Trees 
badly infested are completely girdled and killed. The insects'spend 
the winter as larvae, and in the early summer change to pupae within 
a brown cocoon or cell from seven-eighths to one inch long by one- 
fourth to five-sixteenths inch in diameter, usually projecting into or 
from the gummy mass at the base of the tree. The first pupa was 
found formed within these cocoons on the 15th of June, though the 
majority were being formed about the middle of July. The pupae 
yield moths, the female of which are of a blackish-brown color, with 
partially transparent wings and a black body, circled at about the 
middle with a beautiful orange band. The males are smaller and 
more slender than the females and have a number of smaller, less 
conspicuous bands of yellow about the abdominal segments and with 
more nearly transparent wings. The first moths appeared on July 
6, though the maximum number were not appearing until about 
August 11, a singular fact, since these moths are known to come out 
in greatest numbers in New York state and at Washington, D. C., 
from one and one-half to two months earlier in the season. Eggs 
are laid upon the rough bark about the crown of the tree. The 
eggs, when laid, are oval and of a brown color. Large numbers are 
deposited by each female. On August 6, a single female gave by 
dissection about 400 eggs, 250 of the number at that date being 
brownish in color and well formed, while 150 were white and still 
embryonic in nature. 
Experiments Begun —Its importance made it seem advisable to 
test remedial measures, and various old and some new methods of 
combatting the pest were begun in June, and the final results are still 
pending. 
Following are the measures under comparison in the experiment: 
(1) Carbon bisulfide, 1 ounce per tree about crown. 
(2) Tobacco dust, 2 pounds per tree about crown. 
(3) Tarred felt and wire shields about base of tree. 
(4) Lime dust, 2 pounds to 4 pounds per tree about base of tree. 
(5) Dirt removed and larvae removed by hand. 
(6) Banking earth about tree’s base. 
(7) Tree washes. 
(8) Trees not treated in same orchard to be used as comparison. 
GREEN APHIS OF APPLE. {Aphis pomi.) 
Importance —The unusual abundance of this aphid the past sea¬ 
son upon apple and occasionally upon pear on the Western Slope 
has made it necessary to make observations upon and carry out in¬ 
secticidal tests against it. 
Life History —The green aphis winters as eggs upon the twigs 
of the tree, and the past spring a very large per cent withstood the 
winter. They began hatching about Grand Junction about April I, 
continuing for two weeks or more. The young hatched at about the 
same time the first traces of green foliage appeared, and thus found 
tender food upon which to feed at once. 
