A FEW ORCHARD PLANT LICE 
27 
Sometimes the orchardist thinks that ants are destroying the 
lice upon his trees. This is never the case. The ants visit the lice 
for their sweet secretions and are careful not to harm them and 
they ever stand ready to drive away many of the enemies of the 
lice. 
remedies 
The remedies to use against this insect, from the time the 
buds open in the spring until the leaves drop in the fall, are the 
same as those given for the woolly aphis above ground. Kerosene 
emulsions that is one-fifteenth oil ancl Black Leaf dip, i part in 70 
parts of water, are the two most favored sprays at the preent time 
in Colorado. 
WINTER AND EARLY SPRING SPRAYS 
For several reasons, late winter and early spring are most 
favorable for the destruction of the green apple aphis. The orchard¬ 
ist usually has more time then in which to do the work; the foliage 
being off, it requires less pains, time and material to make a thor¬ 
ough treatment, and by spraying early one avoids destroying the 
plant louse enemies which are killed along with the lice in summer 
spraying. If the work is well done in early spring, the trees should 
be free from lice until the winged migrants have flown in from 
neighboring orchards and established their colonies upon the trees. 
Such orchards will seldom become seriously infested before July, 
if they are at all during the summer, so they are sure to make their 
growth unhindered and will seldom fail to mature their crop in 
good condition. 
Professor Aldrich seems to have been the first to report suc¬ 
cess from winter treatment of orchards for the destruction of the 
eggs of plant lice.* He reported very satisfactory results from the 
use of lime-sulfur sprays made by both the 1-1-2 and the 1-1-4 
formulas (i lb. lime, i lb. sulfur, and 2 gallons water; and i lb. 
lime, I lb. sulfur and 4 gallons water), but did not succeed in 
destroying the eggs with emulsions of kerosene oil. 
In our experiments for the destruction of eggs we have found 
the oil emulsions useless, killing onlv in very high strengths, if at 
all. 
The treatments that we have found quite successful for the 
destruction of eggs are: 
Lime-Sulfur mixture, 1-1-2 formula, sp. grav. 1065. 
Lime-Sulfur mixture, 1-1-3 formula, sp. grav. 1045. 
Rex Lime-Sulfur, 1-8 strength, sp. grav. 1055. 
Rex Lime-Sulfur, 1-4 strength, sp. grav. 1080. 
Black Leaf, 4 per cent strength. 
* Bull. 40, Idaho Exp. Sta., 1904. 
