eT ree ee ee SS — OOO e™ 
9 
THE SPRING CANKER-WORM. 91 
and predaceous enemies is evident from the fact that in a near-by 
orchard, untreated, the insects were excessively numerous, completely 
defoliating the trees during the spring of 1906. Figure 1, Plate IV, 
is from a photograph of trees in the worst infested portion of the 
Lupton orchard in 1905, and shows the injury that had been done 
before the application of the Paris green spray. The condition of 
these same trees, but looking in another direction, on June 9, 1906, is 
shown in figure 2. 
During the spring of 1906 spraying work against canker-worms 
was also carried out in another orchard near Winchester consisting 
of 30 acres of 35-year-old Baldwin trees. This orchard also had been 
entirely neglected as to plowing and spraying for many years past, 
and for some years most of the trees had been completely defoliated 
by the spring canker-worm, some of them and portions of others 
being dead. Arrangements were made to spray a portion of the 
orchard, though it was not considered practicable by the owner to 
have the ground plowed. Arsenate of lead was used as a poison and 
applied at the rate of 3 and 5 pounds per 50 gallons of water for the 
first and second applications, respectively. At the time of the first 
application the leaves were well out, being from three-fourths of an 
inch to an inch in diameter. The canker-worms had almost all 
hatched, very many being in the second stage, and were literally 
swarming over the trees. The second application was made May 5, 
most of the larve at this time being from’one-half to three-fourths 
grown, the untreated trees being already nearly bare of leaves. The 
treated trees, while showing some injury from the larvee, especially 
in the higher parts, were in almost full foliage, though subject to 
infestation from adjacent trees. The second application largely pro- 
tected the trees from further injury, and there is no doubt that if the 
entire orchard had been treated the insects would have been practi- 
cally exterminated. Figure 3, Plate IV, shows the defoliated condi- 
tion of untreated trees June 9, after the larve had all disappeared, 
and the condition of sprayed trees in an adjacent row is shown in 
figure 4 on the same plate. 
RECOMMENDATIONS. 
Orchardists having canker-worms to contend with may confidently 
expect to practically eradicate them in the course of one or two sea- 
sons by following the methods above described, namely, thoroughly 
spraying the trees with a strong arsenical and thoroughly plowing 
the ground during the summer. If Paris green is used, this should 
be applied at the rate of 1 pound for each 100 gallons of water, and 
unless used in Bordeaux mixture there should always be added the 
milk of lime made from slaking 4 or 5 pounds of good stone lime. 
Arsenate of lead may be used at the rate of 6 to 10 pounds to 100 
