The National Nurseryman. 
FOR GROWERS AND DEALERS IN NURSERY STOCK. 
Copyright, 1897, by the Nation*! Nurseryman Pubiishing Co. 
VOL. V. 
SCALE IN NURSERY. 
Experiment Station Investigation of one of 
THE MOST Serious Pests of Deciduous Trees 
—The Responsibility of the Nurserymen. 
In his paper on “ Three Important Insects Injurious to 
Nursery Stock,” before the Western New York Horticultural 
Society, Victor H. Lowe, of the New York State Experiment 
Station at Geneva, said : 
During the past season I have frequently been called upon 
to inspect nursery stock in the western part of the state. 
These inspections were made to enable the nurserymen inter¬ 
ested to comply with the Maryland law regarding the inspec¬ 
tion of nursery trees sold within that state. The three insects 
to which I wish to call your attention are the peach tree borer, 
the wooly louse of the apple, or wooly aphis as it is commonly 
called, and the San Jose scale.” 
Regarding the peach borer I suggest the burning of all 
unsalable stock would remove many breeding places for the 
moth. I think that if nurserymen would refuse to accept 
trees which show any sign of the peach tree borer the increase 
of this pest would be greatly lessened. Experiments showed 
that dendrolene cannot safely be used on nursery stock as a 
preventive of insect depredations, if such prevention requires 
the application of the dendrolene during the growing season to 
all parts of the trunks of young trees. 
The woolly aphis spreads with remarkable rapidity, breed¬ 
ing by the million. An old neglected apple orchard or a few 
neglected apple trees in the vicinity of a nursery may be the 
cause of infected stock in that nursery. Observation has 
shown that trees grown on sandy soil are more likely to be 
infested than trees grown on heavier soil. Reliable writers on 
economic entomology say that strong kerosene emulsion spray¬ 
ed on the infested trees during the summer, is fatal to all of 
the lice it touches ; also that the same insecticide applied to the 
soil about the roots of the infested tree in sufficient quantity 
so that the soil becomes saturated with it, will free the roots of 
these pests. Some nurserymen have thought that ” puddling” 
the infested roots will kill the lice, but this method is not to be 
depended upon, as the cottony covering which the lice always 
provide for th mselves is proof against mud and water as 
shown in the above experiment. 
It may happen, and I think it does often happen even in the 
best regulated nurseries, that many of the apple trees when 
brought to the packing yard will be found harboring a few of 
the woolly lice in the scars on the trunk. It is unfortunate for 
the tree that the deep scars are there, for, in addition to other 
evils, they furnish excellent retreats for the lice. These trees 
are sound in other respects and hence are too good to throw 
away. Some quick, easy and inexpensive method of treating 
them is yet to be devised. At present we can only call atten¬ 
No. 2. 
tion to our experience last season which demonstrated than an 
average small boy with sharp eyes, a small dish of kerosene 
and L short stick with a wad of cheese cloth tied on the end, 
can, in a few hours and hence at a small cost to the dealer, 
transform hundreds of these infested trees from trees which 
should be thrown out as culls to salable stock. We found that 
it was only necessary to touch the infested spots with the oil- 
soaked rag to kill the lice. Fumigating with hydrocyanic acid, 
gas, or dipping the trees in a strong solution of soap suds may 
prove even more satisfactory, but experiments are wanting. 
The San Jose scale belongs to the same order of insects as 
the woolly aphis and to the same family as the common oyster- 
shell bark louse. It differs from this insect in many respects, 
however. The covering which the insect provides for itself is 
in the form of a scale The scale of a full grown female in¬ 
sect is nearly circular and somewhat conical in shape The 
color is dark slate, with a dark spot on the slightly raised por¬ 
tion at the center. The scales are small when compared with 
those of many other species of scale insects, a single scale 
measuring only about one-eighth of an inch in diameter. 
Unless occurring in large numbers, the scales do not readily 
attract attention because of their small size and dull color. As 
a rule, however, they cover a branch so completely that the 
natural color of the bark is obscured and at a little distance 
appears to have turned to an ash gray. The bark under the 
scales will be found in some instances to have turned red. In 
others it is darker colored and somewhat purplish. When at¬ 
tacking fruit, th ^ scales are more conspicuous, as each scale is 
enclosed in a ring of bright red. This is especially true in the 
case of infested pears. When the scales occur in large numbers 
on the fruit, the rings of color will merge into each other 
forming blotches of red. 
The scales infest all parts of the trunk and branches, from 
the crown of the root to the highest twig. The leaves, too, are 
infested and the fruit, as previously indicated. When infest¬ 
ing the leaves, the scales are found in the greatest abundance 
on the under surfaces along the midrib and larger veins. The 
male scale is oblong-oval in shape. It is usually darker in 
color than that of the female. The mature male is very small 
and frail, and is provided with a pair of delicate transparent 
wings. 
At present the San Jose scale is doing its worst work in this 
state on Long Island. It has been found from one end of the 
island to the other. On two different occasions we found 
fruit exhibited at the Long Island fairs which was badly in¬ 
fested. Since that time we have obseived it m the nurseries 
there, and have received specimens from both orchards and 
gardens. The most deplorable part of it all is that some of 
the fruit growers and nurserymen have not taken the trouble to 
become familiar with this insect, while others seem to be indif¬ 
ferent to the whole matter. We have no good reason to expect 
success in our endeavors to eradicate this insect from our state 
or even to prevent its further spread unless every nurseryman 
and fruit grower will take the pains to become so familiar with 
ROCHESTER, N. Y., MARCH. 1897. 
