PARK AND CEMETERY . 
METHODS OF FIGHTING THE SAN JOSE SCALE 
The San Jose or Chinese scale 
(Aspidiotus perniciosus, Comstock) 
infests practically all portions of its 
host plants that are above ground — 
the trunk, limbs and branches — and 
when abundant it may occur on the 
leaves and fruit. Injury results from 
the extraction, by the scale insects, 
of the juices of the plant. At first 
this merely checks growth, but as the 
insects increase in number the speedy 
killing of the branches and twigs fol- 
lows, resulting finally in the death of 
the plants. In addition to the extrac- 
tion, by the scales, of sap as food, 
the puncturing of the bark by the 
slender sucking mouth-parts results 
in a diseased and often pitted condi- 
tion; the inner bark, or cambium, 
showing a reddish discoloration, as 
exposed in cutting with a knife, and 
the bark itself may crack, in stone 
fruits exuding drops or masses of 
gum. A reddening effect is also much 
in evidence as red rings around the 
scales on the bark, especially of the 
apple and pear, and on the fruits of 
these plants, though not characteris- 
tic of any one scale species. 
As perhaps the most dangerous of 
the insect pests of ornamental trees, 
its extermination has been the sub- 
ject of much study and experiment. 
Those who are preparing for either 
winter or early spring spraying for 
this pest will be interested in a very 
exhaustive study of the insect, its his- 
tory, habits, distribution and methods 
of fighting it recently published by 
the Department of Agriculture as 
Circular No. 124 of the Bureau of 
Entomology. 
The scale passes the winter in an 
immature condition fixed to the bark 
of the tree, the small, dark gray or 
blackish scales barely discernible to 
the eye. In early spring with the 
ascent of the tree’s sap, the growth 
of the scale begins, and early in April 
in the latitude of Washington the 
small, two-winged, active males issue 
from the male scales. After mating 
with the females the males die. The 
females continue to grow and in about 
a month begin the production of liv- 
ing young — minute, yellow, oval crea- 
tures, which by very close observa- 
tion may be distinguished without the 
aid of a hand lens, crawling here and 
there on the infested plants in an 
effort to find a suitable place for set- 
tlement. The young insect is active 
for some hours but soon settles, 
pushes its slender, threadlike beak in- 
to the plant, and begins to feed by 
sucking out the sap. After this there 
is no further movement from place 
to place, and the waxy covering, 
which often begins to develop before 
the insect has settled, soon covers it 
completely. 
The San Jose scale, in the absence 
of proper treatment, will quickly bring 
about the death of most plants of 
economic importance. It has been 
amply demonstrated that the scale 
may be very successfully controlled, 
and practically its presence merely 
requires one thorough treatment dur- 
ing the dormant period each year. On 
account of the general distribution of 
the pest, extermination is in most 
cases out of the question. 
Where plants are thoroughly in- 
c’rusted, with consequent death of 
branches and stunting of growth, it 
will, generally be advisable to dig out 
the trees at once and replace with 
new ones. Previous to spraying in- 
fested trees, the dead and weakened 
wood should be pruned out, which 
will simplify the work of spraying 
and will hasten the formation of new 
sound wood. 
There are several scale washes 
which may be employed in the con- 
trol of the insect, and the one should 
be selected which can be most con- 
veniently used and which is econom- 
ical under the circumstances. Thus, 
for spraying on a large scale the or- 
chardist could properly afford expen- 
ditures for the construction of cook- 
ing outfits for lime-sulphur wash 
which would not be justified where 
but a few plants were involved. For 
a few plants it would be better to use 
some one of the prepared washes put 
up by manufacturers. In fact, many 
large orchardists prefer to use sprays 
of this class in preference to making 
the washes at home. The possibility 
of injury to the trees from the sprays 
must also be borne in mind. All treat- 
ments, if possible, should be made 
during the dormant period (this is 
to say, in late fall or early spring, 
or even during the winter in mild 
climates), since at this time washes 
may be applied at much greater 
strengths than when the trees are in 
foliage. The aim is to use the wash 
about as strong as the tree will stand, 
thereby securing the maximum kill- 
ing effect upon the insects. The sev- 
eral sprays in use may be considered 
under the following headings: (1) 
Lime-sulphur wash series; (2) petro- 
leum oil series (including miscible 
oils), and (3) soap wash series. 
LIME-SULPHUR WASHES. 
For many years the cooked lime- 
sulphur wash has been the main re- 
liance in the control of the scale. It 
is made according to the following 
formula: 
Stone lime 20 lbs. 
Sulphur (flour or flowers) 15 lbs. 
Water to make 50 gals. 
Heat in a cooking barrel or vessel 
about one-third of the total quantity 
of water required. When the water 
is hot add all the lime and at once 
add all the sulphur, which previously 
should have been made into a thick 
paste with water. After the lime has 
slaked, about another third of the 
water should be added, preferably 
hot, and the cooking should be con- 
tinued for one hour, when the final 
dilution may be made, using either 
hot or cold water, as is most con- 
venient. The boiling due to the slak- 
ing of the lime throughly mixes the 
ingredients at the start, but subse- 
quent stirring is necessaVy if the 
wash is cooked by direct heat in ket- 
tles. If cooked by steam, no stirring 
will be necessary. After the wash 
has been prepared it must be well 
strained as it is being run into the 
spray pump or tank. The wash may 
be cooked in large kettles or, prefer- 
ably, by steam in barrels or tanks. 
This wash has proved entirely ef- 
fective in controlling the insect on all 
plants, so far as preserving their life 
is concerned, and has been especially 
satisfactory for stone fruits. For the 
apple, however, it has not in all cases 
been so satisfactory, as difficulty is 
experienced, especially in the case of 
large trees, in making the application 
sufficiently thorough to kill all the 
scales. The spotting of the fruit by 
the progeny of those that escape ren- 
ders it unsightly for market purposes, 
though its intrinsic value is but little 
reduced. The presence of the scale is 
furthermore very objectionable for 
the reason that certain foreign gov- 
ernments and certain states in this 
country rigidly quarantine against 
fruits showing the presence of this 
insect. Considerable loss on fruit ex- 
ported thus results to orchardists and 
dealers. 
Some apple growers rely principal- 
ly upon the oil sprays, or use them at 
least every other year, alternating 
with the lime-sulphur wash, and in 
this way keep the scale well in check. 
CONCENTRATED LIME-SULPHUR. 
The inconvenience experienced in 
preparing the lime-sulphur wash by 
