APPLE PESTS 
emulsion is used, and is applied just as 
the eggs are hatching in the spring. Con- 
siderable difficulty may be experienced 
here as the young are at that time con- 
siderably protected by the foliage. To 
secure the best possible results a high 
pressure pump should be used by means 
of which a pressure of 150 to 200 pounds 
can be secured. Apply spray to-all parts 
in as thorough a manner as possible. (Use 
kerosene emulsion 8 to 10 per cent 
strength.) For preparation of kerosene 
emulsion see sprays for aphis. 
PEAR BLIGHT BEETLE.—See Shot Hole 
Borer, under Cherry. 
Periodical Cicada 
Tibican septendecim Linn. 
H. F. WILson 
There are probably very few of us who 
are not acquainted with this insect in 
the adult stage on account of the large 
numbers which appear at one time or an- 
other in various sections of the country. 
The name is applied on account of the . 
fact that the adults only appear at 
periods of every 17 or 13 years. In the 
northern part of the United States it is 
17, in the south 13. During the interven- 
ing time they live- in the ground as 
nymphs and live by sucking the juices 
from the roots of trees. Having reached 
that point where they are ready to become 
adults, they crawl out of the ground and 
on to a stone, tree trunk or anything 
above ground, and shedding the skin for 
the last time, come forth as adults. 
After leaving the old shell they are 
ready to fly about in a day or two, and 
within a week the sexes have mated and 
the females shortly proceed to make their 
Fig. 1. Periodical Cicada: Egg punctures in 
twigs; pupal case and adult insect. (After 
Cordley.) 
533 
egg punctures and deposit eggs here and 
there in the twigs. 
In selecting trees for egg oviposition 
oaks are shown a preference and among 
fruit trees apples seem to be preferred. 
Almost any plant may be attacked. 
The part of the plant selected is almost 
invariably the twigs of the previous year’s 
growth. Occasionally a single nest or two 
will be constructed in a larger limb. 
The result of such work must of a 
necessity be quite detrimental to the trees 
as the twigs are often so weakened that 
they break very easily and an excessive 
pruning results. In the nursery consider- 
able damage may be caused by the after- 
effect, which is shown in the deformities 
of slow-healing wounds. . These wounds 
offer excellent entrance ports for fungus 
diseases and other insects. The woolly 
apple aphis oftentimes locate in these 
scars and instead of healing over they 
become more deformed and susceptible to 
the attacks of fungus and insects. 
In depositing her eggs the female ci- 
cada passes from one limb to another 
until she has deposited all of her eggs, 
which have been estimated to number 
from 400 to 600. The eggs measure about 
one-twelfth inch in length. They hatch 
in six or seven weeks, are pearly white 
in appearance, tapering to an obtuse 
point at either end and_ slightly curved. 
Upon hatching from the eggs the young 
larvae run about for a very short time, 
drop to the ground where they seek out 
a crevice and immediately work their 
way into the soil and begin their long 
underground existence. 
Remedies 
A number of insecticides are quite ef- 
fective against this species, but to be of 
real value must be applied each day as 
long as the insects issue in numbers. 
Pyrethrum powder is a perfectly satisfac- 
tory remedy against newly transformed 
individuals. This should be applied in 
the morning, before the insects have 
gained full strength and while the plants 
are wet with dew. The powder may be 
puffed on the insects while clinging to 
shrubbery or on the lower branches of 
trees. This powder is absolutely worth- 
