PARK AND CEMETERY. 
670 
proportion of the females migrate to 
the twigs, where thej" insert their pro- 
bosces and become fixed for the re- 
mainder of their existence, mean- 
while changing from a greenish color 
to buff and finally brown, with a 
slightly tessellated waxy corering. In 
this condition the winter is passed. 
When the sap begins to flow in the 
early spring the female grows rapid- 
ly, mainly because of the rapid de- 
velopment of great numbers of eggs 
within the body. In ]\Iay or early 
June the ovisac begins to form from 
the fine waxy threads exuded from 
the posterior spinnerets, pushing 
backward and upward until the body 
of the female is almost vertical to 
the twig. IVIeanwhile the ovisac is 
gradually being filled with eggs, which 
hatch and undergo all the changes 
mentioned above. Thus, fortunately, 
there is but a single brood each 
year. 
Notwithstanding the extreme pro- 
lificacy of this insect, it is usually 
held in check by its man}'’ nutural 
enemies. Doctor Howard has ob- 
served the English sparrow apparent- 
ly feeding upon the full-grown scales. 
The twice-stabbed ladybird (Chilo- 
corus bk’ulnenis Muls.) is a common 
enemy of this as of other scale in- 
sects, particularly in iis early stages. 
The smaller similarly marked Hyper- 
apsis binotata Say and H. sigiiafa 
Melsh, are also valuable enemies of 
this species. The writer found m the 
severely infested parks and cemeteries 
in Chicago that the egg-contents of 
80 to 85 per cent of the cottony ovi- 
sacs had been destroyed by the white 
mealy larvje of Hyperaspis. The 
predaceous caterpillar of Laetilia coc- 
cidivora Comst. has been an efficient 
ally in controlling the pest in the vi- 
cinity of Washington, D. C. Several 
species of Leucopis nigricornis, Eg- 
ger, a common dipterous parasite of 
aphides, were reared from cottony 
maple scale. Several species of 
chalcid flies are truly parasitic upon 
the cottony maple scale. There is 
no doubt that many more Pulvinarias 
are killed by these interesting little 
fellows than by all other enemies. 
REMEDIES. 
In dealing with an infestation by 
the cottony maple scale, the most 
important matter to be considered in 
each case is the advisability of arti- 
ficial means of control under the ex- 
isting conditions. The natural ene- 
mies of this pest have done and are 
still doing such effective work in its 
control, that it is a question whether 
remedies should be applied when the 
infestation is not serious. Nature al- 
ways maintains a balance, and this 
pest cannot be in the ascendancy for 
any great length of time. On the 
contrary its parasites will eventually 
multiply so rapidly as to completely 
check its progress, and it may even 
narrowly escape extermination. 
Insecticides applied for a pest al- 
ways kill its parasites and oftentimes 
predaceous enemies are also de- 
stroyed. Hundreds of larvse of Hy- 
peraspis binotata were found to have 
been destroyed by a summer treat- 
ment with kerosene emulsion for the 
cottony maple scale in parks of Chi- 
cago, and no doubt thousands of the 
minute chalcids were killed, as they 
were found quite plentifully on un- 
sprayed trees. 
If it is necessary to resort to arti- 
ficial means of control, as seems to 
be the case in some sections, the 
spraying should be delayed until fall 
or winter, when the Hyperaspis is 
hibernating at the bases of the trees 
among lichens, moss or dried grass. 
Care should be exercised in the use 
of spray, and the bases of trees should 
be covered with canvas or other suit- 
able material to prevent the spray 
from running down the tree-trunks 
and collecting at their bases. 
When the trees have become dor- 
mant, after the falling of the leaves, 
they can be trimmed and thoroughly 
sprayed with a strong kerosene emul- 
sion, which will kill every scale 
reached by the spray, without injury 
to the trees. Scarcely one-fourth the 
quantity of emulsion is required to 
spray a tree in winter condition that 
is necessary when a tree is covered 
with dense foliage and both sides of 
the leaves must be reached with the 
spray. Some excellent results have 
been obtained by Mr. S. Arthur John- 
son in experiments against this pest 
in Denver, Colo. He found that kero- 
sene emulsion 25 per cent or more 
in strength or whale-oil soap at the 
rate of 1 pound to 1 gallon of water 
was very effective, apparently killing 
all scales which received the spray. 
Kerosene emulsion of not more 
than 10 to 12 per cent of oil can be 
thoroughly applied with safety to 
maple trees, but the tips and margins 
of the leaves may be injured even at 
this strength. Box-elder will be al- 
most defoliated with a 12 to 15 per 
cent solution. Less than a 10 per 
cent emulsion will be of little value 
against the young unless they have 
recently hatched. Since the hatch- 
ing period may extend over six or 
eight weeks, it will be seen that more 
than one spraying will be necessary 
to insure success, and, coupled with 
the fact that it is a very difficult and 
disagreeable task to thoroughly spray 
a tree in foliage, the winter treat- 
ment will be found more satisfactory 
in every way. And at that season 
the larvre of predaceous beetles 
would not be destroyed. 
Kerosene Emulsion; Stock solu- 
tion (GO per cent oil). 
Kerosene (coal-oil, lamp-oil), 2 
gals.; whale-oil or laundry soap (or 
1 quart soft soap), pound; water, 
1 gallon. 
Dissolve the soap in boiling water, 
then remove from the fire, add the 
kerosene immediately and thoroughly 
agitate the mixture until a creamy 
solution is obtained. This can be 
done by pouring the mixture into the 
tank of a spray-pump and pumping 
the liquid through the nozzle back 
into the tank. This is a stock solu- 
tion, which must be diluted before 
using. In order to make a 10 per cent 
emulsion, add to each gallon of the 
stock solution about 6 gallons of 
water and agitate thoroughly before 
using. For a 30 per cent solution add 
to each gallon of the stock solution 
1% galons of water and agitate thor- 
oughly. This strength will kill a 
large percentage of the hibernating 
females, without injury to the trees. 
If a good naphtha soap can be ob- 
tained, the preparation of the emul- 
sion will be simplified. It will be 
unnecessary to heat the solution, 
since the kerosene will combine read- 
ily with the naphtha and soap and 
form a perfect, cold, milky-white 
emulsion when the mixture is thor- 
oughly agitated. If naphtha soap is 
used, double the amount called for by 
the formula and emulsify in soft 
(rain) water. 
Keeping Squirrels in Check 
Many complaints regarding the de- 
structiveness of squirrels in the tree- 
lined districts of Chicago have been ad- 
dressed to Mr. J. H. Frost, city for- 
ester. To remedy this Mr. Frost sug- 
gests that to put an end to their op- 
erations in the destruction of birds’ 
nests and young birds, one of the worst 
offenses of the little animal, trees where 
birds are nesting should be surrounded 
by wire collars having points bent out- 
ward and down at close intervals so 
that the animals cannot climb the trees 
and get to the nests. Squirrels also 
destroy garden seeds. He says: “I 
believe the trouble is largely because 
the people have let the squirrels, do as 
they please, and the consequence is they 
are monopolizing some places to the 
exclusion of birds and the like ” 
