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The pine Chermes(Chermes pinicorticts ) is another insect that is giving 
us a great deal of trouble, but we can subdue it most effectually with 
a stiff spray. The tree is then treated with the kerosene emulsion, and 
also those insects collected or washed down around the base of the tree. 
This has to be done at least three times a year. For the past seven 
years I have been using the stiff spray for different work, aud it is one 
of the best means I know of for cleaning maples of Pulvinaria. Three 
years ago Pulvinaria innumerabilis was very abundant on a great 
number of trees in our parks, and I treated them with the hose and 
emulsion until I had them in fair subjection. The Chermes and Pulvi- 
naria were at one time taken off with corn brooms, but the spray is 
much more effectual, and gets in among the small twigs without break- 
ing them. 
Scale insects are treated with washes and taken off with steel brushes, 
and are also sprayed with an emulsion, which covers the smaller 
branches. Eriosoma rileyi is common on our young elms, and these are 
treated with the kerosene and carbolic emulsion. 
The larva ot the larger silk producers are collected and destroyed, 
as well as the cocoons. Datanas are collected by hand, as they are 
assembled in masses, and destroyed. The web- worm, always abundant 
in our parks, is collected either by taking down the twigs or, if the tree 
is a valuable one. by twisting them out and crushing the larvae, 
Alypia octomaculata is abundant where Ampelopsis is grown. These 
are effectually destroyed with the London purple solution. 
The catalpa trees have been affected by a species of Cecidomyia. which 
causes the ends of the branches to turn black and break off". These 
are collected every year and destroyed before the larvae leave the twigs. 
Leaf-skeletonizers are always abundant on many of our trees, and the 
Platanus and Liquidambar species have suffered most. These insects 
are cut off as soon as they can be seen working and destroyed. If left 
for any length of time they make the tree very unsightly. 
Aphis species are treated with the kerosene emulsion after the colo- 
nies have been broken up with the stiff' spray. I have found it impossible 
to get an emulsion to act upon many of the plant-lice on account of the 
secretion; but let me play the hose on them a short time and they are 
disintegrated and demoralized, and many are killed outright by the 
shock: then a fine spray of emulsion will reach them more effectually 
than otherwise. The more I have occasion to use a force of water the 
more I see the benefits that will accrue from it, especially in economic 
entomological work, tor larva of many kinds can be knocked down by 
it, and my men have brought me birds that they have knocked out of 
a tree and captured. 
Other insects that are working on the foliage and in the stems <>t' our 
plants we have in great numbers, but enough has been said to give an 
idea of some of the work we try to accomplish. Could we have suf- 
ficient force to do the work at the proper time there seems to be no 
