92 
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these applications had injured the foliage much, if at all; there 
being some uncertainty upon the subject, from the fact that the 
leaves upon most of these branches had been more or less discol¬ 
ored by the depredations of the insects. At any rate it was evi¬ 
dent that the resinous leaves of the Pine will bear stronger appli¬ 
cations with impunity, than the foliage of the Apple and other 
common fruit trees. 
The practical conclusion is, that owing to the double-brooded 
character of this species, and the protracted manner in which the 
eggs are hatched, no single application of any remedial substance 
will suffice, as it does in the case of the common Bark-louse of the 
Apple-tree. These applications will have to be made at two dif¬ 
ferent seasons of the year in order to reach both broods. I have 
not learned at what precise time the Spring brood hatches, but 
any one can determine this for himself by examining them from 
time to time with a simple pocket lens ; probably sometime in the 
month of May. The second brood will require attention, to sim. 
plify the matter as much as possible, once a week through the 
month of August. 
If soap-suds be used, I would suggest making it, if practicable, 
of the coarse whale-oil soap, which is known to be more destruc¬ 
tive to some species of insects than the common kind. Perhaps 
throwing air-slacked lime into the trees when the dew is on, would 
prove equally or more effectual. The way to apply washes to a 
tree is by means of a garden syringe, which is merely a large syr¬ 
inge made expressly for such purposes, by having the end perfo¬ 
rated with many small holes, so as to throw the liquid in the form 
of a fine shower. 
The difficulties which I have just pointed out as lying in the 
way of any effective counteraction of the depredations of these in¬ 
sects, on our own part, renders it doubly interesting and impor¬ 
tant to determine what prospect there may be of their being ex¬ 
terminated, or effectually held in check by the operation of natu¬ 
ral agencies. My own observations upon this branch of the sub¬ 
ject have been very limited in extent, but highly interesting so 
far as they have gone. 
First, with regard to the parasitic ChalcidLdce, I have seen in a 
few of the scales the round clean-cut holes made by these insects, 
and under others I have found the oval, pellucid larva, exactly 
