92 WHITE-PINE LEAF-LOUSE. 



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 ij 

 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 eSectual. 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 

 wav 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 eub- \ 

 ject have been very limited in extent, but highly interesting so 

 far as they have gone. 



First, with regard to the parasitic ChalGididce, I have seen in a 

 few of the scales the round clean-cut holes made by these insects, i\ 

 and under others I have found the oval, pellucid larva, exactly 



