102 FIFTH ANNUAL REPORT 



proved that, if done in the spring, just at the time or a little after the 

 new year's growth commences, all the old leaves of strohus may be 

 stripped with impunity. It stands to reason that with small trees which 

 are alFected with the Leaf-scale, and which admit of being thus 

 stripped, this is one of the most efficient means of exterminating the 

 lice. As an experiment, I thus stripped two young trees belonging to 

 Mr. Wm. T. Essex, of Kirkwood, and prevented the lice from extending 

 to the newer growth. In this manner the trees recuperated, though 

 so near unto death at the time that Mr. E. was quite willing to risk the 

 operation. By the second year they presented a healthy and clean ap- 

 pearance. This remedy, where it can be employed, has the advantage 

 of being thorough, and of enabling us to save the natural enemies, 

 just enumerated, from the destruction which awaits the lice. 



The White Pine holds its leaves a little over two years on older 

 trees — somewhat longer on younger ones; but as on badly infested 

 trees the old leaves are already well-nigh exhausted, their loss is not 

 so much felt. Moreover, the lowermost branches are always most 

 thickly covered with the lice, and it will often happen that the top of 

 the tree will not need stripping. I have already stated that large 

 trees on which this remedy would be impracticable do not suffer from 

 the scale to the same extent as do smaller ones ; so that where the 

 remedy is most needed it can be applied. Care must be had to collect 

 and burn all the detached leaves, and the operation should only be 

 performed after the new growth of leaves has commenced, but before 

 any of the female lice have settled thereon. 



Powdered or liquid applications, intended to kill the young lice, 

 are of little use, because, as we have seen, the latter do not all hatch 

 out within a few days, as with the Oyster-shell species ; but so irregu- 

 larly as to necessitate continued applications throughout the greater 

 part of the growing season, if intended to reach them all while young 

 and unprotected by scales. For this reason, applications, to be of any 

 value, must be of such a nature as to allow of being dusted or syringed 

 over the trees; and must also have some caustic or penetrating pro- 

 perties, so as to destroy life under the scales, and reach these last in 

 the protective groove in which they more generally dwell. I have 

 tried carbolic soap with not very satisfactory results, except where it 

 was used strong enough to kill all the leaves; and one tree thus 

 treated, when the new growth was starting, recovered, and was freed 

 of lice, but was evidently injured more than those which had been 

 stripped, as I was for some time in doubt whether it would live or not. 

 Dr. LeBaron has made applications of common fish brine, diluted at 

 the rate of one pint to two gallons of water, or made twice as strong; 

 also strong soap-suds, andunleached ashes dusted onto the trees when 

 moist; but while none of them materially injured the trees, they 

 none of them entirely exterminated the lice. Oily solutions, as with 

 the Oyster-shell species, would doubtless prove most effectual here. 



