t [ 267 ] 
set enemies, and if possible, suggest new ones, it is more espe- 
ally bis province to thoroughly study the habits and trace the 
welopment of the noxious species, so as to determine at what 
3riod of their existence, and at what time of the year, and to 
hat part of the infested plant, the proper applications can be 
lade with the most effect. For there is a period in the lives of 
lost of our noxious insects, and that is usually, of course, the 
me of their tender infancy, when some one or other of the com- 
ion remedies, such as soap, tobacco, lime or ashes, is effective in 
estroying them, provided only that it can be made to reach them. 
In illustration of the time when such applications should be 
lade, we may take two of the most destructive foes of the apple 
•ee, the Round-headed borer and the Oyster-shell bark-louse. 
l single application of soap in the one case, and of soap diluted 
fith water in the other, about the last week of May, or the first 
reek of June, will be fatal to every insect which it reaches; 
rhereas the same applications are utterly useless if made at any 
ther time of the year. 
In illustration of the importance of observing, in some cases, 
fie time of day also, in which to make remedial applications, a 
;ood example is furnished by the Rose-slug, which hides under 
he leaves in the day time, and thus escapes our ordinary applica- 
ions, but comes upon the upper surface to feed in the evening, 
md is therefore entirely exposed. 
As regards the particular part of the tree to which to direct our 
•emedies, a very good example is furnished by some observations 
vhich I have been making the past summer, upon the Bark-louse, 
)r more correctly, the Coccus (. Mytilaspis) of the pine, which, in 
his instance, stations itself upon the leaf. It is the habit of this 
nsect, like most others of its family, to become stationary for life 
if ter the first few days^succeeding its hatching; and it is the sin¬ 
gular instinct of this species for the two sexes to fix themselves 
upon different parts of the tree, the males remaining upon the 
same leaves upon which they hatched, whilst the egg-laying fe¬ 
males, which alone demand our attention, for the most part spread 
themselves upon the new and terminal foliage. 
These, and many other examples of the above general proposi¬ 
tions, will be found more fully elucidated in their proper places, 
in the following report. 
