A TREATISE, 
&C. 
APPLE TREE. 
Plant Lice (Aphides ). — The Aphides are 
an extensive genus, and owing to their great multi- 
tudes prove one of the most pernicious tribes of 
the Insect race to the vegetable kingdom. They 
are commonly known by the terms of Green Ely, 
Smother Fly, and sometimes, and more properly, 
Plant Lice. There are two species which appear 
to choose the Apple Tree as their principal support. 
The buds and leaves and young branches appear 
to afford delicious food to one, while the other 
decidedly prefers the trunk and branches. 
I will commence with the former one, by 
giving as clear a description as I am able of some 
of its different processes ; imd as the species are so 
numerous and the difference between them so trifling, 
that no one but an Entymologist could distinguish 
those differences, rather than err in not giving this 
species its proper name, and as it is of little mo- 
ment, I shall decline naming it. It makes its 
appearance upon the buds as soon as they exhibit 
