84 NORTH AMERICAN INSECTS. 
vember nearly twenty generations are born; and if their 
number were not checked by their numerous enemies, as 
well as by wet, damp weather and cold winters, all of our 
vegetable productions would not suffice to nourish them. 
The principal species of this country, which may be seen 
and examined every where, are: 
The Rosr-LowusE (Aphis rose), which is green. 
The Pig-Nut Louse (Aphis carye), which is the largest, viz., one 
quarter of an inch long, and covered with 
a bluish woolly substance. 
The CaBBaGE-Lousk (Aphis brassice), covered with a white mealy 
substance. 
The WILLow-Lowss (.iphis salicis), which is black. 
Shield-lice (Coccus). 
The Suretp-Louss, also called Bark-louse, or Scale In- 
sect, is found upon the branches and leaves of trees and 
bushes, upon which it sits motionless, as if it were glued 
on, looking more like a wart than a living creature. This, 
however, is the case only with the female, who inserts her 
snout into the branch upon which she sits, and remains 
there imbibing the sap of the plant. In this condition also 
she deposits her eggs, and after having done so she dies 
upon the same spot, leaving her dead and dried body a 
cover and shelter to her young ones. ‘The males have no 
snout, and walk about the branches at their pleasure. 
The body of the Shield-louse is oval, and the head, tho- 
rax, and abdomen run into one another so imperceptibly, 
that the whole appearance of the animal is like that of a 
shield or buckler. Hence its name. 
I have before remarked, and I may often have occasion 
to repeat the remark, that to the lover of Nature nothing, 
even the most vile and insignificant object that lives, is 
without some points of interest—each has something curi- 
ous in its construction or mode of life, or manner of repro- 
