40 
RIIYN COTA. 
Aphides with, its sharp ovipositor and to lay therein an 
egg, which will soon turn into an Aphidius larva, feed 
on the bloated Aphis, live in its skin, change into a 
nympha and pupa, then into the winged insect, and eat 
its way out of the now dried and puffed-out skin of the 
Aphis. The reader may often observe on the under- 
side of currant leaves, for instance, certain dry light brown 
shining bodies amongst the live Aphides ; let him look 
closely, their skins unmistakably once belonged to the 
Aphides,, there are their legs, head, anal-tubes; but the 
aphis is quite motionless; there is a small round hole in 
the skin near the posterior extremity ; through this 
back-door the parasite Aphidius has left his home. 
The history of the Aphis is remarkable; fertile 
males and females alone are produced in the Spring 
from eggs laid the previous Autumn; these grow 
rapidly, but do not assume wings ; they lay not eggs, 
but young fertile females, which repeat the same 
process, and so on again and again for nine generations. 
At length, when Autumn arrives, males as well as- 
females make their appearance, and frequently, but not 
always, develop wings; the usual pairing takes place, 
the female lays her eggs, which in the Spring, as I have 
said, will produce fertile females only. 
To the section Monomera belong scale insects, popu¬ 
larly known as Mealy-bugs and Bark-lice; there is 
only one family, the Coccidw , so called from the 
“berry” like form of the female; the term “Mealy¬ 
bugs’’ alludes to the white cotton-like substance which 
envelops the young. To the horticulturist the Coccidm 
are as great a pest as the Aphides to the farmer. In 
greenhouses and hothouses they do great damage. 
