40 RHYNCOTA. 



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 tlie 

 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 Coccidce, 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 Coccidaa 

 are as great a pest as the Aphides to the farmer. In 

 greenhouses and hothouses they do great damage. 



