THE COCHINEAL INSECTS. 309 



crease in summer would be so great as, by wounding 

 and exhausting the tender shoots of the trees, some- 

 times to suppress their vegetation. Among their 

 enemies one of the principal is a small black species 

 of Ichneumon fly *, which darts its pointed tail in- 

 to the bodies of the Aphides, and at the same time 

 deposits in each an egg. This egg afterwards pro- 

 duces a grub, which feeds on the body of the insect 

 till it has acquired its full growth, when it undergoes 

 its change, and entirely destroys its living nidus. 



After a mild spring most of the species of Aphis 

 becomes so numerous as to do considerable injury to 

 the trees on which they are found. The best mode 

 of remedying this evil is to lop off the infected 

 shoots before the insects are greatly multiplied, re- 

 peating the same operation before the time that the 

 eggs are deposited. By the first pruning a very nu- 

 merous present increase will be prevented, and by 

 the second, the following year's supply may in a 

 great measure be cut off j. 



THE COCHINEAL INSECTS. 



These are an extremely fertile race, and many 

 of them are very troublesome in stoves and green- 

 houses. The females fix themselves and adhere 



* The Ichneumon Aphidum of Linnaeus. 



f Richardson on Aphides. Phil. Tian. lxi. p. xSz. 



X3 



