24 



HOW INSECTS ARE CLASSIFIED 



Mallophaga 



These are parasitic insects, commonly known as bird lice, although 

 there are some species that infest domestic animals. 



The metamorphosis is incomplete. Eggs laid by the adult female 



hatch into minute creatures looking 

 much like the mature insect. 



The members of this order are 

 plainly adapted for their parasitic life. 

 The body is flattened. There are no 

 compound eyes. Wings are absent. 

 The antennae are short and simple. 

 The mouth parts are fitted for biting, 

 and the food consists of the hairs or 

 feathers of the host, or loose scales of 

 ''^I^^Hpf' dead skin. The Mallophaga never 



^^^ feed on the blood of their host, as do 



the members of the order Siphonaptera, 

 the fleas. 



^\l;gedTnd naturfl ^zT' ofig- ^^out 2000 species have been de- 

 inal. scribed. 



Odonata 



The adults in this order are the dragon flies, often called " snake 

 feeders " or " darning needles." 



Metamorphosis is incomplete. The nymphs, which hatch from the 

 eggs, are aquatic, spending their lives beneath the surface of ponds or 

 streams, where they lead an active existence, capturing and devouring 

 such other forms of animal life as come within their reach. The mouth 

 parts of the nymph are peculiarly adapted to its needs, being pro- 

 vided with a hinged lower lip which can be extended, and which bears 

 hooks on its farther edge. By means of these the nymph is enabled to 

 catch its prey unawares. 



The adults are large insects, and have two pairs of strong, narrow, 



