Insects and their world 



Fig. 6. A barklouse, one of the psocids^ a member of the Order Psocoptera 



5. Dictyoptera 



Cockroaches. These oval insects are often called 'black-beetles', 'water- 

 bugs', or 'crotonbugs', but are quite unrelated to the true beetles (see 

 Order 29) or the true bugs (see Order 20). The fore-wings are leathery, 

 and act as covers for the hind- wings. Cockroaches are best known in 

 kitchens and cellars, where they feed on scraps of food, usually at night. 

 Many native North American forms commonly occur beneath the bark 

 of trees or are associated with wooded areas and are called 'wood roaches'. 

 The big tropical ones are often brightly coloured. 



Mantids. The 'praying mantis' (Fig. i) is a slender insect, often several 

 inches long, which has powerful, pincer-like fore-legs. It gets its name 

 because it sits motionless in what looks like an attitude of prayer until 

 another insect comes near, then seizes and devours it. There are nearly 

 200 species of mantids, mostly in tropical countries. 



6. Phasmida 



Stick-insects and leaf-insects have the colour and shape of twigs and 

 leaves, and can sit motionless among vegetation without being noticed. 

 Some are big, but they are a perfect example of animal camouflage. They 

 are vegetable-feeders. 



7. Saltatoria 



Grasshoppers; locusts; crickets. This Order falls into two halves, which 

 may be roughly distinguished as those with short antennae and those with 



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