30 INTERRELATIONS OF PLANTS AND ANIMALS 



placed along the side of the thorax and abdomen. Bees also have 

 compound eyes. Wings are not found on all insects, but all the 



other characters just given are marks of the 

 great group of animals we call insects. 



Forms to be looked for on a Field Trip. — 



Inasmuch as there are over 360,000 different 



species or kinds of insects, it is evident that it 



would be a hopeless task for us even to think of 



recognizing all of them. But we can learn to 



^pound eye^ of ^an recognize a few examples of the common forms 



insect (highly mag- that might be met on a field trip. In the nei'ds, 



^ ^ ■ on grass, or on flowering plants we may count on 



finding members from six groups or orders of insects. These may 



be kno^vn by the following characters. 



The order Hymenoptera (membrane wing) to which the bees, 

 wasps, and ants belong is the only insoct group the members of 

 which are provided with true stings. This sting is placed in a 

 sheath at the extreme hind end of the abdomen. Other charac- 

 teristics, which show them to be insects, have been given above. 



Butterflies or moths will be found hovering over flowers. They 

 belong to the order Lepidoptera (scale wings). This name is 

 given to them because their wings are covered with tiny scales, 

 which fit into little sockets on the wing much as shingles are placed 

 on a roof. The dust which comes off on the fingers when one 

 catches a butterfly is composed of these scales. The wings are 

 always large and usually brightly colored, the legs small, and one 

 pair is often inconspicuous. These insects may be seen to take 

 liquid food through a long tubelike organ, called the proboscis, 

 which they keep rolled up under the head when not in use. The 

 young of the butterfly or moth are known as caterpillars and feed 

 on plants by means of a pair of hard jaws. 



Grasshoppers, found almost everywhere, and crickets, black 

 grasshopper-like insects often found under stones, belong to the 

 order Orthoptera (straight wings). Members of this group may 

 usually be distinguished by their strong, jumping hind legs, by 

 their chewing or biting mouth parts, and by the fact that the hind 

 wings are folded up under the somewhat stiffer front wings. 



