20 INTERRELATIONS OF PLANTS AND ANIMALS 



Head of a bee (side 

 view) , showing com- 

 pound eye. 



of a living bee, we notice it moves up and down quite regularly. 

 The animal is breathing through tiny holes called spir'acles, placed 

 along the sides of the thorax and abdomen. Bees have compound 

 eyes composed of numerous units, each of which acts as a tiny 

 camera. Bees are provided also with a pair of j ointed feelers called 

 anten'nce. Wings are not found on all insects, 

 nor is a vesture ; but the other structures 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 more than 450,000 

 different species or kinds of insects, it is evi- 

 dent that it would be a hopeless task for us 

 even to attempt to recognize all of them. But 

 we can learn to distinguish a few examples of 

 the common forms that might be met on a 

 field trip. In the fields, on grass, or on flowering plants we may 

 find members from at least six of the twenty orders of insects. 

 These may be known by the following characters : 



The order Hymeno'p'tera (membrane wings), to which the bees, 

 wasps, and ants belong, is the only insect order of which some of 

 the members are pro- 

 vided with true stings. 

 This sting is placed in 

 a sheath at the extreme 

 hind end of the abdo- 

 men. Other structures, 

 which show them to 

 be insects, have been 

 given above. 



Butterflies and moths 

 will be found hovering 



over flowers. They belong to the order Lepidop'tera (scale wings). 

 This name is given to them because their wings are covered with 

 tiny scales, which fit into little sockets 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 are small, and one pair of 



Worker 



(jueen 



Hymenoptera — bee. 



Drone 



