FRUIT INSECTS 



slender tube. In feeding, the tip of the beak is appUed to the 

 surface of the plant, the bristles are inserted into the tissue and 



the plant juices are sucked 

 out (Fig. 3). Contact insec- 

 ticides must be used against 

 this class. 



3. Lapping insects: In the 

 fruit flies the mouth parts 

 are developed into a tongue- 

 like organ with which the 

 insect is able to lap or lick 

 up liquids (Fig. 4). Arsenical 

 poisons have been used suc- 

 cessfully for the control of 

 this class of insects. 



In different stages of its 

 development the same insect 

 may have different kinds of 

 mouth parts, and may feed 

 on entirely different foods; 

 for instance, caterpillars have 

 biting mouth parts and may 



Fig. 3. — A plant-louse feeding, show- 

 ing the sucking type of mouth parts. 

 From a German drawing. 



feed on leaves, while the adults, moths, 

 have sucking mouth parts with which 

 they extract the nectar from flowers. 



How insects breathe. 



Insects do not possess lungs, but 

 breathe through a series of openings 

 called spiracles extending along each side 

 of the body. These openings connect 

 with tubes called trachesB, which, sub- 

 dividing again and again, extend to all 

 parts of the body. Some contact in- 

 secticides are supposed to clog these 



Fig. 4. — Head of a 

 fruit-fly, showing the lap- 

 ping type of mouth parts. 



