Insect Study 



3*3 



A sphinx moth u'ith the sucking 



tongue unrolled. 

 Photo by M. V. Slingerland. 



leaves, others have a sucking tube for 

 getting the juices from plants or the 

 blood from animals, and others long 

 delicate tubes for sipping the nectar 

 from flowers. 



In the biting insects, the mouth- 

 parts consist of an upper lip, the labrum, 

 and under lip, the labium, and two 

 pairs of jaws between them. The upper 

 pair of jaws is called the mandibles and 

 the lower pair, the maxillae (sing, 

 maxilla). There may be also within 

 the mouth, one or two tongue-like 

 organs. Upon the maxillae and upon 

 the lower lip there may also be feelers 

 which are called palpi (sing, palpus). 

 The jaws of insects, when working, 

 do not move up and down, as do ours, 

 but move sidewise like shears. In 

 many of the insects, the children are 

 able to observe the mandibles and the palpi 

 without the aid of a lens. 



The thorax is the middle region of the insect 

 body. It is composed of three of the body seg- 

 ments more or less firmly joined together. The 

 segment next the head is called the prothorax, the 

 middle one, the mesothorax, and the hind one, the 

 metathorax. Each of these segments bears a 

 pair of legs and, in the winged insects, the second 

 and third segments bear the wings. Each leg 



consists of two small segments next 

 to the body, next to them a longer 

 segment, called the femur, beyond 

 this a segment called the tibia, and 

 beyond this the tarsus or foot. The 

 tarsus is made up of a number of 

 segments, varying from one to six, 

 the most common number being 

 five. The last segment of the tarsus 

 usually bears one or two claws. 



While we have little to do with 

 the internal anatomy of insects in 

 elementary nature-study, the chil- 

 dren should be taught something of 

 the way that insects breathe. The 

 child naturally believes that the 

 insect, like himself, breathes through 

 the mouth, while as a matter of fact, 

 insects breathe through their sides. 

 If we examine almost any insect 

 carefully, we can find along the sides 

 of the body a series of openings. 

 These are called the spiracles, and 



A_ tree hopper, show- 

 ing the mouth as a 



The mouth-parts of a grasshopper 

 dissected off, enlarged and named. 



