6 OUR INSECT FRIENDS AND FOES 



great compound eyes, and upon its upper (dorsal) 

 surface a pair of horns or antennae; and in many 

 species of insects, two or more simple eyes or 

 ocelli. (2) The thorax or middle region, always 

 consisting of three segments, usually firmly 

 united together, bearing on the lower surface 

 three pairs of legs, and upon the upper surface 

 the wings. (3) The abdomen or hind region, 

 composed of seven or eleven segments, carries 

 the sexual organs and, when present, the sting. 

 No legs are present upon the abdomen during 

 the adult stage of the insect's life, but during the 

 larval stage, fleshy tubercules, the Pro-legs, 

 varying in number, are present on the under 

 surface. These pro-legs disappear with the 

 final moult, when the larva or grub enters the 

 pupa stage of its existence. 



The mouth, while varying considerably both 

 in size and shape in different insects, is practically 

 divisible into three clearly defined types the 

 sucking mouth, the biting mouth, and the piercing 

 mouth. The typical mouth of an insect will be 

 found to comprise the following parts : the 

 labruni or upper lip, which is a small plate 

 usually horny in texture, and although really 

 belonging to the head, functionally forms part 

 of the mouth. Insects that bite have immediately 

 behind the labrum a pair of jaw-like organs, 

 frequently of considerable size, and armed with 

 tooth-like projections ; and these biting jaws are 

 called the mandibles. What may be termed the 

 second pair of jaws, or maxillae, are not quite 

 so simple in structure, each bearing a jointed 

 appendage called a palp. Below or behind the 



