8 THE PARTS OF AN INSECT’S BODY 
The remaining prominent structures on the head of an insect are 
the mouth parts. From a practical standpoint, there is no other 
one thing in the makeup of an insect’s body so important as the type 
of mouth parts in a given pest. 
All insects may be divided into two classes, according to whether 
they obtain their food by biting and chewing, or by sucking; in other 
words, whether they have biting or sucking mouth parts. 
Fie. 5.— Mouth parts of a beetle. 
a, labrum; b, mandibles; c, maxille; d, labium; e, hypopharynx. Original. 
If we examine the head of a beetle, for instance, we shall find that 
it possesses a distinct pair of jaws, or mandibles, obviously intended 
for chewing or biting. Above these is an upper lip, or labrum; below 
is a pair of maxille, serving to hold the food and otherwise to assist 
in cating; and below these a lower lip or labium. If we look closely, 
we shall be able to find between the mouth parts the insect’s tongue, 
or hypopharynx. 
