EXTERNAL STRUCTURE OF INSECTS 



in the typical insect, intended for biting, may be modified to form 

 a sucking apparatus, the maxillae and mandibles being lengthened 

 and frequently enclosed in a sheath formed by the labium. 



The stages of an insect's life are commonly the egg stage, the 

 larval stage, the pupal or resting stage, and the adult or imago. 

 In insects without a complete metamorphosis, the larval and pupal 

 stages are both active, and frequently referred to as the nymphal 

 stage, or "the nymph." All growth during an insect's life occurs 

 in the larval or nymph stage, and is accompanied by several 

 moultings of the larval skin. Each moult is called an "ecdysis." 



Kyea 

 1st pair of Legs ' 



1st pair of Wings 

 2nd pair of Leg9 



2nd pair of Wings -.-... 



3rd pair of Legs 



Thorns 



Abdomen 



Tibia 



Tarsus 1 



FIG. 8. Dissection of a locust or grasshopper to show divisions of the body. 



The parts of a typical insect consist of a head, thorax, and 

 abdomen. 



The head bears antennae, a pair of large compound eyes (see 

 Figs. 8 and 9), and a few simple eyes. On the under side of the 

 head occur the mouth parts, viz., the labrum, then a pair of strong 

 mandibles; following these a pair of maxillce, each with palp at- 

 tached, and lastly the labium and labial palps. These typical 

 structures are, as intimated above, modified in some of the orders ; 

 in fact, they are to a certain extent the fundamental cause of some 

 of the groups given below. These variations adapt the possessors 



