1 86 



The Orders of Insects 



stylets, often barbed towards the tip ; these work 

 to and fro within the groove of a stout-jointed 

 beak {rostruni) which is formed by the union of 

 the second maxillae (fig. loi). The head is usually 

 triangular in shape \ the slender feelers have from 

 three to eight segments. The prothorax is free, its 

 tergite (pronotum) always being well-developed ; the 

 legs and wings vary considerably in the different 

 sub-orders. The hind-body usually has nine evident 

 segments whereof the last three are often modified 

 for reproduction ; genital stylets in the males, and 

 ovipositors in the females, are often present. 



1 



Fig. I02. — a. Bed-bug (O'wf-r ft7?//<zr/Kj', Linn.) newly hatched, rom beneath ; 

 b. from above ; d. egg, magnified 25 times ; c. foot of nymph with claws ; c. 

 serrate spine, more highly magnified. From Marlatt, Bull. 4 (n.s.) Div. 

 Ent. U.S. Dept. Agr. (Compare fig. 104). 



The Hemiptera are divided into three well-marked 

 sub-orders characterised by differences in the form of 

 the wings, and in the nature of the hfe-history. 



Sub-Order A. Heteroptera. 



The Heteroptera or Bugs are distinguished by 

 the modification of the forewings into partially horny 

 covers for the entirely membranous hindwings. The 

 scutellum of the mesonotum is always a prominent 



