HEMIPTERA 



141 



of plants. The sucking beak consists of the lahiuin, which, to- 

 gether with the labial palpi, is modified into a jointed sheath. 

 This incloses the mandibles and maxillae, which are changed 

 into long, piercing stylets.^ The labrum or upper lip is small or 

 rudimentary. There are usually four wings. In the typical 

 Hemiptera, as exemplified in the sub-order Heterop'tera, the 

 character of the anterior wings is a distinguishing feature. 

 The basal portions of these wings are thickened and parch- 

 ment-like, while the terminal portions are membranous and 

 overlap when the wings are folded over the back. From the 

 character of these wings the order gets its name — henii, half. 



'Fig. 111. — Bed-bug [Ci'mexlectular'ius): a, Adult female gorged with 

 blood; h, same from below; c, rudimentary wing-pad; d, mouth parts. 

 All enlarged. (Marlatt, Bull. U. S. Dept. of Agriculture, 1896.) 



and pteron, a wing, i. e., the Hemip'tera or " half-winged " 

 insect. The second pair of wings are membranous and fold un- 

 der the fore wings when not in use. The electric-light bugs, 

 bed-bugs, water-bugs, and squash-bugs are familiar examples. 

 In the sub-order Homop'tera the anterior wings are not thick- 

 ened, but are of the same structure throughout, as in the cicada. 

 In the sub-order Parasl'ta are found wingless parasitic hemip- 

 tera which prey upon certain mammals, for example, the head 

 and body lice of man, dogs, cattle, hogs, sheep, mice, and 

 rabbits. 



' See Kellogg, p. 164. 



