650 THE WATER SCORPION AND THE WHEEL-BUG. 



HETEROPTERA. 



These insects are readily kuowu by several conspicuous character- 

 istics. The wings are four in number, and the front pair are very 

 peculiar in their structure, the basal portion being horny, like the 

 elytra of beetles, and the remaining portion membranous, like the 

 hinder wings of the same insect. In some species, however, the wings 

 are wanting, as in the common Bed-bug [Clmex lectularius). The body 

 is always much flattened, the mouth is beak-like, and in the pupal stage 

 the creature is active and resembles the perfect insect, except in its 

 want of wings. 



The family of the Nepidse is represented in England by the common 

 Water Scorpion, a very flat and leaf-like insect, which is found abun- 

 dantly in slow-running streams, ditches, and ponds. It derives its 

 popular name from its scorpion-like aspect, the two slender filaments 

 appended to the abdomen representing the sting-tipped tail, and the 

 raptorial fore legs resembling the claws. It is with these legs that the 

 Water Scorpion catches its prey, which, when once grasped in that 

 hooked extremity, is never able to make its escape. The beak is short, 

 but very strong and sharp, and is not bent under the thorax, as is the 

 case with that of the water boatman. 



The next section of the Heteroptera includes insects which are mostly 

 terrestrial, though some are fond of haunting the surface of water. The 

 Hydrometridse are well-known examples of the latter insects, and are 

 popularly known by the name of Water-fleas. The common Gerris 

 skims over the surface with wonderful rapidity, wheeling and turning 

 as easily as a skater performing his manoeuvres on the smooth ice. 

 But the Hydrometra — a very slender creature, hardly thicker than a 

 needle, and bearing a great resemblance to the well-known walking- 

 stick insect — glides slowly over the surface, mostly keeping among the 

 aquatic plants at the margin, and passing silently as a shadow over the 

 water. 



The family of the Cimicidse is represented by the too common Bed- 

 bug, a creature which is supposed to have been imported into England 

 from America. This odoriferous, flat-bodied, rust-colored insect has 

 derived its very appropriate name from the old English word bugge, 

 signifying a nocturnal spectre, and used in that sense by the old writers. 

 These creatures are enabled, by means of their flat bodies, to creep into 

 the smallest crevices, and when they have once taken possession of a 

 room can with difficulty be extirpated. 



The Reduviidte comprise a great number of terrestrial insects, mostly 

 exotic, but a few being natives of our country. Some of them are very 

 large, and one species, the Wheel-bug (^Arilus serratus), is said to pos- 

 sess electric powers. Its popular name is derived from the curious shape 



