158 PREDACIOUS AND PARASITIC 



distinguishing character is the possession by the imagines of four 

 membranous wings. 



The remainder of the order, designated Hemiptera-Hete/vp- 

 tera, bears in its name a reference to the partially coriaceous 

 nature of the anterior wings, which, whilst serving, as in the 

 Coleoptera^ as a cover for the membranous pair beneath, are each 

 furnished with an asymetrical membranous extension, which 

 enables them to be used as efifeclive instruments of flight. The 

 species of this sub-order are popularly known as ' bugs,' and 

 whether or no the unsavoury association of ideas thus engendered 

 has had its effect upon the studies of naturalists, certain it is 

 that the group, as a whole, has had but little attention devoted to 

 it in comparison with the Diptera, or even with the other section 

 of the same order. Probably, the ' water boatman,' the Ranatra 

 linearis^ the house bug, and a few others which, on account of 

 peculiarities in their structure or habits, have found places in most 

 manuals of microscopy, are almost the only species with which a 

 vast number of naturalists are well acquainted, and we are yet 

 greatly deficient in reliable information as to the development, the 

 diagnosis of the larva, and the conditions under which the species 

 live in the different stages of their existence. 



The species of the Hemiptera diifer greatly in shape and also 

 in colour, bright green, black, red, brown, yellow, grey, etc., being 

 all prevalent, and the generic characters, especially in the Capsidce, 

 require much patience and care in examination to ensure the 

 correct placing of a specimen. 



The great majority of the Hemiptera are vegetable feeders, 

 inserting their rostra much after the manner of their victims, the 

 aphides, into the softer structures of plants, and sucking up the 

 juices through the delicate tubular setae, to be presently described. 

 It has, however, long been known that some species are carnivor- 

 ous, though curiously enough this character has been entirely 

 denied to the CapsidcE by most naturalists. Even Mr. Saunders, 

 in his lately published work, says : — " All species occur in summer 

 and early autumn, and subsist on the juices of leaves, etc." 



Some few species are said to associate with ants, Mr. Douglas 

 having found them in the nest of Forinica rubra, and these may 



