THE CLASSIFICATION OF INSECTS 



165 



The Hemiptera have an incomplete metamorphosis, the young 

 at birth resembling the parents in most essential characteristics 

 except size and the presence of wings. 



The order is sub-divided into three sub-orders, one, the 

 Parasita, composed of wingless species living as parasites on 

 man and other mammals; another, the Homoptera, winged 

 species with fore and hind wings of the same texture through- 

 out and usually held sloping or roof-like over the back; and 



FIG. 77. A water-bug, Serphus dilatalus. (Natural size.) 



another, the Heteroptera, with four wings held flat on the back 

 when folded and with the bases of the front wings thickened, 

 hence the name of the order (hemi-, half, ptera, wings). The 

 Parasita include the sucking lice; the Hetero ptera the squash- 

 bugs, chinch bugs, water-boatmen, assassin-bugs and stink- 

 bugs; while the Homoptera include the cicada or harvest-flies, 

 the tree- and leaf-hoppers, the aphids, or plant-lice and the 

 degenerate scale-insects. Some of the more injurious species 

 of this order are described in Chapters XXX to XXXVII. 



