343 



MANUAL OF ZOOLOGY. 



The order is divided into the following three sub-orders : 

 Sub-order a. Homoptera. The anterior pair of wings of the 

 same texture throughout (membranous) ; the mouth 

 turned backwards, so that the beak springs from the 

 back of the head. The wings fold over one another 

 when the insect is at rest. There are ocelli between the 

 compound eyes, and the antennae are small and composed 

 of few joints. The females often have an ovipositor of 

 three toothed blades. In this section are the Aphides, 

 the Scale Insects (Cocdd<z\ the Cicadas, the Lantern- 

 flies (Fulgora), &c. 



As typical examples of the Homoptera may be taken the 

 Cicadas (fig. 182, D), the males of which are well known for 



Fig. 182. A, Thrips, enlarged; B, Nepa cinerea, enlarged; C, Cicada Anglica, the 

 wings on the right side of the body being omitted ; D, Larva of the same ; E, Pupa 

 of the same. (Figs. C, D, and E are after Westwood.) 



their power of emitting a musical note or chirp. The Plant- 

 lice or Aphides (fig. 181) live upon the juices of plants, an 

 enormous number of species being known. They may possess 

 two pairs of membranous wings, or none, and they give birth 

 to innumerable young in the summer months by a process 

 of parthenogenesis. The singular Scale-insects (Coccidee) have 

 the males winged, whilst the females are deformed, often 

 scale-like, and devoid of wings. The dried female of the 

 Cochineal Insect (Coccus cacti) constitutes the cochineal of 

 commerce, and the Coccus lacca yields shell-lac. 



Sub-order b. Heteroptera. Anterior wings membranous near 



their apices, but chitinous towards the base (hem elytra) ; 



the rostrum springing from the front of the head. The 



