HOMOPTERA. 299 



by Mr. Westwood to have the same origin, though it 

 may be a question whether it does not arise from the 

 hopping, frog-like motions of the insect, which, when 

 come to perfection, no longer inhabits the frothy 

 nest. 



Among the Aphides and their congeners, some species 

 conceal themselves with tufts of a woolly or cottony 

 substance, exuded, like the Cuckoo-spit froth, from their 

 bodies ; others slightly powder themselves over, or en- 

 tirely bury themselves in a fine meal produced in the 

 same manner ; while others, again, as the Scale insects 

 relations of the foreign Cochineals exude a secretion 

 which will be spoken of later. Some Aphides have 

 another mode of concealment, forming gall-like ex- 

 crescences upon trees, within which they live. 



Homoptera is subdivided into three sections : 



1. TRIMERA, in which the tarsi have three joints; 

 the antenna are very small and awl-like ; two or three 

 ocelli are generally present, and the fore-wings are some- 

 times thickened, sometimes clear. 



This contains the Cicada, an insect related to the 

 foreign Fire-flies and the Frog-hoppers. 



2. DIMERA, in which the tarsi have two joints, and 

 the antenna? are considerably longer than in the former 

 sections. 



This contains the Aphis family, and insects not unlike 

 them, the Psyllid and Aleyrodes, tiny little white 

 Moth-like creatures. 



3. MONOMERA, in which the tarsi have only one joint, 

 and which contains the curious Scale insects. 



Cicada, in the first family in TRIMERA, consist of 

 singular-looking insects, with wide head and thorax 

 and a triangular abdomen. The wings are beautifully 



