72 A BOOK OF INSECTS 



the wings are brilliantly coloured. An exotic sub-family 

 includes the genus Flata, to which reference is made in 

 a succeeding chapter. Many of the Fulgoridce secrete 

 large quantities of a white waxy substance from their 

 abdomens. According to Dr. Sharp this wax forms a 

 favourite food of certain caterpillars, and two or three 

 kinds of maggots may frequently be found concealed in 

 the wax of the living insect. The wax is also used by 

 mankind, notably in China, for candles and other purposes. 

 The Fulgoridce are represented in all parts of the world, 

 about seventy small species being found in Britain. 



The frog-hoppers (Cercopidce) are technically dis- 

 tinguished from the Fulgoridce by having the antennae 

 between, not beneath, the eyes. As their popular name 

 implies, the perfect insects have remarkable leaping powers. 

 Most of them are small, but they often injure plants by 

 puncturing the leaves and sucking the juices. The 

 nymphs also live on plants, and commonly surround 

 themselves with a frothy secretion. In its young state, 

 the commonest British species, Pldlcenus spumarius, is well 

 known as the "cuckoo-spit" insect. There is another 

 family of frog-hoppers known as the Iassidce. 



The allied family Membracidce, for which no popular 

 name appears to exist, has only two British representa- 

 tives ; but in tropical countries the species are very 

 numerous. These insects are of small size, but many of 

 them are very remarkable in form. The pronotum — i.e. 

 the dorsal plate of the first thoracic ring — is produced 

 behind into a long process, which varies greatly in shape, 

 and often completely covers the whole of the insect's 

 body. Sometimes this process acts as a kind of mask 

 which suggests an insect of another order, or some object 

 such as a seed or a thorn. 



The plant-lice (Apliidce) are only too well known to 



