APHIDES. 615 



two anterior pair of legs. The dorsal surface in these 

 insects is covered with a mosaic of hexagonal plates, very 

 closely resembling the plates of the carapace of the tor- 

 toise. In this particular our artist has certainly fallen 

 into an error. Another peculiarity is that the body is 

 much flattened out, and looks so much like a scale on the 

 surface of the leaf, that it requires considerable practice, 

 as well as quickness of sight, to detect the young Maple- 

 aphis. One of the lamellae is seen highly magnified at c, 

 and a tenent-hair at 6. The antennae taper off towards the 

 apex, are serrate on both edges, and terminate in fine 

 setae, one of which is shown at a. Below the insertions 

 of the antennae, brilliant scarlet- coloured compound eyes 

 are placed, which receive their nervous supply from the 

 central ganglion. 



Aphides live upon plants, the juices of which they 

 suck, and, when they occur in great numbers, cause con- 

 siderable damage to vegetation ; a fact well known to 

 the gardener and farmer. Many plants are liable to be 

 attacked by swarms of these insects, which cause the 

 leaves to curl up : they grow sickly, and their produce is 

 greatly reduced. One striking instance is presented in the 

 devastation caused by the Hop-fly (Aphis humuli). 



The Aphrophora bifasciata, common Frog-hopper, has 

 the antennae placed between the eyes, and the scutellum 

 visible that is to say, not covered by a process of the 

 prothorax. The eyes, never more than two in number, 

 are sometimes wanting. These little creatures are always 

 furnished with long hind legs, which enable them to per- 

 form most extraordinary 

 leaping feats. The best- 

 known British species, be- 

 cause so very abundant in 

 gardens, is the Cuckoo-spit, 

 Froth-fly, fig. 275. The 

 names Cuckoo- spit and 



Froth-fly both allude to the Fig- w.-Aphrophora sp-um 

 peculiar habit of the insect, cuckoo-spit. 



while in the larva state, of > ^ froth y substance, b, The pupa 

 enveloping itself in a kind of frothy secretion, somewhat 

 resembling saliva ; and this, indeed, was at one time sup 



