164 



CHAPTEE VII. 



CARPENTRY OF TREE-HOPPERS AND SAW-FLIES. 



nPHE operations of an insect in boring into a leaf or a bud to 

 *- form a lodgment for its eggs appear very simple. The 

 tools, however, by which these effects are performed are very 

 complicated and curious. In the case of gall-flies (Cynips), 

 the operation itself is not so remarkable as its subsequent 

 chemical effects. These effects are so different from any 

 others that may be classed under the head of Insect Architec- 

 ture, that we shall reserve them for. the latter part of this 

 volume, although, with reference to the use of galls, the 

 protection of eggs and larvae, they ought to find a place here. 

 We shall, however, at present confine ourselves to those 

 which simply excavate a nest, without producing a tumour. 



The first of these insects which we shall mention is 

 celebrated for its song, by the ancient Greek poets, under the 

 name of Tettix. The Kornans called it Cicada, which we 

 sometimes, but erroneously, translate " grasshopper ;" for 

 the grasshoppers belong to an entirely different order of 

 insects. We shall, therefore, take the liberty of calling the 

 Cicadse Tree-hoppers, to which the cuckoo-spit insect (Teiti- 

 gonia spumaria, OLIV.) is allied ; but there is only one of the 

 true Cicadae hitherto ascertained to be British, namely, the 

 Cicada hcematodes (LINN.), which was discovered in the New 

 Forest, Hampshire, by Mr. Daniel Bydder. 



M. Keaumur was exceedingly anxious to study the economy 

 of these insects ; but they not being indigenous in the neigh- 

 bourhood of Paris, he commissioned his friends to send him 

 some from more southern latitudes, and he procured in this 

 way specimens not only from the South of France and from 

 Italy, but also from Egypt. From these specimens he has 

 given the best account of them yet published ; for though, 



