I 



142 



Harris upon the Ecoriomy of some 



mals, says that " Cassida seems to belong to a peculiar 

 type ;'' that " at present he knows of no analogous form 

 amongst the apterous tribes, and must therefore leave this 

 without a denomination ;" and that " perhaps the larva of 

 Hispa or Alurnus, when known, will throw light upon this 



su 



bject. 



"* 



The larva of Hispa has not the most distant 



resemblance to that of Cassida, or to any other now 

 known among the genera with which it has been arti- 

 ficially associated. So far as mere form is concerned, it 

 is related to the wood-eating larvae of the Capricorn 

 beetles, particularly of the genus Callidium ; while its 

 habits are those of the leaf-mining caterpillars of certain 



moths. 



Towards the eud of July, 1820, 1 perceived upon an 

 apple-tree several leaves which had large brownish spots 

 upon them. These spots were not occasioned by dis- 

 ease, but by the destruction of the Internal pulpy sub- 

 Stance or parenchyma of the - leaf, while the cuticle or 

 skin, both above and below, remained entire. When a 

 leaf was held between the eye and the light, there could 

 be seen, through the discolored but semi-transparent cuti- 

 cle, a little whitish flattened grub, which had devoured 

 the parenchyma, and lay enclosed in the cavity thus 

 formed between the tw^o layers of skip. On being dis- 

 turbed, this insect moved wdth a wriggling motion from 

 one part of its retreat to another, backwards quite as 

 readily as forwards. The shape of the spots w as irregu- 

 lar, and they varied somewhat in size ; but on an average 

 each one might have been about an inch square. Several 

 leaves containing larvae, among which was one that had 

 already passed into the pupa or chrysalis state, were shut 



Kirby & Spence, Introduction to Entomology, III. p. 16G. 



