45 % HABITATIONS OF INSECTS. 



but from the larva, which, in the operation of extracting 

 the sap, in some way imparts a morbid action to the 

 juices, causing the flower to expand unnaturally : and 

 the same remark is applicable to the gall-like swellings 

 formed by many Aphides, as A. PistacicE, which causes 

 the leaves of different species of Pistacia to expand into 

 red finger-like cavities ; A. Pi?ii, which converts the buds 

 or young shoots of the fir into a very beautiful gall, 

 somewhat resembling a fir-cone, or a pine-apple in mi^ 

 niature; and A. Bursarice, which with its brood inha- 

 bits angular utriculi on the leafstalk of the black poplar, 

 numbers of which I observed this year on_ those trees by 

 the road-side from Hull to Cottingham. — The majority 

 of galls are what entomologists have denominated mono- 

 thalamous, or consisting of only one chamber or cell ; 

 but some are polythalamous, or consisting of several, 



Having thus described the most remarkable of the ha- 

 bitations constructed by the parent insects for the accom- 

 modation of their future young, I proceed to the second 

 kind mentioned, namely, those which are formed by the 

 insect itself for its own use. These may be again sub- 

 divided into such as are the work of the insects in their 

 larva state ; and such as are formed by perfect insects. 



Many larvae of all orders need no other habitations 

 than the holes which they form in seeking for, or eat- 

 ing, the substances upon which they feed. Of this de- 

 scription are the majority of subterranean larvae, and 

 those which feed on wood, as the Bostrichi, F. or laby- 

 rinth beetles ; the Anobia, F. which excavate the little 

 circular holes frequently met with in ancient furniture 



