HABITATIONS OF INSECTS. 257 



which Reaumur received from Cyprus^ ; and others again to two-winged 

 flies, as the woody galls of the thistle caused by Trypeta Cardui^, and 

 the cottony galls found on ground ivy, wild thyme, &c., as well as a very 

 singular one on the juniper resembling a flower, described by De Geer^ 

 all which are the work of minute gall-gnats (jCecidomyicB Latr.). Some of 

 these last convert even the flowers of plants into a kind of galls, as T. Loti 

 of De Geer'*, which inhabits the blossoms o^ Lotus corniculatits ; and one 

 which I have myself observed to render the flowers of Err/simiim Barbarca 

 hke a hop blossom. A similar monstrous appearance is communicated to 

 the flowers of Teucrium suplnum by a little field-bug, Tingis Tucr'n of 

 Host^, and to another plant of the same genus by one of the same tribe 

 described by Reaumur.^ In these two last instances, however, the habita- 

 tions do not seem strictly entitled to the appellation of galls, as they ori- 

 ginate not from the egg, 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 appli- 

 cable to the gall-like swellings formed by many Aphides, as A. Pistaci<E, 

 which causes the leaves of different species of Pistacia to expand into red 

 finger-like cavities ; A. Ab'wtis, 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 miniature ; and A. BursaricB, which with its brood inhabits 

 angular utriculi on the leaf-stalk of the black poplar, numbers of which I 

 have observed on those trees by the road-side from Hull to Cottingham. 

 The majority of galls are what entomologists have denominated monotha- 

 lamous, or consisting of only one chamber or cell ; but some are polytha- 

 lamous, or consisting of several. 



Among the more remarkable galls are those so much resembling minute 

 fungi as to have been actually described as such ; as Sclcrotium fasciculatum 

 Schumacher, which is a common gall on oak leaves ; and the Kev, M. J. 

 Berkeley has given an account of a similar one found by W. S. MacLeay, 

 Esq., in Cuba, on the leaf of a plant of the order OclinacccE, which on a 

 cursory examination was regarded by some of our first botanists as an 

 epiphytous fungus, but proved on dissection to be a true gall, and distin- 

 guished from all previously known by its very curious operculum or lid, 

 e\idently meant for the more ready egress of the occupant (which has not 

 yet been ascertained) in its perfect state.' 



Having thus described the most remarkable of the habitations constructed 

 by the parent insects for the accommodation of their future young, I pro- 

 ceed to the second kind mentioned ; namely, those which are formed by 

 the insect itself for its own use. These may be again subdivided 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 eating, the substances upon which they feed. 

 Of this description are the majority of subterranean larvte, and those 

 which feed on wood ; as the Bostricld or labyrinth beetles ; the Anobia, 

 which excavate the little circular holes frequently met with in ancient fur- 



1 Eeaum. iii.418. 2 jijia. 455, s De Geer, vi. 409 



■* Ibid. vi. 421. 5 Jacquin Collect, ii. 255. 



^ Keaum. iii. 427. 7 Trans. Linn. Soc. xviii. 576. 



