TUKNIP AND CABBAGE-GALL WEEVIL. 247 



the same form of earth cells, and the larvae are similarly 

 thicli, legless, corrugated grubs, their heads furnished with 

 strong jaws oclire-coloured, sliaded to dark chestnut at the 

 tips, and armed with two well-defined teeth, and a ihird much 

 smaller one (fig. 1 : A, cabbage larva; B, turnip larva), some- 

 times little more than a tubercle on the inner side. The only 

 difference observable was a rather more ochreous tint in the 

 grub from the turnip than in that of the cabbage, which was 

 almost while; and in the Ceiitorhynchus larvae from galls of 

 swede turnip the general colour was more ochreous still, 

 conjecturally, in both this and ihe white turnip from the 

 nature of the food. Here, however, there was a slight 

 structural difference, for the third tooth or tubercle on the 

 'aws was absent from the larva of the swede weevil in the 

 specimens 1 had ibr examination, and the teeth themselves 

 were smaller (fig. 1 : c, swede larva), and obtuse at the 

 extremity. They formed their earth cases for pupation about 

 the same distance below the surface as the others, but 

 development, from some unknown cause, did not proceed, so 

 that I had no perfect beetles of these for comparison. 



The cabbage and white turnip grubs appear very indifferent 

 to interference : on the galls being opened, whether apparently 

 fully grown or not, they almost invariably buried themselves 

 at once in any earth they might be laid upon ; and if in a few- 

 days their earth-cases were broken into for examination they 

 would reconstruct them. These cases were about an eighth 

 to three-sixteenths of an inch long, obtusely oval, though 

 somewhat irregular in shape, and lying loose in the hollow 

 chamber from which their materials had been taken (like a 

 dry kernel in a nut-shell). The nature of the structure varied 

 a little with that of the surrounding materials, being chiefly 

 of earth, with a few minute pebbles adhering in the case of 

 the turnip larvae, and with the addition of a little vegetable 

 matter in those of the cabbage (fig 2 : cell, and cell in its 

 chamber, magnified). With the cabbage grub the case was 

 sufficiently advanced to cover a quarter of its length two days 

 after it had buried itself The method of procedure appeared 

 first a commencement at the tail end, then holding on by the 

 caudal extremity to this growing structure, so that if disturbed 

 it still carried its partly-foruied husk with it. The larva 

 gradually built its earthy covering onward around it, 



