affect'wci the Turnip- Crop?, 
119 
level, so as to leave enough space for the growth of the turnip, 
potato, corn, or whatever is required for the sustenance of the 
larvae : if the sun shine upon it, it will be necessary to shade the 
plant a day or two from the heat and light by inverting a garden- 
pot over it, the larvas may then be put in, and the top must be 
closed, either by a cover made of wire-gauze, strained over a frame 
and fitting close into the top, or coarse canvas may be substituted; 
and it will give more room for the food to grow up, if two pieces 
of cane or willow-twigs be tied together forming a cross, and the 
four ends bent down inside of the barrel, over which the canvas 
may be tied ; the great objection to this material is, that it soon 
rots when exposed to the weather. Some twigs or dead bushes 
should be stuck round to keep off cats, &c., and the lid or cover- 
ing must be opened from time to time to see what is going on. 
Of course such objects as the larvae live amongst in a natural 
state ought to be introduced, otherwise they will frequently die 
for want of the proper materials to form their cocoons ; moss, dead 
leaves, old bark, rotten wood, green turf, &c., are often required. 
By the method here recommended the magnificent Death's-head 
]\loth,* which feeds upon potato-leaves whilst a caterpillar, has 
been bred with tolerable certainty, but these insects have almost 
always died after passing into the chrysalis state when fed in any 
other way, and I doubt not that the economy of the wire-worm 
might be completely developed by pursuing the same treatment. 
CuRCULio PLKUROSTIGMA. The Turnip-gall Weevil. 
The excrescences (fig. 16) which frequently disfigure the 
turnip-bulbs and are not confined to any particular variety, on 
being opened will be found to contain a small maggot (fig. 17), 
something like that which we represented in pi. F. fig. 26, but it is 
thicker : these galls, or knobs as they are generally calledjf vary 
greatly in bulk, from the size of a pea to that of a large acorn ; 
the smaller ones contain a single maggot, the larger excrescences 
several, as shown by the cavities laid open at fig. 17.| My friend 
Mr. Spence § having bred the Weevil from these galls, we may con- 
clude that, soon after the turnip-bulb is formed, the impregnated 
female pierces a hole through the rind with her proboscis and 
deposits an egg in it, which shortly hatches, and the young maggot 
feeds upon the internal substance of the bulb : the excrescences 
are produced most probably, as in other similar cases, by the in- 
* Curtis's Brit. Ent., fol. and pi. 147. 
■1- Anbury is sometimes improperly applied to this malformation. 
X I found four larvae in one excrescence on the 'Jth of November. 
§ Kirby and Spence's Int. to Ent., vol. i. p. 450. The roots of the char- 
lock and cabbages are similarly affected, but by other species of the same 
genus. 
