THE TURNIP-FLY. 
449 
more than twice that number might have been found, higher up the 
stem, and among the branches of the tree.’’ Other Correspondents 
also state the fact of its being found in winter. Mr. Willey states, 
“In 1825, in the month of January, I was engaged in a turnip field, 
when one of my sons, who was trimming a hedge called to me, and 
shewed me an immense number of the turnip fly, in a state of tor¬ 
pidity. They were lodged in the shattered part of the old stock, 
from which the thorns had been cut a few years before. We ex¬ 
amined several other parts of the hedge, and found almost every cre¬ 
vice, where the thorns had been shattered, completely full of them. I 
took a quantity of them home, in order to shew them to my neigh¬ 
bours, and when they were brought to the influence of heat, they be¬ 
came quite lively, and hopped away, apparently with as much strength 
and vigour as in the month of July.” 
A striking instance of the manner in which these insects will in¬ 
crease when left undisturbed and provided with shelter, is given by 
Mr. Berry ; “ about eight years ago, (he writes) I cleared for culti¬ 
vation a piece of ground, which had probably for centuries been 
woodland ; and was, when I commenced operations, covered with de¬ 
cayed stumps of trees, bushes, and rank weeds. Having been drained, 
it was well worked and limed, and planted with hops and interme¬ 
diate rows of cabbages. When the latter were about a foot high, 
they became covered and ultimately destroyed by myriads of turnip 
flies, which literally blackened the leaves. Having consumed the 
cabbage, they attacked and destroyed the young hops. In the culti¬ 
vation of the same land, during subsequent years, this did not again 
occur.” The inference which Mr. Berry draws, and in which he 
seems warranted, is, that the abundance of shelter and vegetable 
matter always previously found on the spot had produced that won¬ 
derful quantity of flies; but that clearing and cultivation depriving 
them of food and shelter, destroyed or drove them away. This is a 
a fact greatly encouraging, as implying the general decrease of the 
insect on clean well cultivated land. 
Much upon the general habits of the Insect will be gathered from 
what has preceded. “In its food, (as Mr. Henderson remarks,) the 
turnip fly seems to prefer the common turnip to all other Vegetables, 
horse radish, perhaps, excepted; and, as soon as the plants come up, 
they attract all the flies in the immediate neighbourhood. I observed, 
last Spring, that many cruciferous plants, on which they had been feed¬ 
ing, were deserted as soon as the turnips came up; and they have 
continued to reside on the turnip plant ever since, although their 
leaves are old and stiff, and although cauliflower, cabbage, and other 
H h 
