530 
TURNIP-FLY. 
half a mile. It will be necessary to consider this 
part of their history before we enter upon a dis- 
cussion of the remedies. The turnip-beetles hy- 
bernate, or live through the winter, in a torpid 
state, and may be found under the bark of trees, 
as well as beneath the fallen leaves, in the chinks 
of old timber and paling, the stumps of thorns 
and of other bushes, where the bark does not 
adhere close to the stem; and the hollow stalks 
of grass and stubble seem to afford them an asy- 
lum during the inclement months of winter ; but, 
inactive as they then are, the warmth of the 
hand is sufficient to revive them in a few mi- 
nutes, so that an unusually mild day in January 
or March will partially seduce them from their 
retreats, and will render them almost as active 
as would the ardent sun of summer. On the 
first indication of spring, if the weather prove 
fine, warmed by the sun and cheered by his rays, 
they arouse from their slumbers, and perma- 
nently leave their winter quarters for sunny. 
situations, where they may be seen sitting on 
walls in considerable numbers, or sunning them- 
selves on dry banks and on clods of earth, pro- 
tected from the wind. They have been observed 
in gardens on turnips and cabbage-plants as 
early as March, and in April on the crops in the 
fields; but May and June appear to be the more 
usual periods of their first and most fatal at- 
tacks. The autumnal crops have been occasion- 
ally destroyed by them, and in one instance I 
have seen recorded, as late as the middle of Sep- 
tember. They may be said to be abundant from 
May to October amongst the grass, and in all 
fields, whether of wheat, oats, or barley. It 
seems that the taste of the turnip-beetle is far 
less fastidious than is generally imagined. This 
might be fairly inferred from its abounding in 
situations where the turnip does not grow. There 
can be little doubt, however, that it prefers those 
plants which are termed cruciferous, from the 
shape of their flowers, of which cabbages and 
turnips are examples; of these the leaves of the 
horse-radish, the common turnip, and the radish 
are its favourite food, but cabbages, cauliflowers, 
colewort, watercresses, ladies’-smocks, and hedge- 
mustard called jack-by-the-hedge, are often at- 
tacked; the charlock or wild mustard is also 
sometimes covered with them at the end of April, 
and in May the leaves will be seen pierced with 
holes, but as soon as the turnips come up they 
desert other allied plants. Mr. Berry has re- 
corded a remarkable exception, for he says that, 
after consuming the cabbage-plants, the flies 
attacked and destroyed the young hops, which 
belong to a very different tribe of plants. K6l- 
lar also states that both summer and winter 
turnips left for seed suffer in warm and dry 
weather, from the attacks of the fly injuring the 
flowers so as to spoil the produce of the seed. 
“The next subject to be considered is a re- 
medy against the attacks of the turnip-beetle. 
Now with regard to the eggs, we see that they 
are laid on the under side of the rough leaf, 
where they are pretty well secured from rain, 
and also protected by the strong and projecting 
ribs that support the leaf from any injury that 
might occur from the leaves being ruffled by the 
wind or other casualties; and the inferior skin, 
being the most delicate, is best adapted for the. 
entry of the infant and tender maggots into the 
substance of the leaf. It is not, therefore, at 
this stage that much could be done in destroy- 
ing them. The maggots, it is evident, live upon 
the rough leaf, and do little or no mischief to 
the growth of the plants; they dwell perfectly 
secure between the two cuticles, unless it be 
when they leave the burrows they had first com- 
menced, probably not of common occurrence, to 
form new ones at a remote part of the same or 
upon another leaf. At this period they are most 
probably affected by parasitic enemies. The 
chrysalis is buried only just beneath the surface 
of the earth, but it is probably protected in a 
slight web, forming a cradle for it to lie in free 
from pressure. I think some efforts might be 
successfully made for its destruction at this 
time. It is, however, in its last and perfect 
state that the mischief is done. It is the beetle 
which destroys the two first smooth leaves, called 
the cotyledons, and the heart of the plant be- 
tween them, by piercing them like a sieve, 
destroying the cellular tissue and stopping the 
growth of the plant. They also feed upon the 
rough leaves, drilling them full of round holes, 
which are larger on the upper than the under 
side of the leaf; and if the appetite of the beetle 
be not satisfied, he enlarges the aperture and 
thus gives it an irregular form, which dilates 
with the growth of the leaf: hence the large 
holes we see at a later period. After all, it is at 
this stage of their existence, I am inclined to 
believe, that we can attack them with the best 
prospect of success, if they cannot be kept off by 
other means. In collecting the turnip-beetles 
by sweeping and various methods, large numbers 
of small carnivorous beetles, belonging to the 
Carabide and Staphylinide, are found with 
them. These probably feed upon the larve ; but 
from the very recent discovery of the early stages 
of the turnip-beetle, we are yet ignorant of the 
parasites, of which it may be presumed there 
are more than one species, that prey upon the 
maggots and chrysalides; for it is a wise dis- 
pensation of Providence to keep every animal in 
check by some other that is either more power- 
ful or more sagacious than itself; and this coun- 
teracting effect is produced in a degree equal, or 
eventually superior, to the noxious animal, so 
that in a greater or less space of time the de- 
structive power may be rendered no longer for- 
midable, or be absolutely annihilated by the 
attacks of its parasites. This natural process, 
though never failing, is often too slow in its 
operation to secure immediate relief. The far- 
mer must, therefore, devise means, if possible, 
a 
° 
