TUBNIP-FLY. 
93 
Scliemes out of number have been tried to get rid of or 
kill this little pest wherever it has appeared, the particulars 
very soon found that its locality was not confined to turnip-fields, but that it was 
to he met with in grass lands which had not been ploughed for many years, 
and where no turnips were to be found within half a mile. I have since found 
them in abundance in dry situations in all grass lands where I have taken the 
trouble to search for them. Although I found the insect in such abundance, I 
was unsuccessful in my endeavours to discover its mode of breeding until after 
five years, when a small piece of land (the upper part of a field sown with bar- 
ley) in a sheltered situation with a south aspect, and which had been well 
dressed with lime, was sown, early in May, with white stone turnips for the ta- 
ble, but they no sooner appeared above ground than they were destroyed by the 
fly ; it was then sown again and harrowed, and the surface thickly strewed 
over with wood ashes, but the plants were again devoured as rapidly as before, 
and not more than a dozen acquired the rough leaf, and a few of these sur- 
vived till the leaves grew to be six or seven inches in length, but they were 
perforated in every part. Upon examining one of these leaves (a portion of 
which, preserved dry, I send with this paper) against the light with a magni- 
fying glass, I perceived a larva between the upper and under surface, a careful 
inspection of which led me to think it the larva of a beetle^ and probably of the 
one I had been so long in search of. I hastened back to the field, and carefully 
removed the earth around the plant from which the leaf had been taken, and 
there had the satisfaction to find specimens of the larvae and pupce. 
" I had previously endeavoured to breed them, by keeping a number con- 
fined in a small box covered with wire gauze, but as I could in this way only 
feed them by dropping in fresh bits of turnip-leaf daily, I did not succeed in 
my object, although the insects appeared healthy, and I kept them alive in 
this manner from July until February in the following year. The rea- 
son of my failure is now suflScienlly obvious, since it is necessary that 
the leaf should be in a growing state, otherwise the eggs which are laid 
upon it shrivel up when the leaf becomes dry. Being still at fault as 
to the origin of the larvae, I captured ten males and ten females in pairs, 
and inclosed them in a glass tube covered at each end with wire gauze, 
into which I introduced a single leaf of turnip, with water to keep it 
fresh ; by this means I was enabled to examine the insects and leaf on all 
sides with a magnifying glass at any time without disturbing them. Hav- 
ing, previous to introducing the leaf, ascertained, with a strong magnifyer, 
that there were no eggs or larvae upon it, on the following day I had the satis- 
faction to perceive five small, smooth, oval-shaped eggs adhering to the un- 
derside of the leaf, and so nearly resembling it in colour that I was no longer 
