Page:Transactions of the Linnean Society of London, Volume 2 (1794).djvu/125

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Mr. Markwick's Account, &c.
77

the outside, nor could any escape from within. On the 14th of May three small flies were discovered sitting on the inside of the gauze [See tab. 15. fig. d. D.] A few days after three more of the same flies appeared; there were in the flower-pot of bran six roots of diseased wheat, which produced six flies : on examining the roots afterwards, I found an empty shell of the chrysalis in each, so that I think there can be no doubt of the identity of the insect in question.

I mentioned that the larva and chrysalis were always found deposited on the principal stem just above the root. This stem is invariably destroyed, which gave the crop a most disastrous appearance, so that there was scarcely a hope of any produce: but after the larva had changed into its chrysalis state the mischief ceased, and the root was not so materially injured as to prevent its throwing out fresh roots on each side, or stocking itself as the farmers term it; as I experienced by those which I planted in my garden

In short, at harvest time I was most agreeably surprised to find a good crop of wheat, and the ears large and fine throughout the whole field. My friend thinks it the best crop on his farm, and supposes he shall have about three quarters and a half of threshed corn from each acre.

I hope some other gentlemen of the Linnean Society have had opportunities of making their observations upon this subject. I do not pretend to any very great skill in Entomology; I only relate facts, and have endeavoured to be very accurate in stating them

During my observations upon this insect, a variety of thoughts suggested themselves to my mind. It was hinted to me, that possibly this was what has been called the Hessian fly, whose depredations in America have been so notorious. If so, a little good English hus- bandry, by keeping the ground in heart, and thus enabling the wounded roots to repair themselves by strong lateral ones, prevents our being alarmed to so great a degree. I had my doubts how andwhat