XXIII. Observations on the Insects that infested the Corn in the Year 1795. In a Letter to the Rev. Samuel Goodenough, LL. D. F. R. S. Tr. L. S

Thomas Marsham
1797 Transactions of the Linnean Society of London  
Read Ma)) 3,1796. DEAR SIR, OWARDS the end of July lafi, a friend of mine (Mr. Long) T who had the management of a farm in Hertfordkire, was telling me that an infeA had made its appearance among the wheat, which threatened to do much rnifchief; that it was found, in many int'tances, to have attacked one, two, or more grains in a n ear; and that it was difcoverable by thofe grains appearing yellow, or as it were ripe, while all the remaining grains in the. fame ear were perfeAly green.-I
more » ... Aly green.-I defired that gentleman to bring me up €ome of the difeafeed ears, which he did ; and I b u n d them exaaly as he had defcribed them.-On opening thofe grains that feemed Jifeai'ed, I faund in many of them an orange-coloured powdcr, and in ieveral, one or two very minute larue, differing in colour, froin a yellowifh white to a deep yellow. They were.too minute for exainination by the naked eye; but by appIying a deep magnifier I perceived them to be the tarzwof a fmall muJcca, and to rcfemble very much thofe aphidivorous h v e that produce one particular family of the mufie. They were thick at one end, and gradually dimi nifhed to a point at the other, where the head was fituate. They extended and contra&ed thedelves at pleafure ; to which m s added added a leaping motion, frequently jumping full half an inch from the paper on which I examined them. T h e grain whTre thefc in fells I i d IxKcfion nppeareJ a little {hrunk. Bcfides there f(Irvlr, I fr-eqwntly met with the T'hrgs phy/+w running about betwccn t h e huiks, and alfo feveral very i'niali Ichwumns, oxie of which fettled upon a hi-vn while under niy glaCs ; and I Caw it repeatedly wvo~md the litt!e maggot with its tubc, and I have no doubt it cte-poGted its cggj. This WJS feeii alfo by hlr. Al'Lcay, F.L.S. who was examining them with me.-l p l x c d this wheat in water, a n d Mr. Long continued to fupplv me with freih ears every week ; and allo, at my rcquelt, tied fotne gauze round leveral of the difcafed ears, while growing in the field, which hood until the corn was ripe ; but I was not able, with all my care, to difcover the fly produced from the before-inentioned larva. Anxious, however, to determine, if pofible, the hiitory and progref's of this little animal, which now f'eemed to create univerfal alarm; and knowing that my various avocations would prevent my quitting London ; I had written, on the firfl hearins of the inlea, t o feveral of my friends who rehde in the country, and to you among the reit, recluefling their particular attention to this fubjea, and the refult of that application I now give you.-From the oblervations you were enabled to make, you will remember t h a t you had obferved only the Thr@ phjfa;us, which you concluded to have been the infeA, if it was a n i n f e a which did the mifchief, although you could not difcover any material injury that had occurred.-From our truly valuable friends Wm. Markwick, Efq. of Catsfield, near Battle, and the Rev. Wm. Kirby, of Barham, of whofe accuracy and attention to this fubjeCt w e have both received very convincing proofs, I received the following accoui1ts. Mr. Markwick, in his letter of the 9th of Augufi, fays : " I 1-2-" paircd immediately to my wheat fields on receiving your h e r ,
doi:10.1111/j.1096-3642.1797.tb00567.x fatcat:ibdnrbkksfadfbmq55nax2hdqy