Documents de session de l'Ontario, 1871-1972, No.32. Ut M. Walsh a montré de façon satisfaisante que tous ces vers communs, eventtiough qu'ils présentent des variations occasionnelles de couleur, doivent être mentionnés à l'espèce describepar le Dr Harris sous le nom d'Euri/foma [Isjsama] hordei. En ce qui concerne le genre du in.sect (le premier des deux noms scientifiques), il y a eu beaucoup de discussions aussi ; mais ina rapport de ce caractère il est inutile d'ennuyer le lecteur avec lui. Nous allons merelystate que nous avons l'avis que l'insecte appartient À L'Iso.^oma (à laquelle s'applique également lecépage-voir

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Ontario Sessional Papers, 1871-72, No.1-5 . ut it has been satisfactorily shewn by Mr. Walsh that all these Joint-worms, eventtiough they present occasional variations in colour, are to be referred to the species describedby Dr. Harris under the name of Euri/foma [Isjsama] hordei. With regard to the genus ofthe in.sect (the first of the two scientific names), there has been much discussion also ; but ina report of this character it is unnecessary to trouble the reader with it. We shall merelystate that we hold the opinion that the insect belongs to Iso.^oma (to which also pertains thegrape-seed insect [/. vitis, Saunders], described by our coadjutor, Mr. Saunders, in last yearsKeport p. 109). and not to Eart/toma. a genus of parasitic flies. The Joint-worm is a tiny footless grub or maggot, about one-ei<ihth of an inch in length, of a pale yellow colour and with dark browuLsh jaws. It occupies a little swelling or cell Quoted by Dr. Fitch, 7th N. V. Rcport, p. 145. 399 35 Victoria. Sessional Papers (No. 5). A. 1871-2 Fiff. 58.. inside the substance of the straw, and placedgenerally a little above the first or secondjoint from the root. These swellings, or galls, are clearly shown in the accompany-ing illustration i fig. 58, a) ; the black dotsindicate the holes through which the insecthas finally escaped in its winged state (b.At first sight, these knotty swellings ofthe stem are apt to elude observation, be-cause, being almost always situated justabove the joint or knot on that stem—whence comes the popular name Joint-worms—they are enwrapped and hiddenby the sheath of the blade; but on strippingofi the sheath, as is supposed to have beendone in the engraving, they become at once * conspicuous objects. The mode in which the Joint-worm produces its destructive effects upon the small grain may be readily explained.Not only is the sap of the plant extracted on its road to the ear, in order to form the abnormalwoody enlargement or gall, in which the larvae are imb

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• bookauthorontariol
• bookcentury1800
• bookdecade1870
• bookyear1876