Black Fly, an insect that at-tacks the seedling leaves of turnips, cabbages, and many otler vegetables. In summer, it may frequently be seen in swarms on the wing near the ground, search ing for, and settling on the fresh bites; and Urns, in some seasons, destroying thousands of acres. Its ravages may be prevented by the following means :
Mix one ounce of flour of sulphur with three pounds of turnip-seed daily, for three days successively, in a glazed earthen pot, and keep it closely covered, stirring it well at each addition, that the seed may be impregnated with the sulphur : then sow it as usual, on an acre of ground, and the fly will not attack it till the third or fourth seedling leaf is formed, by which time the plant will have acquired a bitterish property, and conse-quently be out of danger. Others advise to fix alder-bows in a harrow, and draw them over the land immediately after the seed is sown. Again, others bruise the bows, and fumigate them with burnt tobacco, and a small quantity of asafoetida. - See Turnip.