This section is from the book "The Gardener's Monthly And Horticulturist V18", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
A Felton, Kent Co., Del. correspondent, says: "I send by mail to-day in a small box, packed in moss, two cabbage leaves of Jersey Wakefield variety. They are spring grown, in a gentle hot-bed; the bed has been only moderately warm at any time. I have observed lately that the leaves have looked yellow, but paid very little attention to them, thinking it was the effect of frosts during the late cold nights. To-day finding them looking worse than ever, I examined the plants and found the leaves thickly covered on the under surface with a white insect, about the size of red spider that infests hot-house plants, perhaps somewhat larger than these. The bed of plants has the appearance of having been scalded. At first they appear in small patches and some leaves have but very few on them, others have, as you see by the specimens I send you, the under surface thickly studded. In the same bed of about 4000 plants are about 1000 of Fottler's Early Drumhead, and these are but slightly, if at all affected.
I have failed to find any reference to such an insect in Henderson's books, the Gardener's Monthly or other Agricultural papers, and I take the liberty of sending you these specimens, hoping they may arrive in good order, and that you may enlighten myself and the many other readers of the Gardener's Monthly in regard to this, to me, singular insect, which I fear may prove a serious hindrance to the already risky business of growing cabbage."
[This is Perojwspora parasitica, near relative of the Potato fungus, and likely to prove a dangerous customer. - Ed. G. M.l