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Show CUCUMBER DISORDER SPREAD BY INSECTS Mosaic Disease Is Widespread in the United States. Wild Cucumber Vine and Common Milkweed Are Principal Host Plants of Malady Eradication Eradica-tion Is Strongly Urged. (Prepared by the Untied States Department of Agriculture.) The wild cucumber vine and the common milkweed, as shown by investigations in-vestigations by the United States Department De-partment of Agriculture, are the principal prin-cipal wild host plants of the cucumber cucum-ber mosaic, or "white pickle" disease. This disease is widespread in the v ? "J Mosaic Disease of Cucumber. United States, but is most gcneru. timl serious in the Middle West, where the major portion of the pickle-growing industry is located. Cucumber mosaic is caused by a virus, and the most common means of spreading it is by two kinds of Insects, the striped cucumber beetle, the melon aphis, and by pickers. The disease is not carried through the winter in the soil or by insects, and trials have shown that seeds from diseased cultivated cucumbers cucum-bers rarely produce mosaic planis. It has been found, however, that seeds from mosaic fruits of the wild cucumber cucum-ber will produce a certain percentage of mosaic plants when planted and the disease may thus winter over on this wild host. Wild cucumber vines appear along fences and streams from three to four weeks before the cultivated culti-vated cucumbers are planted, and the striped cucumber beetle feeds on these wild plants and then Hies to the cucumber fields, carrying the mosaic virus If It exists. . The common com-mon milkweed Is also subject to cucumber cu-cumber mosaic and as it lives for many years the disease Is reproduced each year from the diseased roots. Insects, particularly the melon aphis, are also the ngents width carry mosaic from milkweed to cucumber. Eradication of these wild hosts Is strongly advised as the most effective control measure yet known. Held experiments indicate that such treatment treat-ment not ordy reduces the amount of disease In the fields, bin also lis seriousness seri-ousness by delaying its appearance by two to four weeks just at the time when the plants are producing huge yields. |