Economic entomology for the farmer Economic entomology for the economicentomolo00smit_0 Year: 1896 THE INSECT WORLD. 301 Fig. 339. The ' cotton-worm' is the larva oi Aletia argillacea, about which many volumes have been written, and whose life history has been thoroughly investigated under the direction of the United States Entomological Commission and the entomologists of the United States Department of Agriculture. To one especially interested in this insect these elaborate reports will be useful and must be consulted. It will suffice here to say that the caterpillars pupate in a l
Economic entomology for the farmer Economic entomology for the economicentomolo00smit_0 Year: 1896 THE INSECT WORLD. 301 Fig. 339. The ' cotton-worm' is the larva oi Aletia argillacea, about which many volumes have been written, and whose life history has been thoroughly investigated under the direction of the United States Entomological Commission and the entomologists of the United States Department of Agriculture. To one especially interested in this insect these elaborate reports will be useful and must be consulted. It will suffice here to say that the caterpillars pupate in a loose co- coon spun on the leaves of the plants, and from the dark-brown pupa comes a dull, tawny or clay- colored moth, with indistinct, dark, wavy, transverse lines, and a rather prominent leaden-white spot, more or less margined with black, near the middle of the fore-wings. There are several broods in the course of the year, but only the later ones be- come seriously injurious, the plant then being sometimes entirely de- foliated. A curious feature is that the insects probably do not spend the winter in our territory, but adults immigrate each year from more southern regions. The migrating habit is marked in the later broods maturing on cotton in our country, and the moths have been often seen in great numbers as far north as Canada. As the wings are closely scaled, they do not readily show the wear and tear of long flight, and specimens have been taken in the far north as fresh and bright as if hatched there. It is possible that under favorable circumstances the caterpillars may support themselves on plants other than the cotton, but we have no positive information of their having done so. Of late years the insects are much less injurious than in times past, largely as the result of a diversified agriculture, which has made it less easy for them to increase in abnormal numbers. Planters have also learnt that a prompt application of the arsenites when Cotton-worms, from a
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