Jasper County Democrat, Volume 17, Number 100, Rensselaer, Jasper County, 24 March 1915 — The Corn Root-Worm. [ARTICLE]

The Corn Root-Worm.

Numerous letters have been received by this station recently, concerning two corn-root insects, viz.: the corn root-worm and the corn root-aphis. It is evident, therefore, that these insects have been unusually abundant in certain parts of the state. In fact, both species are more or less abundant in all of the corn growing states of the Mississippi valley. It has, therefore, been deemed best to issue a press bulletin on each of these species, giving to farmers such information as is known concerning their habits, and how to hold them in check. The corn root-worm has destroyed millions of dollars worth of corn during the last thirty years for Indiana farmers, and yet it is one of the easiest species of insects to control, when once the farmer becomes acquainted with its habits. Like most insects of this class, k is useless to attempt to hold it in check by the application of poisons; it covers too much territory, and, during the period when it does its injury, it is concealed beneath the surface of the soil. As one becomes better acquainted with its life history, therefore, the more evident it becomes that the application of good up-to-date farming methods is the only remedy needed. This insect is closely related to the striped cucumber beetle, belonging to the same genus, is about the same size and shape, but the color is a light green. The adult beetles may be found feeding upon the silk and pollen of the corn during the last of July and through August until the corn plants approach maturity, when they lay their eggs on the base of the stalks, just below the surface of the soil, and pass the winter in the egg state. The eggs hatch in late spring or early summer, and at first the larvae eat the smaller roots, but as the plants develop they bore out the larger roots, causing the plants to dwindle and die, or to become so dwarfed as to amount £3 nothing. The full grown larvae are white, chunky individuals, about one-tenth of an inch long, and nearly as thick. They pupate in small oval cells in the ground, and the beetles appear soon after. Remedy—As the larvae 'do not feed upon anything tyut the corn roots, it is evident that if a regular rotation of crops is practised, so that com is grown on the same soil only once, or twice, in three or four years, there will be no chance for the insects to increase. The trouble invariably comes from planting corn after corn, except on river bottoms, which are overflowed several times during each year. Corn has been grown on the bottom lands along the Wabash river near fayette, every year for the past thirty years at least, and I have never known a crop to be injured by this insect; but on the upland, black prairie anti muck soils where corn is the principal crop grown, it is sure to give trouble. On such land, oats and grass should rotate with corn. J. TROOP, Chief in Entomology, Purdue University Agricultural Experiment Station.