|Culy, M - DOWELANCO, DES MOINES, IA|
Submitted to: Down to Earth
Publication Type: Popular Publication
Publication Acceptance Date: December 22, 1995
Publication Date: N/A
Technical Abstract: Earthworms are an integral part of soil ecology and are particularly valuable in reduced-till and no-till cropping systems. Little is known of the impact of agricultural management practices on earthworms. Laboratory and field studies were conducted to determine the impact of soil applied granular insecticides (carbofuran, fonofos, phorate, terbufos, or chlorpyrifos) on earthworms. The earthworm community consisted of night crawlers (Lumbricus terrestris), southern worms (Aporrectodea trapezoides), Canadian worms (A. tuberculata), pasture worms (A. turgida), pink worms (A. rosea), and gray worms (Octolasion tyrtaeum). Laboratory studies showed that chlorpyrifos was the least toxic of the five formulated insecticides tested. Subsequent field studies showed that chlorpyrifos did not affect earthworm numbers and the other insecticides had varying effects and at times significantly reduced earthworm populations. This knowledge will aid growers in the development of management practices that are compatible with earthworms.