dieldrin

views updated May 23 2018

dieldrin An organochlorine insecticide that was formerly used as a seed dressing. In the 1950s seed-eating birds were exposed to lethal doses and predatory birds accumulated doses ingested from their prey, which caused them to lay eggs with shells too thin to protect the embryo adequately. Restrictions on the use of dieldrin, introduced in the 1960s, were followed by a recovery in populations of birds of prey.