AgDaily
When people talk about New World screwworms in the United States, one date gets repeated over and over: 1966.
That is the year the U.S. Department of Agriculture now says the U.S. was declared free of indigenous, or self-sustaining, screwworm populations. It is also the date appearing in many modern explainers — from media outlets to scientific journals to animal health giant Zoetis — as screwworms again threaten livestock and livestock.