05/10/2025
In late 2016, a New World screwworm outbreak occurred in Florida’s Key deer, an endangered species. While the response, including treatment of affected deer and deployment of sterile flies, was relatively rapid (6 months to eradicate the pest), 14% of the key deer population was lost. Because this outbreak occurred outside of fawning season, over 90% of the mortalities were bucks with wounds from fighting during the rut. In other words, the 14% population loss came from a loss of over 40% of the bucks; an outbreak at a different time of year or with a slower or multi-year response time would have been more devastating on Key deer populations.
It is difficult to forecast if the current movement of screwworms through Mexico will reach the U.S. border. But we do know that the eradication of this pest in the U.S. afforded 50 plus years of deer population restoration efforts and that re-emergence of the screwworm will result in a rapid reversal of deer numbers. As pressure from screwworms mounts in Central America and Mexico, it is imperative that Texas and the U.S. are prepared to hold the line, with capacity to respond prescriptively and rapidly to ensure a healthy future for our valuable wildlife resources.
(This is the third post in a three part series on New World screwworm.)
