The looming threat of the New World screwworm, a notorious parasitic pest, is a growing concern for the United States, with Colin Woodall, CEO of the National Cattlemen’s Beef Association, indicating an almost certainty of its re-entry across the southern border. “It’s no longer a question of whether we see a return of New World screwworms in the U.S., it’s a matter of when,” Woodall stated.
The screwworm’s lifecycle poses a significant danger to livestock. Female screwworms deposit their eggs near open wounds on cattle. Upon hatching, these eggs develop into larvae, commonly known as maggots, which then burrow deep into the living tissue of the host, intensely feeding and causing extensive damage. This parasitic activity can lead to severe health issues, debilitating infections, and, if left untreated, even death in affected animals. The economic impact on the cattle industry, should a widespread infestation occur, would be substantial, affecting ranchers, consumers, and the broader agricultural sector.
Historically, the primary and most effective method of controlling screwworm populations has been through the sterile insect technique (SIT). This involves mass-rearing male screwworm flies in specialized facilities, sterilizing them through irradiation, and then releasing them into the wild. When these sterile males mate with wild female screwworms, the eggs produced are infertile, effectively breaking the reproductive cycle of the pest. This crucial process is currently carried out in a factory located in Mexico, making international cooperation very important to manage the threat. It’s also noteworthy that while female screwworms die after laying their eggs just once, the male screwworm continues to live, capable of mating multiple times, which makes the release of sterile males a powerful strategy for control.
The potential re-emergence of the screwworm has not gone unnoticed by USDA. Agriculture Secretary Brooke Rollins recently addressed the House Agriculture Committee, acknowledging the gravity of the situation. Secretary Rollins assured the committee that a major announcement regarding the next preventative steps to combat this impending threat would be made soon. The specifics of these preventative measures are awaited by stakeholders across the agricultural industry, who are preparing for the potential challenges ahead.
Producers can prepare themselves to know what to look for and how to treat animals infected with New World screwworm by visiting ncba.org.
