New World Screwworm Infestation Surges in the United States

By VirentaNews Staff — June 05, 2026

The New World screwworm, a parasitic insect that was once eradicated from the United States, has made an unwelcome return, sparking concerns among farmers and scientists. The screwworm, which feeds on the flesh of warm-blooded animals, poses a significant threat to livestock, particularly in the southern states where it has been spotted. The return of the New World screwworm is a significant development, with implications for the agricultural industry and animal health.

The History of the New World Screwworm

The New World screwworm was once a major problem in the United States, causing significant losses to the livestock industry. However, thanks to a concerted effort by the US Department of Agriculture, the insect was eradicated from the country in the 1960s. The eradication program, which involved the release of sterile male screwworms, was a major success, and the insect was not seen in the US for many years. However, in recent years, there have been reports of the screwworm’s return, and the latest outbreak has sparked concerns among farmers and scientists.

The Current Outbreak

The current outbreak of the New World screwworm is centered in the southern states, where the insect has been spotted in several counties. The outbreak is believed to have originated from an infestation in a neighboring country, and it is thought to have been spread by animal movement and trade. The screwworm is highly infectious, and it can cause significant harm to animals, including death. Farmers and ranchers are being advised to take precautions to protect their livestock, including monitoring their animals closely and reporting any suspicious symptoms to the authorities.

Causes and Effects

The return of the New World screwworm is a complex issue, with multiple causes and effects. The insect’s life cycle is highly dependent on the presence of warm-blooded animals, and its spread is facilitated by animal movement and trade. Climate change is also thought to be a contributing factor, as it allows the insect to survive and thrive in areas where it was previously not found. The effects of the outbreak are significant, with the potential to cause major losses to the livestock industry. According to USDA data, the screwworm infestation could result in millions of dollars in losses to farmers and ranchers.

Implications and Concerns

The return of the New World screwworm has significant implications for the agricultural industry and animal health. The insect’s presence poses a major threat to livestock, particularly in the southern states where it has been spotted. Farmers and ranchers are being advised to take precautions to protect their animals, including monitoring them closely and reporting any suspicious symptoms to the authorities. The outbreak also has implications for international trade, as it could lead to restrictions on the movement of animals and animal products.

Expert Perspectives

Experts are divided on the best course of action to take in response to the outbreak. Some argue that the use of pesticides and other chemicals is the most effective way to control the screwworm population, while others advocate for a more integrated approach that includes the use of sterile male screwworms and other biological controls. According to CDC experts, a comprehensive approach is needed to control the spread of the insect and prevent further outbreaks.

As the situation continues to unfold, it is clear that the return of the New World screwworm is a significant concern that requires immediate attention. Farmers, scientists, and policymakers must work together to develop effective strategies for controlling the insect’s spread and preventing further outbreaks. The use of new technologies and innovative approaches will be critical in this effort, and it is essential that all stakeholders are aware of the latest developments and research on the insect.

Source: The New York Times