Home / Environment / Screwworm's Return Sparks Urgent California Alert
Screwworm's Return Sparks Urgent California Alert
18 Dec
Summary
- Parasitic fly larvae feed on living tissue, unlike harmless relatives.
- California launches statewide monitoring for returning invasive fly.
- Sterile male fly technique is key to stopping potential outbreaks.

Researchers at the University of California Riverside are initiating a statewide monitoring program to detect the New World screwworm, a parasitic fly whose larvae feed on living animal tissue. This invasive pest, which can infest open wounds, has a history of causing significant damage to livestock.
The effort is backed by $507,000 from the California Department of Food and Agriculture. Scientists are deploying traps with lures mimicking rotting flesh across California to identify any early signs of the fly's presence. Historically, the species was eradicated in the U.S. using sterile male flies, a method believed to be effective again.
With the screwworm reappearing in Central America and southern Mexico, experts are concerned about its potential spread to California. The focus remains on protecting the state's vulnerable dairy and cattle industries, with public awareness among veterinarians and livestock handlers being a crucial line of defense.


