New World Screwworm – An Information Webinar for All Livestock Producers

New World Screwworm – An Information Webinar for All Livestock Producers All livestock producers should know the risks of the New World Screwworm (NWS), how to recognize signs of NWS infestations and how to prepare for its possible introduction into California. NWS refers to a species of fly similar in size and appearance to the common blow fly but has maggots that burrow (screw) into wounds with devastating consequences to livestock. 

Dr. Tom Talbot, CCA Animal Health Committee Chair, says that “If NWS were to be detected within the borders of California, I am deeply concerned not only about the health and welfare of our animals, but also about our ability to move animals within the state as well as across state lines.” 

Given the significant threat of NWS to the livestock industry, the University of California Cooperative Extension, in partnership with California Cattlemen’s Association and California Wool Growers Association, is holding a webinar covering this returning threat to the US livestock industry. Eradicated from the US in the 1960s and later pushed as far south as Central America, NWS has recently migrated back north and as of early-October is close to the US-Mexico border. NWS is a unique parasite in that it lays eggs in wounds as small as a tick bite resulting in maggots growing under the skin often undetected until a large wound appears. NWS can have devastating effects on animal health and welfare, livestock movements, and can be lethal to the animal. 

This webinar will be held on Wednesday, November 19, 2025 - 6:00 to 7:30 PM

Registrations are due by 1:00 PM on Tuesday, November 18th.

After you register, you will receive an email message after 3:00 PM on Tuesday, November 18th with instructions on how to join the webinar via Zoom.