Steps to take:
• Frequently inspect cattle and pay close attention to tick bites, cuts and dehorning / branding sites.
• Immediately treat any open wounds, scratches, or scabs. Screwworms in wounds are killed by direct application of a wound dressing.
• Do not let larvae fall onto the ground, as they will pupate and continue the life cycle. Larvae can be killed by placing in alcohol.
• Closely monitor new calves and mothers. NWS often lay eggs on the navel areas of calves, and the vulva and perineum of cows. On bulls and steers, monitor the sheath / prepuce as well.
• Pay close attention to nasal passages and eyes for signs of larvae( maggot) infestation.
• Minimize access of wild animals( birds, feral hogs, etc.) to cattle to the greatest extent possible.
• Practice good biosecurity measures like frequently cleaning clothing, boots, vehicles, and equipment on your farm or ranch.
To find more recommendations for biosecurity practices to implement on your operation to protect your herd, visit www. bqa. org / resources / biosecurity-resources. If you suspect NWS activity in your cattle, contact your veterinarian immediately.
References:
1. Eradicating New World Screwworm with Sterile Insect Technique. https:// www. aphis. usda. gov / sites / default / files / factsheet-eradicating-nws-sit. pdf.
2. USDA Announces Completion of Sterile Fly Dispersal Facility in Texas | USDA. https:// www. usda. gov / aboutusda / news / press-releases / 2026 / 02 / 09 / usda-announcescompletion-sterile-fly-dispersal-facility-texas
3. New World Screwworm Resources. https:// www. ncba. org / education-resources / industry-updates-resources / newworld-screwworm-resources.
NCBA Priorities for Combating New World Screwworm
1 2 3 4
Increase sterile fly production
Enhance coordination with stakeholder groups
Accelerate approval of vital treatments
Strengthen eradication efforts across borders
THINK IT’ S SCREWWORM? HERE’ S WHAT TO DO
Contact your veterinarian.
Spray down potentially infested areas with pesticide / insect sprays.
Seek treatment for your cattle ASAP.
Collect any maggot-like specimens and save them in rubbing alcohol.
Do not move your suspected cattle, except to bring them to the vet.
Wear gloves to protect yourself.
Keep your cattle in a safe contained space.
Scan the QR code or visit ncba. org for more information regarding screwworm. www. NCBA. org NATIONAL CATTLEMEN 11