Here’s what Colorado should know about New World screwworm

Key Points:

• The New World screwworm, a destructive pest that attacks animal flesh, has been confirmed in six cases in Texas and New Mexico, prompting Colorado agriculture officials to activate a response plan and urge vigilance among livestock owners.
• The screwworm fly is larger than a housefly with orange-tinted eyes, and its maggot stage burrows into wounds causing severe injury or death in animals; human infections are rare.
• Colorado is hosting extended webinars to educate livestock owners and the public on identifying and reporting screwworm cases, with instructions to collect larvae samples for analysis if infestation is suspected.
• The screwworm was eradicated in the U.S. in the 1960s but reemerged in Mexico in 2023 and now the southwestern U.S.; control efforts include releasing sterile male flies to reduce the population through sterile egg production.
• Animal owners with suspected cases are advised to contact Colorado’s animal control office via phone or email to report infestations and receive guidance.