COMMISSIONER SID MILLER REAFFIRMS TEXAS’ AGGRESSIVE RESPONSE TO SCREWWORM DETECTION NEAR BORDER (9/23/2025)

Miller calls for the immediate use of pesticide bait following NWS detection 70 miles from the Texas border

AUSTIN—Today, Texas Agriculture Commissioner Sid Miller made it clear that the Texas Department of Agriculture (TDA) is not waiting on the sidelines when it comes to protecting Texas livestock from the New World screwworm (NWS). The agency is taking immediate and aggressive action to use pesticide bait to prevent the pest from re-establishing itself in Texas. While TDA has already been proactive in guarding against NWS, Commissioner Miller is now intensifying those measures following confirmation by Mexico’s SENASICA of a new case in Sabinas Hidalgo, Nuevo León—less than 70 miles from the U.S.–Mexico border.

"The screwworm is dangerously close,” warned Commissioner Miller. "It nearly wiped out our cattle industry before; we need to act forcefully now. That’s why I insist we start using pesticide bait immediately. It took 29 years to eradicate the screwworm with sterile flies alone, and we don’t have that kind of time this time around. Time is of the essence.”

Pesticide baits remain the most immediate line of defense. Historically, Dichlorvos was used to eradicate flies, killing up to 90% of flies on contact. When paired with monitoring systems such as TDA Swormlure, they buy ranchers and veterinarians valuable time to stop outbreaks before they spread.

“Using bait followed by sterile flies is the one-two punch we need to knock the New World screwworm out,” added Miller. "Deploy the bait, stop this pest, and protect our cattle industry. It’s that simple.”

In response to the ongoing spread of the New World screwworm south of the Texas border, TDA has implemented the following measures:

TDA SWORMLURE: ADVANCED EARLY DETECTION

TDA Swormlure is a state-of-the-art attractant using a proprietary polymer and chemical blend. It mimics the smell of rotting flesh, which uniquely targets the New World Screwworm with little impact on other insects and wildlife. It can be rapidly deployed across Texas, providing ranchers and veterinarians with an early-warning system to detect and halt screwworms before they spread.

INOCULATION THROUGH VACCINE: BUILT-IN HERD PROTECTION

TDA is researching a platform vaccine that provides livestock with direct protection against screwworm. This non-mRNA technology modifies proteins in the animal’s blood, preventing screwworm eggs from developing into larvae. Already successful in tick trials, the vaccine is expected to be ready in 5–8 months and will offer ranchers a powerful built-in shield to prevent infection before it occurs.

PESTICIDE BAITS: RAPID RESPONSE DEFENSE

When used alongside a potent attractant like TDA Swormlure, pesticide bait remains the fastest line of defense against screwworm. They give ranchers critical time to stop outbreaks in their tracks. Both the attractant and the bait, when utilized in a trap, will represent a key line of defense for Texas ranchers once tested and deployed at scale.

IVERMECTIN: PREVENTION AND TREATMENT ACROSS HERDS

Unlike past outbreaks, ivermectin is now available in both injection and pour-on forms, functioning as both a preventative and a treatment for screwworm myiasis. TDA is pursuing approval for the use of feed additives to cover herds broadly and is exploring options to protect wildlife, such as high-fence deer, to close potential pathways for the pest to spread.

IMPROVE PUBLIC TESTING ACCESS

TDA has secured specimen collection kits for ranchers and TDA field staff to use when suspected cases are reported. Samples will be collected on-site, either by the rancher, veterinarian, or by TDA personnel, and sent directly to USDA-APHIS for confirmation testing. By expanding access to these kits, TDA is empowering ranchers and its own teams to act quickly, ensuring faster sample submission and reducing response times in the fight against infestation.

 “The recent case found only 70 miles south of our border should trigger serious concern,” Miller emphasized. “Although it hasn't crossed into our territory yet, its proximity means we must get ready for its potential arrival. Innovation, science, and prompt action are crucial in defending against the screwworm threat and ensuring that Texas will not allow this pest to establish itself.”

WHAT YOU CAN DO

NWS maggots can infest livestock, other warm-blooded animals, and humans. They most often enter an animal through an open wound and feed on the animal’s living flesh. 

1. TDA urges residents on the southern Texas border to check their pets and livestock for signs of NWS.
2. Look for draining or enlarging wounds, as well as signs of discomfort. Also look for screwworm larvae (maggots) and eggs in or around body openings, such as the nose, ears, and genitalia, or the navel of newborn animals.

Although it is uncommon in people, if you notice a suspicious lesion on your body or suspect you have contracted screwworm, seek medical attention immediately.

If you suspect your animal is infected with screwworm, contact the TDA or a USDA area veterinarian immediately.