Texas Just Released Its First New World Screwworm Zones

Texas confirmed its first New World screwworm case on June 3, 2026. Starting in late August, USDA's Animal and Plant Health Inspection Service (APHIS) began releasing infested zones from movement restrictions one by one, and that pattern has continued through September — the clearest tangible sign yet that the outbreak response is working, even though the broader situation isn't fully resolved.

What a zone release actually means

The first two Texas zones released, on August 31, were Infested Zone 02.A, covering La Salle and Webb counties, and Infested Zone 03, covering Gillespie, Kerr, and Kimble counties, according to APHIS and corroborating coverage from Beef Magazine. A Texas Animal Health Commission executive order dated August 31 confirms the release and lifts the movement restrictions that had applied to livestock and other regulated articles in those areas. The release followed active surveillance work: per APHIS, the Texas Animal Health Commission's executive director found no sign of an established wild New World screwworm population remaining in the released zones before the restrictions were lifted. New Mexico's sole infested zone, which had seen no additional cases since its initial June 7 detection, followed the same pattern — sustained absence of new findings, then an official release, on August 30. More releases followed in Texas: National Hog Farmer reported Infested Zones 01.B and 05 were released on September 3, and further zone releases continued in the weeks after that, according to subsequent industry trade coverage.

The broader case count, as of the most recent verifiable data

The most recent well-corroborated case tally traces to a DTN report dated September 21, 2026, citing USDA data: 49 total confirmed US cases, 48 in Texas and 1 in New Mexico. No cases had been detected in wildlife, and no screwworm flies had turned up in US fly-trapping surveillance, per the same reporting. Widely syndicated news coverage reported separately, on September 7, that USDA had released its one-billionth sterile fly in the response effort, with fewer than 50 total US cases recorded for the year at that point — broadly consistent with the slightly higher count reported two weeks later. No case-count or facility-status update newer than late September turned up in research for this piece; the outbreak response is ongoing, and these figures should be read as the most recent reliably confirmed snapshot rather than a final, closed-out tally.

Why sterile flies are the core long-term strategy

New World screwworm is controlled primarily through the sterile insect technique: breeding and releasing large numbers of sterile male flies that mate with wild females, whose eggs then fail to develop, gradually collapsing the wild population's ability to reproduce. Meat+Poultry reported in March 2026 that USDA and the US Army Corps of Engineers had announced a construction contract for a new domestic sterile-fly production facility at Moore Air Base in Edinburg, Texas, with an initial target of 100 million sterile flies per week, aimed at scaling toward 300 million per week over time. That facility was originally targeted for a November 2027 opening; USDA Secretary Brooke Rollins said in separate, earlier reporting the agency expected it to open ahead of that schedule. A separate sterile-fly dispersal facility at the same base had its grand opening back in February 2026, serving as a distribution point for flies produced elsewhere, including an expanded production facility in Metapa, Mexico, which opened in mid-2026 to supplement a long-running sterile-fly plant in Panama.

• Texas released its first two New World screwworm infested zones (La Salle/Webb and Gillespie/Kerr/Kimble counties) on August 31, 2026 — nearly three months after its first case — with additional zones (01.B and 05) following on September 3 and more releases continuing through September.
• New Mexico's only infested zone, with no new cases since its June 7 detection, was released one day earlier, on August 30.
• The most recent well-corroborated case count (per a Sept. 21, 2026 DTN report citing USDA data) puts total US infestations at 49 (48 Texas, 1 New Mexico), with no cases in wildlife and none detected in fly-trap surveillance.
• USDA reported releasing its one-billionth sterile fly in the response effort around September 7, 2026.
• A new domestic sterile-fly production facility at Moore Air Base, Texas — targeting up to 300 million flies a week eventually — broke ground in April 2026, potentially opening ahead of its original November 2027 target.

An outbreak response built around zone-by-zone release, rather than a single all-clear announcement, is a reminder that invasive pest containment is usually a gradual, area-by-area process. A free Sevacorp inspection can help identify early warning signs of unusual pest activity on a property, regardless of the pest involved.

• Sources:
• USDA APHIS — "APHIS Approves Release of New World Screwworm Infested Zones in Texas" — https://www.aphis.usda.gov/news/agency-announcements/aphis-approves-release-new-world-screwworm-infested-zones-texas
• USDA APHIS — "APHIS Approves Release of New World Screwworm Infested Zone in New Mexico" — https://www.aphis.usda.gov/news/agency-announcements/aphis-approves-release-new-world-screwworm-infested-zone-new-mexico
• Texas Animal Health Commission — Executive Order, Infested Zone Release (Aug. 31, 2026) — https://www.tahc.texas.gov/regs/pdf/2026-08-31_EDO_InfestedZoneRelease_03.pdf
• Beef Magazine — "Two Screwworm Infested Zones in Texas Released" — https://www.beefmagazine.com/livestock-management/two-screwworm-infested-zones-in-texas-released
• National Hog Farmer — "Texas Releases More New World Screwworm Infested Zones" — https://www.nationalhogfarmer.com/livestock-management/texas-releases-more-new-world-screwworm-infested-zones
• DTN — "NWS Zones Released Across Texas" (Sept. 21, 2026) — https://www.dtnpf.com/agriculture/web/ag/livestock/article/2026/09/21/texas-gains-ground-screwworm-zones
• Meat+Poultry — "USDA Announces Construction Contract for Sterile Fly Production Facility in Texas" (March 2026) — https://www.meatpoultry.com/articles/33227-usda-announces-construction-contract-for-sterile-fly-production-facility-in-texas
• KY3 (Gray Television) — "Government Released Its Billionth Fly. Here's Why." (Sept. 7, 2026) — https://www.ky3.com/2026/09/07/government-releases-billions-flies-heres-why/