Modern New World Screwworm Eradication Plan

Current Situation: As of early June 2026, New World screwworm has reached Texas again. USDA's current-status page tracks U.S. detections, Mexico cases, movement restrictions, and response actions. The current response includes sterile-fly dispersal, border controls, movement restrictions, public reporting, and expanded production/dispersal infrastructure. USDA has invested in Moore Air Base in Texas as a domestic sterile-fly dispersal site.

Historical Lesson: The historical eradication program worked because it combined: 1. Sterile insect technique, released continuously and at scale 2. Rapid case detection through rancher reports and larval identification 3. Animal movement controls and inspection lines 4. Wound prevention and wound treatment 5. Aerial release logistics using grids, swaths, and release-density planning 6. International rollback from the U.S. southward through Mexico and Central America 7. A permanent biological barrier in Panama/Darien

Objective 1 — Stop establishment in the United States Prevent the Texas detections from becoming a self-sustaining U.S. population.

Objective 2 — Suppress northern Mexico and the U.S.–Mexico border zone The U.S. border cannot function as the final barrier if the fly is abundant just south of it.

Objective 3 — Expand sterile-fly production and release capacity SIT only works when sterile males greatly outnumber fertile wild males. Production capacity is the strategic center of gravity.

Objective 4 — Push the eradication front south Once northern Mexico is stabilized, operations should move south in stages until the Panama/Darien barrier is restored.

Objective 5 — Build permanent readiness After eradication, do not dismantle all capacity. Maintain production, surveillance, contracts, and contingency plans.

Create a Unified Screwworm Eradication Command — a formal joint command, not an informal coordination group.

Core participants: • USDA APHIS • Texas Animal Health Commission • State animal-health agencies in border and livestock-heavy states • Mexico SENASICA • COPEG / Panama-U.S. screwworm commission • FAO / IAEA technical advisers • U.S. Fish and Wildlife Service • Texas Parks and Wildlife Department • U.S. Customs and Border Protection • State veterinary diagnostic labs • Land-grant university extension services • Cattle, sheep, goat, horse, wildlife-ranching, dairy, and pet-industry representatives

Zone 1 — Infested Zone (area around confirmed cases): • Mandatory reporting of suspect wounds • Veterinary inspection of livestock and high-risk domestic animals • Immediate wound treatment • Ban or permit-only movement of susceptible animals • Larval sample submission before disposal • High-density sterile-fly release • Adult suppression around high-risk locations • Trap deployment • Daily situation reporting

Zone 2 — Surveillance Zone (buffer around infested zone): • Market, sale barn, feedlot, dairy, ranch, veterinary clinic, wildlife facility, and border-corridor surveillance • Sampling kits distributed to producers • Weekly trap review • Targeted sterile-fly release if trap or case data show risk • Movement certification for animals leaving the zone

Zone 3 — Sterile-Fly Barrier Zone (broad band along invasion front): • Continuous aerial sterile-fly dispersal • Release density adjusted by season, case data, trap data, animal density, wind, and terrain • Buffer releases on both sides of the border • Rapid surge when cases move north

Zone 4 — Rollback Zone (areas farther south): • Sequential suppression • Intensive SIT • Local movement controls • Producer education • Field diagnostics • Transition from emergency response to verification of freedom

Core Principle: Treat sterile flies like ammunition. Production, quality, storage, transport, and release must be managed as an integrated supply chain.

Production Targets: • Minimum North American capacity: 500 million sterile flies per week (floor, not ceiling) • Surge capacity goal: 750 million to 1 billion per week during continental emergency

Production Facilities: Immediate: Maximize Panama output, accelerate Mexico Metapa renovation, use Moore Air Base for Texas/northern Mexico, contract aircraft and ground-release crews. Medium term: Bring Texas production online, establish modular backup insectaries, stockpile critical inputs, maintain redundant irradiation. Long term: Maintain standby domestic production, keep at least one fully operational U.S. dispersal hub, keep Mexico and Panama facilities funded.

Aerial Release (default for broad coverage): • Grid-based dispersal • Release density adjusted by risk • Denser release around confirmed cases • Wider release barrier along movement corridors • Repeated release cycles, not one-time drops

Ground Release for: ranch clusters, livestock markets, sale barns, dairies, feedlots, veterinary hospitals, border inspection stations, wildlife rehabilitation facilities, urban/peri-urban pet clusters.

Release Density determined by: confirmed cases, trap counts, larval submissions, temperature/humidity, rainfall, wind, livestock density, wildlife density, animal movement data, terrain, proximity to source zones.

Quality Control — every batch monitored for: emergence rate, flight ability, longevity, mating competitiveness, sterility, sex ratio, release survival, dye/marking performance, geographic release accuracy.

Channel 1 — Producer Reporting: Every livestock owner receives: larval collection vials, wound-inspection instructions, QR-code reporting links, hotline numbers, prepaid sample mailers, approved wound-treatment guidance, movement-restriction explanations.

Channel 2 — Veterinary Reporting: Required for: cattle, sheep, goats, horses, dogs, cats, exotic hoofstock, wildlife ranch animals, zoo animals, wildlife rehabilitation cases.

Channel 3 — Trap Network: Deploy at: confirmed-case ranches, neighboring ranches, sale barns, feedlots, dairies, slaughter facilities, livestock-event grounds, border crossings, quarantine stations, river corridors, wildlife migration corridors, high-density deer areas, illegal dumping/offal sites.

Channel 4 — Wildlife Surveillance: Priority: white-tailed deer, exotic deer, feral hogs, coyotes, wildlife ranches, hunting preserves, wildlife rehabilitation centers, roadkill clusters, areas with high tick burden.

Channel 5 — Human and Pet Surveillance: Public-health and veterinary channels should be linked for travel-associated cases, pets, and wound myiasis.

Animals covered: cattle, sheep, goats, horses, swine, dogs, cats, camelids, exotic hoofstock, zoo animals, wildlife rehabilitation animals, captive deer and game animals.

From Infested Zones: • No movement without inspection • Wounds must be treated • Suspect wounds require sample submission • Infested animals require treatment and hold period • Movement certificates required • Destination notification required

From Surveillance Zones: • Inspection before movement • Wound-free certification • Record retention • Event-specific requirements for rodeos, fairs, shows, auctions

Border Controls: • Suspend or restrict live-animal imports from affected regions • Require inspection and certification • Target illegal animal movement and smuggling • Use detector dogs where feasible • Maintain livestock port protocols tied to current risk

The fly needs wounds. Reducing wounds reduces reproduction.

Postpone in high-risk zones: castration, dehorning, branding, ear tagging if avoidable, elective surgery, shearing when injury risk is high, invasive wildlife handling.

Required practices: • Inspect newborn navels daily • Treat wounds immediately • Control ticks and biting flies • Separate animals with suspicious wounds • Use veterinary-approved larvicidal/wound treatments • Document wound cases • Submit larvae before destroying evidence

Producer Incentives — reimburse: veterinary farm calls, sample submission costs, quarantine losses, additional labor for inspection, wound-treatment supplies, losses from movement restrictions.

A reporting system that punishes the first rancher who reports will fail. A system that pays for early reporting will work.

Use adult suppression selectively around: confirmed premises, neighboring premises, livestock concentration points, sale barns, feedlots, dairies, slaughter-adjacent areas, offal/disposal sites, high-risk wildlife corridors, border choke points.

Do not overuse broad insecticide campaigns — they create environmental, political, resistance, and non-target risks. Purpose is to support SIT, not replace it.

Modern SWASS-style program includes: attractant-baited stations, trap-and-kill units, adulticidal bait deployment, monitoring of non-target effects, GIS tracking, strict label/legal compliance, removal after suppression objective is met.

Create a Screwworm Common Operating Picture — all partners see the same map.

Data Layers: confirmed cases, suspect cases, negative submissions, trap results, sterile-fly release polygons, release density, wind/weather, livestock density, wildlife density, animal movement permits, markets/sale barns, vet clinics, feedlots/dairies, border crossings, quarantine zones, lab turnaround times.

Analytics — predict: fly dispersal, livestock movement spread, weather-favored reproduction, insufficient sterile-fly density, weak trap coverage, anomalously low reporting.

Key Metrics: days from wound detection to report, days from report to lab confirmation, days from confirmation to sterile-fly surge, larval submissions, percent negative submissions, trap-positive rate, wild-to-sterile ratio, new premises per week, distance of newest case from previous front, release density by zone, movement violations, producer reimbursement speed.

Messaging Principles: Be direct. Avoid panic. Tell people exactly what to look for. Make reporting easy. Emphasize pets and wildlife, not just cattle.

Ranchers: "Inspect wounds and navels. Treat wounds. Save larvae. Report immediately. You will not be punished for early reporting."

Veterinarians: "Report suspicious myiasis immediately. Submit samples. Treat aggressively. Document animal movement."

Hunters and Wildlife Managers: "Report animals with foul-smelling wounds, visible larvae, abnormal behavior, or head/ear/genital/navel lesions."

Pet Owners: "Check wounds, ears, noses, and surgical sites. Seek veterinary care if larvae are present."

Local Officials: "Support movement controls, carcass disposal, public reporting, and producer assistance."

1. Better Sterile Strains: higher mating competitiveness, better flight performance, longer field survival, genetic sexing strains, gene-editing approaches if safe/legal/accepted.

2. Better Lures and Traps: more sensitive adult detection, species-specific attractants, low-maintenance field traps, automated image recognition, eDNA or environmental surveillance.

3. Faster Diagnostics: field PCR, mobile lab confirmation, image-assisted larval ID, veterinary clinic sample kits.

4. Better Release Systems: drone release for small areas, precision aircraft release, GPS/telemetry verification, automated temperature tracking.

5. Better Wound Therapeutics: approved larvicides, long-acting wound protectants, producer-safe treatment protocols, wildlife-compatible delivery.

Phase 0 — Immediate Containment (Days 0–30): 1. Activate Unified Command 2. Define infested/surveillance/buffer zones 3. Restrict animal movement from infested zones 4. Surge sterile-fly release around detections 5. Deploy traps and mobile response teams 6. Distribute sample kits 7. Create producer reimbursement mechanism 8. Inspect livestock markets, feedlots, dairies, events, border corridors 9. Begin daily GIS reporting 10. Launch public education campaign Success: No unlinked cases outside surveillance zone, reporting increases, lab confirmation <48h, releases verified, movement compliance >95%.

Phase 1 — Border Stabilization (Months 1–6): 1. Expand sterile-fly release polygons along border 2. Coordinate U.S.–Mexico surveillance data 3. Enforce permitted livestock movement 4. Deploy adult suppression around clusters 5. Increase trap density 6. Expand wildlife surveillance 7. Pre-position emergency fly shipments 8. Producer outreach in English and Spanish 9. Contract additional aircraft/pilots 10. Independent review of sterile-fly quality Success: Cases decline weekly, no sustained US trap positives, wild-to-sterile ratio favors sterile, Mexican northern front declines, no movement-related jumps.

Phase 2 — Mexico Rollback (Months 6–36): 1. Divide Mexico into eradication blocks 2. Pair sterile release with movement controls 3. Maintain barrier behind the front 4. Use SWASS ahead of releases 5. Certify zones after surveillance proves freedom 6. Keep border releases active until northern Mexico stable 7. Increase public-private cost sharing 8. Use mobile labs in outbreak regions 9. Integrate wildlife/free-ranging livestock surveillance 10. After-action reviews every 90 days Success: Case front moves south, northern Mexico maintains freedom, border release demand declines, reinfestations detected/extinguished quickly.

Phase 3 — Central America Rollback (Years 2–7): 1. Support COPEG and national vet services 2. Maintain high-output sterile-fly production 3. Staged eradication blocks 4. Support small producers 5. Strengthen movement controls 6. Control illegal livestock movement 7. Maintain permanent sterile barrier at Panama/Darien 8. Build local diagnostic/surveillance capacity Success: Panama barrier restored, Central America north of barrier free, routine surveillance replaces emergency response, permanent funding established.

Phase 4 — Permanent Prevention (Year 7+): 1. Keep U.S. sterile-fly production/dispersal capability 2. Maintain Panama barrier releases 3. Fund Mexico/CA surveillance 4. Keep emergency aircraft contracts 5. Maintain trained response teams 6. Annual exercises 7. Keep producer reporting kits updated 8. Maintain lab proficiency 9. Preserve legal authorities for rapid movement control 10. Maintain public-facing reporting tools

Production: insectaries, larval rearing systems, diet production, environmental controls, irradiation equipment, quality-control labs, emergence rooms, sterile-fly marking/dye systems, packaging lines, backup power, redundant water/HVAC.

Distribution: refrigerated trucks, aircraft loading facilities, fly release boxes/automated release machines, GPS-tracked aircraft, ground-release vehicles, temporary forward operating bases, cold-chain monitoring.

Surveillance: larval sample kits, adult traps, bait/lure supplies, mobile diagnostic labs, microscopes/molecular diagnostic tools, sample chain-of-custody system, GIS platform, mobile reporting app, hotline/call center.

Field Response: PPE, wound-treatment supplies, animal-handling equipment, portable corrals/chutes, veterinary medications, approved larvicides, carcass/offal disposal equipment, biosecurity supplies, signage/checkpoint supplies.

Enforcement/Logistics: movement permits, inspection stations, detector-dog teams, livestock transport tracking, law-enforcement liaison, bilingual field teams, reimbursement/payment system.

Bucket 1 — Emergency Containment: response teams, aircraft, sterile-fly dispersal, traps, mobile labs, producer reimbursement, quarantine enforcement.

Bucket 2 — Production Capacity: Moore Air Base production, Metapa expansion, Panama support, modular backup facilities, irradiation redundancy.

Bucket 3 — Mexico and Central America Rollback: bilateral field operations, movement-control support, surveillance, producer education, mobile labs, regional sterile-fly distribution.

Bucket 4 — Innovation: better lures, better traps, genetic sexing, improved sterile strains, precision release technology, diagnostics, therapeutics.

Bucket 5 — Permanent Prevention: Panama/Darien barrier, standby U.S. capacity, annual exercises, surveillance maintenance, staff training.

Decision Point A — Is the U.S. outbreak contained? Criteria: no new cases outside known zone for two fly generations, traps show no wild-fly expansion, all suspect premises investigated, movement tracing complete, sterile release verified. If yes: continue barrier release and surveillance. If no: expand infested zone, increase release density, tighten movement restrictions.

Decision Point B — Is northern Mexico suppressed? Criteria: declining cases, low wild-fly trap counts, effective movement controls, release density adequate, no repeated border-adjacent detections. If yes: begin rollback south. If no: increase sterile-fly capacity and adult suppression.

Decision Point C — Is sterile-fly capacity adequate? Criteria: release plan fully supplied, reserve capacity available, no skipped release cycles, quality metrics acceptable. If no: prioritize production over almost every other expenditure.

Federal Level: 1. Declare a multi-year eradication campaign, not a temporary emergency response 2. Fully fund Texas, Mexico, and Panama production/dispersal capacity 3. Set a public sterile-fly production target 4. Build a national screwworm GIS dashboard 5. Create a producer indemnity/reimbursement program 6. Expand border and wildlife surveillance 7. Establish a standing scientific advisory panel 8. Fund Mexico/CA operations as U.S. prevention infrastructure

State Level: 1. Activate state animal-health emergency authorities 2. Restrict animal movement from infested zones 3. Coordinate sale barn and event inspections 4. Train veterinarians and extension agents 5. Push reporting kits to producers 6. Integrate wildlife agencies 7. Reimburse compliance costs quickly

Producer Level: 1. Inspect animals daily in high-risk zones 2. Treat wounds immediately 3. Watch newborn navels 4. Save larvae for identification 5. Report suspicious wounds 6. Delay elective wound-causing procedures 7. Control ticks and biting flies 8. Follow movement restrictions

Veterinary Level: 1. Treat suspect cases immediately 2. Submit larvae 3. Report cases 4. Educate clients 5. Document animal movement 6. Help verify wound-free movement status

Do not let the wild population outrun sterile-fly capacity.

Everything else supports that principle. Reporting, trapping, movement control, wound prevention, adult suppression, aircraft logistics, production plants, border coordination, and international rollback all exist to keep the sterile-to-wild ratio high enough for SIT to collapse the population.

The historical program proved the method works. The modern challenge is whether we can rebuild the scale, speed, discipline, and international coordination fast enough.