Screwworm Crisis: A Wake-Up Call for Regenerative Agriculture
How a Parasitic Fly Exposes the Fragility of Our Food System and the Urgent Need for Resilient, Regenerative Practices
The screwworm threat at our southern border reveals critical vulnerabilities in industrial agriculture and highlights why regenerative practices matter now more than ever.
What You'll Learn in This Article
Why the USDA closed the US-Mexico border to livestock trade (again)
How screwworms devastate both livestock and wildlife populations
The connection between climate change and expanding pest threats
Why regenerative agriculture offers crucial resilience against biosecurity threats
How biodiversity loss amplifies agricultural vulnerabilities
What this crisis reveals about our food system's weaknesses
The U.S. Department of Agriculture's decision to close our southern border to livestock trade on July 9, 2025, marks the third such closure in eight months. As New World Screwworm advances northward—now detected just 370 miles from the U.S. border—this crisis exposes fundamental flaws in our industrial agricultural system while highlighting the critical importance of regenerative practices.
Understanding the Screwworm Threat to Regenerative Agriculture
The New World Screwworm isn't just another agricultural pest—it's a parasitic fly whose larvae literally eat living flesh. Unlike most fly larvae that consume dead tissue, screwworm maggots burrow into open wounds of warm-blooded animals, causing excruciating pain and often death if untreated.
For regenerative farmers and ranchers who prioritize animal welfare and natural grazing systems, this screwworm threat to regenerative agriculture represents a particularly cruel irony. The very practices that make regenerative systems healthier—outdoor grazing, natural breeding, minimal confinement—also create more opportunities for screwworm infestation.
Historical data reveals the devastating potential: before eradication efforts succeeded in 1966, up to 75% of newborn deer died from screwworm infections. In livestock operations, mortality rates could exceed 50% in heavily infested areas. The economic toll was staggering—adjusted for inflation, a similar outbreak today could cost billions.
Climate Change: Amplifying Agricultural Vulnerabilities
Here's what should terrify every farmer: climate change is creating perfect conditions for screwworm expansion. These parasites thrive in temperatures between 77-86°F with moderate humidity—conditions that climate change is pushing further north each year.
The pest's previous containment to Central and South America depended on cold winters killing overwintering populations. But as freezing temperatures become less frequent and less severe, previously protected regions become vulnerable to year-round establishment. This isn't a temporary threat that will die off come winter—it's a permanent shift in agricultural risk.
Key Insight: The northward advance of screwworms represents a canary in the coal mine for climate-driven agricultural disruption. What other pests and diseases are waiting in the wings as our climate warms?
Why Industrial Agriculture is Uniquely Vulnerable
The current crisis exposes critical weaknesses in our industrialized food system:
1. Dependency on Cross-Border Trade Mexico supplies 60% of U.S. cattle imports—over 1.25 million head annually worth $1.3 billion. This concentrated supply chain creates massive vulnerabilities when borders close.
2. Monoculture Mindset Industrial operations that concentrate thousands of animals create perfect conditions for explosive pest outbreaks. One infected animal in a feedlot could rapidly spread screwworm to hundreds.
3. Loss of Natural Resilience Decades of breeding for production over hardiness have created animals poorly equipped to handle parasitic challenges. Heritage breeds maintained in regenerative systems often show greater parasite resistance.
4. Chemical Dependency While sterile insect technique offers hope for screwworm control, it requires massive infrastructure and ongoing investment—another technological band-aid rather than addressing root causes.
The Regenerative Agriculture Advantage
Regenerative practices offer multiple layers of protection against threats like screwworm:
Enhanced Biodiversity
Diverse pastures with multiple species create complex ecosystems where beneficial insects and birds help control pest populations. Dung beetles, ground beetles, and parasitic wasps all play roles in disrupting fly life cycles.
Soil Health Benefits
Healthy soils support robust plant growth, providing better nutrition for grazing animals. Well-nourished animals with strong immune systems better resist parasitic infections and heal faster from wounds.
Rotational Grazing
Moving animals frequently disrupts pest life cycles and reduces parasite load in any given area. This natural break in the transmission cycle provides protection without chemicals.
Heritage Genetics
Many heritage livestock breeds maintained on regenerative farms evolved with natural parasite resistance. These genetics become increasingly valuable as chemical controls fail and new threats emerge.
Integrated Pest Management
Regenerative farmers already use multiple strategies—from companion planting to beneficial habitat—that create resilience against various pests. These systems adapt more readily to new threats.
The Wildlife Connection: Ecosystem Health Matters
The screwworm threat to regenerative agriculture extends beyond livestock to entire ecosystems. Wildlife populations serve as both victims and vectors for screwworm spread. A single infected deer can travel 125 miles, spreading the pest far beyond any containment effort.
This highlights a crucial principle of regenerative agriculture: farm health and ecosystem health are inseparable. Industrial operations that view wildlife as competitors miss the critical roles these species play in maintaining ecological balance. When we destroy habitat and reduce biodiversity, we eliminate natural pest controls and create vulnerabilities.
The potential wildlife devastation from screwworm establishment would cascade through ecosystems:
Pollinator populations could crash as infected animals die
Seed dispersal patterns would shift as wildlife numbers plummet
Predator-prey relationships would destabilize
Nutrient cycling would be disrupted
These ecosystem services directly benefit agricultural operations. Their loss would require expensive technological replacements—if replacement is even possible.
Economic Reality Check
The numbers tell a stark story. Texas alone sees $4.6 billion annually from deer hunting, supporting 24,000 jobs. Nationwide, wildlife-related recreation generates over $140 billion yearly. A screwworm outbreak wouldn't just impact agriculture—it would devastate rural economies dependent on healthy ecosystems.
For regenerative farmers building diverse income streams through agritourism, hunting leases, and ecosystem services, screwworm establishment could eliminate multiple revenue sources simultaneously. This economic fragility reveals why resilience—not just efficiency—must guide agricultural decision-making.
Building Agricultural Resilience
The screwworm crisis offers crucial lessons for building resilient food systems:
1. Diversification is Non-Negotiable Relying on single supply chains, single species, or single management strategies creates unacceptable vulnerabilities. Regenerative systems that integrate multiple enterprises spread risk.
2. Regional Self-Sufficiency Matters The ability to close borders instantly highlights why regional food security matters. Communities dependent on distant supply chains face disruption from countless potential crises.
3. Ecosystem Health Equals Farm Health Protecting biodiversity isn't environmental luxury—it's agricultural necessity. Every species lost reduces system resilience and increases vulnerability to the next threat.
4. Prevention Beats Treatment The U.S. successfully eradicated screwworm through massive investment. But preventing reestablishment through strong biosecurity and healthy ecosystems costs far less than another eradication campaign.
5. Climate Adaptation Can't Wait If we're not planning for climate-driven pest expansion, we're planning to fail. Regenerative practices that build soil health, biodiversity, and system resilience offer the best defense.
The Path Forward
Secretary of Agriculture Brooke Rollins called screwworm "absolutely devastating" to the cattle industry, but the threat extends far beyond cattle. This crisis represents a fundamental challenge to how we produce food in an era of climate change and ecological disruption.
Regenerative agriculture offers a path forward—not through technological fixes or chemical interventions, but through working with natural systems to build resilience. By prioritizing:
Soil health that supports robust plant and animal health
Biodiversity that provides natural pest control
Regional food systems that reduce vulnerability
Animal welfare that prevents suffering
Ecosystem services that benefit all
We can create agricultural systems capable of weathering whatever threats emerge.
The screwworm at our border is a warning. We can heed it by doubling down on industrial approaches that create vulnerability, or we can embrace regenerative practices that build true resilience. The choice we make will determine not just whether screwworm establishes in the U.S., but whether our food system can handle the mounting challenges ahead.
FAQs About Screwworm and Regenerative Agriculture
How does rotational grazing help prevent screwworm infestations?
Rotational grazing moves animals frequently between paddocks, disrupting fly breeding cycles and reducing parasite loads in any area. This practice also maintains shorter, healthier pastures where wounds from tall, sharp grasses are less likely. The rest periods between grazing allow beneficial insects to establish and help control pest populations naturally.
Can heritage livestock breeds really resist parasites better?
Yes, many heritage breeds evolved alongside parasites and developed natural resistance mechanisms. For example, some cattle breeds have thicker hides, faster wound healing, or behavioral adaptations that reduce fly strikes. These traits were often lost in modern breeds selected solely for production. Regenerative farmers maintaining heritage genetics preserve crucial resilience for threats like screwworm.
What immediate steps should regenerative farmers take regarding the screwworm threat?
Monitor animals daily for wounds and unusual behavior, maintain good fence conditions to prevent injuries, time breeding to avoid fly season peaks, and establish relationships with large-animal veterinarians familiar with screwworm. Build habitat for beneficial predators like birds and wasps that prey on flies. Most importantly, advocate for policies that support regional food security and ecosystem health rather than just emergency responses.