US Drops Sterile Flies in Panama to Protect $1B Livestock Industry

Half as Interesting

By pushing an irradiated fly perimeter to the narrow Darién Gap, the US shields North American livestock from a $1 billion annual parasite threat for roughly $15 million a year.

AI-assisted summary of Why the US Drops 14.7 Million Worms On Panama Every Week — original source. Check the original for full context.

Source published: 2024-06-06

Key ideas

The United States maintains an ongoing aerial barrier along the Panama-Colombia border, dispersing millions of sterile New World screwworm flies to prevent a flesh-eating parasite from re-entering North America. (0:00)
Re-establishment of the New World screwworm in the United States would inflict an estimated $1 billion in annual damages on the livestock industry. (0:00)
A specialized facility in Pacora, Panama, produces roughly 20 million sterile screwworms each week using Cobalt-60 radiation to exploit the female fly's single-mating biology. (1:50)
Decades of bilateral campaigns pushed the biological boundary from the US-Mexico border south through the Isthmus of Tehuantepec to the Darién Gap, maintaining the barrier at a cost of roughly $15 million per year. (5:18)

Detailed notes

## Background Published on YouTube by the educational channel Half as Interesting on June 6, 2024, and written by Amy Muller, the video explains the biological containment efforts between the United States and Panama. The video's show notes provide promotional codes for meal service sponsor Factor alongside links to channel merchandise, social media accounts, and sister projects Wendover Productions and Jet Lag: The Game.

## TL;DR To protect North American livestock, pets, and humans from the flesh-eating New World screwworm, the United States partners with Panama to continuously maintain an invisible biological barrier along the Darién Gap. Utilizing the sterile insect technique pioneered by Edward Knipling and Raymond Bushland, an industrial bio-factory in Pacora produces irradiated, sterile screwworms that are air-dropped by the millions to mate fruitlessly with wild populations. Decades of diplomatic and logistical campaigns pushed the pest south from the American border and across Central America, backed by intensive ground surveillance in Panama to prevent a resurgence that would otherwise cause an estimated one billion dollars in annual livestock damage.

## Atmosphere & style The presentation is brisk, irreverent, and witty, juxtaposing gruesome parasitological details with snappy deadpan humor and absurdity. It transforms what could be dry agricultural history into an entertaining logistical caper, celebrating bizarre solutions like sleep-inducing cold storage, floor chutes on turboprop planes, and medicated doughnut holes. The viewing experience feels like an energetic, engaging dive into an unexpectedly brilliant government triumph driven by passionate science.

## Bulletin - [00:00](https://www.youtube.com/watch?v=Olj8arvfYj4&t=0s) The United States maintains an ongoing aerial barrier along the Panama-Colombia border, dispersing millions of sterile New World screwworm flies to prevent a flesh-eating parasite from re-entering North America. - [00:00](https://www.youtube.com/watch?v=Olj8arvfYj4&t=0s) Re-establishment of the New World screwworm in the United States would inflict an estimated $1 billion in annual damages on the livestock industry. - [01:50](https://www.youtube.com/watch?v=Olj8arvfYj4&t=110s) A specialized facility in Pacora, Panama, produces roughly 20 million sterile screwworms each week using Cobalt-60 radiation to exploit the female fly's single-mating biology. - [05:18](https://www.youtube.com/watch?v=Olj8arvfYj4&t=318s) Decades of bilateral campaigns pushed the biological boundary from the US-Mexico border south through the Isthmus of Tehuantepec to the Darién Gap, maintaining the barrier at a cost of roughly $15 million per year.

## Key takeaways - [00:00](https://www.youtube.com/watch?v=Olj8arvfYj4&t=0s) The New World screwworm (*Cochliomyia hominivorax*) infests warm-blooded mammals by depositing eggs in open wounds, where larvae feed on living flesh. - [00:00](https://www.youtube.com/watch?v=Olj8arvfYj4&t=0s) A domestic return of the screwworm would cost US livestock producers approximately $1 billion annually in fatalities and management. - [01:50](https://www.youtube.com/watch?v=Olj8arvfYj4&t=110s) Entomologist Edward F. Knipling developed the Sterile Insect Technique after observing that female screwworms only mate once in their lifetime. - [01:50](https://www.youtube.com/watch?v=Olj8arvfYj4&t=110s) Pupae are sterilized via X-rays or Cobalt-60 radiation at precisely 5.5 to 5.7 days of development, rendering them infertile without preventing normal mating behavior. - [01:50](https://www.youtube.com/watch?v=Olj8arvfYj4&t=110s) The COPEG plant in Pacora, Panama, houses 115 staff producing 20 million sterile screwworms weekly using a nutrient broth of milk, eggs, cellulose, and powdered cattle blood. - [01:50](https://www.youtube.com/watch?v=Olj8arvfYj4&t=110s) Flies are chilled to induce torpor and dropped from retrofitted cargo planes through automated chutes, awakening as they descend over the jungle canopy. - [03:51](https://www.youtube.com/watch?v=Olj8arvfYj4&t=231s) Surplus sterile production acts as a strategic reserve, successfully deployed during emergency outbreaks in Aruba and a 2016 infestation among Florida Keys deer. - [03:51](https://www.youtube.com/watch?v=Olj8arvfYj4&t=231s) The Darién province relies on 13 field outposts running regular livestock inspections and applying antiparasitic paint to ensure fertile flies cannot bypass aerial drops. - [05:18](https://www.youtube.com/watch?v=Olj8arvfYj4&t=318s) Initial USDA campaigns eliminated the screwworm from the American Southeast by 1959 and the broader United States by 1966. - [05:18](https://www.youtube.com/watch?v=Olj8arvfYj4&t=318s) To reduce the prohibitive cost of guarding the 2,000-mile US-Mexico border, a 1972 joint agreement relocated the barrier south to Mexico's 120-mile-wide Isthmus of Tehuantepec. - [05:18](https://www.youtube.com/watch?v=Olj8arvfYj4&t=318s) Subsequent treaties through Central America culminated in anchoring the permanent barrier at the Darién Gap, with costs shared under an 85/15 funding model.

## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=Olj8arvfYj4&t=0s) The Flesh-Eating Threat: What is the New World Screwworm?

On any given day, there is roughly an 86% chance that the United States government is actively air-dropping millions of live flies along the border between Panama and Colombia. Rather than an odd military prank, this operation forms the frontline of a decades-long international program that shields the North American continent from the very pest being dropped: *Cochliomyia hominivorax*, better known as the New World screwworm. Described lightheartedly as an “idiotic insect sex scheme,” the effort relies on round-the-clock industrial insect breeding, cargo aircraft, checkpoint inspections, radiation, and surprising supplies like doughnut holes.

The New World screwworm poses a devastating threat to warm-blooded life. If the pest were still active in the United States, agricultural estimates indicate it would cost livestock producers approximately one billion dollars per year in animal fatalities. Unlike standard houseflies—which screwworms dwarf by about double the size—screwworms attack any living, warm-blooded mammal, including wildlife, cattle, pets, and human beings.

The parasite’s lifecycle lasts between 10 and 30 days. It begins when an adult female deposits several hundred eggs directly into the broken skin or open wound of a host, whether caused by tick bites, barbed-wire scratches, or freshly severed umbilical cords on newborns. Once hatched, the larvae burrow into the living flesh with sharp mouth hooks and consume the tissue alive. This process induces intense pain, tissue destruction, and eventual death if untreated. After the larvae reach maturity, they fall out of the host into the soil, pupate, transform into winged adult flies, and repeat the cycle.

- **Estimated agricultural damage:** Roughly $1,000,000,000 annually if re-established in the United States. - **Vulnerable hosts:** Any living warm-blooded animal, ranging from livestock and domestic dogs to humans. - **Egg-laying behavior:** Females deposit clusters containing hundreds of eggs inside fresh cuts, tick bites, or open wounds.

[01:50](https://www.youtube.com/watch?v=Olj8arvfYj4&t=110s) The Sterile Fly Solution and the Pacora Factory

The scientific breakthrough that halted the screwworm was pioneered by entomologist Edward F. Knipling, who grew up fighting infestations on his family's farm. Knipling realized an essential biological vulnerability: female screwworms mate only once in their lifetime. If female flies could be tricked into mating exclusively with sterile males, the wild population would rapidly collapse into extinction within a few generations. Alongside his colleague Raymond C. Bushland, Knipling spent years experimenting with radiation, ultimately determining that screwworms could be reliably sterilized by exposing them to X-rays between 5.5 and 5.7 days into their pupal stage.

This discovery gave rise to an invisible biological barrier dubbed the “Great American Worm Wall.” At the heart of the operation is an industrial bio-factory located in Pacora, Panama, operated by COPEG (the joint Commission for the Eradication and Prevention of Screwworms), which employs 115 workers to churn out roughly 20 million sterile screwworms every week. The larvae are nurtured in climate-controlled incubation rooms designed to mimic the heat and moisture of an infected mammal's wound. They feed on a nutrient broth made from reconstituted milk, eggs, powdered cattle blood, and cellulose thickeners.

Once developed, the pupae are sterilized with ionizing radiation using radioactive Cobalt-60. The sterile pupae are then transported to an airbase in chilled coolers, spread across emergence trays, and brought to adult maturity. Before flight operations, adult flies are placed into cold rooms to induce torpor, making them dormant and easy to handle. Retired military turboprop planes, retrofitted with specialized chutes in their floors, dispense the sleepy flies at calibrated release rates across the rainforest, where they awaken mid-fall to mate with wild populations. As the program’s logic is neatly summarized: “Flies that will wake up as they hurdle down to earth to eradicate their own species or as I like to put it, the screw worms screw worms to screw screwworms.”

```mermaid flowchart TD accTitle: Screwworm Factory and Eradication Pipeline accDescr: Step-by-step process of rearing, irradiating, packing, and dispersing sterile screwworms. subgraph Rearing["Factory Rearing (Pacora, Panama)"] A["Larvae in wound-simulating rooms"] --> B["Feed on egg, milk, blood slurry"] B --> C["Pupae stage reached"] end

subgraph Sterilization["Sterilization & Prep"] C --> D["Gamma irradiation with Cobalt-60"] D --> E["Coolers to airport emergence trays"] E --> F["Cold storage induces torpor"] end

subgraph Dispersal["Airdrop Operations"] F --> G["Retrofitted turboprop aircraft"] G --> H["Dispersed through floor chutes"] H --> I["Sterile flies mate with wild flies"] end ```

- **Sterilization timing window:** 5.5 to 5.7 days into the pupal stage. - **Factory production volume:** Approximately 20,000,000 sterile screwworms produced per week by 115 staff members in Pacora. - **Airdrop mechanism:** Retrofitted turboprop cargo planes dropping 2.1 million flies per 4-hour flight through calibrated floor openings, replacing old manual box drops that failed to open reliably.

[03:51](https://www.youtube.com/watch?v=Olj8arvfYj4&t=231s) Emergency Outbreaks, Doughnut Budgets, and the Darién Ground Game

Although routine flights drop around 12.6 to 14.7 million sterile flies across six weekly missions, the surplus flies from the 20-million-fly weekly production run serve as strategic reserves to suppress unexpected outbreaks. Screwworms remain endemic throughout South America and in certain Caribbean islands such as Cuba. When isolated infestations struck Aruba in 2004 and 2011, or when a sudden outbreak hit endangered Key deer in the Florida Keys in 2016, emergency reserves were mobilized. In the Florida Keys response, the USDA released 190 million sterile flies over three screwworm lifecycles, wiping out the threat in months.

The Florida containment also required unique field operations: a team of 200 workers combed through the Keys feeding wild deer oral antiparasitic medication covertly hidden inside commercial doughnut holes, prompting the joke that the federal government maintains an official "Federal Doughnut Budget."

Beyond aerial releases, COPEG maintains an intensive ground campaign across Panama's Darién province to halt fertile flies attempting to move northward from South America:

> “Yes the Its Raining Men Strat does a lot but Copeg also monitors animals across the Darion ensuring fertile screwworms that slip through the cracks don't make it far.”

Operating from 13 remote field stations, personnel travel via motorized boats, horses, and motorcycles to inspect livestock holdings on regular schedules dictated by risk models (monthly, every four months, or annually). All cattle transported out of the Darién region must pass mandatory inspections; any discovered wounds are treated with thick, antiparasitic topical paint to instantly kill lingering larvae.

- **Florida Keys response (2016):** 190 million sterile flies released across three insect generations, alongside doughnut-based deer baiting. - **Darién infrastructure:** 13 permanent field outposts staffed with inspectors on motorcycles, horses, and riverboats. - **Inspection schedules:** Farms evaluated and inspected monthly, triannually, or annually according to risk profile. - **Annual operating cost:** Roughly $15 million per year to maintain the entire biological barrier.

[05:18](https://www.youtube.com/watch?v=Olj8arvfYj4&t=318s) Pushing the Wall South: From the American South to Panama

The sterile insect technique first proved effective in field tests on the island of Curaçao. Encouraged by these results, the United States Department of Agriculture initiated a massive domestic program east of the Mississippi River in 1957. By 1959, the screwworm had been eliminated across the American Southeast. Eradication campaigns pushed westward, culminating in the United States declaring itself screwworm-free by 1966, supported by an active production facility in Texas.

However, holding a biological perimeter along the 2,000-mile United States–Mexico land border proved extraordinarily expensive and difficult to defend. In 1972, the American and Mexican governments concluded an agreement to push the barrier south to the narrowest bottleneck available: the Isthmus of Tehuantepec, which spans just 120 miles from coast to coast. Costs were divided based on the value of livestock protected, with the U.S. covering 80% and Mexico contributing 20%. By 1982, the original Texas rearing facility was retired and replaced by a new factory in Tuxtla Gutiérrez, Chiapas, as northern Mexican states like Sonora and Baja California Norte were cleared of the pest.

Recognizing that Central America offered even tighter geographic chokepoints, the United States negotiated subsequent bilateral treaties with each Central American nation between 1987 and 2006. Despite diplomatic tensions in the region during those decades, the countries agreed to an 85/15 cost-sharing formula with the United States. Today, the biological frontline rests permanently at the Darién Gap, maintained through shared Panamanian and American management under COPEG, with neighboring Colombia providing recurring monthly airspace clearances to allow fly-drops within its side of the protective buffer zone.

Reflecting on the scale of the program, the host observes:

> “Put another way it's a great example of what's possible when you combine passionate if slightly wacky scientists with government agencies that are actually willing to foot the bill for weird expensive but ultimately great solutions to big problems.”

[07:23](https://www.youtube.com/watch?v=Olj8arvfYj4&t=443s) Sponsor: Factor

Turning away from recipes involving powdered cattle blood, the host transitions into an endorsement for Factor, a prepared-meal delivery service. The service offers chef-crafted, pre-cooked meals shipped directly to customers' doors in plans ranging from 4 to 18 meals per week. Because meals only require heating in minutes, they provide a reliable, nutritious alternative to expensive takeout or time-consuming weeknight cooking. Factor is owned by HelloFresh. Viewers are offered a promotional deal at factor75.com using the discount code HAI50 for 50% off their first box and 20% off the following month.

## Notable quotes > [05:18](https://www.youtube.com/watch?v=Olj8arvfYj4&t=318s) Put another way it's a great example of what's possible when you combine passionate if slightly wacky scientists with government agencies that are actually willing to foot the bill for weird expensive but ultimately great solutions to big problems. — Sam from Half as Interesting

## Mentioned New World screwworm, Cochliomyia hominivorax, Edward F. Knipling, Raymond C. Bushland, COPEG, Pacora, Panama, Colombia, Darién Gap, United States Department of Agriculture, Factor, HelloFresh, Amy Muller, Sam from Half as Interesting, Half as Interesting

## Video description Use code HAI50 to get 50% OFF your first Factor box plus 20% off your next month at https://bit.ly/4aKohl9!

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Video written by Amy Muller

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[Source](https://www.youtube.com/watch?v=Olj8arvfYj4)

中文简报

美国在巴拿马投放绝育蝇以保护十亿美元畜牧业通过将辐射绝育蝇防线推进至狭窄的达连隘口，美国每年仅耗资约1500万美元，便使北美牲畜免受每年达10亿美元的寄生虫威胁。为保护北美的牲畜、宠物及人类免受食肉性新大陆螺旋蝇的侵害，美国与巴拿马合作，沿达连隘口持续维持一道无形的生物屏障。该项目利用爱德华·克尼普林（Edward Knipling）与雷蒙德·布什兰（Raymond Bushland）开创的昆虫不育技术，由位于帕科拉的一家工业化生物工厂生产经辐射处理的不育螺旋蝇，并空投数百万只以与野生种群进行无效交配。经过数十年外交与后勤行动的推进，该害虫已被从美墨边境一路向南驱赶并穿过中美洲，同时依托巴拿马境内密集的地面监测防止其卷土重来，否则每年预计将给畜牧业造成10亿美元的损失。美国在巴拿马与哥伦比亚边境持续维持空中屏障，投放数百万只绝育新大陆螺旋蝇，以阻止这种食肉寄生虫重新侵入北美。 (0:00) 新大陆螺旋蝇若在美国卷土重来，预计每年将对畜牧业造成10亿美元的损失。 (0:00) 巴拿马帕科拉的一处专门设施利用钴-60辐射，每周生产约2000万只不育螺旋蝇，以利用雌蝇仅交配一次的生物特性。 (1:50) 历经数十年的双边行动，生物防线已从美墨边境向南推进，穿过特万特佩克地峡直至达连隘口，目前维持该屏障的年耗资约为1500万美元。 (5:18)

Reading summary

To protect North American livestock and humans from the devastating New World screwworm, the United States and international partners maintain an invisible biological barrier along the Panama–Colombia border. The program relies on the sterile insect technique, which floods the wild population with lab-sterilized flies to collapse reproduction and hold the pest at a narrow geographic chokepoint. The Flesh-Eating Threat and Agricultural Stakes (0:00) The New World screwworm (*Cochliomyia hominivorax*) is a destructive parasite targeting any living, warm-blooded mammal, including livestock, pets, wildlife, and humans. Adult female flies deposit several hundred eggs into minor breaks in the skin, such as tick bites, wire scratches, or newborn umbilical cords. Once hatched, the larvae use sharp mouth hooks to burrow into and feed on living flesh, causing severe tissue destruction and fatal infections if untreated. The insect completes its lifecycle within 10 to 30 days before dropping into the soil to pupate and reproduce. If the pest were to re-establish itself in the United States, agricultural estimates calculate it would inflict approximately $1 billion annually in livestock fatalities and management costs. The Sterile Insect Pipeline in Pacora (1:50) The eradication strategy rests on a biological vulnerability identified by entomologist Edward F. Knipling: female screwworms mate only once in their lifetime. By flooding the wild environment with sterile males, wild females lay unfertilized eggs, rapidly driving local populations to extinction. Alongside Raymond C. Bushland, Knipling discovered that pupae could be reliably sterilized with ionizing radiation between 5.5 and 5.7 days into development. Today, the joint Commission for the Eradication and Prevention of Screwworms (COPEG) operates an industrial rearing facility in Pacora, Panama. Staffed by 115 employees, the bio-factory produces roughly 20 million sterile flies per week. Larvae are raised in wound-simulating climate rooms on a slurry of reconstituted milk, eggs, powdered cattle blood, and cellulose, before undergoing Cobalt-60 gamma irradiation. The sterilized pupae are chilled into torpor to permit safe handling and loaded onto retrofitted turboprop aircraft, which disperse them through calibrated floor chutes over target jungle corridors. Strategic Contraction to the Darién Chokepoint (5:18) The United States eradicated domestic screwworm populations east of the Mississippi River by 1959 and declared the entire country screwworm-free by 1966. However, defending the 2,000-mile United States–Mexico border proved unsustainably expensive. In 1972, the American and Mexican governments agreed to push the biological frontline south to the 120-mile-wide Isthmus of Tehuantepec, splitting expenses through an 80/20 cost-sharing agreement and opening a major rearing facility in Chiapas. Between 1987 and 2006, subsequent bilateral treaties with Central American nations pushed the barrier further south under an 85/15 funding model. Today, the biological frontline rests permanently at the Darién Gap along the Panama–Colombia border. This narrow geographic bottleneck significantly reduces surveillance territory, supported by recurring monthly airspace clearances from Colombia to drop sterile flies within a shared buffer zone. Ground Surveillance and Emergency Outbreak Containment (3:51) Aerial releases run six days a week, disbursing between 12.6 and 14.7 million sterile flies, while the factory's remaining output serves as a strategic reserve against foreign outbreaks. This surplus proved critical during reinfestations in Aruba in 2004 and 2011, as well as an outbreak among endangered Key deer in the Florida Keys in 2016. In Florida, the USDA mobilized 190 million sterile flies alongside field workers who hand-fed wild deer antiparasitic drugs hidden in commercial doughnut holes. On the ground in Panama, COPEG maintains 13 permanent field stations across the Darién province. Personnel patrol via riverboats, horses, and motorcycles to inspect domestic herds on schedules calibrated by local risk models. Mandatory livestock checkpoints examine every animal leaving the province, immediately applying thick antiparasitic paint to open cuts to ensure fertile flies do not migrate northward. Operating at roughly $15 million per year, the biological wall demonstrates how international diplomacy and targeted insect genetics can defend an entire continent from an endemic parasite by consolidating defense lines into a manageable geographic bottleneck.

精炼阅读摘要

美国政府与巴拿马等国通过联合管理机构COPEG，每周在巴拿马与哥伦比亚边境空投多达1470万只人工绝育的螺旋蝇，以构筑一道阻断活肉寄生虫北上的生物防线。据农业部门评估，这项年均耗资约1500万美元的多国防控项目，成功庇护了北美大陆，避免了该害虫若重新传入美国本土每年可能造成的约10亿美元畜牧业直接损失。食肉寄生虫的危害与单次交配弱点 (0:00) 新大陆螺旋蝇（Cochliomyia hominivorax）是一种对所有温血动物构成致命威胁的寄生昆虫，其成虫体型约为普通家蝇的两倍。雌蝇极具攻击性，专门在宿主皮肤的新鲜伤口处产下数百枚卵，无论是蜱虫叮咬、铁丝网刮伤还是新生牲畜未愈合的脐带，都会成为感染源。孵化出的幼虫凭借锐利的口钩钻入活体组织啃食活肉，引发严重感染、剧痛乃至死亡；成熟幼虫随后钻出肉体落入土壤化蛹，完成10至30天的生命周期。除牛羊等牲畜外，野鹿、宠物乃至人类均是其攻击目标。昆虫学家Edward F. Knipling与Raymond C. Bushland发现了打破这一破坏循环的生物学突破口：野生雌性螺旋蝇一生仅交配一次。研究证实，在螺旋蝇蛹期发育的第5.5至5.7天对其施加X射线或辐射，可使其完全绝育而不影响活动能力。只要向自然界释放压倒性数量的绝育雄蝇，诱使野生雌蝇与其无效交配，该区域的野生种群便会在数代之内迅速崩溃并走向灭绝，这为不育昆虫技术（Sterile Insect Technique）奠定了核心科学依据。帕科拉超级工厂与低温休眠空投 (1:50) 为了长期维持阻击屏障，美巴联合消灭和预防螺旋蝇委员会（COPEG）在巴拿马帕科拉建立了高度工业化的生物反应工厂，雇佣115名专业人员，每周繁殖并处理约2000万只绝育螺旋蝇。幼虫在模拟哺乳动物伤口温湿度的恒温孵化室中培育，摄食由复原牛奶、鸡蛋、牛血粉和纤维素增稠剂配制的营养流质，其环境完全模仿被感染的活体创口。在幼虫化蛹的关键窗口期，工厂使用放射性同位素钴-60产生的电离辐射对蛹实施灭菌。绝育后的蛹随后被送往空军基地羽化成虫，并在飞行前移入专用冷库降温诱导进入休眠状态，以方便安全搬运与计量。执行任务的改装退役军用涡桨运输机利用机腹底部的校准滑槽，在每次4小时的飞行中将约210万只沉睡的绝育蝇抛洒至热带雨林上空。休眠蝇在坠落过程中受热气流刺激苏醒并四散飞翔，主动寻找野生种群交配，从空中实现种群阻断。达连地堑地面巡查与突发疫情扑灭 (3:51) 帕科拉工厂每周生产的2000万只绝育蝇中，常规巡航投放约1260万至1470万只，剩余配额则作为战略应急储备以遏制突发疫情。螺旋蝇目前在南美洲全境及部分加勒比岛屿仍属地方性流行。例如2016年美国佛罗里达群岛的濒危基鹿（Key deer）暴发螺旋蝇感染时，美国农业部（USDA）紧急调拨储备，在三个害虫生命周期内投放了1.9亿只绝育蝇；同时派驻200人地面团队，将口服抗寄生虫药塞入市售甜甜圈球中喂食野鹿，成功在数月内将疫情扑灭。除空中压制外，COPEG在巴拿马达连省（Darién）常年维持着严密的地面监控。该机构在交通不便的边境热带雨林设立了13个野外哨所，技术人员骑乘马匹、摩托车或驾驶摩托艇穿梭巡查。农场根据风险评估模型按月、每四个月或每年接受定期检疫。所有运出达连省的牲畜均须通过强制检查站，一旦发现任何表皮伤口，工作人员便会涂覆浓稠的抗寄生虫药膏，就地杀死可能残留的幼虫，防止活虫突破边境。节节南推的地缘战略与多国协同机制 (5:18) 从美墨边境撤退至巴拿马狭窄地峡，是美国历经数十年的地缘防线收缩战略。该灭绝技术在库拉索岛验证后，美国农业部于1957年启动密西西比河以东的肃清计划，并于1959年实现东部清零，随后向西推进，至1966年正式宣布美国本土根除螺旋蝇。然而，要在长达2000英里的美墨边境维持常年无缝的生物屏障，经济和操作成本难以承受。 1972年美墨达成协定，决定将防线向南推移至宽度仅120英里的特万特佩克地峡（Isthmus of Tehuantepec），由美国承担80%、墨西哥承担20%的运营成本，并在墨境内建设繁殖工厂。此后在1987至2006年间，美国进一步与中美洲多国签署双边协议，以85/15的费用分担模式逐步将防线推进至美洲大陆最狭窄的天然瓶颈——巴拿马达连地堑。如今，整条生物防线每年维持费用约为1500万美元，邻国哥伦比亚亦按月向联合飞行任务发放领空许可，允许在缓冲地带南侧执行跨境投放，形成了稳固的多国常态化防御机制。该防线是前沿生物学技术与长期跨国公共治理结合的代表案例。尽管绝育投放已成功守护北美数十年，但鉴于螺旋蝇在南美洲大陆仍广泛存在，达连地堑的防线必须依赖持续的财政投入与严格的地面检疫常态化运转；一旦空中投放或边境检疫出现停滞，寄生虫反扑将对中美洲及北美脆弱的野生动物和畜牧产业链造成灾难性打击。

Source quotes

[5:18] Sam from Half as Interesting: Put another way it's a great example of what's possible when you combine passionate if slightly wacky scientists with government agencies that are actually willing to foot the bill for weird expensive but ultimately great solutions to big problems.

Original transcript

[0:00] fun fact there's a roughly 86% chance [0:02] that today the day you're watching this [0:05] the United States Air dropped millions [0:07] of live flies over the Panama Columbia [0:09] border and no it wasn't one of our [0:11] classic pranks like when we dropped that [0:13] big pie on B no this is a part of a [0:16] decades long collaboration that keeps [0:17] nearly the entire North American [0:19] continent safe from and bear with me [0:21] here the exact species of fly were [0:23] dropping but this massive intricate and [0:25] deeply weird quote idiotic insect sex [0:28] scheme is actually working but how what [0:31] on a day-to-day basis does it take to [0:33] keep flying flesh eating freaks out of [0:36] this much space the short answer a 24/7 [0:39] bug Factory planes boats trucks loads of [0:41] inspectors x-rays cow blood wound paint [0:43] and this is true doughnut holes also [0:46] grit and gumption and the spirit of a [0:47] champion but as for the long answer it [0:49] starts with knowing our enemy the new [0:51] world screwworm and I know neither you [0:54] nor I want to look at them so here's the [0:55] plan one we're putting in a progress bar [0:57] two I've encouraged my editors to make [0:59] this as metaphor as possible three [1:01] Dancing Clown so here we go first [1:04] they're not nice guys if they were still [1:06] bugging around the us today they'd be [1:08] costing Farmers somewhere in the [1:09] ballpark of a billion dollars in dead [1:11] livestock a year and it's not just [1:13] cattle at risk these things can infect [1:15] even kill any living warm-blooded mammal [1:18] yes including people yes including your [1:20] dog yes including gritty these bad boys [1:23] are about twice the size of a normal [1:25] house fly and a thousand times as rude [1:28] their 10 to 30-day lifespan begins when [1:30] females lay their eggs hundreds at a [1:31] time in a live animal's open wound tick [1:34] bites scratches fresh belly buttons they [1:36] hatch as worms and hook into the [1:38] animal's flesh which they then eat which [1:40] is extremely painful and often deadly [1:42] for the host animal once the wormies are [1:44] fattened up they drop to the ground [1:46] pupate emerge as flies and the cycle [1:48] repeats okay we're done this is Edward F [1:51] Kipling he grew up dealing with [1:53] screwworms on his family's farm and went [1:55] on to spend most of his career [1:56] researching them and here was his big [1:58] finding female screw worms only mate [2:01] once in their lives which means that if [2:03] you can mess that up they destroy [2:05] themselves in a couple generations and [2:07] after many years and many Thursday [2:09] afternoon trips to the military hospital [2:10] with his buddy Raymond to blast worm [2:12] larvey with x-rays Kipling learned that [2:14] you can sterilize a fly if you X-ray it [2:16] 5.5 to 5.7 days into its pupil stage [2:19] that Discovery is the backbone of what [2:21] I'm calling the Great American worm wall [2:24] you can't see it from space or from the [2:26] ground it's invisible but it's [2:28] nevertheless an extremely tight border [2:30] here's how it works here in pakora [2:32] Panama this Factory employs 115 people [2:35] to cook up and CH out sterile screw [2:37] worms 20 million of them a week the [2:39] young flies are raised in a series of [2:41] humidity and temperature control rooms [2:43] that mimic the warm and inviting [2:44] atmosphere of an open wound they eat a [2:46] nasty Brown goop made of reconstituted [2:49] milk egg and powdered cow's blood [2:51] thickened with some cellulose which is [2:52] actually good to know because I have all [2:54] this powdered cows blood in my cabinet [2:55] which I bought for like one recipe and [2:56] now I have all this left over and [2:57] nothing to use it for so annoying once [3:00] the worms are old enough they each get [3:02] hit with radioactive Cobalt 60 and it's [3:04] off to the airport the sterilized pupe [3:06] arrive in coolers then get sorted into [3:08] trays and once they grow into adult [3:09] flies they go to a cold room where they [3:11] get nice and sleepy before what is sure [3:13] to be one of the craziest possible days [3:15] any creature on this planet can have but [3:17] now the fun part airplanes Copeg The [3:21] Joint us Panama commission that runs [3:23] this whole thing and also a heavy [3:24] lifting acronym uses retired military [3:26] turbo prop planes that have been [3:27] specially retrofitted to drop flies [3:29] through the the floor of the plane at an [3:30] adjustable rate Once Upon a Time [3:32] technicians just threw cardboard boxes [3:34] out but those didn't always open on [3:36] impact which defeated the whole purpose [3:38] over the course of a 4-Hour flight the [3:40] plane will drop 2.1 million flies over [3:42] this region of Panama flies that will [3:44] wake up as they hurdle down to earth to [3:45] eradicate their own species or as I like [3:48] to put it the screw worms screw worms to [3:50] screw screwworms now the math whizzes [3:52] among you may have worked out that 2.1 [3:54] million flies over six weekly flights [3:56] doesn't add up to the 20 million the [3:58] factory produces week but there's plenty [4:01] of use for the leftovers see the new [4:03] world screw worm hasn't actually been [4:04] eradicated from all of North America [4:07] Cuba for example still has them and [4:09] they're still rampant in South America [4:11] so all those excess worms fight [4:13] outbreaks when they happen Aruba had [4:15] ones in 2004 and 2011 and when they [4:17] popped up in the Florida Keys in 2016 [4:19] the USDA rocked up with 190 million [4:21] flies released three generations and re [4:24] eradicated them in a matter of months [4:26] also part of that effort they had 200 [4:28] people trolling around the keys feeding [4:29] and infected deer anti-parasite Med [4:31] stuffed in dnut holes which implies the [4:32] existence of a federal doughnut budget [4:34] or FDB which is exciting to me but this [4:37] also brings up another part of the worm [4:39] wall the ground game yes the Its Raining [4:42] Men Strat does a lot but Copeg also [4:45] monitors animals across the Darion [4:47] ensuring fertile screwworms that slip [4:48] through the cracks don't make it far [4:50] they work from 13 field posts traveling [4:52] on boat horse and motorcycle to monitor [4:54] atrisk Farms every Farm gets an [4:56] inspection either monthly four monthly [4:58] or annually depending how Copeg has [5:00] assessed their risk and cattle leaving [5:02] the Daran all get inspected and any [5:04] worms they have get coated in [5:05] anti-parasite paint that would kill any [5:07] screw worms that might be in there in [5:09] all the worm wall costs about $15 [5:11] million a year more money than the worm [5:13] wall in my apartment cost but an [5:15] incredible deal for the money and lives [5:17] it saves but the project didn't come out [5:19] of the gates this well oiled or this [5:21] cheap see after scientists proved the [5:23] sterile insect technique would work on [5:25] screw rooms in CAU the USDA took up the [5:27] project here east of the Mississippi and [5:29] 1957 2 years later screwworms were gone [5:32] from the southeast and the effort moved [5:34] West we declared ourselves screwworm [5:36] free by 1966 and had a sterile fly [5:39] Factory up and running in Texas but [5:40] maintaining the Border in the west [5:42] proved challenging and expensive maybe [5:44] because while the Eastern range of the [5:46] fly was bordered by water the Western [5:48] Range was bordered by well more range [5:51] with that in mind in 1972 the US struck [5:53] up a deal with Mexico instead of having [5:55] to maintain a 2,000m great American worm [5:57] wall at the US Mexico border how about [5:59] about we eradicate all the way down to [6:01] here the ismus of tantek which is only [6:03] 120 M across the two countries agreed to [6:06] split the bill based on the value of the [6:08] livestock it would save in each Place [6:10] Mexico paid 20% while the US paid 80% [6:12] and by 1982 the Texas worm Factory was [6:15] closed and replaced by one in TLA Mexico [6:17] and Mexico declared Sonora and Baja [6:19] California Norte worm free but why stop [6:23] there if you're going to move the worm [6:24] border here why not move it here and so [6:27] began the not always smooth process of [6:29] TR to work in agreement with every [6:30] individual country in Central America [6:32] having them work alongside the US with [6:34] whom they didn't all have um awesome [6:36] relationships at the time to go [6:38] screwworm free and it worked from 1987 [6:41] to 2006 they eradicated the screwworm [6:43] from all these places with the Central [6:45] American country splitting costs with [6:46] the us at a ratio of 15 to 85 and the US [6:49] and Panama ending up with shared [6:50] responsibility for Staffing the border [6:52] and Colombia still having to give [6:54] monthly permission to copc to drop a [6:55] bunch of screwworms in the part of the [6:57] buffer zone They control all to say the [6:59] Great American worm wall is a pretty [7:01] amazing thing it's effective it saves [7:03] tons of lives and money and it does its [7:05] job so well that most of us don't even [7:07] know it's there put another way it's a [7:08] great example of what's possible when [7:10] you combine passionate if slightly wacky [7:12] scientists with government agencies that [7:14] are actually willing to foot the bill [7:15] for weird expensive but ultimately great [7:17] solutions to big problems too bad that [7:20] lesson isn't applicable literally [7:21] anywhere else oh [7:23] well okay so remember earlier when I [7:26] said I had a bunch of powdered blood in [7:27] my kitchen that was a lot what I [7:30] actually have in my kitchen is delicious [7:32] pre-made meals from this video sponsor 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