SPEAKER_04 0:00

There's another national economic story today. It concerns a tiny insect which is threatening the health of California's multi-billion dollar agricultural industry. Today efforts got underway to try to prevent the spread of the destructive fruit fly.

SPEAKER_00 0:14

This is the army California is sending into the suburbs south of San Francisco to rout the invader, threatening the state's $12 billion agricultural industry. 500 conservation workers are going house to house, stripping the trees of all fruit, which serves as the host to the Mediterranean fruit fly. The med fly, as the pest is called, plants its eggs under the skin of the fruit, where the contamination is invisible as the maggot devours the fruit from the inside. The state has tried to kill the species with ground spraying of pesticides and even mating sterile males with females. Nothing has worked. Soldiers in the latest attack were given a send-off by Governor Jerry Brown, who predicts that if the infestation spreads, the impact could be nationwide.

SPEAKER_02 1:02

The Mediterranean fly, or medfly for short, originated in the Mediterranean region, but it has now spread around the world through the establishment of global trade routes. Oh, okay.

SPEAKER_06 1:14

So the medfly traveled along with traders from region to region. What attracted the medfly to those specific ships? Did they just happen to all carry the same fruits?

SPEAKER_05 1:24

Well, the medfly can utilize up to 300 different fruits as their host fruit. They can infest apples, melons, oranges, lychee, and even vegetables like avocados, tomatoes, and bell peppers. The diverse range of host fruits that the medfly can utilize is what makes it one of the most economically important fruit fly species in the world.

SPEAKER_02 1:44

Yes. And adding on to that, the wide range of host fruits and vegetables enable the medfly to actually spread really quickly and efficiently because of how many possible trade routes they could have been a part of.

SPEAKER_06 1:57

So how does it survive the journey from destination to destination? I mean, it's it seems like it'd be pretty easy to spot the cargo that's already been been infested with the medfly.

SPEAKER_02 2:08

Well, adult female medflies actually burrow into a fruit and they lay a batch of eggs just under the skin of the fruit. The larvae then consumes the inside of the fruit as they grow into their pupae and adult life stages. In a batch of hundreds of fruits, it can be very hard to detect the handful of infested fruits. The medfly may sound perfect, but it also has several crippling weaknesses. The medfly is susceptible to colder temperatures and they tend to die off and propagate less under cold environmental stress. In addition, there are numerous natural predators of medflies, such as the parasitoid, wasp, ants, spiders, and mantids.

SPEAKER_06 2:49

What about man-made interventions?

SPEAKER_05 2:51

When the medfly was first introduced in California in June of 1980, the government enacted quarantine protocols in 1981 to counteract the so-called medfly invasion. The quarantine region covered the entirety of Santa Clara County, including the big cities such as Oakland, Dublin, Livermore, Pleasanton, San Mateo, Newark, Milpitas, San Jose, and many, many more.

SPEAKER_02 3:18

And one of the main ways that they attempted to counteract the medfly was actually through aerial spraying of pesticides.

SPEAKER_04 3:26

Crews spraying malathion are moving from house to house, but the medfly is also on the move. In the early 80s, the state responded to a medfly invasion by spraying the pesticide Malethion on the crops, trees, and people. Many have been scared by scientists who say malethion causes cancer.

SPEAKER_01 3:44

We feel like we are just cracked here and we're going to be sprayed. We're going to be living in the city of Malethion. We can have a two-pound baby instead of a nice, healthy, seven-pound baby.

SPEAKER_02 3:55

In total, over 400,000 residencies were aerially sprayed by as many as 24 times during the quarantine period. The government took it so seriously that newspapers back then would title the event as the Medfly War. The governor of California at the time, Jerry Brown, initially hesitated to allow weekly aerial spraying of malthion, especially with the pushback from the public. However, the government left no room for hesitancy and actually enforced it on hand.

SPEAKER_06 4:28

Okay, wow. That sounds apocalyptic. I can only imagine what it must have felt like to stay like indoors and watch military planes just going around spraying chemicals all around you. Um but you mentioned something earlier. What is malathion? Just the name, I mean, sounds super dangerous.

SPEAKER_02 4:47

Yeah, a malethion, it's actually an insecticide that's commonly used in stored products, golf courses, home gardens, outdoor sites, and even to treat headlights on humans. According to the Center for Disease Control or the CDC, Malathion breaks down naturally in the environment and is generally harmless. The CDC acknowledges malathion's harmful effects on the nervous system, but claims that relationships to cancer and other diseases remain a bit uncertain.

SPEAKER_05 5:20

During the Medfly invasions of the 1980s, the general public, which includes teachers, kids, parents, neighbors, and so on, feared the harmful effects of aerial pesticide sprays. They didn't believe in the government's reassurances that malathion was safe. It didn't matter which scientist or which government officials said that it was safe, nobody believed it.

SPEAKER_02 5:42

There was so much public outcry against the aerial sprays that they no longer do them today, at least for mallethion. Scientists have now developed a technique called the sterile insect technique. And the goal of the sterile insect technique is to reduce the propagation of medflies by hindering medfly reproduction. Sterile male medflies are bred in a lab by the Medfly Preventative Release Program for the California Department of Food and Agriculture of the CDFA. And then the males are sterilized with radiation in the pupase stage and tagged with ultraviolet marker dyes. The CDFA says they're sourcing approximately 24 million male flies per day, seven days a week. And the flies are then put into a cold coma and move into release boxes holding about six to nine million flies based on the release area.

SPEAKER_05 6:35

But no matter how amazing our science developments have been, the problem is that they keep coming back. And every time they come back, we have to keep on returning to pesticide sprays in some way or another to make them go away.

SPEAKER_06 6:49

What do you mean by coming back? How do we know that the medfly is gone in order to say that we know it's come back?

SPEAKER_02 6:57

Well, the CDFA's current protocol for the medfly quarantine states that the quarantine region will be undergoing sterile insect technique at an established area of at least a 4.5 mile radius. And the procedure for the removal of an infested area designation is if no additional life stages are detected by trapping or visual surveys for three life cycles after the last detection. So, simply put, the government lifts quarantine protocols and declares that medflies have been successfully eradicated if no additional medflies are detected for three life cycles.

SPEAKER_06 7:34

So the government has a protocol that defines when invasions have been successfully eradicated, but yet the medflies still continue to invade every year. I mean, it's in the name. Mediterranean, they're from outside. And that's exactly what the government, scientists, and the average person believes. You can see it in the way that the government tries to stop the medfly. Whether it be random border stops and individual checks for any sign of the medfly, or even putting bounties on immigrants alleged to be throwing diseased fruit into the backyards of innocent people. Every policy that our government enacts relies on the underlying assumption that the source of the medfly is somewhere abroad. The scientists who support this viewpoint point towards California's flourishing fruit trade as the primary culprit. Whether it be large industrial-sized shipments of fruit, or even just a traveler bringing in a mango from abroad. These are supposedly the likely sources of contamination. However, not all scientists think this way.

SPEAKER_02 9:02

Let's welcome James Carey, a distinguished professor of entomology at UC Davis, investigating the differences between the establishment and invasion theories of the Metfly.

SPEAKER_03 9:13

Well, um, this is well before Google era. And I got a map of Southern California, well, Northern California too, but of SoCal LA Basin. And I got uh overlay paper, that's how we did it back then, and a big drafting table, and identified where or found where these med flies had been found back in earlier. And I plotted these points, and they were right back exactly where they'd been found before. But that they were right back there. I go, This is not being reintroduced, and that was the argument then. They're always being reintroduced by oh, people coming from Hawaii on vacation or migrants coming from Central America, blah blah blah, that sort of thing. And I just could not buy that. It was my background is in insect ecology and it just didn't make sense. Then it was so bad that the California legislature called a what they call a committee of the whole, which is to say the entire legislature came, and I and a number of others testified to the legislature, and my testimony was these are not being reintroduced, they're resident here.

SPEAKER_05 10:35

Why was your claim so hotly contested?

SPEAKER_03 10:38

Oh, they're always pushing back. My specialty is demography, but I've stayed current with this med fly and more generally the fruit fly situation. And uh, I'm the only person in the state that's willing to call them out on this because there's so much at stake. California Food and Ag and the USDA are sources of funding for many of the entomologists, and so they do not want to get on the wrong side of these institutions. But the thing is, I mean, for there's one of me, and there's 150 entomologists that the government can line up to say it's not true.

SPEAKER_05 11:20

Um, but you also said that the agricultural companies played a role in this too, right?

SPEAKER_02 11:25

I sure did. But to get into that, we actually first need to establish who the actual experts are in this field.

SPEAKER_06 11:35

That's right. I actually did some research into this topic, and let me introduce you to these people that I learned about. Basically, their organization called Beyond Pesticides. This nonprofit group headquartered in Washington, D.C., the center of our nation, was founded in 1981 with the express purpose of exposing hazardous materials just like the pesticides we talked about. And also they helped provide everyday people with the information they needed to make healthy choices and avoid exposure from these pesticides, from these dangerous chemicals, from all of that.

SPEAKER_05 12:12

I'm not really following here. So, how does this group relate to the big agricultural companies and the medflies?

SPEAKER_06 12:21

Okay, so we all know that pesticides are the number one way of getting rid of medflies. But have you stopped to think of the number one producer of those pesticides? Let me guess. The agricultural companies. Spot on. So Beyond Pesticides has spent much of their existence locked in this struggle with these agricultural companies because they produce the very hazardous pesticides that their organization is sworn to fight against.

SPEAKER_02 12:50

So let me get this straight. Mudflies are actually supposedly successfully exterminated every year using these pesticides. So it's in the company's best interest to make these pesticides easier to use and to sway against any alternative approaches.

SPEAKER_06 13:07

Recently, Beyond Pesticides published an article meant to bring attention to a collection of the US's largest agricultural companies, known as the Modern Ag Alliance, which attempted to influence legislation at the federal level to make it more difficult to sue agricultural companies for failing to put proper warnings on their pesticides. Legal action like this is incredibly common for these large agricultural corporations, and it's their primary method of ensuring that pesticides remain easily accessible and commonly used by the government in order to exterminate pests like the medflies. Okay, so most people view a piece of fruit as just a simple light snack, but through the lens of biosecurity, that orange or that bell pepper or that strawberry that you're just eating, that actually represents a multi-billion with a B dollar liability for the entire state's economy, especially for California, which relies so much on the agriculture.

SPEAKER_02 14:22

Yep. And as we know it, everything runs on money.

SPEAKER_05 14:28

That's right. And the invisible front line of this war actually began long before fruits where 3.3 billion annual air passengers serve as a constant human vector for infestation.

SPEAKER_02 14:42

And as we explore the economic defense of these programs, we also have to confront the documented human cost, where the state's agricultural reputation has often been prioritized over the health and safety of the people living in the spray zones.

SPEAKER_06 15:00

Not only are we the vector that's supposed to be causing all of these agricultural problems, but we're also at the same time the people who are getting impacted the most. To understand why the state is so aggressive, we have to look at the realized economic value of these interventions. An example is the 1907 eradication in New Zealand, which was estimated to have averted losses up to 10.2 billion New Zealand dollars by the year 2020.

SPEAKER_05 15:30

It's a staggering figure because 90% of those benefits actually went to the kiwi fruit industry, a sector that didn't even exist as a commercial export until 70 years after the initial fly invasion was eradicated.

SPEAKER_06 15:45

So this $10.2 billion, this is based on analysis and deep correlational studies between like medflies, expected profit losses, that kind of thing?

SPEAKER_05 15:57

Yeah, we rely on these correlational studies because we can't run a control group experiment with California's economy.

SPEAKER_06 16:06

Oh, true. And these models reveal time-lagged benefits. And this correlation is the only way to justify spending millions today to protect industries that might not even exist yet.

SPEAKER_02 16:20

So the state views these successes as a permanent environmental and economic asset. Yet that narrative often ignores the social and scientific critiques of the eradication programs themselves.

SPEAKER_06 16:33

In California, we're currently protecting a $43 billion industry and over 250 host crops. And a single establishment of the Medfly could slash the gross state product by $1.2 billion.

SPEAKER_03 16:50

There's huge pressure. I mean, it's a $50 plus billion dollar agriculture industry in the state. And so that there's huge costs. And some of the larger ag corporations can withstand losing part of the crop. But these smaller growers, I mean, the smaller growers aren't little mom and pop things. They're still, you know, moderately sized operations. They can't. I mean, it's just devastating. So that the sooner you can lift the quarantine, the sooner growers can start shipping their fruit, their commodities again. So that there's a huge pressure to call it eradicated so you can lift the quarantine. So invasion biology, that's the underlying science. And that's another reason I'm critical of USDA. They don't use any of these principles. This is like, you know, with epidemiology. You use epidemiology to understand COVID and the spread through populations and so forth. You have a foundational science to use to bring to bear and so forth. It's the same thing as that there's general principles of invasion biology. For example, you have introduction. Well, you have to get from the source to the destination, so that's introduction stage. Then you've got to be able to go through at least a one or two generations, and then you have naturalization. That's a big one because you can't just begin exploding immediately. You have to adapt to the local conditions. Most of these flies that are introduced are tropical. We're in a desert environment here, they cannot just start breeding uh immediately. And then the last phase is spread. You have year after year after year outbreaks here. How can they be reintroduced and defy the basic law of having to naturalize? That's the basic principle of invasion, is that you you need to adapt to the situation.

SPEAKER_05 18:58

The difficulty is that we're fighting a moving target because 50 years of climate data shows that rising temperatures have reduced cold stress, allowing the fly to expand its range northward into places like San Francisco. The medfly itself is a tropical fruit fly, so with rising temperatures, it can now expand into these newer habitats that it couldn't have previously inhabited.

SPEAKER_02 19:26

And as the medfly actually moves into these urban landscapes, the government response transforms these private gardens into quarantine areas and can even turn an ordinary citizen into a criminal for simply keeping fruit on their trees.

SPEAKER_06 19:42

Yeah, unfortunately that is the case. We saw this in a 1981 case of Martin V Municipal Court, where a resident was prosecuted for a misdemeanor after refusing an emergency order to strip 210 pounds of fruit from his private property.

SPEAKER_05 20:01

That era, often called the Medfly War that we referred to earlier in the 1980s, featured the helicopters flying information over Los Angeles and led to mass panic among the residents below.

SPEAKER_02 20:14

And that panic was genuinely justified. During the 1989 to 1990 campaign, the state distributed fires claiming that there was actually no health hazard, absolutely none. Yet, a young boy named Juan Macaus was left legally blind after being covered in malathion spray.

SPEAKER_06 20:50

I mean, think about it. You're just sitting there and someone's telling you you can go blind because of something the government's doing that's completely out of your control.

SPEAKER_05 20:58

Today, the state claims that we've moved past the quote unquote bad old days of toxic aerial spraying and into a more ecologically friendly method like the sterile insect technique or sit.

SPEAKER_02 21:13

But even organic tools like spinocad or high-tech techniques can really create their own issues, especially when you consider that forty percent of agricultural pesticides in California are still contaminated with forever chemicals like PFAS. And these chemicals, they're going to stick around for a long time.

SPEAKER_06 21:36

At what point is it too much? The pressure to eradicate remains because global trade networks actually enhance the flies' invasiveness through an almost genetic paradox where multiple introductions of the med fly from different source areas, like from Egypt or from the Mediterranean or from wherever in the world, these different introductions. Once combined together, will make the medflies more resilient.

SPEAKER_05 22:04

This is why when only two female flies were found in Santa Clara County recently, the state felt justified in releasing 60 million sterile males per week to disrupt the cycle. That's 60 million sterile males for two female medflies.

SPEAKER_02 22:23

And what happens to the people living there? In 1998, Florida used malathion and diazine in areas where 132,000 people lived, resulting in documented cases of respiratory diseases and poisoning. These are long-term health impacts for the people who are just living there.

SPEAKER_06 22:45

But in the end, it was all from a business perspective. The Western Growth Association emphasizes that these quarantines are essential to maximize economic profits and ensure that the international markets remain open to California's exports.

SPEAKER_05 23:00

And we are now entering a new frontier with genetically modified flies, like the ones developed by Oxitech, which utilize a female killing trait.

SPEAKER_02 23:10

This technology is actually particularly controversial because the female offspring die as a larvae inside the fruit, meaning consumers could be eating fruit contaminated with these dead genetically modified maggots.

SPEAKER_06 23:27

That's a massive economic risk for organic farmers because contamination with GM larvae could destroy their organic certification and block them from zero tolerance international markets.

SPEAKER_05 23:39

There's also the risk that these genetically modified insects, which are reared on a diet of tetracycline, could spread antibiotic-resistant bacteria into the environment through their gut microbiota.

SPEAKER_02 23:52

And it seems like the strategy has actually shifted from chemical warfare to biological and genetic warfare. But the underlying lack of transparency regarding public health risks seems very consistent.

SPEAKER_06 24:07

Exactly. It seems like no matter how far science progresses, it's still the average person who ends up having to bear most of the cost. We have to remember the example of Chile, where regional collaboration and SIT techniques allowed them to successfully eliminate the pest and drive international economic growth.

SPEAKER_05 24:25

But Chile's success is being challenged globally as climate change increases the climatic suitability for the fly in previously cold regions like Austria.

SPEAKER_02 24:36

And if the fly is becoming endemic, as some of the scientists suggest, then these periodic eradication campaigns might just be a way for the state to protect its $40 billion reputation through permanent surveillance.

SPEAKER_06 24:51

The economic argument is that biosecurity provides unimagined benefits for centuries to come, creating a stable environment for future industries that haven't been even invented yet.

SPEAKER_05 25:02

But the biological cost is a landscape where millions of flies are released weekly, potentially serving as carriers for other diseases or creating ecological imbalances we don't yet understand.

SPEAKER_02 25:15

And the social cost is a legal system that allows private manufacturers to hide behind the state's emergency powers to avoid liability for the injuries their chemicals cause.

SPEAKER_06 25:26

Yeah, it's a delicate balance. If we don't intercept those flies at the airport, where Florida catches three times more than California, the entire domestic food supply becomes vulnerable.

SPEAKER_05 25:37

We've even seen how these biological crises can radicalize a population, like the Breeders Group in the 80s, who allegedly sabotaged efforts by releasing more flies. They sent a letter into the LA Times and they allegedly claimed that the new invasions that were happening in the San Joaquin Valley were a result of the Breeders Group releasing flies rather than new invasions. And although the claims were never taken incredibly seriously, there were some discrepancies in the medfly invasion at the time that could signify foul play, such as the lack of larvae found correlating to the number of medflies that were found.

SPEAKER_02 26:25

Yep. And when you treat a neighborhood like a battleground and the residents like human vectors, you actually lose the public trust that's required for any long-term health initiatives.

SPEAKER_06 26:36

But at the same time, the CDFA's recent success in Alameda County, clearing up 213 square miles, is still held up and the system works to protect the $43 billion agricultural industry.

SPEAKER_02 26:52

And do you know how they apparently released 250,000 sterile mills per square mile? So within 213 square miles, we're talking about billions of medflies that were released.

SPEAKER_06 27:11

Yeah, and there's economic costs associated with even just producing, storing, and distributing these billions of sterile medflies that you're talking about.

SPEAKER_05 27:20

We are now looking at the whole genome sequence of the fly to improve female-to-male conversion, essentially trying to engineer our way out of a problem created by our own global trade.

SPEAKER_02 27:33

But engineering a solution shouldn't mean drowning the fruit in kerosene or ignoring the presence of PFOS in the very chemicals we use to protect our foods.

SPEAKER_06 27:44

Yeah. Ultimately, this fly war shows us that in a globalized economy such as the one we have today, every country has a stake in the safety standards of its least developed trading partner.

SPEAKER_05 27:57

But it also shows that as the climate warms, the front line is shifting faster than our regulatory systems can keep up with.

SPEAKER_02 28:06

And we must ask, what is the realized value of an industry if the people it serves are left with the long-term health repercussions of its supposed protection?

SPEAKER_06 28:17

Aaron Powell If we've learned anything today, I think it's that the debate between economic survival and human safety is far from over.

SPEAKER_05 28:25

Yeah, and this is largely because the medfly has reappeared in California in 41 of the last 44 years.

SPEAKER_06 28:33

Yeah. What's the point of calling it an eradication method if, I mean, they're never truly eradicated?

SPEAKER_02 28:39

Which means for the people on the ground, this is not just a policy. It's actually a permanent state of emergency. The war between the government and Medwise is one where citizens become the soldiers, victims, and the perpetrators all in one.