Medflies Fruits And Nuts

The Mediterranean fruit fly (Ceratitis capitata) is the world's most destructive pest of fruits, capable of causing staggering agricultural losses and triggering massive control programs. It is also one of the prettiest pests, with the house fly—size adults sporting wings that look like stained glass in earth tones (see Figure 21.1). The larvae, on the other hand, are voracious little maggots that gorge themselves on everything from avocados, coffee, olives, and tomatoes to bananas, citrus, mangos, and peaches. Although the species is found in Hawaii, it has not become established on the mainland—and the agricultural industry desperately wants to keep it that way.

The reproductive potential of the Medfly means that even a few stowaways on a fruit shipment could spell disaster. During warm weather, the insect can produce a new generation every two weeks—and a female can crank out 800 eggs in her lifetime. Assuming that just half of each generation survived, in just two months a founding population of 100 individuals could balloon to 80 billion flies. But the direct economic losses would only be a drop in the bucket.

Countries without Medflies understandably impose strict quarantines. If just one major importer of American produce, Japan, imposed an embargo on California fruits and vegetables due to Medflies, within a year the industry would lose a $600 million market. To scale up the potential disaster, an international embargo on Californian fruits would cost 35,000 jobs and at least $3.6 billion. And in a near worst-case scenario—just to make clear the economic scale of agriculture—with a total quarantine of California fruits, both nationally (after all, Florida and other fruit-growing states don't want to host Medflies, either) and internationally, the loss would be 132,000 jobs and $13.4 billion.1 By way of comparison, the Loma Prieta earthquake that

Figure 21.1. The Mediterranean fruit fly, if permanently established, would cost California agriculture as much as $1.9 billion annually—more than the gross domestic product of 30 of the world's poorest countries. The pest can devastate both farmers and politicians. In 1982, then-Governor Jerry Brown's mishandling of the Medfly outbreak sent his approval ratings plummeting and derailed his bid for election to the U.S. Senate. (Photo by Scott Bauer, USDA/ARS)

Figure 21.1. The Mediterranean fruit fly, if permanently established, would cost California agriculture as much as $1.9 billion annually—more than the gross domestic product of 30 of the world's poorest countries. The pest can devastate both farmers and politicians. In 1982, then-Governor Jerry Brown's mishandling of the Medfly outbreak sent his approval ratings plummeting and derailed his bid for election to the U.S. Senate. (Photo by Scott Bauer, USDA/ARS)

struck the greater San Francisco area in 1989 was the costliest natural disaster in California's history. The total property damage was $6 billion.

It's no wonder that when localized Medfly infestations are detected, colossal eradication programs ensue. In 1980—82, an incipient outbreak in the San Francisco Bay area triggered the aerial application of malathion-laced bait over an area of 1,400 square miles at a cost of $100 million. As a nerve poison, malathion is toxic to a broad spectrum of insects and vertebrates, including people. Although it is one of the safer organophosphate insecticides, malathion had more than sufficient hazards to raise the ire of environmental activists.2 So when pockets of Medflies were found again in 1988, radical environmentalists were primed to sabotage the insecticide program.

By 1989, the state's aerial campaign against the Medfly was in full swing. The entomologists were armed with tons of chemical weapons, and the ecoter-rorists were armed with biological weapons. In early December, the environmentalists' bizarre counteroffensive was announced to the public. The headline in the Los Angeles Times announced: Mystery Letter Puts a Strange Twist on Latest Medfly Crisis. The upshot of the story was captured in the first few lines:

The Mediterranean fruit fly crisis has taken an odd turn with law enforcement officials tentatively investigating a mysterious letter from a group that claims to be breeding and spreading the pest throughout Southern California. The group, calling itself the "Breeders," said in an unsigned letter to Mayor Tom Bradley, agricultural officials and media that it was angered by repeated aerial spraying of pesticide to eradicate the fly and "decided to make the Medfly 'problem' unmanageable and aerial spraying politically and financially intolerable."3

The two-page typewritten letter opened with a diatribe concerning "aerial spraying of carcinogenic pesticides over populated urban areas" and then asserted that "the biosphere of the planet is on the verge of collapse . . . pesticides are in the food, the water, the soil and the air. All this because some of us suffer rapacious and narrowminded greed."4 According to the letter, the Breeders had been clandestinely producing Medflies and releasing them to continuously expand the spray areas in Los Angeles and Orange counties. Having already forced the treatment program to encompass 232 square miles, the Breeders were prepared to up the ante. If the spray program was not terminated, they threatened to spread the infestation into the enormously valuable and productive San Joaquin Valley.

As evidence of their handiwork, the Breeders pointed out, "State officials have probably noticed an increase as well as an unusual distribution of Medfly infestations in Los Angeles County since March of 1989." The allusion to an "unusual distribution" of Medflies described the patterns that were being seen by field workers. Rex Magee, associate director of the California Department of Food and Agriculture, noted that "this particular infestation has had some characteristics that we have not seen in the past." Although officials couldn't be certain that ecoterrorists were to blame (some attributed the expanding infestation to private citizens smuggling infested fruit out of quarantined areas), there was no doubt that someone was desperate to stop the spray program, and ordinary Californians were being drawn into the fray. Pat Minyard, the director of Plant Health and Pest Prevention Services for the California Department of Agriculture, was sent a package labeled "Danger" and "Toxins." When the police bomb squad opened the box, they found oranges apparently sent by a citizen from within a treated neighborhood.5

Many officials suspected that the Breeders were a hoax, but those who understood the ecology of the Medfly and the operations of the control program were alarmed.6 An internal report by the USDA strongly favored the possibility that the Breeders were for real. According to this document (the author was anonymous, although clearly an expert in the field), four lines of evidence gave credence to the ecoterrorists' claims. First, the timing of the fruit flies' appearance was unusual: "We have never had these types of population buildups. . . . Programs in the past have had detection in late August and September, but [populations] rapidly dropped off once cooler fall and winter temperatures took hold."

Next, the distribution of the insects was worrisome: "This spread from one location to another, 15 to 20 miles apart is not normal. In addition, in my recollection, we have not had flies show up in an area repeatedly without our having found a substantial larval infestation." Third, a piece of evidence never revealed to the press pointed to an unnatural situation. Both the Medfly and its cousin, the Oriental fruit fly (Bactrocera dorsalis), were found in the same areas, a situation apparently without precedent (neither insect is native to the United States, so the chances of both arriving at the same time is rather remote). Finally, the author noted that although in earlier infestations mated females had occasionally been detected prior to finding males, this odd sequence was "an area of major concern" in 1989. The bottom line was that the circumstantial evidence pointed to a human agency in the ongoing outbreak.

Roy Cunningham, a USDA entomologist and dean of the state's Medfly scientific advisory panel, asserted that the Breeders' logic was terribly flawed, as any expansion of the infestation would simply result in more spraying—precisely the opposite outcome than the terrorists sought. But he also understood that terrorism can proceed along utterly unexpected and seemingly unreasonable paths. Cunningham launched his own investigation to determine the veracity of the Breeders' claims.7

On December 6, he convened a panel of experts in Los Angeles to evaluate the possible reasons for the peculiar features of the Medfly infestation. The meeting was considered a private gathering, so no public announcement of the findings was made. However, the Los Angeles Times managed to glean a sense of the proceedings. It seems that the panel was deeply divided, with some members interpreting the pattern of trap catches to be the result of natural processes and others concluding that someone must have been purposely breeding and releasing Medflies (see Figure 21.2). Those who suspected human duplicity would soon have further evidence of ecoterrorism.

Figure 21.2. Medfly traps are essential for survey and monitoring, and during the early stages of an infestation these devices can play a role in reducing pest densities. This trap uses a blend of chemical attrac-tants. In addition, the cylindrical shape mimics the three-dimensionality of host fruit, and the clear panels exploit the flies' tendency to move toward light, where sweet and lethal bait awaits them. (Photo by Peggy Greb, USDA/ARS)

The January 4, 1990, edition of the Los Angeles Times reported not only that scientists were trapping flies in odd locations but also that the biology of the insects raised suspicion:

The latest find of a female fly just outside a previous spray zone continues a pattern that has baffled scientists associated with the state and federal Medfly project. The scientists believe they should be trapping more males and that it is curious that so many recent fly finds have occurred close to the borders of previous spray zones. . . . Scientists also are unable to fully explain why they have not found larvae in large quantities in the infestation areas.8

Whatever the origin of these pests, the immediate result was precisely what the Breeders had claimed to be their short-term objective. Officials were forced to expand the spray program to encompass an additional 15 square miles, on top of the already treated 300 square miles. And public opinion was also beginning to shift toward the ultimate goal of the ecoterrorists. People in the treated areas were not at all pleased to find themselves within an entomological war zone. With the economic and political costs of the eradication program mounting, law enforcement stepped up its efforts to find the perpetrators.

The Los Angeles Police Department (LAPD) pursued its investigation in parallel with the USDA's Office of Inspector General (OIG). The Breeders toyed with law enforcement, sending copies of their letter to various newspapers and mailing postcards with messages such as "For Real. 'The Breeders.' " In February, LAPD detectives and OIG special agents repeated their earlier efforts to contact the terrorists by placing an advertisement in the "Personal Messages" section of the classified advertisements of the Los Angeles Times, per the instructions of the Breeders. The notice stated:


If you're for real send one of your little friends to: P.O. Box 1549, LA CA


We want to talk. Call John at USDA 213/894-5828 bet. 9 & 10 a.m.9

This time, an unidentified male called the listed number and said, "John, this is the Breeders, a Medfly is on its way to you in the mail. We are definitely going to release again if any more spraying is done. Bye."10 No package arrived, but the bizarre pattern of pest dispersion continued to befuddle and worry agriculture officials.

Meanwhile, investigators pursued new leads but they all led to dead ends.11 Federal agents looked into the actions of several disgruntled state and federal employees who might have had reason to undermine the Medfly eradication program, but investigators found no hard evidence of duplicity. The LAPD received a tip on the California Crime Hotline alleging that a science teacher had been raising and releasing Medflies, but the fellow had only been turning loose common house flies as part of an experiment with his students. Although law enforcement could not find the bioterrorists, agricultural agents had no difficulty finding troubling evidence.

A February 10 story in the Los Angeles Times reported that county fly trappers have found far fewer larvae than expected in an infestation this large, and the discovery of new adult flies often have [sic] occurred just outside of the infestation boundaries, forcing a steady expansion of the

spraying zone.12

Many found the Breeders' plot just too convoluted to believe, but a state official noted that "you got 8I/2 million people out there. You never know, there's always the chance that someone out there has a loose screw." The most reasonable tactic may not occur to the terrorist, who is motivated by passion. And the Breeders' tactic—whether rational or insane—seemed to be working. Not only was the public increasingly upset with the health, environmental, and economic costs of the program, but pest managers were starting to second-guess their operation.

The Los Angeles Times article noted that "the mere possibility [of reared and released insects] has forced officials to become a bit more cautious in their campaign against the Medfly." The California Department of Food and Agriculture announced a two-week delay after finding new flies in their traps on the Cal Poly Pomona campus. "We're always cognizant of the Breeders thing," said the county agricultural commissioner, "We wanted to make sure these were really wild flies. We can't afford to start a new treatment area until we know what we've got."

Over the next few months, the infestation in southern California declined. With fewer and fewer Medflies, the controversial insecticide spray program wound down. Agricultural officials, law enforcement agencies, and policy analysts were left to debate whether they'd been duped or whether they'd dodged a bioterrorist's bullet.

An independent analysis by the Belfer Center for Science and International Affairs at the Kennedy School of Government in 2001 concluded that the extortionists had been for real: "The Breeders used a biological means, Medfly, to attack crops in California. By contrast, most attacks have either been hoaxes or relied on chemical agents to attack agriculture."13 People closer to the case seem to waffle, unable to fully embrace the bioterrorist explanation. James Reynolds, the Western Regional Director for USDA at the time of the incident, maintains that the Breeders claimed to be raising flies in a garage somewhere in the LA basin. It seemed possibly credible at the time since we were chasing Medfly throughout the LA basin and we had several situations where we found flies just outside the treatment area requiring us to increase treatment and regulatory boundaries. While there was a biological explanation, sabotage also could have been an explanation . . . I am not aware that OIG ever came close to any credible lead which would suggest the letter was a hoax.14

Other officials are less convinced, but unwilling to dismiss the possibility. Pat Minyard, the California official who had been sent the box of fruit labeled

"Toxins," now believes that the Breeders were probably a hoax, based on the screwy logic of the purported terrorists.15 To really bring California agriculture to its knees, the Medflies should have been released in the state's agricultural Mecca, the Central Valley, rather than the Los Angeles Basin. Moreover, Minyard asserts that because these insects are difficult to rear, the enormous numbers of flies necessary for an effective attack would challenge the capacity of a highly skilled and well-organized terrorist cell—and the Breeders did not appear to be such an organization.

Minyard finds some relief in the realization that even a rather weak system of survey and inspection might be adequate to protect California farms from Medflies, which is fortunate in today's world, for he also contends that agriculture is more vulnerable now than it was before 9/11. According to Minyard, Homeland Security officials have much less interest in protecting crops and livestock than did the USDA's former Plant Protection and Quarantine program. The fact that we've not experienced an attack on agriculture by foreign terrorists is, in his assessment, a matter of either the terrorists being inept or the nation's defense being competent. He suspects the former.16

Perhaps Minyard's most penetrating insight regarding the case of the Breeders was in recognizing that even a hoax is a wickedly effective weapon for bioterrorists when the target is greenbacks rather than green plants. Economic damage can be inflicted without actually harming crops or livestock. His concerns are echoed by James Carey, a professor of entomology at the University of California, Davis, who has made the following argument:

If you find what they call a "Class-A pest" like the Mediterranean fruit fly and you have someone with a bottle full of Medflies deliberately planting them in traps, what happens is that it sets in motion the eradication campaign programs, the quarantines, because it's very difficult to distinguish between a real outbreak and one that's deliberately planted. So I can see that as the worst nightmare situation.17

While hoaxes are problematical, the focus of national defense is on actual releases of organisms that would directly damage agriculture or spread disease among people, livestock, or crops. And in such cases, the country's counterattack would depend heavily on its stockpile of chemical weapons—insecticides. But insecticides are a double-edged sword.

In 1996, a disgruntled supplier of National By-Products dumped chlordane—a banned insecticide, related to DDT—into a load of animal car casses destined for conversion into animal feed for Purina Mills.18 His note to officials in Wisconsin said to expect widespread animal mortality. The authorities realized that even if dairy cattle didn't die in droves, their milk would be rendered worthless. As little as 300 parts per billion (about 3 cups of liquid in an Olympic swimming pool) of chlordane would render milk unfit for human consumption. Remarkably rapid action on the part of the company minimized the damage to their business and reputation by ensuring that the contaminated feed never entered the human food chain.

The adulteration resembled a case 15 years earlier, in which a herd of beef cattle was poisoned with an organophosphate insecticide that was dumped into a farm silo. Although the culprit was never found, police suspected that the attack was meant to settle a grudge against the farmer.

The cases of angry environmentalists releasing insects and aggrieved farmers dumping insecticides illustrate several important aspects of agricultural bioterrorism. First, relatively localized acts of sabotage (or even the threat of damage) have the potential to generate enormous economic and social costs. Next, the perpetrators are extremely difficult to apprehend. And finally, government agencies struggle to neutralize even middling acts of entomological terrorism.

Such attacks on agriculture were the work of a few angry citizens lacking the funding, fervor, and facility to hijack airplanes and turn them into missiles. But on September 11, 2001, the people of the United States realized the terrible potential of a well-organized and utterly ruthless enemy. And Americans must now ask (and their government ought to answer): What could happen if such an opponent targeted the nation's heartland?

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