medfly on apple

Mediterranean fruit fly
pierces an apple
Photo: USDA

It’s enough to sting any farmer’s heart with terror. Ceratitis capitata, the Mediterranean fruit fly, has reappeared in California. In September thirteen Medflies were trapped in a peach tree in the farming community of Dixon between San Francisco and Sacramento. Dixon (Solano County) lies north in the Central Valley, the state’s bountiful agricultural plain. The dreaded Medfly, which can infest over 260 types of fruits and vegetables, hadn’t been seen here since the days of Governor Jerry Brown, the early 1980s.

So why now? UC-Davis entomologist James Carey contends the Medfly has taken up residence in California; it was never actually eradicated, as so many in the state’s $34 billion ag industry had hoped and believed. But many others — including Solano County farmers and U.S. Rep. Dennis Cardoza of California’s ag-heavy 18th Congressional District farther south — say that lax inspections are to blame. In March of 2003, the duty of checking agricultural products entering the U.S. shifted from the US Department of Agriculture to the newly created Department of Homeland Security. According to Cardoza, who chairs the House Agriculture Subcommittee on Horticulture and Organic Agriculture, “The transfer has been a colossal mistake and a colossal waste of taxpayer money.” (See Kate Campbell’s piece via the California Farm Bureau Federation for lots more discussion.)

In October, less than a month after the Medfly discovery, the federal Government Accounting Office presented a report to Cardoza’s subcommittee. Lisa Shames, director of natural resources and the environment for GAO, testified that since Customs and Border Protection had assumed responsibility for the Animal and Plant Health Inspection Service (APHIS) “the mission has been compromised.” The GAO reported multiple problems, including understaffing, faulty equipment, and failure on the part of the Department of Homeland Security to measure the efficacy of its ag inspection procedures. The upshot has been a decline in interceptions — down by 43%.

california fruit flies

Prime pests of California farmers

Rep. Cardoza said in October’s hearings, “DHS is absolutely failing at its mission to prevent bug and pathogen infestations from coming into this country.” He called for a joint meeting of the House Agriculture and Homeland Security Committees.

Eric Bailey, writing for the Los Angeles Times, describes the SWAT procedures that follow a Medfly discovery. “Crews strip trees within 100 meters of infested fruit. They spray insect-killing Sinosad, an organic formula derived from a naturally occurring bacterium, within 200 meters of a find. And they spread millions upon millions of sterile male Medflies — their bodies dyed pink so they can be identified — over the infestation zone. The flies, raised in a Los Angeles-area lab, are chilled to 38 degrees to immobilize them for a ride aboard a twin-engine plane, and then dropped in weekly runs. They thaw as they fall and reach ground level ready for romance.”

Farmers who hope to harvest and sell produce from areas of quarantine also have to follow elaborate protocols involving chemical treatments (each requiring a permit), special packaging, labeling and transport — all overseen by the California Department of Food and Agriculture. That office estimates that a permanent Medfly infestation “would result in estimated annual losses of $1.3 billion to $1.8 billion.”

While the Mediterranean fruit fly is “public enemy No. 1,” according to Solano County’s ag commissioner Jerry Howard, it’s not the only six-legged terrorist in California. Inspectors in Escondido found Mexican fruit flies (Anastrepha ludens) just last week and will soon quarantine some 81 square miles of San Diego County. A 10-month quarantine for the Mexican fruit fly here in 2002 cost growers $7 million.

apple moth spray area

Area of recent spray for brown apple moth, N. Salinas/Boronda area of Monterey Co., CA
Map: California Department of Food and Agriculture

And in Monterey and Santa Cruz counties, the state has been spraying to kill off brown apple moth (some Santa Cruz residents filed an objection to the chemical pheromone sprays, but were overruled by a judge). The UC-Davis entomologist James Carey likewise believes that the brown apple moth has settled in California for keeps.

He and others say that the most dire effect of the brown apple moth isn’t loss of crop but the huge costs that added inspections and trade restrictions incur. Carey says this “double bind” has the state of California struggling to impose eradication programs of dubious efficacy, since “To acknowledge the truth is to trigger these embargoes and quarantines that are absolutely devastating, so they’re always playing this game that it’s ‘eradicable.'”

The Medfly is an old enermy of farmers and a gourmand, with a taste for everything from walnuts to tomatoes, peaches and coffee. Long a bedevilment in fields and orchards, it’s revealing some wormy branches of federal and state government, too.

Creative Commons License

Republish our articles for free, online or in print, under a Creative Commons license.