By:
Paul Kimpel

Source:
Marjorie Hoy mahoy@gnv.ifas.ufl.edu, (352) 392-1901, ext.153

View Photo

GAINESVILLE, Fla. — A group of state lawmakers is scheduled next week to tour Miami International Airport and see first-hand a potential gateway for what a University of Florida researcher says could threaten the nation’s food supply: agricultural bioterrorism.

Entomology Professor Marjorie Hoy said U.S. borders are vulnerable, and bacteria, viruses and insects may at some point be used to attack agricultural targets.

“Every day, destructive organisms are brought into the country at airports, seaports and land borders. Those same pathways could be used for intentional attacks,” said Hoy, whose research at UF’s Institute of Food and Agricultural Sciences involves the biological control of invasive insects.

Hoy is a member of the national Committee on Biological Threats to Agricultural Plants and Animals, which says certain nations may be inclined to direct biological attacks against the U.S. food supply.

The committee, formed in March by the National Academy of Sciences, held its second meeting last week and is evaluating U.S. preparedness for such an attack.

According to the U.S. Department of Agriculture, some of the country’s high-risk pathways are Miami, Los Angeles and New York, where the majority of the nation’s visitors and commercial shipments enter the country.

Hoy said Florida is a particularly vulnerable pathway because of the large number of visitors to the state. Florida had more than 11 million international air passenger arrivals in 1999, almost one-fifth of the U.S. total, according to the USDA. Moreover, one-third of imported produce and plants enter the United States through Miami.

Major U.S airports such as Miami’s are guarded by the USDA’s Animal and Plant Health Inspection Service, which is the agency responsible for protecting the nation’s crops and livestock from invasive organisms.

The agency intercepted 1.8 million illegal plants and animals in 1999, of which more than 52,000 were threats to U.S. agriculture or the environment.

While that may sound like a lot of seizures, statistics show the agency inspects only 2 percent of inbound shipments and travelers. Hoy said such weaknesses in the system increase the probability that agricultural bioterrorists could enter the country undetected.

“We need a more efficient inspection system,” Hoy said. “Officers who inspect cargo and passengers are overwhelmed.”

During the tour of Miami International scheduled for Wednesday (8/29), Florida legislators will witness the increasing volume of cargo and passengers that is making a tough problem much more difficult.

In addition to traditional shipments and passengers, Hoy said, international mail is another high-risk pathway for bioterrorism.

In Miami, for instance, 10 million international mail packages arrived in 2000. Of those, 14,500 packages — less than 0.2 percent — were inspected. In the inspected packages, agents found 1,017 actionable threats to U.S. agriculture, according to the USDA.

Threats ranged from Mediterranean fruit flies, which caused an outbreak in Florida in 1997 that cost the state $32 million to eradicate, to citrus canker bacteria, which has cost $170 million to fight since 1994.

A report by Cornell University estimates that invasive insects, animals, plants and microbes — all termed “pests by scientists — cost the United States $123 billion a year.

Other biological threats to agriculture that concern officials are: foot-and-mouth disease, hog cholera, tick-borne heart-water disease from the Caribbean, fruit flies, and many other disease-bearing insects and parasites.

Although international mail and air shipments are a major concern, not all pathways are from overseas.

During a three-day blitz in July, federal agents seized more than 2 tons of illegal produce and meat at U.S.-Canadian border crossings. Of 226 vehicles stopped, 91 had hidden, prohibited materials.

Hoy said Canada does not inspect exotic fruit shipments because insects and other pests cannot become established in Canada’s climate. But insects are a major concern in Florida and California, where much of America’s produce is grown.

Hoy’s job is to anticipate and defend against threats to agriculture.

“Right now, we are preparing for a feared citrus disease called ‘greening,’ which is spread by a tiny insect called the Asian citrus psylla,” Hoy said.

Although greening disease is not yet in the United States, the Asian citrus psylla arrived in Florida in 1998, and has been impossible to eradicate.

Hoy, an eminent scholar in entomology, has been developing biological controls for the Asian psylla.

“If greening disease is introduced to the United States, either intentionally or accidentally, we will attempt to suppress it by controlling the insect that spreads it,” she said.

Hoy said that by developing solutions for current problems with smuggling or accidental introductions of pests, the nation is preparing for intentional attacks.

“From a scientific standpoint, these problems are two sides of the same coin,” Hoy said. “Whether it’s intentional or accidental, most scientific responses would be similar.”

Hoy and other researchers use several methods of controlling insects.

One method involves breeding sterile insects that mate with the target insect, thereby reducing its chances of reproducing. Another method increases the population of natural predators to destroy the target insect. A third method introduces a parasitoid from the target insect’s home country. A parasitoid is an insect that lays its egg inside the target insect, thereby destroying the host.

To control the Asian citrus psylla, Hoy has introduced two, tiny parasitoid wasps from Asia. Surveys are being done to evaluate their effectiveness.

For researchers such as Hoy, the challenge is having a control in place before invasive pests arrive, regardless of how they arrive.

“We knew we might get the Asian psylla in the United States, so we were prepared for its arrival,” Hoy said. “But threats exist that are unknown to scientists.”

Hoy said authorities need to work smarter, and said the committee hopes to discover better methods and technologies to defend the country.

“Our borders will never be 100 percent secure,” Hoy said. “But we can and must do better.”

-30-

0