Project: Biocontrol research

By JEANNE MALMGREN

© St. Petersburg Times, published September 26, 1999

Sawfly larvae, seen here leaf-munching leaves in a Gainesville quarantine lab, may be the latest biological weapon against melaleuca. Researchers have applied for state and federal permission to release the insect in the wild. [Photo: Gary R. Buckingham, USDA/ARS]

GAINESVILLE -- Gary Buckingham's job is to be careful.

At a quarantine laboratory in Gainesville, he studies the eating patterns of insects. That might sound mundane, but the stakes are high. Release the wrong insect from the safe confines of quarantine, and it could be an ecological disaster for Florida.

Buckingham, a U.S. Department of Agriculture entomologist, looks for insects with an appetite for pest plants. This is the latest weapon in the war on botanical invaders, and it's called biological control or biocontrol. If we can find an insect that keeps a plant at manageable levels in its native range and import that insect here, perhaps it would perform the same service in Florida.

But Buckingham and his colleagues first have to make sure the insect wouldn't also chomp on common Florida plants -- not just landscape material, but also the economically important crops of citrus and sugar cane.

"One thing we do know is that most insects are pretty host-specific," Buckingham explains. "They have a limited range of plants they'll eat."

Many insects eat only one plant, he adds. "What we're doing is utilizing that fact of nature."

Chemical control is useful for bringing large pest plant infestations under control initially, Buckingham says, but biocontrol is valuable as a long-term solution.

"We have to use this technique," he says. "We just have to be careful how we use it."

Evaluating an insect as a biocontrol takes years. First, scientists travel to the home range of a pest plant and observe which insects are eating it there. Then they secure permits to bring back some of those insects for testing.

Because many of Florida's pest plants have come from Australia, the USDA has a research laboratory in Brisbane. Many insects are initially tested there.

Others make it all the way to Gainesville, the largest quarantine facility in Florida. There, exhaustive trials are carried out.

"We put different stages -- the larva, the nymph, the adult -- on a specific plant, to see which attacks it."

Mission: Kill the creeps Florida is crawling with non-indigenous pest plants -- one step behind Hawaii. Most of us are blissfully unaware of the invasion, and how much it costs to combat it. Project: Eradicate Old world climbing fern Jim Goodwin lets the swamp buggy roll to a stop on a steamy September morning and turns off the engine. He looks around at the tea-brown water beneath and the green walls rising on all sides. Project: Eradicate Burma reed Burma reed is "public enemy No. 1 in Miami-Dade County," says Roger Hammer, a botanist with Natural Areas Management, a division of the county's park and recreation department. Say goodbye to these 11 plants The Florida Nurserymen and Growers Association has asked nursery owners to stop selling these plant species.

Behind the lab's double-door, airlock entrance, small greenhouses are crowded with melaleuca saplings in pots. Each one has netting tied around its foliage. Inside some, sawflies buzz around. In others, tiny caterpillars crawl on the leaves.

In 1997 Buckingham and his colleagues scored a major success. At 11 sites in South Florida, they released snout-nosed beetles, insects they had proven would eat only melaleuca.

"It has been doing some tremendous damage," Buckingham says. "It eats young growth on saplings and even goes up to the tops of 60-foot-tall trees."

But back-ups are needed. In biocontrol, it's ideal to have several insects attacking one plant species, Buckingham says. He has applied to the USDA to release another melaleuca bug, a sawfly, and is testing a third insect, the psyllid.

"That one has the potential of really damaging the plant. We think it's going to be pretty spectacular."

The beauty of biocontrol, from researchers' point of view, is that it will extend the war against invasive plants all across the state. Hungry insects, of course, don't distinguish between a pest plant growing in a state park or in someone's back yard. It's equal-opportunity chomping.

"Will people appreciate what we're trying to do, when our insects start eating all their Brazilian peppers? We worry about that," says Buckingham.

Critics say the work of entomologists like Buckingham is dangerous, that it inevitably will lead to mistakes. We might end up with an insect that proves to be a greater pest than the plant it was brought in to eradicate.

But Buckingham says the exhaustive tests and lengthy permitting process (usually several years) prevent that.

"We try hard to show that an insect isn't safe, instead of the other way around," he says. "We consider ourselves our No. 1 critics. None of us want our names to go out on a pest insect."

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