Impact Magazine - Spring 2008 - (Page 20)

Eliminating the Evil Weevil Invasive Pest news updates bug known as the “evil weevil” may have met its match. Since 1989, the invasive Mexican bromeliad weevil (Metamasius callizona) has wreaked havoc on the state’s native bromeliads, but researchers with UF’s Institute of Food and Agricultural Sciences have released a parasitic fly (Lixadmontia franki) that kills the weevil’s larvae and could help save the tree-dwelling airplants, many of which are threatened or endangered. In the first of several releases, 56 adult flies were recently set free at Northwest Equestrian Park in Hillsborough County, where the Mexican bromeliad weevil is attacking four species of airplants unique to Florida, said Ron Cave, an associate professor of entomology at UF’s Indian River Research and Education Center in Fort Pierce. Cave discovered the beneficial insect in the mountain forests of Honduras in 1993. After 14 years of study, researchers will learn if it can survive Florida’s hot, humid climate. “I think the chances are good that it can, because insects are very adaptive,” he said. “We hope that the flies will be able to find cool, shady and moist conditions in the canopy of an oak hammock, down amongst the leaves of a bromeliad holding water — little microhabitats where they’ll be able to survive very well.” It’s the first release of an organism reared at UF’s Biological Control Research and Containment Laboratory in Fort Pierce, Cave said. The facility opened in 2004. Teresa Cooper, a graduate student in UF’s College of Agricultural and Life Sciences, built traps from wooden trays with wire-mesh bottoms that are baited with pineapple tops, each containing a weevil larva to attract the flies, said Howard Frank, a professor of entomology in Gainesville. The traps were put out six weeks after the initial release of the flies, he said. The results have shown that the second generation of flies can find and parasitize the weevils A eVIl WeeVIl Invasive Pest in the Florida environment. Follow-up releases have been done at the Loxahatchee National Wildlife Refuge in Palm Beach County, Enchanted Forest in Brevard County, Big Cypress National Preserve in Collier County and Highlands Hammock State Park in Highlands County. To breed the fly, researchers first had to raise large numbers of the weevils. But finding a food source for them was a major hurdle. “We’ve tried various ways of rearing the larvae,” Frank said. “We can’t take bromeliads from nature to rear the weevils because they’re protected. But pineapple tops are trash, they’re thrown away. So we have to persuade grocery store managers to save them for us.” Pineapples are part of the bromeliad family, though not native to Florida, he said. The state is home to 16 species of bromeliads, all of which grow in trees. Larger plants are at risk because they have bigger stems that the weevil larvae mine, killing the plants. The weevil, native to Mexico and Guatemala, was detected in Fort Lauderdale in 1989, where it is believed to have arrived in a shipment of Mexican bromeliads. In some South Florida areas, such as Myakka River State Park, the weevil has nearly eliminated the endangered giant airplant. Researchers are most concerned about Fakahatchee Strand Preserve State Park, which contains the state’s densest concentration of bromeliads, said park manager Dennis Giardina. So far, the weevil has had minimal impact at the park, home to 14 native species. “We haven’t seen the kind of wholesale die-offs that have been seen in other areas,” said Giardina, who funds expeditions to Central America with Frank to seek more natural enemies to fight the weevil. “So it wouldn’t be a good idea to release the flies here right now because they might not find enough weevil larvae to feed upon and perish.” If the fly is effective, researchers will need to keep breeding and releasing the insect to ensure it gets distributed throughout South Florida as quickly as possible, said Jay Thurrott, president of the Florida Council of Bromeliad Societies, which has supported the research for years. n – tom nordlie Eliminating the For more information, contact: ron cave howard frank dennis giardina (772) 468-3922 rdcave@ufl.edu (352) 392-1901 jhfrank@ufl.edu (239) 695-4593 dennis.giardina@dep.state.fl.us Ron Cave examines a vial containing larvae of the Mexican bromeliad weevil to distinguish them from larvae of the native Florida bromeliad weevil. photo by thomas wright 20 IMPACT | Spring 2008

Table of Contents Feed for the Digital Edition of Impact Magazine - Spring 2008

Impact Magazine - Spring 2008 Contents A Big Boost for Biofuels Top Priority Partnerships for Sustainable Agriculture Eliminating the Evil Weevil Invasive Pest Defeating Resistant Roaches Biodiesel Boon User-Friendly Updates for FAWN Flat-Out Great for the Grill! Laser Labeling Cashing in on Caviar Saving Water with Soil-Moisture Sensors Spotlight IFAS Development News

Impact Magazine - Spring 2008

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