By Joel Hood
South Florida Sun-Sentinel
October 13, 2007
They came to this northern edge of the Everglades to catch a silent and almost invisible killer.
The posse: Scientists, researchers, environmentalists, politicians and about two-dozen grade-school children.
The target: An invasive insect from Mexico that's destroying native plants in South Florida's forests and wetlands at an alarming rate.
The weapon: A fly born and raised in a lab that, scientists hope, can tell the difference between the bad bugs they want to get rid of and the good bugs they want to keep.
"Florida is under assault like no other state in the U.S.," said University of Florida scientist John Capinera. "Insects, lizards, plants, diseases that come here and attack native species: It's been a problem for decades and it's not getting better. It's getting worse."
The front line of this war against invasive species came to the Loxahatchee National Wildlife Refuge west of Boynton Beach on Friday. While university scientists have worked with these Honduran flies in captivity for almost 15 years, this is the first time they're putting the flies into action.
They released only 120 of them into the refuge's thick canopy of towering cypress with the hope that they will breed and seek out and kill the Mexican bromeliad weevil, which nests and feeds off a variety of tropical plants considered integral to the Everglades' ecosystem.
Cameras clicked and children from Orchard View Elementary School in Delray Beach crowded around when the flies were released from their protective netting. U.S. Rep. Ron Klein, D-Boca Raton, and a representative for state Rep. Shelly Vana, D-Lantana, mingled with scientists, environmentalists and the curious.
At the center of the gathering was Howard Frank, a University of Florida scientist who was one of the first to see the potential in the fly after it was found in the Honduran mountains almost 20 years ago.
Scientists suspect the flies will attack the larvae of the Mexican weevil embedded in the plants before the pests have a chance to kill them. The flies, which have a life cycle of about 50 days, feed on the weevil larvae and organic matter. They aren't expected to create the kind of problems other invasive species do.
But scientists admit they're speculating about the behavior of the flies based on what they've seen in the lab. There's no way to know how animals or insects introduced into the wild will react, Capinera said.
The insect attack plan represents a new wrinkle for universities and state and federal officials who've partnered to restore and replenish the Everglades after decades of growth and environmental changes. The federal government has promised to spend $1.8 billion next year and the state more than $2 billion to continue the effort they launched in 1993 to return a natural water flow and improve habitat over several million acres of wetlands from Miami to Lake Okeechobee.
Finding and eliminating invasive plants, animals and insects has become a critical part of the overall Everglades restoration plan, officials said. The list of threatening foreign-born species that have taken root in the Everglades ranges from tiny insects such as the Mexican weevil to 15-foot Burmese pythons. But it also includes vegetation such as Brazilian pepper trees, melaleuca and the old world climbing ferns that flourish in the mild tropical weather, blocking sunlight and sapping nutrients from native plants.
Scientists can already see some of the impact from these invasive pests, from shrinking habitat to dwindling food supplies that have caused many native species to die off. In the Loxahatchee Refuge, about 100 workers a day are spraying herbicide to stop the climbing ferns throughout the park's 140,000 acres.
"And they'll never get it under control," said LeRoy Rodgers of the South Florida Water Management District's invasive species program. "These species are a permanent thing for Florida. We're never going to win the battle outright."
Officials are encouraged by what they've seen from the Honduran flies in tests at the Biological Control Research and Containment Laboratory in Fort Pierce. The facility, along with its sister lab run by the U.S. Department of Agriculture in Davie, is on the cutting edge in this area of study by using natural predators such as the Honduran fly to go after exotic pests.
It could be years before anyone knows whether the plan will work, said scientist Michael Burton.
"We've been studying these flies for 17 years, but there's still a lot we don't know," Burton said. "This is going to be a great test."