Bug Being Readied To Battle Melaleuca Trees, Save Everglades
MIAMI (AP) _ Tall, white-trunked trees brought from Australia about 100 years ago are choking out native vegetation in the Everglades and sucking up precious water.
The melaleuca tree, however, may soon have some visitors from its homeland to contend with: two tree-eating bugs that could help rescue the Everglades.
Experts warn that left unchecked, the melaleuca could transform the swampy heart of the sawgrass prairies into thick forests like the ones already crowding the fringes of the vast wetland.
The Australian melaleuca weevil would chomp through the soft, birchlike trees but wouldn’t eat enough native vegetation to cause a problem, said Gary Buckingham, a research entomologist with the Department of Agriculture in Gainesville.
``The reason the plant has been so successful here is because it has no natural enemies,″ Buckingham said Monday. ``We’re hoping (the weevil) will slow the growth.″
The weevil, which has been tested since 1992, could be released into the Everglades in a few months or in a year or two, depending on when state and federal officials give the go-ahead, Buckingham said. Federal scientists also are testing another Australian insect, the sawfly.
Melaleucas, which grow as tall as 50 feet, were introduced to southern Florida for decorative purposes and some farmers planted them to block crops from wind. But the trees multiplied rapidly in subtropical heat, quickly becoming the most plentiful plant pest in the Everglades, a slow-moving sheet of water stretching some 100 miles from Lake Okeechobee to Florida Bay.
Federal officials, while waiting and hoping for an effective way to combat melaleucas, have been relying on hard labor to try to slow the trees’ growth.
Workers chop down the trees and coat the stumps with poison, or bore holes in the white bark and inject chemicals, said Burkett Neely, manager of the Loxahatchee National Wildlife Refugee in Palm Beach County.
But the techniques are time consuming and ineffective because the trees bloom three times a year, releasing thousands of seeds each time, Neely said.
He is lobbying for the bug to be released in his 146,000-acre preserve.
``The weevils eat the fresh sprouting blooms at each tip. They won’t get rid of the older trees, but they’ll keep them from producing new trees,″ Neely said.
The South Florida Water Management District also is eager to let loose the weevils and is lobbying the federal government to approve their release quickly, spokesman John Neuharth said.
Four years ago, Buckingham received shipments of weevils and began extensive tests on the quarter-inch-long bug, a type of grayish-brown beetle that has a snout.
He found that the bugs, which are under quarantine, are partial to young saplings and melaleuca blooms. They may eat some native vegetation but not enough to cause habitat loss, he found.
In 1994, the federal government gave him permission to begin testing the sawfly, a type of nonstinging wasp that gorges on older melaleucas. Sawfly testing will continue for a few more years.
Scientists say the insects are not a panacea for all of the Everglades’ problems. Harmful runoff should still be curtailed and habitat restored _ and people should learn about the harm exotic species can cause.
``(The insects) by themselves are not going to take it back to a pristine state,″ Buckingham said. ``If we want natural parts in this country, the public and administrators need to realize they are threatened by these exotic species.″