Transmitted by the redbay ambrosia beetle, the laurel wilt fungus has killed red bay and swamp bay trees, which are closely related to avocado trees.
Since first identified in 2002 in Port Wentworth, Ga., the disease quickly spread to counties in North Carolina, Mississippi and almost all of Florida.
As the exotic beetle moved closer to the state’s commercial avocado growing region, researchers including a working group of grower-shippers and extension agents have been working to stop the disease.
The Florida Department of Agriculture and Consumer Services regularly checks 45 traps in Miami-Dade County, where the bulk of the state’s avocados are grown.
During the 2013-14 fiscal year, entomologists determined 135 of the 1,019 beetles trapped were redbay ambrosia beetles.
From 29 calls to the agency’s help line, 16 trees and 19 of 30 plant specimen samples sent to a lab for diagnosis tested positive for the fungus.
Beetle behavior research by the University of Florida’s Institute of Food and Agricultural Sciences shows encouraging results.
Avocado fruit does not carry laurel wilt in the pulp or seeds and the beetles seem to prefer redbay trees to avocado trees. But in the absence of redbay trees, avocado trees remain at risk.
Grower-shippers learn about the problem through monthly meetings, and there appears to be optimism that researchers could find a cure or a way of curbing the disease’s spread.
Eddie Caram, general manager of New Limeco LLC in Princeton, Fla., points to increased grower plantings.
“They wouldn’t be planting new crops if they thought they could be wiped out,” Caram said. “They wouldn’t be investing in new groves if they were alarmed.”
The industry has lost 4,000 of nearly 800,000 trees, said Bill Brindle, vice president of sales management for Homestead, Fla.-based Brooks Tropicals Inc.
“We are working with the scientific community and our growers to limit the spread of laurel wilt,” he said.
“We have developed best practices that include prevention, removal and beetle control. These activities are now part of being an avocado grower.”
As the number of infected trees rises, the industry should seek more partnerships with researchers, regulators and private industry.
While not wanting to lessen its potential damage, many growers seem to be building a familiarity with it and say they feel they can control it better than citrus greening, which has devastated the state’s citrus groves.
The fight is important because the future of the 7,500-acre, $30 million-crop, the second-largest U.S. avocado-producing region, remains in the balance.
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