Red bay tree and the ambrosia beetle. John spots the trees on the property
Channel: BlakesNaturelife
Date: 2021-05-12

#RedBaytree
A tree that needs saving, that all trees and plants do.

I found this online check it out. http://bugs.ufl.edu/bug-pix/redbay-ambrosia-beetle/

Florida’s $100 million avocado industry faces grave danger from the redbay ambrosia beetle and related insects, which transmit the pathogen responsible for laurel wilt, a fungal disease that kills avocado trees.

Estimated losses: $4.2 million in lost trees, $450,000 per year in lost future avocado sales from those trees. 

The redbay ambrosia beetle is a tiny insect that colonizes the sapwood of trees in the Laurel Family, which includes native trees such as redbay and swampbay and the fruit crop avocado. The beetle transmits a pathogenic fungus to host trees, causing a disease known as laurel wilt. Currently, it is believed that laurel wilt disease is also spread by several additional ambrosia beetle species in South Florida. The disease has been documented to kill 98 percent of infected native host trees.

The redbay ambrosia beetle was first reported in the U.S. in 2002, in Savannah, Ga., on the Atlantic coast. In 2003-2004, scientists recognized the connection between the beetle and laurel wilt disease. By then, the beetle had begun expanding its initial range, spreading north and south along the coast, as well as moving inland. Laurel wilt disease killed millions of native redbay trees in Georgia and South Carolina within two to three years of its establishment. In Florida, the laurel wilt was first reported in Jacksonville in 2005, and the nation’s first confirmed avocado tree death from laurel wilt occurred in Jacksonville in 2007.

In 2011, a redbay ambrosia beetle was captured in Miami-Dade County, home of the state’s avocado industry, which has a total economic impact of about $100 million annually. The first reports of laurel wilt disease in commercial avocado trees occurred in 2012. As of May 2016, the disease has killed about 12,000 commercial avocado trees, or 1.5 percent of the state’s inventory. Recent UF/IFAS research has implicated not only the redbay ambrosia beetle, but other ambrosia beetles as capable of transmitting the laurel wilt pathogen in Florida avocado groves. Growers are taking steps to discourage fungal infections and reduce populations of the ambrosia beetles. However, there is no cost-effective cure for laurel wilt disease and its impact on the industry may increase in years to come.

BASICS
Common Name: Redbay ambrosia beetle

To produce food, ambrosia beetles carry fungal spores everywhere they go, and grow fungal “gardens” inside galleries excavated in the trees they colonize. The redbay ambrosia beetle is associated with a fungus known scientifically as Raffaelea lauricola, the pathogen responsible for laurel wilt disease. Scientists once believed that each ambrosia beetle species was associated with only one species of fungus, but recent studies have shown that some ambrosia beetle species associate with more than one fungus, sometimes carrying spores from multiple fungal species at the same time.

What It Does: All ambrosia beetle species can carry fungal spores on their exoskeletons and in specialized fungal carrying pouches called mycangia. When adult ambrosia beetles colonize a host tree they first bore holes in the trunk to gain entry, then excavate tunnels known as galleries through the sapwood. There, the beetles begin cultivating fungus in some galleries, by depositing spores they keep stored in their mycangia. The beetles farm the fungus and use it as their only food source.

The redbay ambrosia beetle colonizes trees in the Laurel Family. Unlike many ambrosia beetles, this species will readily colonize healthy trees, as UF/IFAS research has demonstrated. It carries and cultivates a fungus that’s deadly to host trees, Raffaelea lauricola. As the fungal gardens grow, they cause the host tree to weaken and potentially die, apparently because the tree reacts to the fungal infection by reducing the activity of its xylem, the equivalent of the tree’s circulatory system. In a worst-case scenario, laurel wilt disease can kill a tree within four to eight weeks after the initial infection.

Who Is Affected: The most obvious stakeholder group affected is the Florida avocado industry, which involves about 7,000 acres and 500 growers, almost all in Miami-Dade County. Florida is the nation’s second-largest avocado producer, after California, and avocado represents the state’s second-largest fruit tree industry, after citrus. Florida growers produce primarily green-skinned avocados, which represent about 12 percent of U.S. avocado production and generate about $100 million in total output contribution. Because laurel wilt disease has begun killing commercial avocado trees, the growers’ livelihood is in jeopardy.

In addition, some Florida residents are affected because laurel wilt disease has killed an unknown number of the state’s estimated 250,000 dooryard avocado trees.