First observed in 2002 in Georgia, the devastation of the ambrosia beetle rapidly spread both to the north and the south along the coastline of the southeast. In 2005 the beetle had moved into Duval County, Florida, and in just four years has since moved as far south as Okeechobee and Indian River counties. Reports vary, but some sources say the advance of the beetle has been from 15 to 20 and up to 34 miles per year.

Described as “fungus farmers,” the little black beetles which are most active during June through October, bore tunnels in the trunks of trees, leaving behind laurel wilt fungus spores that grow and eventually provide a food source for the beetles. The fungus obtains its nutrition from the tree, and this activity combined rapidly causes the leaves of the infected trees to wilt  and turn brown. Although the process often takes about a year, the tree eventually dies.

A number of factors have been attributed to the fairly rapid spread of the insects. Logs, limbs, stumps and sections of limbs of diseased trees could all be infected with insects, their larvae and the laurel wilt fungus. Firewood or tree trimmings, even wood chips moved from infestation sites to landfills or other sites are some of the ways the problem has already been spread. In addition, female ambrosia beetles fly.

IFAS is studying the infestation and has extensively reported on this issue, but has yet to develop a practical solution, and is still calling for reports of the advance of the insect. Currently IFAS suggests:

• Report any suspicious redbay (and other native host trees) and avocado trees to Department of Plant Industry (http://www.fl-dpi.com) and Division of Forestry (http://www.fl-dof.com/).

• Redbay and other host woody forest species should not be moved or sold as firewood, tree trimmings, BBQ smoke-wood, mulch or wood-trimming materials.

The ambrosia beetle threatens trees in the laurel family.

 

 

• Extreme caution should be used in moving host trees (e.g., redbay, avocado) and wood products into counties where the pest is not yet found. Insect- and disease-free containerized host trees should only be purchased from reputable nurseries and trees showing any signs of wilt or dieback should be destroyed immediately.

 

Among those species apt to be attacked by the ambrosia beetle are trees in the laurel family: redbays, bay trees, camphor, sassafras, pond berry, swampbay, pond spice and avocado trees. There are some 13 species of laurels found in Florida, including forest trees, ornamental and landscape trees, as well as a major commercial crop (avocado).