Laurel wilt kills infected trees by depriving them of water. The disease, which threatens avocado trees, has been found throughout Florida. / Courtesy Fresh from Florida Plant Industry

Laurel wilt is damaging and, in many cases, killing avocados in many areas of Florida. “The disease is caused by a fungus (Raffaelea lauricola) that is introduced into host trees by a nonnative insect, the redbay ambrosia beetle (Xyleborus glabratus),” according to the Florida Department of Agriculture and Consumer Services.

Symptoms of laurel-wilt infestation include dark staining of the sapwood (visible after removing the bark). “The dark color of the outer ring of sapwood below the bark indicates the tree has been infested by the redbay ambrosia beetle and the wood has been colonized by the laurel wilt pathogen. (This) … blocks movement of water and nutrients in the tree,” said the University of Florida’s Institute of Food and Agricultural Services’ website.

Laurel wilt was first noticed in Florida in 2005 – in Duval County – according to UF’s IFAS. In 2015, infestations of the disease, which kills the trees, were found in Southwest Florida (Lee, Hendry, Collier, and Monroe counties) as well as the Panhandle (Gadsden and Liberty counties). Take a look at how laurel wilt has spread.

To learn more about this disease, check out this Laurel Wilt Disease video courtesy of Fresh from Florida.