Redbay trees (Persea Borbonia) are experiencing a high mortality rate as a result of an invasive species known as the redbay ambrosia beetle. The beetles were first introduced into the United States through imported wood and the effect it is now having on the native trees is devastating. The beetles are directly affecting the Lauraceae family and the ecological and commercial impact is creating a problem. It is a major concern that has to be addressed or risk pandemic proportions.
In addition, the Laurel wilt disease, caused by Xyleborus glabratus, has been associated with the mortality of not only the redbay tree, but also from sassafras (Sassafras albidum (Nutt.) Nees), pondspice (Litsea aestivalis (L.) Fernald), pondberry (Lindera melissifolia), and avocado (Persea americana) (Mayfield and Thomas, 2007) trees. These beetles do not use the wood to feed but mainly to be able to produce fungi to feed the larvae and keep reproducing.
The ecological impact is alarming: at the site of the beetle�s initial detection in Florida, redbay mortality has increased from 10% to nearly 60% in a period of only nine months (Haack, 2006). Redbays provide fruit, seeds, and foliage for deer, wild turkeys, quail, and black bears (Rabaglia and Fraedrich, 2006). If these invasive species keep spreading at this rate, avocado trees which are important food staples will affect the economy and our backyards.
Just what makes these trees susceptible is unknown but what is of great importance is investigating just how many other trees could be affected. At this time there are no tested or proven treatments for prevention or control of this insect and its associated pathogen (Rabaglia et. al 2006).
References
Fraedroch, S.W., T.C. Harrington, R.J. Rabaglia, M.D. Ulyshen, A.E. Mayfield, J.L. Hanula, J.M. Eickwort, D.R. Miller. 2008. A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other lauraceae in the Southeastern United States. Plant Disease 92 (2): 215-224.
Haack, R.A. 2006. Exotic bark- and wood-boring Coleoptera in the United States: recent establishments and interceptions. Canadian Journal of Forest Research 36 (2): 269-288.
Mayfield, A.E., M.C. Thomas. 2007. The Redbay Ambrosia Beetle, Xyleborus glabratus Eichhoff (Scolytinae: Curculionidae). Florida Department of Agriculture and Consumer Services.
Rabaglia, R.J., S.A. Dole, A.I. Cognato. 2006. Review of American Xyleborina (Coleoptera: Curculionidae: Scolytinae) Occurring North of Mexico, with an Illustrated Key. Annals of the Entomological Society of America 99 (6): 1034-1056.
Rabaglia, R.J., S. Fraedrich. 2006. The association of Xyleborus glabratus and an Ophiostoma species with mortality of red bay and sassafras in the southeastern U.S.. U.S. Department of Agriculture: 81.