Skip to Main Content
A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other lauraceae in the Southeastern United StatesAuthor(s): Fraedrich. S.W.; T.C. Harrington; R.J. Rabaglia; M.D. Ulyshen; A.E. Mayfield; J.L. Hanula; J.M. Eickwort; D.R. Miller
Source: Plant Disease. 92(2): 215-224
Publication Series: Miscellaneous Publication
PDF: View PDF (762 KB)
DescriptionExtensive mortality of redbay has been observed in the coastal plain counties of Georgia and southeastern South Carolina since 2003 and northeastern Florida since 2005. We show that the redbay mortality is due to a vascular wilt disease caused by an undescribed Raffaelea sp. that is a fungal symbiont of Xyleborus glabratus, an exotic ambrosia beetle. Trees affected by the disease exhibit wilt symptoms that include a black discoloration of the sapwood. Redbay trees and containerized seedlings died within 5 to 12 weeks after inoculation with the Raffaelea sp. When redbay seedlings were challenged with X. glabratus, the beetles tunneled into 96% of the plants, 70% died, and the Raffaelea sp. was recovered from 91%. X. glabratus and the Raffaelea sp. have also been associated with mortality of sassafras, and the Raffaelea sp. has been isolated from wilted pondberry and pondspice. Additional inoculation studies have shown that the Raffaelea sp. is pathogenic to sassafras, spicebush, and avocado, but not to red maple. Female adults of X. glabratus have paired mycangia near the mandibles, and the Raffaelea sp. is routinely isolated from the heads of beetles. The fungus is apparently introduced into healthy redbay during beetle attacks on stems and branches. The wilt currently affecting redbay and sassafras represents a major threat to other members of the Lauraceae indigenous to the Americas, including avocado in commercial production.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationFraedrich. S.W.; Harrington, T.C.; Rabaglia, R.J.; Ulyshen, M.D.; Mayfield, A.E.; Hanula, J.L.; Eickwort, J.M.; Miller, D.R. 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
- North American Lauraceae: terpenoid emissions, relative attraction and boring preferences of redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae).
- Biology and host associations of redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae), exotic vector of laurel wilt killing redbay trees in the Southeastern United States
- Effect of tree species and end seal on attractiveness and utility of cut bolts to the redbay Ambrosia beetle and granulate Ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)
XML: View XML