Recovery Plan for Laurel Wilt of Avocado, Caused by Raffaelea lauricola

Abstract

Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial production in the United States and other countries, and currently impacts the avocado industry in Florida. As laurel wilt spreads, the National Germplasm Repository for avocado in Miami (USDA-ARS) and commercial and residential production in other states (e.g., California and Hawaii), U.S. protectorates (Puerto Rico), and other countries are at risk. In the United States, value-added production of avocado of more than $1.3 billion/year is threatened. This recovery plan was produced as part of the National Plant Disease Recovery System (NPDRS), called for in Homeland Security Presidential Directive Number 9 (HSPD-9) to insure that the tools, infrastructure, communication networks, and capacity required to mitigate the impact of high-consequence plant disease outbreaks are such that a reasonable level of crop production is maintained. It is intended to provide a brief primer on the disease, assess the status of critical recovery components, and identify disease management research, extension, and education needs.

Laurel Wilt in Natural and Agricultural Ecosystems: Understanding the Drivers and Scales of Complex Pathosystems

“…Although little is known about symbioses that are established between R. lauricola and different ambrosia beetle species, some of these insects may be involved in the ongoing epidemic in the southeastern United States [28,70]. In no-choice experiments, Carrillo et al [69] reported that six and two species other than X. glabratus transmitted R. lauricola to potted redbay and avocado trees, and that laurel wilt developed in six and one of these interactions, respectively.…”

“…Although beetle attraction to, or avoidance of, R. lauricola may impact whether it is a factor in the epidemiology of this disease [28,70], it is unclear whether species that are repelled by R. lauricola in olfactometers could still be occasional vectors of the pathogen and whether attracted or neutral species would disseminate the pathogen more frequently. Clearly, the involvement of other ambrosia beetle species in the laurel wilt epidemic requires more study.…”

“…Of economic concern is the potential impact of the disease in currently unaffected avocado-production areas [28]. Avocado is a subtropical/tropical tree, and a significant fruit crop.…”

“…However, the short time laurel wilt has been in South Florida (where most commercial production occurs), the great susceptibility of avocado to this disease, and experience with other lethal, invasive diseases [11,114] suggests that laurel wilt will, in the future, cause increasing damage on avocado in Florida. Laurel wilt imperils avocado production in other states (e.g., California and Hawaii), USA protectorates (Puerto Rico) and neighboring countries such as Mexico [28].…”

“…[26], their attractiveness to X. glabratus [66,78], the rapid increase in X. glabratus numbers in affected stands of these trees [58], and the substantial amounts of inoculum that most females of X. glabratus carry [70]. Furthermore, tree-to-tree spread via interconnected root systems, which has been suspected in avocado [28] and sassafras [147], and demonstrated in pondberry [148], enables movement of the pathogen without vector assistance. It is hard to imagine a more efficient means for killing trees than this disease.…”