Decontamination of Ceratocystis pathogens responsible for rapid ʻŌhiʻa Death

Plant Health Progress
By: , and 



Rapid ʻōhiʻa death (ROD) is caused by two recently described species of Ceratocystis, C. lukuohia and C. huliohia. These fungi are decimating ʻōhiʻa lehua (Metrosideros polymorpha), the keystone native tree species of Hawaiʻi. Viable Ceratocystis propagules can persist in ambrosia beetle frass (Coleoptera: Scolytinae), and movement of the frass may play a key role in the spread of the disease. In order to prevent the spread of ROD, we developed effective and practical surface (e.g., tools and shoes) decontamination methods to be used by researchers, managers, and the public alike. We first tested different household and laboratory disinfectants on the Ceratocystis fungi in culture, and then we applied the effective culture disinfectants to contaminated ambrosia beetle frass. Laboratory-grade ethanol (70, 80, and 95%), Clorox bleach (10%, 0.825% active ingredient [a.i.]), and isopropanol (70 and 91%), were all equally effective at decontaminating cultured C. lukuohia and C. huliohia. Although all concentrations of isopropanol (50, 70, and 90%) and ethanol (50, 70, and 90%) were effective disinfectants of Ceratocystis-contaminated frass, treatments of frass with up to 20% Clorox bleach (1.2% a.i.) were not completely adequate at killing the fungus. These data reveal that bleach is not a sufficient ROD disinfectant when frass is present, and isopropanol or ethanol are the more reliable options.

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Publication type Article
Publication Subtype Journal Article
Title Decontamination of Ceratocystis pathogens responsible for rapid ʻŌhiʻa Death
Series title Plant Health Progress
DOI 10.1094/PHP-06-20-0051-RS
Volume 21
Year Published 2020
Language English
Publisher American Phytopathological Society
Contributing office(s) Pacific Island Ecosystems Research Center
Description 5 p.
First page 301
Last page 305
Country United States
State Hawaii
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