Kaua‘i DLNR Division of Forestry and Wildlife (DOFAW) botanist Adam Williams discovered at least five ʻŌhiʻa trees in the Moloa’a Forest Reserve that appeared to be dead from symptoms associated with what has been called Rapid ʻŌhiʻa Death or ROD. As a result, a rapid response team of experts from state and federal agencies and non-government organizations formed over the last week to investigate the issue.
The rapid response included drone and helicopter surveys, laboratory confirmation of the presence of the fungus known as Ceratocystis huliohia (formerly called Ceratocystis “species B”) and training for Kaua‘i-based teams on how to identify the fungus and sample for it.
On Wednesday, a multi-disciplinary team from DLNR/DOFAW, Dr. Keith’s USDA lab, the University of Hawai’i’s College of Tropical Agriculture and Human Resources (CTAHR), the Kaua‘i Invasive Species Committee (KISC), and The Nature Conservancy (TNC) hiked into the forest reserve to get a closer look at the two trees already confirmed to be infected with Ceratocystis huliohia. The team then received field training from Dr. Marc Hughes of USDA/ARS on how to spot the signs of ROD and how to take samples to send to the USDA/ARS lab in Hilo for further verification.
Dr. Wade Heller of USDA/ARS demonstrated how to enter data into a smart phone-based field application that tracks location, symptoms, sample collection and photographs in a central data base to ensure accurate tracking of each infected tree. After these demonstrations, field teams from KISC, TNC, and DOFAW practiced sampling techniques on the two trees positively identified as having Ceratocystis huliohia and four other nearby trees that showed symptoms. Overnight testing at the USDA/ARS lab resulted in confirmation of an additional three infected trees, for a total of five.
DLNR spokesperson, Dan Dennison indicated there could be more trees on Kauaʻi and possibly other neighbor islands afflicted by the less aggressive pathogen.
Dr. Lisa Keith from the USDA Agricultural Research Service (ARS) is an expert on Rapid ʻŌhiʻa Death (ROD). In the video below, she explains that the term, “Rapid ʻŌhiʻa Death” or “ROD” is more of an umbrella that describes two different pathogens, Ceratocystis lukuohia (species A) and the Ceratocystis huliohia (species B). Ceratocystis lukuohia (species A) is the more aggressive of the two species and is responsible for widespread tree death affecting over 135,000 acres on Hawai’i Island. Ceratocystis huliohia (species B) is the species that was discovered on Kaua‘i, and its impacts are much less severe and slower moving.
She explains that ROD occurs when a tree is wounded and then the pathogenic fungus enters the wound. In effect, the fungus clogs the tree’s vascular system causing wilt and death.
Sanitation protocols have been developed on the Big Island to keep the pathogen from spreading. Rob Hauff, State Protection Forester for DLNR/DOFAW explained that these protocols include scrubbing boots and other footwear with 70% isopropyl alcohol after any forest activity and thoroughly washing any equipment and vehicles that enter or are used in the forest. Melissa SP Fisher, Director of TNC’s Kaua‘i Forest Program hopes that everyone on Kaua‘i will be vigilant in practicing these protocols.
Experts agree that Kaua’i is fortunate to be dealing with the less aggressive pathogen, or the “not so” Rapid ʻŌhiʻa Death. In fact, it’s pretty amazing that such a diverse group of experts was assembled within a matter of days to address the issue.
CTAHRs recommendations for preventing the spread of ROD:
WHAT CAN WE DO?
Help prevent spreading Rapid ʻŌhiʻa Death by practicing these five things: