Oahu Invasive Species Committee (OISC)

ROD – OʻAHU

Send photos and locations of symptomatic ʻōhiʻa:  CLICK HERE TO REPORT!

ROD Symptoms in ʻōhiʻa trees = brown leaves attached

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Healthy ʻŌhiʻa 

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Rapid ʻŌhiʻa Death (ROD) Detections on Oʻahu (as of June 2021) CLICK HERE FOR UPDATED MAP

  • Over 356 ʻōhiʻa trees have been sampled to test for the presence of ROD…
  • Only eight (8) trees have tested positive for the less aggressive ROD fungus, Ceratocystis huliohia.
  • There have been no detections of the very aggressive species, Ceratocystis lukuohia.

What Should You Do To Prevent the Spread? 

  • Don’t injure ʻōhiʻa trees.
  • Clean soil from shoes and tools and spray with 70% rubbing alcohol if can.
  • Don’t move ʻōhiʻa logs or plant parts.
  • Don’t transport ʻōhiʻa inter-island.
  • Wash any vehicles/bikes that have been off-road with high pressure hose.

What is ROD?

Rapid ʻŌhiʻa Death (ROD) is a fungal pathogen new to science not ever seen before 2014. There are two (2) species of ROD:

  1. Ceratocystis lukuohia – VERY aggressive and rapid death as occurs in as little as two weeks.
  2. Ceratocystis huliohia – Less aggressive and death can take many months.

Quick Facts About ROD:

  • Symptoms of ROD are dead or dying ʻōhiʻa trees with brown leaves still attached.
  • Both species of ROD present the same symptoms: brown leaves on branches or entire tree.
  • ROD fungus lived INSIDE the tree, you cannot see it on leaves, branches or flowers.
  • ROD enters the ʻōhiʻa tree through a wound…do not injure ʻōhiʻa trees.
  • If you see suspect ROD, send photos to OISC via email: oisc@hawaii.edu or text to: 808-286-4616.
  • You can also always report using the free smartphone app: 643PEST

A variety of things can kill ʻōhiʻa trees and we canʻt know if itʻs ROD unless we get a sample of the wood from inside the tree. You cannot see ROD on leaves or branches…it grows inside the sapwood. This is where the tree moves water around. When the fungus plugs up the sapwood, no water can be moved and the leaves turn brown.

About ʻŌhiʻa

ʻŌhiʻa is the dominant canopy forest tree in the state with over 350 million trees across 800,000 on all the main Hawaiian islands. It is a keystone species, meaning itʻs integral to the ecosystem and the services they provide like clean water, water capture, as well as flood and erosion control. ʻŌhiʻa is also significant to Hawaiian culture and represented in numerous hula, moʻolelo, mele and oli. There are five species of ʻōhiʻa in Hawaiʻi. They are all endemic to our state, meaning they are found nowhere else in the world…and two of those five are endemic to Oʻahu island! You can see ʻōhiʻa in yards and in the forest.

For more details about ROD and ʻōhiʻa, visit: www.rapidohiadeath.org

FOURTH DETECTION OF RAPID ʻŌHIʻA DEATH ON O‘AHU

Dead leaves still attached to ʻōhiʻa (as seen here from the air)…this is known as “flagging” and symptomatic of potential presence of ROD inside the tree.

(Honolulu) – An aerial survey of some 20,000 acres of forest on O‘ahu has resulted in the fourth detection of Rapid ʻŌhiʻa Death (ROD) in an ʻōhiʻa in the Moanalua Section of the Honolulu Watershed Forest Reserve above Tripler Army Medical Center.

“Fortunately,” explains State Protection Forester Rob Hauff of the DLNR Division of Forestry and Wildlife (DOFAW), this tree is infected with Ceratocystis huliohia, the less aggressive species of the fungus associated with ROD.”  The tree was located using a helicopter-mounted camera system developed by the University of Hawai‘i-Hilo, Spatial Data Analysis and Visualization Lab (SDAV).  The collected images were analyzed in partnership with staff from the O‘ahu Invasive Species Committee (OISC) and DOFAW, as part of an on-going effort to improve the ability of field personnel to spot potentially infected trees.

The previous detections of the same species on O‘ahu include single trees on Kamehameha Schools land in Waiawa, and on two private properties in Windward O‘ahu residential areas. Nathan Dube, the manager of the OISC said both of those trees were planted ʻōhiʻa. He said, “Both of these detections were from concerned landowners, who reported their dead or dying ʻōhiʻa to OISC.  An OISC field team cut down the trees, dissected them, and sent samples to a lab in Hilo for positive confirmation and for research purposes.”

The aerial survey that picked up the tree in the Honolulu Watershed Forest Reserve, focused on the area adjacent to the earlier Waiawa detection. Surveyors identified about 40 additional trees from the images that need to be sampled for the disease, including ground-truthing. That process will take some time, as the area is rugged and difficult to reach.  DOFAW and OISC crews, with the help from experts on Hawai’i Island, decided to remove the infected branch of the tree and monitor it monthly for further signs of disease. Crews used a sealant on the wound to prevent additional disease infection.

*Please report location of dead or dying ʻōhiʻa trees with dead leaves still attached on O‘ahu to OISC at: oisc@hawaii.edu  (Photos are helpful)

Surveying 20,000 acres of forest on Oahu. using helicopter mounted camera system designed by UH-Hilo, Spatial Data Analysis and Visualization Lab.

 

 

 

 

 

 

 

 

 

Residents and visitors can help protect our remaining ʻōhiʻa forests with the following actions:

  • Avoid injuring ʻōhiʻa. Open wounds on ʻōhiʻa are an entry point for disease spores. The disease can also spread from tree to tree on machetes or other tools.
  • Don’t transport ʻōhiʻa inter-island.
  • Don’t move ʻōhiʻa wood or vegetation, especially from areas known to have ROD.
  • Clean your hiking boots/gear/tools. Scrub off all dirt and spray boot soles and tools with 70% rubbing alcohol, and wash your clothes in hot water and use a dryer to ensure the disease is not spread on boots and clothing.
  • Wash your vehicle if driving near ʻōhiʻa forests. The disease can remain alive and infectious in soil, so wash all dirt off vehicles.

Rapid ʻŌhiʻa Death has now been detected on Hawai‘ Island, Maui, Kaua‘i and O‘ahu since the fungal disease was first discovered in 2014. To date, the more aggressive form of the disease has not been found on Maui or O‘ahu, and is extremely limited on Kaua‘i.

Rapid ʻŌhiʻa Death Detected on Oʻahu

DEPARTMENT OF LAND AND NATURAL RESOURCES NEWS RELEASE: July 31, 2019

RAPID ʻŌHIʻA DEATH NOW DETECTED ON FOUR ISLANDS: Less Aggressive Strain Discovered on O‘ahu

(Honolulu) – One of the species of fungus causing Rapid ʻŌhiʻa Death was recently detected for the first time on O`ahu. A team of natural resource managers from the O`ahu Invasive Species Committee (OISC) and the Ko’olau Mountain Watershed Partnership (KMWP) recently sampled a dead ʻōhiʻa tree on private land in a remote area in the Ko’olau Mountains above Pearl City.

The sample was analyzed by the USDA Agriculture Research Service lab in Hilo. It confirmed the presence of Ceratocystis huliohia. Although this is the less aggressive of the two Ceratocystis species associated with ROD, it still has the ability to kill ʻōhiʻa trees.

A partnership of state, federal, university, and non-government organizations have been conducting systematic helicopter and ground surveys to look for Rapid ʻŌhiʻa Death since 2016.  On Oʻahu, 150 dead or unhealthy ʻōhiʻa trees have been sampled for the disease in the past three years, and all have been negative until now. The location of the infected tree is extremely remote and it is considered highly unlikely to have been spread by people. Researchers are still trying to understand the source of the two Ceratocystis pathogens and are looking at any possible patterns of dispersal.

This first detection on O‘ahu has initiated a rapid response which includes additional surveys to determine how widespread the disease is. A combination of helicopter, UAS (drone) and ground surveys are planned with OISC, DLNR and KMWP playing lead roles. The landowner, Kamehameha Schools, is working closely with the response agencies to coordinate access to the property so agencies are able to test for the fungus and prevent it from spreading.

Rapid ʻŌhiʻa Death threatens Hawaii’s most important tree species. ʻŌhiʻa grows throughout the Ko’olau and Waianae mountain ranges across approximately 50,000 acres. ʻŌhiʻa serves as a keystone species providing important watershed cover for recharging the island’s aquifer, habitat for endangered species, and cultural uses such as hula performances.

Residents and visitors can help protect our remaining ʻōhiʻa forests with the following actions:

  • Avoid injuring ʻōhiʻa. Open wounds on ʻōhiʻa are an entry point for disease spores. The disease can also spread from tree to tree on machetes or other tools.
  • Don’t transport ʻōhiʻa inter-island.
  • Don’t move ʻōhiʻa wood or vegetation, especially from areas known to have ROD.
  • Clean your hiking boots/gear/tools. Scrub off all dirt and spray boot soles and tools with 70% rubbing alcohol, and wash your clothes in hot water and use a dryer to ensure the disease is not spread on boots and clothing.
  • Wash your vehicle if driving near ʻōhiʻa forests. The disease can remain alive and infectious in soil, so wash all dirt off vehicles.

Rapid ʻŌhiʻa Death has now been detected on Hawai‘ Island, Maui, Kaua‘i and O‘ahu since the fungal disease was first discovered in 2014. To date, the more aggressive form of the disease has not been found on Maui or O‘ahu, and is extremely limited on Kaua‘i.

RESOURCES (All images/video courtesy: DLNR)

To report dead or dying ʻōhiʻa on Oʻahu please call or text the Oahu Invasive Species Committee at (808) 286-4616 or e-mail oisc@hawaii.edu.

Additional information about Rapid ʻŌhiʻa Death can be found at www.rapidohiadeath.org.

Media Contact: Dan Dennison, Senior Communications Manager (808) 587-0396,  DLNR.comms@hawaii.gov

 

 

Contact Us

Oahu Invasive Species Committee (OISC)
Office: (808) 266-7994
Fax: (808) 266-7995

OISC Manager: Nate Dube
E-mail: oiscmgr@hawaii.edu
OISC Outreach Coordinator: Erin Bishop
E-mail: oisc@hawaii.edu

Pest Hotline: 808-643-PEST (7378)
Report a Pest Online