The development of drone technology by the University of Hawaii raises hopes for combating invasive species threatening Hawaii’s native plants.

Rapid Ohi’a Death (ROD) has caused the death of hundreds of thousands of Ohi’a trees, a  species native to Hawaii.  

ROD causes previously healthy trees to die within weeks of infection.

These trees are ill-equipped to combat ROD, as it is caused by a type of fungi not native to Hawaii.  

Researchers say that this invasive species is most likely carried in by unassuming tourists.

Biologically, the importance of the Ohi’a tree comes from the fact that it is endemic to Hawaii due to the isolated nature of the island chain.

The losses so far have been quite devastating from a biodiversity perspective.

Culturally, the Ohi’a holds religious significance for the indigenous people, as its flowers have been referenced as favored by the goddess Pele.

The tree itself is also an integral part of countless rituals.

Obviously, the losses due to ROD are devastating in both aspects, with local caretakers and environmental researchers alike scrambling for solutions to protect this important tree.

Initially, measures against ROD were mostly preventative in nature, such as spraying the shoes of tourists with disinfectants before they entered any nature reserves. 

While this somewhat prevented the spread of the fungi into other uninfected reserves, it proved futile for places already affected by the disease.

More recently, researchers at the University of Hawaii in Hilo have collaborated with those at ETH Zurich to develop specialized drones.

This has allowed them to take on a more active role in conservation efforts.

The team, spearheaded by Professor Ryan Perroy, developed a unique chainsaw arm attachment for the drones for the purpose of acquiring samples from trees suspected of disease.

While ETH Zurich had already developed an arm capable of cutting off small branches, Perroy states that to accurately detect ROD, a bigger sample was necessary.

Using 3D printing as  the main source of fabrication for the arm, they were able to develop one that could cut off samples up to seven centimeters in diameter, with pincer-like grips for picking up the branches, leading Perroy and his team to coin it “Kūkūnau”, Hawaiian for a type of crab.

The bigger samples allow for a 77 percent accuracy rate, and UH Hilo has been able to detect countless infected trees using this technology, effectively tracking the development of the ROD outbreak.

Previously, samples had to be acquired by a team trekking through the often dangerous mountainscape, with many areas simply being inaccessible to humans.

The mobility of these drones has opened up these areas for research purposes and allowed Perroy and his team to better assess the spread of the disease.

If an area is confirmed to be infected, the team can then send another drone to disperse fungicide in the near vicinity, hopefully wiping out the disease.

With this new technology aiding in the battle against the disease and continuous preventative measures taking place, Perroy hopes to be able to keep Rapid Ohi’a Death under control, if not completely eradicated.

Jonathan Moon
Grade 10
Singapore American School