10 Years with CRB in Hawaii

The Coconut Rhinoceros Beetle was first found in a trap at Mamala Bay golf course on JBPHH close to the airport on Oahu on December 23, 2013. CRB had already infested many other pacific islands prior to Oahu and this trap was part of the state’s early detection and monitoring program. In early 2014, the CRB Response was established and traps were distributed across the island for delimiting surveys. During 2014, CRB were found in Navy Marine Golf Course, Iroquois point, Ewa Beach and Nanakuli. By 2015, CRB had spread to Pearl City Peninsula. Besides the few finds in Nanakuli, the slow spread over the first few years were limited to areas around Pearl Harbor. 

In 2017, CRB was detected for the first time in Kunia. This find was significant because it’s an area with a lot of breeding material and host plants, factors that make the CRB population thrive. By 2018, CRB had also spread to Waimanalo and south Mililani. This faster and wider spread shows evidence of accidental human vector spread due to movement of host material such as mulch and compost.

CRB trap catches between 2014-2018 (left) and 2019-2022 (right). The fast geographic spread on the right is most likely due to accidental movement of host material. 

When CRB was first found on Oahu, there were very few options to treat for CRB. Joint Base Pearl Harbor Hickam (JBPHH)  implemented a strict, zero tolerance green waste policy following the first infestation. Curtain burners were used to burn any green waste accumulated on site and no mulch was allowed to be brought in. This method, even though it was expensive, showed to be effective and by 2018, the area that had the first confirmed infestation had no trap finds. 

In 2019, we welcomed our 3 CRB detection dogs and their handlers to the team. This helped our field crew who up until now had to dig through any potential breeding material by hand. With the help of our sniffing dogs, we were able to survey a lot more breeding material without tiring out our field crew. 

After years of experiments in the lab and in the field, in 2020 field treatments of injecting palms with imidacloprid and acephate started. This treatment showed to be effective when performed on a landscaping level and combined with green waste management. Since field treatments started, CRB response has treated over 7000 individual palms. 

Not long after we started injections as a palm treatment, we explored new treatments for breeding material. In 2021, the vacuum steam unit (VSU) was introduced. Infested material is loaded into a chamber in the VSU that draws a vacuum and injects steam. This quickly heats the material to a temperature fatal to CRB. This treatment was successful in killing CRB, however, it was labor intensive and not a lot of breeding material could be treated at once. In 2022, we started treating breeding material through fumigation. Similar to tenting your house, fumigating breeding material with sulfuryl fluoride to 2000CT showed to kill all life stages of CRB. This treatment dramatically increased the capacity of material that could be addressed. 

Different treatment methods, injections (right), VSU (middle), fumigation (right).

Unfortunately, even with all these amazing new tools to treat CRB, by 2023 the increased population and spread of CRB on Oahu lead to CRB Response shifting focus on Oahu from eradication and long term management. In May of 2023, CRB was detected on Kauai, this was the first find on a neighboring island. 5 months later, in October, CRB was found on Hawaii Island. In November, it was also found on Maui. 

Hopefully, with everything we learned and the tools developed under the 10 years since CRB first arrived in Hawaii, we will be able to eradicate CRB from Maui and Hawaii Island as well as slowing the spread on Kauai and minimizing palm damage on Oahu. There is also so much research still ongoing for new, more effective treatments and management tools. Only the future can tell what’s going to happen next but we have not given up the fight against CRB!