Across Hawaii, what looks like a bad haircut on the landscape is marking the slow death of the coconut palm, that icon of paradise. The culprit: the coconut rhinoceros beetle, a glossy, thumb-size scarab that bores into the crowns of palms to feed on sap. Today, all that stands between the beetle and a palm-poor Hawaii is a small team of scientists, field crews and grub-sniffing dogs.
When the coconut rhinoceros beetle, or CRB, arrived in Hawaii more than a decade ago, the threat seemed under control. But in recent years the beetle has spread. Palms near Waikiki have been showing signs of the beetle — V-shaped cuts in their fronds, bore holes in their trunks — prompting officials to treat hundreds of Honolulu’s palms with insecticide. This spring, traps set on the Big Island caught 10 beetles.
The beetle can still be eradicated on the Big Island, but on Oahu and Kauai, containment is the only option. The work falls to the Coconut Rhinoceros Beetle Response, an Oahu-based organization focused on creating 1,500-foot “exclusion” zones around high-risk sites — airports, harbors, compost facilities, plant nurseries and the like — to intercept beetles before they proliferate. The team sets traps, treats palms and tests ways to kill the beetle. And to find the larvae, they deploy two trained dogs, Bravo and Penny. All told, the dead-beetle tally is at least 144,503.
One morning in May, Keith Weiser, deputy incident commander for CRB Response, drove to a military housing neighborhood near Pearl Harbor to observe a field crew. A dead beetle in a bottle rattled in the cup holder. The smell, akin to that of spoiled shrimp, filled the cab.
“Usually bugs dry out so quickly,” Weiser said. “But these guys are so big they actually rot.”
Outside a house with a single coconut palm in the yard, two crew members unloaded what amounted to an arboreal first-aid kit: an air-powered, piston-driven syringe, some insecticide and a drill. One of them sanitized a drill bit, bored a hole in the palm’s trunk and inserted the syringe to deliver imidacloprid, the insecticide, to the tree’s circulation system. (The team avoids flowering trees to reduce risks to pollinators.) It takes about a month for the insecticide to reach the crown of the tree, at which point it kills any beetles unfortunate enough to make it that far.
The coconut (Cocos nucifera), known in Hawaii as a canoe plant, is not native to the islands. Polynesians brought it by canoe, along with taro, banana and other staples, to use for food, drink and crafts. The coconut rhinoceros beetle (Oryctes rhinoceros), native to Southeast Asia, is considered invasive. In 1909, it arrived in Samoa from Sri Lanka, in planting material. It then dispersed across the South Pacific, feeding on a range of plants.
When the beetle reached Guam in 2007, it devastated the coconut population. It then found its way to Papua New Guinea, Palau and the Solomon Islands.
CRB was first detected in Hawaii on Dec. 23, 2013, at a golf course on Hickam Air Force Base, tucked between the runways of Honolulu International Airport.
“It showed up on their property,” but who was responsible is “really hard to prove,” Weiser said. “You’d have to find the infested goods that came in years before we even knew CRB were here.”
At first, the beetle population appeared to be under control. But in 2019, it began its great expansion.
“We basically lost control once it hit central Oahu,” said Michael Melzer, a professor at the University of Hawaii’s College of Tropical Agriculture and Human Resilience and the principal investigator behind CRB Response’s grants. “With the tools we have, we’re not going to eradicate on Oahu.” After that determination, the U.S. Department of Agriculture told the team to pull back to the ports, in order to focus on sanitizing and stopping beetle hitchhikers there.
When the beetle was discovered on Kauai in 2023, Melzer thought there was a chance of eradication. “But it turns out the beetle was already widespread there,” he said. “Kauai’s a couple years behind Oahu.”
For now, no beetles have been found on Maui or Molokai. In May and July, beetles and larvae were discovered in two shipments on Lanai and were destroyed. On the Big Island, the team is trying to eradicate the beetle, which was found in March, before it’s too late. A crew traveled there in June, flying drones to spray pesticide into the crowns of the palms near the Kona airport.
The state is stepping in to help. This spring, the Hawaii Legislature allocated $500,000 annually for the next two years to CRB Response. The same bill added “Biosecurity” to the name of the Hawaii Department of Agriculture, in a show of a growing sense of urgency.
The timing is critical, since the USDA has, under other administrations, provided the majority of their funding. “We should be prepared if there is no funding from the USDA,” Weiser said. “The unofficial writing on the wall is it’s going to be much more difficult next year.”
Ultimately the team can only delay the beetle’s spread, Weiser said.
“We don’t have the resources to stop it,” he said. “I think we’ve just given people more good years with palms.”
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This article originally appeared in The New York Times.
Source: The Garden Island
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