Four months after live coconut rhinoceros beetles were found at a Kīhei golf course on Maui, the state Department of Agriculture says no other evidence of the invasive pest has been found since.
Last November, 17 larvae were found in a palm tree at the golf course. The department and other organizations treated the tree, and nearly 80 others, with a pesticide in February and again in late March.
Following the second treatment, the trees were monitored for about two weeks. No other beetles have been found during that monitoring period.
“It is encouraging that no CRB have been detected on Maui in four months,” Sharon Hurd, chair of the agricultural department, said in a statement.
“However, the department and its partner organizations will continue (to) be vigilant and work to prevent CRB from becoming established in uninfested areas."
She said the DOA encourages the public to be on the lookout for CRB and to check green waste and compost piles, which are notorious breeding grounds.
Additionally, the beetles might not have spread from the initially infested tree. Dexter Kishida, Hurd’s deputy, said the pesticide Cypermethrin was used to treat the trees and would have turned up dead beetles.
“A golf course on Kauaʻi was experiencing some severe damage, and we were able to treat a majority of their trees. And in that event with the same process, there were a significant number of beetles falling from trees pretty quickly during treatment," Kishida said.
"So, knowing those results weren't duplicated on Maui, it's pretty encouraging that in four months, no live CRB have been detected,” he said.
There are limited ways to wipe out coconut rhinoceros beetle populations in infested areas, and there are currently federal restrictions on how widely Cypermethrin can be used.
The invasive beetles can damage and kill palm trees along with other crops in Hawaiʻi. They were first detected on Oʻahu in 2013 and were recently discovered on Kauaʻi, Maui and Hawaiʻi Island.
