By Lt. j.g. Eric Galassi, Navy Region Hawaii Public Affairs
The coconut rhinoceros beetle (CRB) was first discovered in a trap at Joint Base Pearl Harbor-Hickam (JBPHH) on Dec. 23, 2013. In January 2014, CRB eggs, larvae and adults were confirmed to be present in a large mulch pile on the Mamala Bay Golf Course on base.
Efforts have been underway since January to determine the extent of the beetle’s infestation on Oahu. This has been done with a combination of methods, including conducting visual surveys of coconut trees and manila palms for feeding damage, searching through mulch and green waste piles for larvae, and by placing a variety of traps that lure and capture adult beetles if they are in the area. Some of these traps are placed in Joint Base Pearl Harbor-Hickam (JBPHH) communities, while many more are placed on other military and public grounds around the island.
The State of Hawaii Department of Agriculture (HDOA) is the lead agency in this effort. Navy Region Hawaii and JBPHH have remained in close coordination with HDOA and United States Department of Agriculture (USDA) while also working together with U.S. Fish and Wildlife Service, University of Hawaii, Department of Land and Natural Resources (DLNR), and Animal and Plant Health Inspection Service Plant Protection and Quarantine (APHIS-PPQ). This team has been performing the surveys, extermination and public awareness work to minimize the spread and eventually eliminate the beetle on Oahu.
“Unfortunately, it appears that the beetle found favorable breeding habitat in areas of the Mamala Bay Golf Course where green waste had accumulated or was being composted [and] was continuously moistened by the course irrigation system,” said Dr. Cory Campora, natural resources specialist at Naval Facilities Engineering Command (NAVFAC) Hawaii. The green waste or debris in the areas that were confirmed as CRB breeding sites was excavated and ground twice on site using a “tub grinder,” similar to a wood-chipper but capable of reducing material to a smaller size.
The ground mulch was then enclosed in tarps and netting to deter adult beetles from laying additional eggs in or surviving life stages from moving out of the mulch while it awaits further treatment.
“Similar areas of green waste or mulch are present in other areas of the base but so far have been negative for CRB eggs and larvae. Because these are all potential breeding sites, all material at these sites are under quarantine, meaning they cannot be moved, until they are treated to ensure that no CRB are present,” Campora explained.
The advantage provided by the Navy-funded grinding process is that it eliminates all but the earliest life stages of the CRB. Adults, pupae and large larvae are destroyed by the grinding. With only the early stages of eggs and small larvae remaining, this technique then provides time to develop and perfect methods for eradication.
The CRB has a hard black shell with a horn on its head that is larger in males. Adult beetles are nocturnal and can grow to more than two inches in length. The beetle feeds on such plants as coconut palm trees, oil palms, other palm species, banana, sugarcane, papaya, sisal and pineapple. The CRB can often kill a palm tree when feeding on it, which makes it a very destructive species for Pacific islands.
The female adult beetles lay their eggs in decomposing organic matter where they develop into large C-shaped grubs before transforming into beetles, a process which takes about three to four months from egg to adult. Guam has experienced a particularly extensive infestation of the CRB that has killed off a significant number of the coconut palm trees on the island.
“It is unknown at this time how the CRB arrived at JBPHH, and it is very difficult to determine the method of arrival,” Campora said.
It is possible the CRB could have come on either military or civilian flights from many possible locations. In early November, inspectors at Honolulu airport picked up a CRB in luggage from a flight arriving from Japan but this was determined to be an isolated incident.
Since this effort began, approximately 500 adult and 600 larval beetles have been found. Of these, only 13 adults have been discovered outside of the JBPHH boundaries.
Residents can report any sighting of the beetle to the state pest hotline at 643-PEST (643-7378). Information such as physical address, latitude and longitude, and/or a description of where it was found is needed.