By Lt. j.g. Eric Galassi, Navy Region Hawaii Public Affairs
For the past year, a team has been working to eradicate the invasive coconut rhinoceros beetle (CRB) from the island of Oahu. This team is comprised of personnel from Joint Base Pearl Harbor-Hickam (JBPHH), the Hawaii Department of Agriculture (HDOA), the U.S. Department of Agriculture (USDA), Oahu Invasive Species Committee (OISC), University of Hawaii (UH) and other organizations.
The CRB team has been performing the surveys, extermination and public awareness work to minimize the spread and eventually eliminate the beetle on Oahu.
HDOA is the lead agency in this effort, but the Navy and Air Force have played a major part, particularly as the beetle was first discovered on JBPHH. Work performed by personnel on JBPHH includes constructing traps and disposing of material that is infested or potentially infested by CRB.
Rob Curtiss, incident commander for the CRB team, said this is still just the beginning in work against the CRB. “So far things are going well. We still have a long way to go, but we have made some great progress. In addition, the relationships that have been established between agencies will continue to be the best thing to come of this entire program,” he said.
Curtiss explained that the focus of this effort is eradication of the beetle. The team would only change to a posture of limiting the beetle’s spread if funding of the program were discontinued or if the beetle managed to become widespread.
Since the initial discovery in December 2013, more than 2,600 adult and larval beetles have been captured on Oahu. CRB larvae have been discovered in a variety of mulch piles composed of materials such as tree trimmings, grass cuttings and wood chippings. Virtually all plant waste that is left uncovered has the potential to become a nest for the CRB.
Several ideas were first considered to mitigate the problem of CRB infestation. A variety of insecticides have been tested; however, they were found to be ineffective when applied to CRB adults and larvae in legal quantities. Further tests are currently being conducted using different insecticides before application on mulch and trees around the island.
An initial measure that was devised to limit the growth of the CRB population was to grind the mulch being used as nesting material in a tub grinder. While this was not an efficient means of destroying the eggs, it would kill later immature stages and a significant number of adults, giving the program additional time to develop more effective treatments.
Mulch was double-ground and covered to impede adults from laying more eggs.
Composting was introduced as another method of managing infested plant waste. Forty-cubic-yard roll-off containers were simply configured as in-vessel composting reactors. The temperatures within the containers reach as high as 170 degrees within 70 to 80 hours. Laboratory research indicated that at a temperature of 140 degrees for one hour, 100 percent of both larval and adult CRB were exterminated.
In addition to composting, air curtain burners are currently being used to incinerate green waste. Several burners have been purchased by the Navy, USDA and HDOA to rapidly dispose of plant material that is or could become a CRB nest. Incineration is a very effective method as one air curtain burner can dispose of up to four tons of green waste an hour while producing minimal ash and smoke.
To provide financial support for the CRB eradication effort, funding has been allocated from several agencies. The USDA has provided $2.8 million, HDOA has given $1.5 million, HISC has contributed $425,000, and the Navy has allotted $2.19 million for the project.
The CRB has a hard black shell with a horn on its head. Adult beetles are nocturnal and can grow to more than two inches in length. The beetle feeds preferentially on coconut palm trees, but will also feed on 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.
To prevent additional CRB infestations, residents are encouraged to dispose of all green waste in receptacles made of a hard material. Plastic tarps are not sufficient to keep beetles out of potential nests.
Residents can report any sighting of the beetle to the state pest hotline at 643-PEST (643-7378).