The state Department of Agriculture is asking for the public’s assistance in tracking down the source of a recently discovered coconut rhinoceros beetle infestation in Nanakuli.

Robert Curtiss, an entomologist with the department’s Division of Plant Industry and beetle incident commander, said insects found in three separate cases in Nanakuli likely originated from an infested load of organic material.

The department is asking people who live between Lualualei Homestead Road and Nanakuli Avenue to allow inspectors to examine mulch or compost on their properties for signs of beetle infestation.

"No one is going to get in trouble," Curtiss said. "We just want to get to the source and prevent it from spreading any further."

Residents in the designated area are asked to call 943-PEST (7378) or email stoprhino@gmail.com.

The department destroyed the last known beetle breeding site at Iroquois Point last week.

"Now comes the hard part where we have to try to find the small ones," Curtiss said.

The large, destructive beetles can damage or kill coconut and other palm trees by boring into their crowns to feed on sap. They have been the focus of intensive eradication efforts on Guam.

The beetles, which measure about 2 inches long as adults, breed in piles of decaying organic matter.

The infestation was first detected on Oahu in December 2013 on a golf course at Hickam Air Force Base.

Since then, Curtiss’ department has set and maintained hundreds of traps across the island.

In the first two weeks of February, 55 adult beetles were found in traps and mulch surveys, and 14 dead or damaged palms were removed.

A recently identified method of trapping the beetles using Chamorro fishing nets may eventually aid in the effort to prevent further infestations.

Scientists in Hawaii had been using layers of bird netting to trap the beetles, prompting their counterparts in Guam to conduct their own experiments with different types of netting.

Entomologists at the University of Guam discovered that "tekken," a type of gill net, was already being used by some fishermen to prevent beetles in compost heaps from attacking nearby trees.

The nets are made of nylon monofilament strong enough to withstand the beetles’ powerful, spiny forelegs. University of Guam extension agents Aubrey Moore and Roland Quitugua are developing tekken net traps that can be used to cover compost piles and suppress the emergence of adult beetles.

"As a barrier for potential or active breeding sites, the tekken trap is an affordable and easy to use method of reducing rhino beetle populations in residential areas," Quitugua said in a statement.

Hawaii entomologists have been using tekken in combination with other types of netting. However, Curtiss said use of tekken for rhino beetle control is still in the experimental stage.