State officials have extended an interim rule restricting the interisland movement of palms and other plant materials to help contain the destructive coconut rhinoceros beetles.

The Hawaii Department of Agriculture said its advisory committee on plants and animals on Friday recommended the extension of the interim rule — a newly expanded one established last October — for another year.

HDOA Chairperson Sharon Hurd signed the interim rule Friday, which became effective immediately.

It restricts the movement of palm plants as well as decomposing plant material including compost, wood or tree chips; mulch; potting soil; and other landscaping products that may harbor CRB, from infested areas to non-infested areas. It also restricts the movement of palm plants taller than 4 feet.

The extension comes shortly after the Honolulu Department of Parks and Recreation removed dozens of infested palms at Kaiaka Beach Park on Oahu’s North Shore. DPR said some 80 trees on the North Shore have already been tagged for removal, and that it would be surveying its shoreline parks all the way to the windward side and doing the same there.

The news comes as no surprise to those who have been battling the invasive beetles for years, and who have been urging HDOA to finalize a permanent rule.

The invasive beetles, first discovered at Joint Base Pearl Harbor-Hickam in 2013, have already threatened the historical royal palms in Wahiawa, and destroyed palms along much of the leeward coast.

The invasive beetle — first detected on Oahu in December 2013 — is a serious pest of palm trees, primarily coconut palms, and can easily damage and kill them by boring into their crowns to feed on the trees’ sap.

The dead trees in turn pose a safety hazard as they may fall unexpectedly after their trunks rot.

Any individual, company or organization that violates the rule will be charged with a misdemeanor and fined $100 up to $10,000, according to the department.

Penalties for a second offense committed within five years will require the violator to pay for the cost of clean-up and removal of contaminated materials, and the cost to fully eradicate any CRB infestations caused by the violation, HDOA said.

Repeat violators will be fined $500 up to $25,000.

HDOA says this interim rule is valid for a year as HDOA finalizes a permanent rule, to be considered by the Hawaii Board of Agriculture later this month.

“Residents on all islands are asked to be vigilant when purchasing mulch, compost and soil products, and to inspect bags for evidence of entry holes,” said HDOA in a news release.

The adult beetle measures about two inches long and is all black, with a single horn on its head. Adults prefer to feed on coconut and other larger palms while CRB grubs, or larvae, live in decomposing plant and animal waste.

Reports of possible CRB infestations can be reported to the state’s pest hotline at 808-643-PEST (7378).