An invasive pest that damages coconut trees and other palm plants has been caught and state agriculture officials are trying to determine if there are more in Hawaii.

Coconut Rhinoceros beetle were caught at Joint Base Pearl Harbor-Hickam on Dec. 23 during routine surveys.

Samples of the suspect beetle were sent to the U.S. Department of Agriculture entomology laboratory in Miami and confirmation was received on Jan. 3.

The discovery of the rhinoceros beetle occurred the same day that little fire ants, Wasmannia auropunctata, were discovered on hapuu, Hawaiian tree fern, at a garden shop on Maui and subsequently confirmed on Oahu.

Since the discovery, the state Department of Agriculture and the U.S. Department of Agriculture’s Plant Protection & Quarantine have been working jointly with the military and the University of Hawaii to survey and conduct trapping activities in the Pearl Harbor – Hickam area to determine the extent of the infestation. Nine beetles have been caught so far.

It is a major pest of palms in India, the Philippines, the Palaus, Fiji, Wallis, Nukunono, American and Western Samoa and Guam. It is not known exactly how the beetles arrived in Hawaii.

"The threat of the coconut rhinoceros beetle has been a growing concern in Hawaii since it turned up in Guam in 2007," said Dr. Neil Reimer, administrator for state agriculture’s Plant Industry Division. "We have initiated the strong, coordinated efforts among HDOA, USDA, UH and other partners that will be required to effectively manage this invasive pest."

The beetle is mainly a pest of coconut and oil palms, but may also attack other palm species. Adult beetles are dark brown in color and measure 1 to 2 inches long. Larvae are white in color with a brown head. 

The beetles damage palms by boring into the center of the crown where they injure young, growing tissue and feed on the sap. As they bore into the crown, they cut through developing leaves, causing damage to the fronds. V-shaped cuts in the fronds and holes through the midrib are visible as leaves mature and unfold. 

Natural enemies include pigs, rats and ants. They may also be killed by two diseases, a fungus and a virus; however, both are not known to occur in Hawaii.

Suspected beetles on coconut and palm plants on all islands should be reported to agriculture department’s pest hotline – 643-PEST (7378). This is also a toll-free number for neighbor islands.