Meet the beetle: Hawaii keeps nervous eye on horned invader

HONOLULU — Late in the afternoon on a Monday in July, pairs of men and women in reflective vests and hard hats, carrying binders, backpacks and long poles topped off with hooks, begin to trickle into a large conference room in the plant quarantine branch of the Hawaii Department of Agriculture. They have spent all day surveying traps and have brought back their finds, three enormous shiny beetles held in clear plastic bottles.

Every day for weeks, this field crew of 32 has reported to the conference room, which serves as the incident command center for a multi-agency effort to eradicate the coconut rhinoceros beetle from Hawaii. The giant flying beetle feasts on and kills palm plants, including the coconut palm tree, that iconic symbol of the Hawaiian landscape, and a major source of income for the Hawaiian nursery industry. The beetle is just one of dozens of invasive species that plague the Hawaiian islands, costing the state millions of dollars in crop losses, extinction of native species, destruction of native forests and spread of disease.

Thought to have hitched a ride to Hawaii from Guam, the coconut rhinoceros beetle is often referred to simply as the rhino beetle, for the rhino-like horn on its snout. A live beetle, which can measure up to two inches long, fits neatly in the palm. The beetles’ larvae are even larger than the beetles themselves, ghostly white and covered in deep ridges with featureless snouts. In Japan, the beetles are kept as pets, set against one another in beetle wrestling tournaments that are gambled upon, according to one Hawaii Department of Agriculture official. 

The rhino beetles were first discovered in Hawaii on Dec. 23 at the Mamala Bay Golf Course of the Joint Base Pearl Harbor-Hickam, Honolulu’s Navy-Marine military base. Given that the beetle had never before been seen in the U.S. and was already on a federal quarantine list, an emergency response program kicked in. Federal authorities threw $2.4 million in farm bill money at the effort. The state of Hawaii pledged additional funding.

Since the beetle was discovered, incident command staff have been working 6 days a week, 14 hours a day to combat the pest, according to Rob Curtiss, the acting manager of the Hawaii Department of Agriculture’s plant pest control branch and one of two incident commanders on the project. The 32 field staffers were hired temporarily to track and trap the beetles, and 16 trucks were leased to ferry the workers around the island.

On July 7, the field crew brought bad news: one of the beetles was found in a trap outside the quarantine zone, on private land belonging to Hawaiian Earth Products, a company that makes mulch sold throughout the state. Previously the quarantine zone was confined to the military base, which is working with the state in the eradication effort. This finding was particularly unfortunate as the beetles like to breed in mulch. But after the company was approached by officials from the Department of Agriculture, Hawaiian Earth Products voluntarily agreed to stop transporting mulch in or out of the area and to stop selling mulch that was bagged in the area, as well, according to Curtiss. 

“They’ve been very cooperative,” said Curtiss. “They don’t want to be known as the cause of spreading this around.” Hawaiian Earth Products has three or four other sites on the island, so it is only partially shut down, he explained, and the company is expecting the Department of Agriculture to come up with a pesticide treatment that can be used to kill the beetles. The agency is currently testing various potential pesticides in a lab at the plant quarantine branch. State officials are also in the process of drafting a rule that would restrict individuals and companies from transporting any plant material out of the quarantine area. He expects a rule will be rolled out within the next couple of months.

In the meantime, subsequent surveys of mulch piles on Hawaiian Earth Products land have not yielded any more adults, larvae or eggs, said Curtiss. “Because we found one adult there we’re proceeding as if we found an infestation there, but it’s possible it was a hitchhiker on a truck.” He is optimistic.