Pests Arrive with Christmas Trees to Hawai’i

File photo by Wendy Osher.

By Maui Now Staff

Shipments of Christmas trees arriving from the Pacific Northwest are widely infested with slugs and other invasive pests, causing about half of the shipments to be held for treatment by the Department of Agriculture’s Plant Quarantine Branch.

Of the 150 containers inspected by state officials, authorities say, 74 were or are being held for pest identification or improper paperwork.

The containers include shipments of Christmas trees and wreaths from six maritime voyages.  Agricultural officials expect an additional 100 containers to arrive between now and Christmas.

Of the 74 containers held, state officials say: six containers have been treated and released; 15 containers were released due to low risk pests of pests that are already found in Hawai`i; four containers were sent back to the shipper at the shipper’s request; and 49 containers were pending treatment as of Friday morning, Nov. 23.

Plant Quarantine inspectors say they are ordering treatment of the infested containers by two methods, depending on the type of infestation. Inspectors will utilize a 100% shaking method for treating shipments that are infested with wasps; and a hot-water treatment will be used for containers infested with slugs.

The concern about the heavy infestation of slugs is that they may carry the parasite, Angiostrongylus cantonensis, or rat lungworm, which causes a disease that affects the human brain and spinal cord.

Once an invasive pest or disease becomes established in Hawai`i, state officials say it may have a devastating impact on the island’s agriculture by causing damage to crops.  This becomes costly for the state and growers to control. Invasive species may also harm Hawaii’s unique ecosystem.

According to information released by the state Department of Agriculture, the methods have been used in years past, but infestations found this year are being described as “very extensive.”

Christmas tree shippers are required to provide labor power to unload, shake and reload Christmas trees under the supervision of Plant Quarantine inspectors.

While department officials say they realize that Christmas trees are a treasured holiday tradition, Carol Okada, Manager of the Plant Quarantine Branch, said crews are doing their best to treat and clear the trees as soon as possible.