Department of Agriculture

NEW MACADAMIA NUT PEST FOUND IN HAWAII

HONOLULU – A new pest advisory has been issued by the Hawaii Department of Agriculture (HDOA) after the discovery of new insect pest that has invaded macadamia nut orchards in South Kona on the Big Island.  The insect, called the macadamia felted coccid (MFC) (scientific name:  Eriococcus ironsidei Williams), was first reported by a commercial macadamia nut farm and specimens were collected on February 25^th and sent to the University of Hawaii’s College of Tropical Agriculture and Human Resources (CTAHR) for identification.  Specimens have also been sent to the U.S. Department of Agriculture Systematic Entomology Laboratory in Beltsville, Maryland, for confirmation.

“Researchers and entomologists with CTAHR and HDOA began working immediately to identify the pest and are working with farmers to survey the affected area,” said Sandra Lee Kunimoto, Chairperson of the Hawaii Board of Agriculture.  “At the moment, they are continuing efforts to assess the full extent of the infestation and control methods are already being deployed in the affected areas.”

One control method that is being tested in the orchards involves the use of a horticultural oil, which has proven to be a safe and effective method in controlling this particular pest in Australia.  Also, the utilization of predatory bio-control insects is being explored.

HDOA is working with the Hawaii Macadamia Nut Association to inform the industry’s 650 farms about this newly discovered pest and to encourage farmers to survey their orchards and report any possible infestations to HDOA.  The HDOA Pest Advisory will be distributed to farmers and processors on the Big Island and is available on the department’s website at:  https://www.hawaiiag.org/hdoa/npa/npa05-01-MFC.pdf

MFC is native to Australia and its only known plant host is macadamia nut trees.  MFC belongs to a species of scale insects and have piercing-sucking mouthparts, which are inserted into the vessels of the plant, resulting in yellowing of leaves and subsequent decay and death of plant tissue.  The most severe symptoms are defoliation and dieback of branches.  In bearing trees, nut production is reduced and the fall of mature nuts is delayed. 

After hatching, MFC appear as tiny crawlers, almost microscopic in size.  They may be easily dispersed by wind; carried by birds and ants; or they may hitchhike on people, vehicles, or farm equipment to other areas.  Adult female MFC do not have wings; however, adult males are able to fly and have a gnat-like appearance. 

The first macadamia nut trees were planted in Hawaii in about 1890.  After it was observed that they grew and produced nuts so well in Hawaii, an orchard of approximately 2,000 trees was planted on Round Top in Honolulu and about 6,000 trees were planted in Kona on the Big Island.  Today, macadamia nut production is a major agricultural industry with an annual farmgate value of more than $32 million, which ranks as the fourth largest agricultural commodity in the state.

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Related Internet Links:

HDOA Pest Advisory:  /hdoa/pi/pi_pc/npa05-01-MFC.pdf

Hawaii Agricultural Statistics Service webpage on most current statistics on macadamia nut industry in Hawaii: https://www.nass.usda.gov/hi/fruit/mac-fin.htm

Hawaii Macadamia Nut Association:  https://www.hawaii-macadamia-nuts.com/contact/contact.htm

HDOA Media Contact:

Janelle Saneishi
Public Information Officer
Hawaii Department of Agriculture
Phone: (808) 973-9560
To E-mail, click here