Posted on: Saturday, March 12, 2005

Mac-nut pest a 'serious' problem

By Curtis Lum
Advertiser Staff Writer

An insect that has caused problems in the macadamia-nut industry in Australia has been found in orchards in South Kona on the Big Island, and agriculture officials here are trying to determine how widespread the infestation may be.

The insect, macadamia felted coccid, was first reported on a commercial nut farm in Honomalino in South Kona on Feb. 25. The macadamia felted coccid is native to Australia and its only known plant host is the macadamia-nut tree.

The insects have piercing-sucking mouth parts that are inserted into the vessels of the plant, resulting in yellowing of leaves and the decay and death of plant tissue, the Department of Agriculture said. The most severe symptoms are defoliation, a dieback of branches, and reduced nut production.

Hawai'i's macadamia-nut production is valued at $32 million annually, ranking it as the fourth-largest agricultural commodity in the state, the department said. There are about 650 macadamia-nut farms in Hawai'i, primarily on the Big Island.

Spokeswoman Janelle Saneishi said the department is working with the macadamia-nut industry to assess the extent of the infestation and possible damage.

But David Rietow, president of the Hawai'i Macadamia Nut Association, said he considers the problem "serious," as does Australia.

The department and association want all growers to inspect their orchards and report any possible infestations. A "pest advisory" is being distributed to all farmers and nut processors on the Big Island.

Sandra Lee Kunimoto, chairwoman of the Hawai'i Board of Agriculture, said control methods already have been sent to the affected areas.

One method involves the use of a horticultural oil, which Kunimoto said has proven to be safe and effective in controlling the macadamia felted coccid in Australia. The department also is considering using insects that are predators of the macadamia felted coccid.

Rietow said early eradication of the macadamia felted coccid is crucial to the industry.

"We don't want it having any sort of negative impact on the industry whatsoever ... ," he said. "I'm hoping that we can contain it where it is and that it hasn't gone any farther."

Reach Curtis Lum at 525-8025 or culum@honoluluadvertiser.com.