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Officials hope tiny
By Rod Thompson
wasp will ward off
citrus pests
Star-BulletinHILO -- The state Department of Agriculture says it is confident two tiny wasps can save Hawaii's backyard citrus crops from attack by an equally tiny fly.
Citrus of all types came under attack from the one-sixteenth-inch-long citrus blackfly in 1996 when the first infestation was discovered on Oahu, a department statement said.
The fly spread to Maui and the Big Island within a month. Kauai held out until this year.
Although the blackfly really is black, it belongs to a group of insects called whiteflies which can seriously damage citrus trees by sucking nutrients from their leaves.
Entomologist Ken Teramoto, head of the Agriculture Department's Bio-Control Section, said there are about 30 kinds of whiteflies in Hawaii, none native.
When the various flies arrived in the past, they usually came with their own parasitic wasps, so they didn't become serious problems, Teramoto said.
The blackfly arrived without wasps.
Fortunately for Hawaii, the blackfly, spreading from its native India, reached Florida first. Agriculture officials there in the 1960s already found Central American wasps to combat the pests.
A Hawaii official went to Guatemala in 1998, got more wasps for testing, then began releasing them, starting with Oahu last year.
There is no danger the wasps will go after native Hawaiian insects, Teramoto said. "These wasps are highly specific."
The success of the wasps is good news for back-yard citrus growers, but won't have much effect on Hawaii's citrus industry because it barely exists.
Hawaii's only commercial citrus grower, Morton Basson, with a "few hundred" acres of oranges at his Kau Gold farm at the southern end of the Big Island, says he has lots of bugs but not the blackfly.
He'd like to see the state get rid of the much larger fruit flies. A new X-ray treatment kills fruit fly larvae in fruit to be shipped out of state, but does nothing to stop the flies from getting into the fruit, Basson said.
Teramoto has no handy little wasps for that problem, but he does believe keeping the blackfly population down will help any future expansion of a Hawaii citrus industry.
