Isle fight against WAILUKU >> The battle is being waged against fruit flies on the farm fields of Oahu, Maui and the Big Island -- and the annihilators have won some major fights.
fruit flies making
some headway
Officials are spreading
news about the tactics
that are succeedingBy Gary T. Kubota
gkubota@starbulletin.com
Male fruit flies, attracted by a chemical scent, fly into a trap and die.
STAR-BULLETIN / 1997
Hawaii Area Wide Fruit Fly Integrated Pest Management Program officials are targeting four fruit fly species, including the Mediterranean fruit fly, shown above.
The technique called "male annihilation" and a combination of other methods have had such success in controlling fruit flies that state officials are telling others in Hawaii agriculture about it.
Project officials spoke about the fruit fly control program yesterday at the 12th annual International Tropical Fruit Conference at the Keauhou Beach Resort on the Big Island.
Starting next week, officials plan to begin disseminating information about tactics used in fruit fly control to agricultural agents, high school teachers, and master gardeners.
Cost-benefit studies are still being conducted on the effort. State and federal officials say the estimated dollar losses from fruit fly damage in Hawaii are unavailable right now.
But officials said the potential direct and indirect losses could amount to $1.1 billion annually in California alone, if the fruit fly enters the Golden State.
The five-year Hawaii Area Wide Fruit Fly Integrated Pest Management Program began about three years ago, with about $5 million in federal funding.
The program encompasses 1,800 acres in central Oahu, upper and lower Kula on Maui, and the Hawaiian homestead and Laulamilo farming area on the Big Island.
Officials are targeting four fruit fly species: the melon fly, Bactrocera cucurbitai; Mediterranean fruit fly, Ceratitis capitata; oriental fruit fly, Bactrocera dorsalis; and solanaceous fruit fly, Bactrocera latifrons.
Other fruit fly control techniques include releasing sterilized males so the females are unable to reproduce, spraying a protein called "GF-120" on nearby trees and foliage, and removing infested fruits and putting them in mesh-enclosed bins.
"The program is doing really well. We're pretty happy with what's going on," said Jari Sugano, a University of Hawaii cooperative extension agent.
Sugano said last year the techniques were used to reduce fruit fly damage to persimmons in upper Kula by about 80 percent and also has helped zucchini farmers on Maui.
Ricky Kametani, a Maui farmer who grows zucchini, said the techniques helped to reduce fruit fly damage to his crop by 50 percent.
The program has also helped farmers in Waimea on the Big Island, enabling one grower to plant zucchini throughout the year.
"It's going very well," said Big Island farmer Earl Yamamoto.
Yamamoto said he had given up growing zucchini about five years ago because of fruit fly damage, but he grows some year round now, along with watermelon, cantaloupes, and persimmons.
Yamamoto, who has participated in the program for 2 1/2 years, said crop damage from fruit flies have gone down by at least 65 percent.
Some persimmon growers on Maui are saying that, although harvesting is just beginning, the results don't look as good this season.
Persimmon grower Melvin Matsui said he doesn't know what's happened, but most of his persimmon seems to have been stung by fruit flies.
Ronald Mau, a state entomologist, said the cause of recent problems in Kula is under investigation but he suspects it's related to a fungus that prematurely ripens persimmons and increases susceptibility to fruit fly damage.
Mau said the problem may be treated with a fungicide.
He said, according to farmers, the melon fly infestation rate has been reduced to 5 percent from 50 percent in Kula for zucchini and summer squash.
A side benefit is a reduction in insecticide spraying.
Mau said that at a farm on Oahu, insecticide spraying has been reduced by 66 percent and the infestation rates have dropped to about 5 percent for zucchini, cantaloupes and honeydew melon.
Sugano said that in her talks in classrooms, young boys express dismay at the way male insects have been singled out for sterilization and annihilation, especially after learning that the female fruit flies are the ones stinging the fruit.
Sugano said scientists decided not to sterilize females and release them for practical reasons.
"In the past, they would release the females and the females would sting the fruit," she said.
Hawaii Area Wide Fruit Fly Integrated Pest Management Program
