Fruit fly pests have plagued Hawai‘i farmers since 1895. Today the state is home to four invasive fruit fly species, each of which attacks a different set of fruits and fleshy vegetables. Together, they cost the state many tens of millions of dollars per year in direct losses, quarantine costs, and the inability to establish commercial production of vulnerable host crops.
In 2000, the U.S. Department of Agriculture’s Agricultural Research Service, the Hawai‘i Department of Agriculture, and CTAHR launched a collaboration with Hawai‘i farmers and backyard growers to limit fruit fly damage. Through the Hawai‘i Area-Wide Fruit Fly Pest Management program (HAW-FLYPM), more than 2,500 cooperators on more than 15,000 acres have put into practice a straightforward, environmentally sensitive approach to fruit fly control:
- sanitizing fields by removing infested fruit,
- monitoring traps that contain species-specific male lures or attractants to assess the size and composition of the fruit fly population,
- targeting females with food lures such as protein bait plus a low-toxicity insecticide approved for conventional and organic crops,
- annihilating males through the use of abundant lure traps.
HAW-FLYPM has changed Hawai‘i’s diversified agriculture. Squashes and melons that incurred heavy losses despite weekly cover sprays of the pesticide malathion are now grown with minimal losses and no cover sprays. Tomatoes once harvested green can be vine-ripened for the gourmet market. Improved persimmon yields have given rise to popular value-added products. New crops can be grown profitably, including Halloween pumpkin and dragonfruit (pitaya). Uninfested fruits command better prices and are cheaper to harvest and grade. Declining fruit fly populations offer hope of less expensive quarantine regimes. Benefits to industry, currently estimated at $2.6 million per year, are projected to increase to $6 million by 2011.
In the words of a Moloka‘i farmer who previously lost 30–40 percent of his mangos and 50–60 percent of his watermelons and now loses less than 1 percent: "This is government at its best."