University seeks OK for wasps that eat fruit flies

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HONOLULU — A tiny wasp that attacks harmful Mediterranean fruit flies could be released in Hawaii.

HONOLULU — A tiny wasp that attacks harmful Mediterranean fruit flies could be released in Hawaii.

The University of Hawaii has applied to a state agency for permission to release wasps to attack the pest also known as “medflies” that cause millions of dollars in damage to crops, the Honolulu Star-Advertiser reported.

“They cause direct economic damage by reducing yield, they increase farm costs (labor and insecticides) and they lead to expensive post-harvest quarantine treatments of produce for export markets,” university researcher Russell Messing said.

The gnat-size wasp is from Kenya. Fopius ceratitivorus can’t sting human beings. However, it lays eggs in the young of the Mediterranean fruit fly, and the wasp larvae eat the young fly, according to university researchers.

The Hawaii Department of Agriculture Plant Quarantine Branch could issue the permit to release the wasp in Hawaii. An environmental assessment by the university concluded the wasp would cause no significant impact. The findings are on the state Office of Environmental Quality Control website, and the deadline for public comment is Oct. 23. The state Board of Agriculture would have to approve release of the wasp.

Messing imported the wasp into quarantine and for several years conducted tests on it. He worked with colleagues from Florida and Texas conducting studies in Kenyan coffee fields.

Mediterranean fruit flies are one of four fruit flies in Hawaii. State and federal agricultural researchers tried fighting them with pesticide-treated bait sprays, field sanitation and the release of sterile females.

Fruit flies are a threat to crops, said Larry Jefts of Sugarland Farms.

“Anything like natural predators that help reduce the use of pesticides — I’m all for that,” said Jefts, who farms thousands of acres on Oahu and Molokai. “It would help everyone.”

Besides fruits, the flies threaten his cucumbers, Jefts said, and they increase his costs for approved pesticides. “They’re not inexpensive,” he said.

The university proposes an initial winter release of several hundred to 1,000 Fopius ceratitivorus wasps at the Kauai Agricultural Research Center.

In Guatemala, field releases of the wasp in coffee plantations resulted in a 50 to 60 percent reduction of the medfly, researchers said.

Mediterranean fruit flies were first found in Hawaii in 1907 and became established by 1910.