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DNA tests used to discover origin of new medflies

Scientists are using DNA testing in an attempt to explain why a potentially devastating outbreak of medflies is occurring in such an unlikely place _ on the northern edge of the Florida citrus empire, far from a port or airport.

All medflies look alike, said Richard Gaskalla, director of the Division of Plant Industries, the state agency charged with eradicating the pests before they lay waste to crops. But their DNA, their genetic fingerprint, is distinctive and may tell scientists what region of the world they are from.

Researchers most want to know whether these are descendants of medflies from last year's infestation in five counties in the Tampa area that cost $25-million to fight.

"I suspect they are going to be connected with Tampa," said Gary Steck, a state entomologist in charge of fruit fly identification in Gainesville. "We should have a good idea in a week."

During last summer's outbreak in Tampa, two male medflies were discovered in Zellwood, about 20 miles south of the current hot spot north of Umatilla, Steck said."If these are connected with Tampa, it suggests that they have been out there breeding since last summer."

While scientists in the lab worked on DNA identification, pickers in Lake County yanked sour oranges from hundreds of gnarly, freeze-damaged trees. Nearby, a backhoe operator dug an 8-foot-deep pit to bury tons of the infected fruit.

Crews are already fighting a much smaller outbreak in Miami-Dade County and just finished mopping up one of the worst infestations in years in Hillsborough County. The tiny creatures have an appetite for more that 250 fruits and vegetables. They bore through the skin and lay eggs that become maggots, ruining the fruit.

This weekend, teams on the ground and in the air will spray insecticide over 12 square miles in north-central Lake County, about 40 miles north of Orlando.

The latest battle began Monday with the discovery of one medfly in a trap. Inspectors found 62 more over the next two days, including 47 in one trap.