The Mediterranean fruit fly outbreak in Lake County was apparently triggered by a survivor of the Tampa infestation that state officials thought had been wiped out.
Tests of genetic material from flies found in an abandoned Umatilla grove indicate they are the same strain of medflies that were found in Tampa last summer, said Maeve McConnell, a spokeswoman for the Florida Department of Agriculture.
Meanwhile, spraying is to continue in a new area around Umatilla this morning.
The Tampa outbreak was discovered in May 1997 when a medfly was found in a backyard kumquat tree in Hillsborough County.
The Tampa outbreak spread as far as Orlando before a massive aerial spraying program got it under control.