A fifth colony of Africanized bees has been found and destroyed near Lost Hills in Kern County, but experts say the foreign intruders are interbreeding themselves out of existence. Lab tests confirmed that the aggressive African bees, which are believed to have arrived in June on oil well equipment, had invaded one of 140 colonies in a commercial apiary a mile south of the original find, Len Foote, director of the state bee team, said. The state is making an aerial survey of the area and has passed the halfway mark in testing all hives in a 400-square-mile quarantine zone, Foote said. Meanwhile, a panel of bee experts said "genetic dilution" is in progress and predicted that the African traits will disappear. The experts also recommended that all bees be removed from Kelso Valley near Lake Isabella, where the fourth Africanized colony was found. They said the area should be kept free of bees until next June.