The first laboratory tests of bees involved in a mass stinging episode in Whittier that killed a small dog and injured two larger ones Wednesday showed that the bees were of a commonly occurring European variety, not the more dangerous African variety as had been feared, an official said Thursday.
John Hurley, Los Angeles County's bee inspector, said that when he submitted captured bees to lab analysis, they proved to have a wingspan consistent with a European strain that has long been active here.
But in Orange County, where three dogs were hospitalized Thursday after another mass stinging in the city of Orange, a pest control expert said that more extensive DNA tests would be necessary to determine whether the bees were a hybrid variety: part African and part European.
Bee experts including David Marder, operator of Bee Busters of Laguna Beach, who was called in to handle the Orange County episode, said that ever since the African strain, often called "killer bees," arrived in Southern California within the last few years, there has been much crossbreeding with the European bees.
There is concern that attacks by the hybrids are more likely to be deadly to both humans and animals, although even for the African bees it takes about 1,100 stings to kill a person weighing 150 pounds.
Lisa Aragon, a Whittier resident whose 12-year-old daughter, Jazmin, was stung once Wednesday, and whose Chihuahua, Ole, died after receiving scores of stings, said she and her husband, Steve, had noticed a bee problem in their garage about a month ago.
"We tried to douse the hive with water," she said, "and then we bought a device that we were told would destroy the hive. But neither worked. Now, it's cost us $145 to have it taken care of professionally."
Altogether, Hurley said, about 6,000 bees were involved in the swarm that killed the Chihuahua, and stung two other dogs belonging to the Aragons.
In the Orange County attacks Thursday, an estimated 50,000 bees were involved.
Bob Gordon, owner of Gordon Termite and Pest Control, the exterminators who were called to the Aragon home, said Thursday that it is not a good idea for people who aren't trained in handling bees to try to deal with the hazard.
The bees easily become "aggressively defensive" when they feel their hives are under attack, Gordon said.
Eric Mussen, an agriculturist at UC Davis, agreed. "Call in the professionals," he said.
"And the best bet when a stinging episode begins is to put as much distance between yourself and your pets and the bees as you can by running away completely or into a closed house or car."
Mussen said that when bees sting, they emit an odor, a bit like that of bananas, that attracts other bees to the scene in a hurry.
Even though the bees involved in the attacks Wednesday and Thursday may not have been of the African variety, tests have shown that they have spread rapidly from Southern California into Central California since entering the state a year or two ago.
But Hurley said the overall danger can be exaggerated. He cited national statistics showing that since 1990, when the killer bees first entered the U.S., only eight people have died from their stings.
Altogether, he said, an average of 11 people per year have been killed by all kinds of bee stings in the United States in recent years. Children and older men have been the most frequent victims.
Outside the Aragon garage Thursday morning, there were still many bees flying around, although the family said it was assured by experts that once the queen was killed, the rest of the bees would soon go away.