By DONNA BETH WEILENMAN
Joshua Kohn, a University of California-San Diego, professor of biology, has been tracking the northern progress of Africanized bees.
In his report published in the September issue of the peer-reviewed research journal PLOS ONE, he said evidence of the bees’ presence was found in samples taken during the spring of 2014.
Jones said a couple of the hybrid bees apparently were found on the Lafayette side of the 6,117-acre park, but said Bay Area scientists have not found any bees of that type.
“It’s too cold here to establish a colony,” she said.
Africanized bees are a hybrid of European, especially Spanish and Italian, honey bees with African honey bees. The crosses were done when African honey bees were shipped to Brazil in an attempt to increase honey production. However, 26 swarms escaped quarantine and spread. They reached North America in 1985.
They gained a reputation for aggressiveness, and received the nickname “killer bees,” although Kohn has said they are not more aggressive than European bees.
Nor is their sting more potent than those of the European honey bee, which is a larger insect.
However, they have been known to defend their hives more quickly and in greater numbers, inflicting more stings than other bees. Their hives can be managed, and most reports of attacks come from accidental encounters, according to several published reports analyzing their behavior.
Beekeeping organizations in places where Africanized bees establish have started managing their hives in ways that discourage the hybrid bees from displacing the gentler species’ queens, according to keepers from Florida to California who have spoken publicly about the matter.
Just because no colony has been found at Briones Regional Park doesn’t mean there are no Africanized bees in the area, Jones said. But she called the ones Kohn found “strays” that may have arrived because of the warmer winters the area has experienced in recent years.
The numbers could increase if the area continues to experience frost-free winters, Jones said. “Last winter, we had frost once or twice,” she said. If the frosts keep coming, the bees would be unable to establish a colony, she said.
“It’s not a huge worry. In fact, some think killer bees are great.”
African hybrid bees are described as having greater survival skills and are harder workers than domestic bees. Florida producers that incorporate hybrid bees have reported increases in honey output.
Their hives also seem to be more resistant to diseases that are threatening the more conventional honey bee species, including colony collapse disorder.
According to a report released by the U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS,) honeybees “have been under serious pressure” since 1980 from the disorder, which it calls “a mystery problem” that results in dead colonies or just a live queen and immature bees.
No definitive cause has been found, although researchers are examining viruses, mites, fungi, poor food supply and sublethal doses of pesticides.
“We haven’t received any reports from the public, but if a killer bee is found, we’ll refer it to Vector Control,” Jones said. The specific office consulted, in Alameda or Contra Costa County, would depend on where the bee was found. “Then we would take their lead.”