A line of guards near the entrance of the feral colony. (Photo by Kathy Keatley Garvey)

Many of us have never seen the Seven Wonders: the Great Pyramid of Giza, Hanging Gardens of Babylon,Statue of Zeus at Olympia,Temple of Artemis at Ephesus,Mausoleum at Halicarnassus, Colossus of Rhodes and Lighthouse of Alexandra.

And many of us have never seen the exposed, natural comb of a feral honey bee colony. It's an architectural wonder. It's a marvelous fusion of art and science.  It's an engineering masterpiece, stunning in detail and workmanship. Indeed, we humans have long admired-- and tried to copy--the perfect hexagonal wax combs. But to honey bees, it's simply their home, a place to rear their brood and to store honey and pollen.

Which brings us to this: there's a wondrous feral honey bee colony in a Eucalyptus tree in an unpopulated area of Vacaville. It's sheltered from the elements, far away from a residential neighborhood, and it's hidden from predators (including humans who might want to exterminate it, claim it, throw rocks at it, cut it from the tree as a "trophy," or grab the honey).

The several people who know where it is are not disclosing the location, and rightfully so. It needs to be protected and prized. The recent incident in Concord involving defensive European honey bees drew all kinds of negative coverage. Headlines screamed “Killer bees!” And "Killer Bees Are in Concord!" They were wrong. DNA tests from the California Department of Food and Agriculture confirmed that the bees were European, not Africanized.

The honey bee is not native to the Americas. European colonists brought the honey bee to the Jamestown colony, Virginia, in 1622. Then 231 years later, in 1853, bees arrived in California (San Jose area). Africanized bees settled here   (southern California) in 1994.

Honey bees are an ancient species, dating back 130 million years ago during the Cretacious period. Ancient civilizations hunted, located and raided honey bee colonies. In many parts of the world, they still do.

Meanwhile, this colony of Italian honey bees in a Eucalyptus tree in Vacaville is thriving. It's a strong colony. The bees are building and defending their home, the queen bee is laying eggs (in peak season, a queen can lay 2000 eggs a day), and the worker bees are out foraging for pollen, nectar, propolis and water.

This feral bee colony probably started out as a swarm from a local beekeeper's hive--or it could have been from another feral colony. At first, the swarm clustered on the Eucalyptus tree, looking for their next home. Then they apparently decided that this is "home, sweet home." They settled in and went about their bees-ness. First project: making the comb.

How long has it been there? The comb is quite fresh (much of it is white, not discolored) so it's probably been there since spring, surmises “honey bee guru” Extension apiculturist (emeritus) Eric Mussen of the UC Davis Department of Entomology and Nematology, who retired in June 2014 after 38 years of service.

“Everyone needs to leave it alone,” he says. “It's away from people. It's not bothering anyone. The bees are out pollinating our fruits and vegetables.”

Africanized honey bees arrived in southern California in 1994 and are expanding north. How far north are they now?

That's the question being asked all over Central and Northern California, especially since "The Concord Incident" or what happened along Hitchcock Road, Concord last Friday and Saturday. Apparently a backyard beekeeper was trying to move two hives on Friday to allow his father to do some landscaping. The beekeeper reportedly moved the first hive successfully, but when he tried to move the second hive, the bees became highly defensive and wreaked havoc. They killed two dogs, attacked a mail carrier, and stung a number of passersby. 

Were they Africanized bees? DNA tests will determine that.

Meanwhile, what is the northern boundary for Africanized bees?

Extension apiculturist (emeritus) Eric Mussen, who retired in June 2014 after 38 years of service, explained it this way:

"The northern boundary of AHBs depends upon the criteria you use to analyze an individual:

1. Mitochondrial DNA: Used by California Department of Food and Agriculture (CDFA) to call them Africanized

2. Morphometrics: Measure quite a number of anatomical features and compare them to features of EHBs and AHBs.  Hybrids are hard to categorize, thus not used by CDFA, but the USDA likes it (they "invented" it)

3. Isozymes: Enzymes from AHBs and EHBs have different amino acid arrangements

There are "pockets of bees having one or two of the three criteria, but bees with all three criteria haven't been demonstrated more than about half way up the state from the southern end," Musssen said. Africanized honeybees or AHBs from San Diego, etc., have all three criteria."

And the farthest north they've been found? "If I remember correctly, Angels Camp (Calaveras County) vicinity was farthest north find of samples with all three criteria positive," Mussen related. "Samples around the Concord area had two criteria (up to now). Two samples from very southern Oregon had one criterion."

UC San Diego scientists reported in a press release issued Sept. 11, 2015 that "Africanized bees continue to spread in California."

The study, published that week in the journal PLOS One, "found that more than 60 percent of the foraging honey bees in San Diego County are Africanized and that Africanized bees can now be found as far north as California's delta region," wrote news communicator Kim McDonald.

Said biologist Joshua Kohn, a biology professor who headed the study: "“Our study shows that the large majority of bees one encounters in San Diego County are Africanized and that most of the bees you encounter are from feral colonies, not managed hives,” said Joshua Kohn, a professor of biology at UC San Diego who headed the study."

McDonald explained that "Africanized bees are hybrids of a subspecies from southern Africa that were brought to Brazil to improve bee breeding stock and honey production, but escaped and spread throughout South America and Central America, arriving in Mexico in 1985 and Texas in 1990. Their aggressive behavior and tendency to swarm victims have led them to be dubbed 'killer bees.'"

Kohn and his graduate student Yoshiaki Kono "found Africanized genetic traits in honey bees as far north as 40 kilometers south of Sacramento in the state's central valley," McDonald wrote. "In the bees they collected in San Diego, they also discovered that more than 60 percent of foraging honey bee workers have Africanized genetic traits, but that African traits are found in only 13 percent of managed or commercial hives."

The scientists said the Africanized bees' northward expansion has slowed considerable, and that these bees have a limited ability to survive cold temperatures. In other words, they cannot survive cold winters. However, their presence may "improve the genetic stock of honey bees used in agriculture," according to Kohn.

At UC Davis, assistant professor Brian Johnson of the Department of Entomology and Nematology, is doing research on  genetic dispersion of AHBs around the state.  He has collected and frozen a large number of feral bee samples from around the south and central portions of the state.

After what happened last weekend, interest in AHB expansion has definitely accelerated. Stay tuned.

As 2012 approaches, it's "out with the old and in with the new!"