What about those Africanized honey bees? Where are they located in California?

Hollywood movie refer to them as "killer bees."  Ditto, the news media.

"The known natural distribution of Africanized honey bees (AHB) in California is along a line that runs diagonally from northeastern Tulare County to southwestern San Luis Obispo County, then south to Mexico," says Extension apiculturist Eric Mussen of the UC Davis Department of Entomology. "A colony of AHB was found in Madera County following almond pollination, and the agricultural commissioner decided to call the county colonized instead of participating in a delimiting survey.  However, beekeepers in Fresno County are just beginning to report encountering a few more considerably defensive colonies than they used to."

"In southern California, where AHB has been since 1994, they have pretty well filled the basin," Mussen reports. "The last time tests on feral (not human-kept) honey bee colonies and swarms were conducted, AHB were determined to be a little over 80 percent of the totals.  That still may be the case with feral bees in that area, although one would expect a bit lessening of defensive behavior over time, as has happened in Brazil."

But, as Mussen points out, "it took 40 years to reach the point that AHB are not too problematic in Brazil.  We have had them in California only 18 years."


Want access to the very latest in agriculture news each day? Sign up for the Western Farm Press Daily e-mail newsletter.


“There’s no way to tell if honey bees are Africanized without DNA testing,” says Mussen, who writes from the UC Apiaries and Bee Briefs on the UC Davis Department of Entomology website.  “They look about the same as the European honey bee.  They tend to be a little darker than European honey bees and a little smaller. What sets them apart is their intensive defensive behavior. They’ve been known to chase their victims a quarter of a mile.”

When beekeepers find intensive defensive behavior in their hives, they kill the queen bee and “requeen” the colony. “Over four to six weeks, the original workers die of old age and the new queen replaces them with more daughters,” Mussen said. 

Africanized honey bees are the result of attempts to hybridize European honey bees (Apis mellifera) with an African race. Researchers brought Tanzanian queen bees (Apis mellifera scutella)  to Brazil in the 1950s.  In 1957, some of the African bee descendants escaped from the researchers and beekeepers and began progressing north.  

The descendants reached southern Texas in 1990 and southern California in 1994. “In California, they were first found “just outside of Blythe, in Riverside County,” Mussen recalls.