What Makes a Mean Bee Stay Mean?

Is the highly defensive behavior of Africanized honey bees simply genetic, or it is due to their social environment?

That's a question that Agricultural Research Service (ARS) entomologist Gloria DeGrandi-Hoffman is trying to answer. She is the research leader of the ARS Carl Hayden Bee Research Center in Tucson, Ariz.

Africanized honey bees (AHBs) more ardently defend their nests than do the European honey bees (EHB) that are common to the United States. AHBs sting in greater numbers with less provocation.

No honey bees are native to the New World. European colonists brought honey bees with them, some of which became feral. But honey bees are essential to U.S. agriculture, pollinating more than 90 crops. That pollination leads to yield and quality improvements worth more than $14 billion annually.

DeGrandi-Hoffman is marking EHB worker bees just as they emerge from their pupal stage and placing them in AHB hives, and vice versa. Then she tracks the age at which the bees first forage and exhibit defensive behavior.

Once these behaviors are exhibited, she quick freezes the bees and sends them off to a collaborator at the University of Illinois who analyses them for gene expression.

There are very minor genetic differences between African and European honey bees, but it is not yet known whether these differences govern the honey bee traits that people are most concerned about.

Read more about the research in the February 2007 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's chief scientific research agency.