Fingerprinting the mean bees.

Fingerprinting the mean bees

The bullies of the honeybee world come from Africa, wherecenturies of human raids on hives for honey, rather than beekeeping, encouraged the survival of the very meanest bees. African bees and their "Africanized' offspring--hybrids of African and the more gentle European bees--are infamous for their aggressive swarming attacks on chickens, furred animals and humans. Since the African honeybee was introduced to Brazil in 1956, there's been much concern that Africanized bees, also known as killer bees, would spread and come to dominate the bee populations in the Americas. Researchers say the bees have now migrated to southern Mexico and far into Argentina.

An essential part of monitoring the spread of Africanizedbees is distinguishing between them and their similar-looking European cousins. The most commonly used method for identifying a bee's race has been to measure the length of its wings. But according to Dave Carlson at the U.S. Department of Agriculture in Gainesville, Fla., there is considerable variation in wing length within each race. So Carlson, an organic chemist, has pursued what he feels is a more exact method of identifying bees.

In the March 15 ANALYTICAL CHEMISTRY, he and Barry Lavine,from Clarkson University in Potsdam, N.Y., describe a method of examining the relative amounts of different hydrocarbons found in beeswax and in a bee's cuticle, the sheath that covers the entire body of the adult insect. After studying bees collected in Central America, Venezuela and Florida, they conclude that "information derived solely from the cuticular hydrocarbons could correctly categorize the bees by race. . . .'

Carlson says he has been asked to use this technique in anumber of cases, including one in which a swarm of bees killed a horse in Florida. At this week's International Africanized Bee and Bee Mite Conference, held at Ohio State University in Columbus, he reported his findings on another case, in which a group of 500 to 600 angry bees was seen attacking a rabbit near Bakersfield, Calif., a year and a half ago. The bees, which some people suspected were Africanized bees carried to California in oil drilling equipment, were destroyed and their burrow filled in, but state officials worried that some had escaped to join local populations. Applying his technique to beeswax found in their nest and to a few bees in the vicinity, Carlson concludes that Africanized bees had indeed lived in the burrow for some time, but the hydrocarbon patterns of local bees do not contain an Africanized signature.