Forum—Africanized Honey Bees: The March North Has Slowed

On October 15, 1990, the Africanized honey bee—also known as the 'killer bee"—finally reached the United Stales. A swarm was found in an Agricultural Research Service (ARS) honey bee trap just outside the south Texas town of Hidalgo.

The arrival did not come as a surprise to ARS scientists. Researchers had been monitoring the northward movement of Africanized honey bees for years.

The progenitors of the Africanized honey bee were brought from Africa to Brazil in 1956 by a Brazilian geneticist. In 1957, some of those bees escaped into the wild and interbred with existing honey bee populations, resulting in the infamous hybrid.

Africanized honey bees are actually a far cry from the image of the fearsome marauders constantly hunting for human victims that media hype has created.

What is true is that they are more defensive and generally will sting more—with less provocation—than the European-descended honey bees that are common in the United States.

The Africanized hybrids are harder for beekeepers to manage because their temperament makes them more of a problem to transport to fields and orchards and because they do not store as much honey as European honey bees.

So it is not surprising that ARS has been concerned about the spread of the hybrid into this country.

Our researchers have been studying the bees to understand how fast they will spread and what happens when they reach areas with large populations of European bees.

No honey bees are native to the Western Hemisphere. Europeans brought them to the New World as far back the 1600's. Native Americans called these new insects white man's flies, and their appearance in a new area indicated the movement west of Europeans.

European honey bees evolved in a temperate climate and therefore thrive in North America's similar climate. They don't do as well in tropical environments. This was the impetus behind Brazil's importing of African honey bees that had evolved in a tropical climate.

Africanized bees have flourished in the New World tropical environment. Their spread into northern Mexico several years before they reached the United States presented ARS scientists with an opportunity to observe what happens when the hybrids reach an area where the ecological niche is already filled with European honey bees.

There is no way to wipe out Africanized bees that would not also kill our indispensable European bees. Africanized honey bees are a problem agriculture and the public are having to learn to live with.

Pollination by honey bees is essential to agricultural production in this country. More than 90 of our crops require pollination by honey bees—about S20 billion worth of agricultural production a year. One mouthful in three of the U.S. diet directly or indirectly involves bee-pollinated crops.

By the time hybrid bees were found in Texas, ARS scientists had begun to develop recommendations for beekeepers to minimize the trouble that these bees could create.

A healthy population of European bees, kept that way by beekeepers regularly requeening hives with honey bees of known docile parentage, may be an area's best defense against the spread of Africanized hybrids.

In addition, ARS scientists and public affairs personnel have been working with state researchers, extension specialists, and educators, as well as other USDA agencies, to inform people about the true degree of risk that Africanized bees represent to the general public.

People are learning to avoid honey bee swarms because it is impossible for the untrained eye to tell the two strains of honey bees apart. And the defensive behavior of the two types can completely overlap; that is, some aggressive European bees are more prone to stinging attacks than some milder Africanized bees.

Individual honey bees out foraging for pollen and nectar represent no more danger than a single sting. But if a person disturbs a nest, honey bees of either type may sting in large numbers to protect their home.

Today, almost 6 years after Africanized honey bees arrived in the United States, they are found in parts of Texas, Arizona, New Mexico, California, Puerto Rico, and St. Croix.

How far north the Africanized hybrids will eventually go in the United States is still a matter of debate. But their spread has been much slower than predicted. Interbreeding with resident honey bees, disease, parasites, and cold weather may all be playing a part in slowing the Africanized honey bee's northward migration.

Hachiro Shimanuki
National Coordinator
Africanized Honey Bee Program