A dozen years after they were first discovered in New Mexico, aggressive, Africanized “killer bees” have spread to 12 counties, recently reaching rural Roosevelt County, and are likely to continue buzzing their way north.

“They’re well established and will be in New Mexico for the foreseeable future,” said Carol Sutherland, an entomologist with New Mexico State University’s Cooperative Extension Service.

Other counties where the Africanized honey bees have been found are Catron, DoZa Ana, Eddy, Grant, Hidalgo, Lea, Lincoln, Luna, Otero and Sierra. NMSU scientists have evaluated bees from several other counties, including a hybrid colony that was confirmed in eastern Bernalillo County several years ago.

“Africanized and regular honey bees are so similar in appearance that lab testing is necessary for exact identification,” Sutherland said. “In most cases, the bees are sampled after a pest control operator eliminates a problem swarm for testing.”

New Mexico’s first swarm of Africanized bees was found in the rangeland of Hidalgo County in 1993. The latest colony was found in Roosevelt County in late May in the wall of a house in the Causey-Lingo area.

In addition to New Mexico, Africanized honey bees have been found in Arizona, California, Florida, Nevada, Texas and Utah. They were confirmed in Oklahoma in 2004, and in Arkansas this year. The latest occurrence came in Tampa, Fla., where officials believe they arrived on a commercial ship.

Domestic bees, bred for gentleness and honey production, have lived among people for thousands of years, Sutherland said. On the other hand, Africanized bees are totally wild and aren’t the least bit comfortable around people or animals.

Highly protective of their hives, Africanized bees are more likely to sense a threat at greater distances, become agitated quicker and sting in greater numbers. Safety around bees depends on knowing what to do long before an encounter occurs.

“Avoid areas where bees are foraging and avoid disturbing them, if possible,” Sutherland said. “Learn to look and listen for bee activity wherever you happen to be. And if you find yourself in a situation where bees are numerous, noisy or acting strangely, escape to safety as quickly as you can. Run and don’t stop until you reach safety, such as a building with doors and windows that close.”

The so-called killer bees are the result of honey bees brought from Africa to Brazil in the 1950s in hopes of breeding a bee better adapted to the South American tropical climate. These honey bees were shipped to Brazil in the mid-1950s where they escaped and became established in the wild.

They then spread south and north until they officially reached southern Texas in 1990. Today, more than 60 percent of Texas counties have Africanized bee populations.

While a sting from an Africanized bee is no more toxic than that of a European honey bee, Africanized bees are more aggressive. Africanized bees will usually attack with less provocation, and the angry bees will pursue people or attackers for longer distances.

Lucille Kincaid, 74, of Carlsbad, died of cardiac arrest in the summer of 2000 after she was stung multiple times by Africanized bees in her backyard. A number of others have been hospitalized after receiving numerous stings.

There have been 11 deaths associated with the Africanized bees in Texas in the 15 years since they were found, and hundreds more people have been stung. Nearly 100 animals have been killed.

Still, the bee’s killer reputation is somewhat overstated. “Africanized bees don’t roam in big swarms searching out victims,” Sutherland said.

If a swarm or colony is discovered, have it removed by a professional exterminator or pest control operator, she said. Beekeepers may not be interested in collecting bees when Africanized honey bees are known to occur in the area.

“Don’t wait for a determination of whether or not your bees are Africanized,” Sutherland said. “After Africanized honey bees are confirmed, further identifications can be just of academic interest.”

How much farther Africanized honey bees may spread is still unknown.

“Some expected these bees to be a major threat to agriculture and life in the Southwest,” Sutherland said. “Others expected an initial surge of activity and then the problem would somehow go away. The truth in New Mexico is somewhere in between.”