Dry weather forces Africanized bees into urban areas for food

Patrick Graham

Friday, April 21, 2000 | 4:46 a.m.

PHOENIX - Confronted with unseasonably dry weather, the easily agitated Africanized honeybees are moving from the parched desert regions to the bountiful cities.

The wild plants that normally provide nectar and pollen have shriveled up. So the so-called killer bees are heading into urban areas - like someone's backyard - in search of new honey sources.

"In periods of dry weather, these bees will pack up and move on. They're going to where the water and flowers are," said Dave Langston, an Africanized honeybee expert and superintendent of the University of Arizona's Maricopa Agriculture Center.

"We have more bees looking for places to live. That increases bee-human interaction."

The dry weather doesn't make the bees more aggressive, but increases the chances of swarming encounters. With less bees foraging for food, there are more bees in the hive to defend their precious honey reserves and brood, experts say.

"A colony of Africanized honeybees will employ more guard bees to fend off would be intruders," said Tom Martin, owner and president of AAA Africanized Bee Removal Specialists in Tucson and Phoenix.

Normally, most bee attacks occur in July when honey stores dry up and in October when the bees are looking for new homes and honey sources.

Already this spring, a 76-year-old man suffered more than 300 stings at his home and seven men working on a grocery store roof in Tucson were attacked and injured.

The bees hit Arizona in 1993 and have been blamed for the deaths of four people since then. The bees also have killed numerous animals that were penned or chained and unable to flee.

Experts say Arizona's drought-like conditions are exasperating an ongoing problem: the bees' numbers are multiplying and they now outnumber the docile European honeybees.

"They grow geometrically," said Martin, a former commercial beekeeper and researcher with the Carl Hayden Research Center for the U.S. Department of Agriculture in Tucson. "It's a serious, serious problem."

Africanized varieties tend to create new hives as often as every six weeks compared to about once a year for domestic bees, experts say.

As both Africanized bee and human populations increase in Arizona, there is a greater probability that someone or some animal will encounter the bees' fury, experts say.

"What we are seeing is the proliferation of the bees in our communities," said Eric Erickson, director of the Carl Hayden Bee Research Center, though he noted that most people will never encounter the insects.

Once the bees establish a home, their numbers can increase significantly in a short time and their behavior becomes more aggressive. The bees generally keep to themselves but if a threat is perceived, attack is eminent. The bees remain agitated for as long as eight hours and will chase an intruder up to a quarter-mile.

Operating power equipment, such as a lawn mower, within 100 feet of the hive, or any movement within 50 feet, can set the bees off.

Stings from Africanized bees are not more potent than the European varieties. But when they attack, tens of thousands of bees bolt from the hive and then overwhelm and sting the intruder.

So far, the bees have settled in Arizona, California, New Mexico, Nevada and Texas.

In the 1950s, a Brazilian scientist wanted to crossbreed the gentler European bees with the wild South African bees to create a tropically adapted breed that didn't sting excessively.

But the African bees were accidentally released and thrived. They entered the United States at the Texas border in 1990. They can cover up to 200 to 300 miles a year. Most of Arizona has been colonized.