Colorado State University Tri River Area Extension recently reported the presence of a hive of Africanized honey bees in Palisade, Colo., making it the first confirmed case of them in the state.
Prior to this discovery, the most northern location of known Africanized honey bees was southern Utah.
Commonly referred to as “killer bees,” Africanized honey bees pose no more “killer” threat than their cousin the European honey bee, which currently inhabits the northern part of the country. Their stings carry no more venom, but they earned their nickname, “killer bees,” because of their aggressive nature and tendency to swarm and defend their nest from a distance.
Palisade, a major fruit producing area in Colorado, is home to many honey bee hives used by commercial fruit and honey producers and hobby beekeepers.
Prior to this spring, the beekeeper who owned the hive had worked with it for the past few years only wearing a long sleeve shirt and beekeepers veil for protection.
But when he went to check on the hive this spring, the usual protective gear was not enough.
“It was the aggressive nature that led to their discovery,” said local entomologist Bob Hammon at the Colorado State University Tri River Extension office.
The beekeeper contacted Hammon about the situation after having difficulty with the hive.
Africanized honey bees and European honey bees can be difficult to distinguish from one another. Experts usually conduct a series of measurement test, which include measuring wing span before confirming that the bees are Africanized.
Because Colorado has never had reason to test for Africanized honey bees, Hammon had to send the sample to a U.S. Department of Agriculture lab in San Francisco. The lab results confirmed with 99 percent likelihood that the hive was Africanized.
The beekeeper has since destroyed the hive.
Africanized honey bees are hybrids of the European and African honey bees. The two subspecies can hybridize fairly easily but Africanized colonies cannot usually survive winters in Colorado.
“We’ve always thought the cold weather eliminate those genetics,” Hammon said. “I don’t know why it didn’t this time.”
But, Gloria Degrandi-Hoffman, an entomologist at the USDA Bee Research Center in Tucson, Ariz. said they have found colonies of Africanized bees in Flagstaff, Ariz. which has similarly cold winters, so the possibility exists that they could have adapted to colder weather.
Native to sub-Saharan Africa, a Brazilian scientist introduced Africanized honeybees in Brazil in the 1950s to help increase honey production in the country. Since then the Africanized bees have made their way north and entered the United States in the 1990s, Degrandi-Hoffman said.
Both subspecies have spread widely outside their native range due to their economic importance as pollinators and producers of honey.
It is unclear how the hive became Africanized in the first place. But, it is not usual to have a sighting of African bees outside their southern region as they can come into an area in many different ways, Degrandi-Hoffman said.
Africanized bees will abandon their hives and swarm elsewhere sometimes landing on trains or trucks and end up in other parts of the country. The hive could have become Africanized this way or from an imported queen with Africanized genetics.
“Because you’ve detected Africanized bees, that does not necessarily mean you have an established population in Colorado. You’d have to do a lot more sampling to see how prevalent it is,” Degrandi-Hoffman said.
The hybridization of the one hive appears to be an isolated incident at this time. However, if Africanized honey bees have begun to establish themselves in Colorado, there is no great cause for alarm. Many of the southern states have dealt with them for years without widespread or permanent damage. Just be aware of hives around you as you would with any stinging insect, Degrandi-Hoffman said.
“If you have nests in or around your home you really need to have them removed by professional who can take them out with minimal amount of colony disturbance,” Degrandi-Hoffman said.
In response to the discovery of the hive, CSU Extension and the USDA Animal Plant Health Inspection Service have made efforts to set up a protocol for testing for Africanized hives in Colorado.
“We’re going to take that testing protocol and share it with CSU Extension so then they can start examining the samples themselves,” said APHIS state plant health director Pat McPherren.
Hammon anticipates that this discovery will lead to some more questions about the honey bee population in the area but suggested that for now the biggest thing is patience.
“I’m sure that beekeepers will be now more aware of the possibility and if they have an aggressive hive won’t want to write it off.” Hammon said, “But only time will tell if it’s going to have to change the way we manage our bees here.” ❖