A Phoenix, Arizona, mother and her two children were hospitalized this week after being attacked by a swarm of bees. The bees came out of a shed and attacked the group. It is unknown whether the attack was provoked.
Firefighters called to the scene sprayed the bees with foam to allow the family to escape. Foam kills the bees. The woman and children were in stable condition when taken to the hospital.
The species of bee that attacked is unknown. In May, an aggressive swarm of bees in Tucson killed three dogs. The type of bee that attacked in that case also has not been reported.
It’s likely in both cases that the attacking bees are Africanized. Starting in the 1950s, swarms of Africanized bees began to spread across the Americas. They are now common in the southwestern U.S.
African bees are far more aggressive than European bees. If African bees mate with European bees, the resulting colonies often are more aggressive. Africanized bees commonly swarm and sting people or animals even if they have not been provoked. They have been known to attack “invaders” as far as 100 yards away.
The bees also are more likely to build nests in cavities such as holes in the ground. The best way to avoid bee attacks is to scan the area for insects flying near the entrance of their hive and taking care near fallen trees and trash piles. Swatting at the bees is likely to anger them and increase the chances of further attack. If a person is being swarmed, he or she should seek shelter indoors.
So, are the bees likely to spread to the rest of the United States? Maybe not. The bees so far seem to avoid colder climates, stopping no further north in North America than California and no further sound in South America than northern Argentina. Recently, scientists from University of California, Davis, genome-sequenced hundreds of bees and found that the numbers of Africanized hives begin to decline gradually over hundreds of miles from these northern and southern limits. Bees with more African ancestry cannot tolerate colder winters.
European honeybees (Apis mellifera) were brought to the Americas as early as the 1600s. African honeybees (Apis mellifera scutellate) were brought to Brazil in 1957 for use in experiments and escaped from their hives. They began interbreeding with the European bees. African bees both exhibit defensive behavior and offer resistance to bee-killing Varroa mites, a double whammy for their population growth vs. the European bees.
In the University of California study, published in PLOS Genetics, the researchers found that bees near the northern and southern edges of the range varied greatly in whether they had African or European ancestry. Bees found at higher latitudes were less Africanized.
However, noted study first author Erin Calfee of University of California, the scientists also found evidence that some African bee genes were not tied to climate sensitivity. The African bees were found to be more genetically diverse than the European bees, and that diversity wasn’t lost as the bees expanded across the Americas. The good part is that beekeepers may be able to tap into this genetic diversity to breed for more desirable traits.
That is, if they can survive the aggressive swarms.
Disclaimer: This article does not provide medical advice. Do not take action based solely on this article and always consult with an appropriate healthcare professional. This article is purely for informational purposes.