In 1957, a simple act at a Brazilian research station led to the escape of 26 African bee queens, whose descendants became infamous 'killer bees' across the Americas.
Experiment with African bees begins
In October 1957, a Brazilian research station removed queen excluders from hives, an act attributed to Warwick Kerr, a geneticist who conducted the experiment. The goal was to obtain a bee more productive in honey production under tropical conditions than the European bee, which was then used throughout North, Central, and South America.Imported queens and their survival
Out of 63 queens imported in 1956, only 48 survived, meaning 15 queens were missing even before the experiment began. The Brazilian government had asked Kerr for a bee adapted to the country's climate. The geneticist knew African bees were aggressive but expected their crossbreeding with local strains to produce a gentler and more productive insect.Queen excluders and the escape
The African colonies, known for being very defensive, were kept in hives equipped with queen excluders. These screens allow workers to pass through but retain the queen and drones. According to Kerr, a local beekeeper passing by the station noticed the excluders in October 1957 and removed them. This act is based entirely on this testimony, and the explanations provided about the visitor's motivations are hypotheses.Escape and spread of the swarms
In October 1957, 26 queens and their swarms escaped into the nearby forest. A swarm consists of a queen accompanied by a part of her workers, who leave to found a new colony elsewhere. These swarms do not remain in one place. They are capable of traveling 60 miles or more, nearly 97 kilometers.Africanized bees and their nickname
What this episode reveals is the fragility of the barrier. A removable barrier placed on colonies known for being defensive, which a visitor could remove: the entire containment objective depended on this. The descendants of the escapees interbred with local European bees. The result is known as the Africanized bee. The media and cinema renamed it "killer bee," a nickname that the Encyclopedia Britannica classifies among sensationalist phrases.Spread across continents
A shadow remains: none of the consulted sources name the visitor. They do not detail the route either, which only a few milestones allow to summarize: Panama reached in 1982, North America in 1985, then Texas in 1990. October 15, 1990: Hidalgo, then more than 100 counties. On October 15, 1990, near Hidalgo (Texas), the first natural colony was discovered.Expansion and current presence
For three years, their spread remained confined to the south of Texas, according to a synthesis from the university extension service. The expansion then resumed. Britannica places the spread to several states in the south and west of the country at the beginning of the 2000s. Today, the colonies have gained a lot of ground.Impact and danger of Africanized bees
An Africanized colony disturbed reacts faster than an European colony and can pursue a person up to 400 meters. Victims receive about 10 times more stings than during an attack by European bees. Available syntheses attribute to these bees approximately 1,000 human deaths, as well as the death of horses and other animals.
