The History of Killer Bees: From Brazil 1957 to Arizona
The Africanized honey bee didn’t come from nowhere. It came from a deliberate, well-meant attempt to give Brazilian beekeepers a better bee, followed by an accident that let African bees loose. The result became one of the best-documented insect invasions in history. This post walks through the timeline. For what these bees are and how they behave, see What Are Killer Bees? and our Killer Bees 101 hub.
The problem Brazil was trying to solve
No honey bees are native to the Western Hemisphere. USDA ARS notes that Europeans brought honey bees to the Americas starting in the 1600s. Those European bees did well in temperate North America, where their habit of storing big honey reserves for winter paid off. In tropical South America they did poorly.
University of Florida entomologists explain that Brazilian scientist Warwick Kerr traveled to southern Africa to screen African honey bee subspecies for productivity and suitability. African bees had evolved in a tropical climate, and Kerr hoped to breed their strengths into a bee Brazilian beekeepers could manage.
1956: The import
USDA ARS dates the import of African bees to Brazil to 1956. The subspecies was Apis mellifera scutellata, the East African lowland (savannah) honey bee. Kerr’s plan, as UF/IFAS describes it, was to breed gentleness into the African stock through experiments and selection while keeping its good traits.
1957: The escape
The breeding program never finished. In 1957 African bees swarmed out of quarantine. UF/IFAS puts the number at 26 queens that were accidentally released. Ohio State’s entomologists note that the escaped queens mated with local European drones, which produced the hybrid now called the Africanized honey bee.
Several traits made the escape a success for the bee:
- More drones. Africanized colonies produce more drones, so in a mixed area, European queens are more likely to mate with African drones.
- Faster development. An African-type queen develops in about 14 days versus 16 for a European queen. The first queen out kills her unhatched rivals.
- Frequent swarming. Africanized colonies can swarm 10 or more times a year, filling an area with new colonies.
- Takeovers. Small African swarms can move into European colonies, and the European queen is lost.
- Pest and disease resistance. UF/IFAS notes that African bees resist many honey bee pests and diseases better than European bees.
1957–1990: Across a continent
With nothing to stop them in the tropics, the bees spread south and north. UF/IFAS estimates the spread through South and Central America at 200 to 300 miles a year, mostly without human help. That earned the bee a reputation as one of the most successful invasive species ever recorded.
The arrival changed beekeeping across Latin America. UF/IFAS’s Solutions for Your Life notes that honey production and pollination dipped during the transition, but countries in South and Central America are exporting honey again, and beekeepers there have adapted their methods. Some South American countries are now among the world’s top honey producers largely because of African-derived bees.
The bees reached northern Mexico several years before the U.S. border, which gave USDA scientists time to study what happens when Africanized bees meet a region already full of European bees. USDA ran monitoring traps and began writing guidance for beekeepers and the public.
The Hollywood years
While the bees moved north, the movies got there first. USDA ARS wrote in 2004 that Hollywood had made Africanized bees “a frightening villain of mythic proportions.” UF/IFAS names two B-movies, Killer Bees (1974) and The Swarm (1978), as how many Americans first heard of them. That’s where the nickname “killer bee” became fixed. The scientific name is still Africanized honey bee, and extension services work hard to replace the fear with facts.
October 15, 1990: Texas
USDA ARS records the date exactly. On October 15, 1990, a swarm was found in an ARS honey bee trap just outside Hidalgo, Texas. It was the first Africanized honey bee colony confirmed in the United States.
Texas tried to slow them by monitoring and regulating commercial bee movement. Natural migration continued anyway. By August 2006, the Texas Apiary Inspection Service had detected Africanized bees in 163 of the state’s 254 counties.
1993: Arizona
University of Arizona Extension says Africanized bees were first seen in Arizona in 1993, reached Yavapai County in central Arizona by 1997, and have since been recorded statewide. Extension now advises that any wild honey bee in Arizona should be considered Africanized. Arizona is probably the state most associated with killer bees today.
By 1996, USDA reported the bees in parts of Texas, Arizona, New Mexico, California, Puerto Rico, and St. Croix. By 2004 the list included Nevada.
Puerto Rico: the bees that got gentler
Africanized bees reached Puerto Rico in 1994. Ohio State’s summary of the research says a 2017 genomic study found a sharp drop in defensive behavior in Puerto Rico’s Africanized bees within about 12 generations (1994–2006). The researchers suggested that conflict with people, island isolation, and low predation may have favored gentler colonies. It’s the only place in the Americas where gentle Africanized bees are known to have evolved. What that means for beekeeping is covered in Can You Keep Africanized Bees?
2001 onward: Florida and the Gulf
UF/IFAS documents Africanized bees near the Port of Tampa in 2001. By 2003 colonies were established around Tampa, and they have since spread through the southern half of Florida. By 2012, UF listed nine states: Texas, California, New Mexico, Arizona, Oklahoma, Louisiana, Arkansas, Alabama, and Florida. Current range details are in Where Do Killer Bees Live?.
Why the march slowed
Early forecasts predicted a fast sweep north, and it didn’t happen. USDA said in 1996 that the spread had been “much slower than predicted,” pointing to interbreeding with resident bees, disease, parasites, and cold weather. Later work tied the limit to climate: roughly 34° north latitude, and possibly heavy year-round rainfall. That’s why there are no established killer bees in places like Ohio. See Are There Killer Bees in Ohio?.
Frequently asked questions
Who created killer bees?
Nobody set out to create them. Brazilian scientist Warwick Kerr imported African honey bees in 1956 to breed a better tropical honey bee. Queens escaped in 1957 and hybridized with local European bees.
How many queens escaped?
UF/IFAS cites 26 queens.
When did killer bees reach the United States?
October 15, 1990, near Hidalgo, Texas, according to USDA ARS.
When did they reach Arizona?
1993, according to University of Arizona Extension.
Why are they called killer bees?
Because of their mass defensive response, made famous by 1970s films. Their venom is no stronger than a European honey bee’s. See How Dangerous Is a Killer Bee Sting?.
Related reading
Sources
- UF/IFAS EDIS EENY-429, “African Honey Bee, Africanized Honey Bee, Killer Bee”: https://edis.ifas.ufl.edu/publication/IN790
- UF/IFAS EDIS ENY-147, “Differences Between European and African Honey Bees”: https://ask.ifas.ufl.edu/publication/IN784
- UF/IFAS EDIS ENY-170, “Living with the African Honey Bee”: https://ask.ifas.ufl.edu/publication/IN1205/pdf
- UF/IFAS Solutions for Your Life, “Africanized Honey Bees”: https://sfyl.ifas.ufl.edu/natural-resources/africanized-honey-bees/
- USDA ARS, “Africanized Honey Bees: The March North Has Slowed” (1996): https://agresearchmag.ars.usda.gov/1996/mar/forum/
- USDA ARS, “The Latest Research on Africanized Honey Bees” (2004): https://www.ars.usda.gov/news-events/news/research-news/2004/the-latest-research-on-africanized-honey-bees/
- Texas Apiary Inspection Service, “Africanized Bees”: https://txbeeinspection.tamu.edu/public/africanized-bees/
- University of Arizona Extension, “Feral Honeybees” (2023): https://extension.arizona.edu/sites/extension.arizona.edu/files/attachment/FeralHoneybees.pdf
- Ohio State University BYGL, “Myths and facts – Africanized honey bees”: https://bygl.osu.edu/node/2431