Africanized Honey Bee (Killer Bee)

The Africanized honey bee — popularly called the 'killer bee' in 1970s-1980s media — is a hybrid between the European honey bee (Apis mellifera mellifera, ligustica, carnica, etc.) and the African subspecies Apis mellifera scutellata. The hybrid originated by accident in 1957 at the Rio Claro experimental apiary in São Paulo, Brazil, where Brazilian geneticist Warwick Kerr was conducting research crossing African with European honey bees to develop a tropics-adapted commercial bee. 26 swarms with African queens escaped from the apiary in October 1957 (the 'unmanaged release'), interbred extensively with local European-managed colonies, and produced the hybrid that has since spread across the Neotropics and into the southern US. The hybrid inherited the African subspecies' defensive behavior, which is dramatically more aggressive than European honey bee defense: colonies respond to disturbance with mass attack of hundreds to thousands of workers (vs. dozens for European bees), pursue intruders for distances of 400+ meters (vs. 30 m for European), respond to threats at much greater distances, and remain agitated for hours after the original disturbance. Sting venom is identical to European honey bee venom (the same melittin and phospholipase A2 cocktail), but the much greater number of stings inflicted in a typical attack drives the medical danger: documented victims have received over 1,000 stings in a single attack. Estimated cumulative human deaths since 1957 exceed 1,000 across the Americas. The hybrid's range expanded from Brazil northward at approximately 500 km/year and reached southern Texas in 1990, where it now occurs across most of the southern US. Despite the danger, Africanized honey bees are also commercially valuable: they produce honey at higher rates than European bees in tropical climates, are highly disease-resistant, and forage at higher temperatures.