During an unsuccessful biology experiment in Brazil back in 1956, twenty-six Tanzanian Queen Bees were accidentally released from captivity and allowed to interbreed with local drones.  The original experiment was to combine the excellent honey producing abilities of the Tanzanian Bee with the docile nature of the European Bee in hopes of a more suitable offspring, and almost the exact opposite ended up happening.  The offspring produced not only harvested honey slightly less than the European Bee but it was also far more likely to swarm and defend its colony aggressively.  This new strain of offspring became known as Africanized Bees or Killer Bees because of these traits, and this species has slowly advanced north and finally into Texas in 1990, Arizona in 1993, and Florida in 2002.

During their northward advancement scientists noticed distinct differences in the Africanized Honey Bee.  They were much more likely to abandon an area if food sources were not readily available, and when a threat was perceived they were much more likely to attack in much higher numbers than was normal for European Bees.  They would also chase intruders much further than their close relatives would, sometimes as far as a half a mile.  This new race of bee appeared near impossible to domesticate because of these traits, so limiting their chances of expansion seemed like the most solid alternative.

Since this species is literally indistinguishable to the naked eye when compared to our native Honey Bees it is often impossible for beekeepers to tell when their hives are endangered before more interbreeding takes place.  Their offspring are also more aggressive and likely to abscond, and the initial effects have already reduced many beekeepers’ hives throughout the Southwest by 30% or more; by replacing aggressive queens this behavior has been somewhat controllable.

If you see any bees in Phoenix, there is a strong likelihood that they are Africanized and will be very aggressive. It is very important that you contact a professional to remove the bees from your property lest they harm your family and pets.