Africanized honey bees, known colloquially as "killer bees", are a hybrid variety of the European honeybee (Apis mellifera), generated by a man-made breeding of the African honey bee

African bee

The African honey bee is a subspecies of the Western honey bee. It is native to central and southern Africa, though at the southern extreme it is replaced by the Cape honey bee, Apis mellifera capensis....

, A. m. scutellata, with various European honey bees such as the Italian bee A. m. ligustica

Italian bee

Apis mellifera ligustica is the Italian bee which is a sub-species of the western honey bee .- Origin :The Italian honey bee is thought to originate from the continental part of Italy, South of the Alps, and North of Sicily...

and A. m. iberiensis. These bees are far more aggressive than the European subspecies. Small swarms of Africanized bees are capable of taking over European honey bee hives by invading the hive and establishing their own queen after killing the European queen.
The Africanized honey bees in the Western Hemisphere

Western Hemisphere

The Western Hemisphere or western hemisphere is mainly used as a geographical term for the half of the Earth that lies west of the Prime Meridian and east of the Antimeridian , the other half being called the Eastern Hemisphere.In this sense, the western hemisphere consists of the western portions...

 are descended from 26 Tanzania

Tanzania

The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

n queen bee

Queen bee

The term queen bee is typically used to refer to an adult, mated female that lives in a honey bee colony or hive; she is usually the mother of most, if not all, the bees in the hive. The queens are developed from larvae selected by worker bees and specially fed in order to become sexually mature...

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