A. mellifera has 24 different races.
A. mellifera ligustica is the so called 'Italian' bees and is perhaps the most common bees kept, although by and large, most bees kept in North America has become a mix of ligustica and a few other races. The Italian bees are golden yellow and winters in large population, with a high consumption of honey during the winter.
A. mellifera carnica (Carniolan bees) are also widely bred and used in North America due to their gentleness. Bees are darker and overwinter in smaller populations.