How far north can Africanized killer bees be found?

The southernmost southwestern United States of America is how far north the Africanized killer bees have made it as of 2004. Subsequent data-collecting efforts offer indications of isolated presences in the southernmost Southeast from Louisiana to Alabama, Arkansas, Florida, Georgia, Mississippi, and North and South Carolina. The insects in question (hybrid Apis mellifera) seems to travel at a rate of 200+ miles (321.87 kilometers) northward per year since populations introduced into Brazil in 1956 escaped in 1957.