In the 1990s, as Africanized honey bees spread into Arizona around 1993, the USDA-ARS Carl Hayden Bee Research Center (CHBRC) in Tucson became the key facility for official identification of feral colonies. Arizona relied on CHBRC's morphometric analysis, measuring wing vein lengths and 37 body characteristics from bee samples to distinguish Africanized bees from European ones with high accuracy. Genetic methods like mitochondrial DNA (mtDNA) analysis and PCR assays emerged during this period to