Altitudinal effects on the africanization of honey bees colonies (Apis mellifera L.) in Jalisco, Mexico

Mexico is one of the world's foremost producers and exporters of bees' honey ( Apis mellifera L.), and the state of Jalisco is one of the top three honey producers in Mexico. However, the Mexican beekeeping industry is affected by the high defensive behavior and lower honey production of Africanized honey bees compared to European bees. The objective of this study was to determine the African or European ancestry of honey bee colonies in six regions of temperate and subtropical climates in the state of Jalisco, Mexico, using morphometric and mitochondrial DNA analyses. More than 50% of the colonies in Jalisco had African mitotype and morphotype (59.0% and 62.5%, respectively). The frequency of africanization of the studied colonies was significantly higher (p < 0.05) in regions of low altitude and in subtropical climates, such as the Southeast and Southwest regions, than in regions of higher elevation and in temperate climates, such as Los Altos. There was a significant correlation between the forewing length of the bees and the altitude at which their colonies were located (r = 0.51, p< 0.01), indicating that the lower the altitude, the higher the degree of africanization of the bees. Future studies are warranted to determine if the degree of africanization of honey bee colonies increases or remains in equilibrium. These studies will make it possible to design mitigation strategies against the negative effects of the africanization of honey bees.