Increasing the overall genetic diversity of honey bees will lead to healthier and hardier bees that can better fight off parasites, pathogens and pests, says bee breeder-geneticist Susan Cobey of the University of California, Davis and Washington State University.

Just as stock improvement has served the poultry, dairy and swine industries well, the beekeeping industry needs access “to stocks of origin or standardized evaluation and stock improvement programs,” Cobey said.

Cobey is the lead author of the chapter “Status of Breeding Practices and Genetic Diversity in Domestic U.S. Honey Bees” of the newly published book, Honey Bee Colony Health: Challenges and Sustainable Solution.

“The many problems that currently face the U.S. honey bee population have underscored the need for sufficient genetic diversity at the colony, breeding, and population levels,” wrote Cobey and colleagues Walter “Steve” Sheppard, professor and chair of the WSU Department of Entomology and David Tarpy of North Carolina State University, formerly a graduate student at UC Davis.

“Genetic diversity has been reduced by three distinct bottleneck events, namely the limited historical importation of a small subset sampling of a few honey bee subspecies, the selection pressure of parasites and pathogens (particularly parasitic mites) and the consolidated commercial queen-production practices that use a small number of queen mothers in the breeding population,” Cobey pointed out.

The honey bee, Apis mellifera, originated in the Old World where it diverged into more than two dozen recognized subspecies, they related. However, only nine of the more than two dozen Old World subspecies ever made it to the United States and only two of these are recognizable today.

European colonists brought one subspecies, Apis mellifera mellifera or “The Dark Bee” of Northern Europe, to America in 1622, establishing it in the Jamestown colony. The bee was the only honey bee present in the United States for the next 239 years (1622 until 1861).

The Italian or golden honey bee, Apis mellifera ligustica, was introduced into the United States in 1859 and is now the most common honey bee in the United States. “Currently available U.S. honey bees are primarily derived from two European subspecies, A. m. carnica and A. m. ligustica,” the bee scientists said.