Evaluating the strength and defensiveness of western honey bee (Apis mellifera) stocks

When honey bee (Apis mellifera) breeders select traits, emphasis is often placed on selecting bees that are less defensive. Historically, one of the barriers for US beekeepers preferring a hygienic stock that can naturally reduce pest and pathogen levels is the belief that these stocks display elevated defensive behaviors. Here, we examined the US stocks: New World Carniolans, USDA Pol-Line, Russian, and a local stock of mixed breed. We developed a method to measure and compare the defensiveness of the colonies. Additionally, we compared strength measurements across stocks.