Case Report: Emerging Losses of Managed Honey Bee Colonies

Abstract

United States commercial beekeepers prepare honey bee colonies for almond pollination in California each year in late January to early February. This represents the largest managed pollination event in the world and involves more than half of all U.S. honey bee colonies. In winter 2023, numerous colonies in Florida, which were graded as suitable for almonds (larger than ten frames of bees), dwindled suddenly or altogether died within several weeks, just prior to movement for almonds. The timing of these losses and the resulting morbidity caused severe economic harm to affected operations. This study reports interviews with affected stakeholders, their economic harm, and analyses of pathogens and parasites found in their colonies.

Keywords: agricultural pests; collapse; economic harm; honey bees; parasites; pathogens.

Figure 1

(Left) The number of colonies in each operation that suddenly dwindled. (Right) A typical dwindled colony with a patch of brood and insufficient adult bees to cover the brood area. This colony lost approximately 90% of its adult bee population in the span of 3 weeks.

Figure 2

Varroa destructor detections on adult bees in colonies of various sizes (r(51) = 0.03, p = 0.83). Dots represent individual colonies, shown with regression fit line and 95% confidence band.

Figure 3

Pathogen targets in sampled colonies, box plots showing 95% confidence interval, line showing standard deviation.

Figure 4

Of the 12 beekeepers surveyed in this study, 9 were commercial migratory beekeepers who performed pollination services. These operations were expected to bring thousands of colonies to California to fulfill pollination contracts. Operations missed out on an estimated USD 3,451,420 of income due to the severe losses and morbidity in late January.