COMB: Conventional and Organic Management of Bees

Goals: Project COMB (Conventional and Organic Management of Bees) aimed to determine the impacts of various management systems on honey bee colony health. Specifically, our goal was to do a side-by-side comparison of conventional, organic, and chemical free management systems to determine how beekeeping practices impact colony health and productivity, disease and pest tolerance, and how all of these factors impact beekeeping economics.

Conventional: A system that allows the use of chemicals (synthetic and natural) and antibiotics to control parasites and pathogens in colonies.

Organic: A system that only allows mechanical and non-synthetic chemical treatments to control parasites and pathogens in honey bee colonies. [

Chemical-Free: A system that relies primarily on the genetics of the colony to control parasites and pathogens in honey bee colonies.

What we did: In November 2017, we met with 27 stakeholders, ranging from hobbyists to commercial beekeepers, to develop the protocols for each management system (read more) based on their current practices.

We developed detailed protocols for each management system. Below, you will find details about each management system in a summary figure (Figure 1) and table (Table 1). Note that figure 1B details the timeline of the applications of miticides throughout the duration of the project.

Figure 2

Figure 1. Summary figure of the differences in practices incorporated in the conventional (CON), organic (ORG), or chemical-free (CF) management system.

Table 1. Details of the differences in equipment, disease treatments, and feeding incorporated in the conventional (CON), organic (ORG), or chemical-free (CF) management system.

In April 2018, we began the experiment with the establishment of 288 colonies; 216 in Pennsylvania and 72 in West Virginia (see locations on map). Colonies were managed and monitored for three years. We regularly sampled colonies for various diseases and pests to measure colony health, including varroa mites, nosema, and two viruses (DWV and IAPV). In addition, we conducted an economic analysis to quantitatively compare the costs and benefits of the different management systems. 

Key finding #1: Overwintering survival was on average 84% for conventional, 81% for organic, and 27% for chemical-free systems (Figure 1). Colonies were checked monthly over the winter, to determine when the losses occurred. These results indicate that (1) controlling mite populations is critical for honey bee colony survival, and (2) beekeepers do not need to use synthetic miticides to control mites.

Figure 2. Summary of colony survival (A) Number of colonies throughout the duration of the study. (B) Average overwintering survival for the three years of the study in apiaries managed under conventional (CON), organic (ORG), and chemical-free (CF) management systems.

Key finding #2: Honey production per apiary was lower in the chemical-free than in the conventional and organic systems. The averages for the three years of the study were 23, 46 and 50 kg for chemical-free, conventional and organic.
Figure 3. Average amounts of honey (in kg) produced by apiaries in the conventional (CON), organic (ORG), and chemical-free (CF) management systems.
Key finding #3: Overall, the management systems that actively controlled varroa populations (both conventional and organic) supported colonies with fewer mites, lower nosema, and virus levels, and lower expression of genes related to stress (Figure 4).

Figure 4. Summary figure showing how conventional and organic management is positively associated with colony survival and negatively associated with pests, pathogens, and the expression of genes associated with stressed immune systems.

Overall, we found that the organic management system supports healthy colonies without the need to apply synthetic chemicals to the colonies. While beekeepers are encouraged to consider organic beekeeping management in their operations, keep in mind that you cannot certify the products coming from these colonies as organic because of the potential exposure to environmental pesticides coming from the landscape.

You can read more details about this study in this peer-reviewed publication:

Underwood RM, Lawrence B, Turley NE, Cambron-Kopco L, Kietzman P, Traver BE, López-Uribe MM. (2023) A longitudinal experiment demonstrates that organic beekeeping management systems support healthy and productive honey bee colonies. Scientific Reports 13(1): 6072 [LINK HERE]

Questions about this project?

Please contact Robyn Underwood