I spotted an article about some interesting honey bee research (details below) in the excellent Beekeepers Quarterly (BKQ) magazine. Not everyone reads that, despite its excellence, so I thought I’d write a little about the research. The use of “Chemical-Free” in the headline refers to any chemicals, including organic acids and thymol (which are, of course, chemicals). So, here’s my take on research which shows that chemical-free management fails to sustain healthy honey bee colonies.

Positive Message

The summary of the research findings below is all about a very positive message, which is that using organic methods of managing honey bee colonies is perfectly viable and at least as good as using conventional methods. This is research done in the USA, so their idea of “conventional” may not quite square with ours in the UK, but it’s in the same ballpark. However, what caught my attention was the relatively disastrous performance of the colonies managed using chemical-free methods.

The experiment seems, to this walrus, to have been quite well-designed, and it ran for three years. The whole point was to see what difference the type of beekeeper management made to the health and survival of the bees, and their honey production. Apiaries were made up of 12 colonies (4 from each group – conventional, organic, and chemical-free), and three such apiaries were set up on each farm. The farms were certified organic, so that chemical effects were hopefully limited to what the beekeeper added to the hives. Wax foundation was pesticide-free because it was collected in an area with no proximity to agricultural chemicals by a beekeeper who does not use in-hive chemicals.

All colonies were headed by sister queens reared and openly mated near Utica, NY (USA). Queens were produced via grafting from a colony that had not been treated for varroa mites for at least seven years. After the colonies were established, no other bees or queens were brought into the study. To keep the colony density at 12 per apiary, they made splits from surviving colonies and placed them in empty spaces. These colonies were maintained using the management system of their origin.

Many UK beekeepers use organic varroacides such as thymol, oxalic acid, and formic acid. The difficulty with calling honey ‘organic’ (assuming no use of “hard” chemicals such as amitraz) is to do with the land over which bees forage. Who can say how far they have roamed, and whether they alighted on flowers that have been sprayed with some form of pesticide? It will probably not shock anyone that the organic treatments – at least those listed here – are as effective as amitraz. The organic and conventionally managed colonies were similar in honey production and health.

However, the chemical-free management system did terribly. Here are some quotes from the ‘discussion’ section of the paper:

“These results indicate that despite the myriad of biotic and abiotic stressors impacting honey bees, beekeeping management is the most important factor associated with colony health and productivity for stationary honey-producing colonies.”

“Beekeepers that use a chemical-free management system oppose the use of chemical miticide treatments and interventions in the colonies because of the potential negative impacts of these treatments on the bees. Our results demonstrate that the benefits of miticide treatments outweigh their detrimental effects on honey-producing operations. Indeed, the lack of miticide treatments led to unhealthy colonies that were five times more likely to die than colonies treated for mites. While there is substantial evidence supporting that honey bee populations can persist in unmanaged conditions without varroa mite treatments, our results demonstrate that the chemical-free system is not suitable for honey-producing beekeeping operations. Colonies under the chemical-free management system experienced mortality of 70% yearly despite the use of queens from a local colony that had not been treated with miticides for 7 years.”

Summary of Main Points from the Research Paper

Title: A longitudinal experiment demonstrates that honey bee colonies managed organically are as healthy and productive as those managed conventionally

Authors: Robyn M. Underwood, Brooke L. Lawrence, Nash E. Turley, Lizzette D. Cambron-Kopco, Parry M. Kietzman, Brenna E. Traver, Margarita M. López-Uribe

Published in: Scientific Reports (2023)

DOI: https://doi.org/10.1038/s41598-023-32824-w

Background:

• Honey bee colonies face numerous challenges such as pests, pathogens, poor nutrition, and pesticide exposure.

• Beekeeping management practices significantly influence colony health and productivity.

• This study investigates three beekeeping management systems: conventional, organic, and chemical-free.

Methods:

• A longitudinal study over 3 years with 288 colonies established at eight certified organic farms in Pennsylvania and West Virginia, USA.

• Colonies were divided into three management systems: conventional, organic, and chemical-free.

• Various biomarkers, including pathogen levels and gene expression, were measured to assess health.

Management Systems:

1. Conventional:

• Frequent interventions.

• Use of synthetic chemicals.

• High survival and honey production.

2. Organic:

• Interventions as needed.

• Use of organic-approved chemicals (formic acid, oxalic acid, thymol) for mite control.

• Similar survival and honey production to conventional.

3. Chemical-free:

• Minimal interventions.

• No chemical treatments.

• Lowest survival and honey production.

Key Findings:

Survival Rates:

• Conventional and organic systems had similar survival rates, which were 2.8 times higher than chemical-free.

• Organic and conventional systems showed an average overwintering loss of 23%, lower than the national average of 40% in USA.

Honey Production:

• Conventional and organic systems produced 102% and 119% more honey, respectively, compared to chemical-free.

Health Biomarkers:

• Pathogen levels (Varroa mites, Vairimorpha apis, Vairimorpha ceranae, DWV, IAPV) were significantly lower in conventional and organic systems compared to chemical-free.

• Gene expression related to immune function (def-1, hymenoptaecin, nkd, vitellogenin) varied, with organic and conventional systems showing better health indicators.

Pests and Pathogens:

• Varroa mite levels were substantially reduced in conventional and organic systems.

• Chemical-free colonies had high mite loads and associated viral levels, leading to higher mortality.

Conclusions:

• Organic management is a viable, sustainable approach for honey bee colonies, offering comparable health and productivity to conventional methods.

• Chemical-free management is not suitable for honey-producing operations due to high colony mortality and low productivity.

• Effective management practices, including targeted chemical treatments for pests, are essential for maintaining colony health and productivity.

Implications:

• Beekeepers should consider organic management practices to achieve sustainable beekeeping while minimising the use of synthetic chemicals.

• Continuous monitoring and appropriate interventions are crucial for the survival and productivity of honey bee colonies.

This study provides strong evidence that organic beekeeping practices can support healthy and productive honey bee colonies, making it a promising approach for sustainable apiculture.