MSU Extension Pollinators & Pollination

The beekeeping industry and community continues to face challenges and experience high levels of honey bee colony losses. The 2023-2024 national survey of honey bee colony losses, conducted by Auburn University, the Apiary Inspectors of America and Oregon State University, reported a loss of over 55% of managed honey bee colonies. Educational programming and years of experience can help beekeepers diagnose some problems through visual inspection or field tests. Other problems cannot be diagnosed or confirmed without submitting samples to honey bee diagnostic labs for analysis. The results from these tests can inform a beekeeper’s management, which may help decrease losses and increase revenue.

Types of diagnostic services

Analysis of honey bees or hive products runs the spectrum of very targeted testing for a specific entity (such as a specific pathogen, parasite or chemical) to testing materials for an array of possible elements. For example, a diagnostic test for American foulbrood is usually performed after a combination of symptoms are observed (such as sunken, perforated and/or greasy brood cappings; irregular brood pattern; dark scales that are difficult to remove from the cells; and/or foul odor), but suspected pesticide-related bee kills involve testing for roughly 100 or more pesticide residues. As a result of the vastly different testing protocols, equipment and trained personnel required, diagnostic testing can vary in the time it takes to receive results and the cost of services. Costs range from free to hundreds of dollars per sample and are subject to change. Please see Table 1 and visit laboratory websites for information about their current pricing and turnaround time.

Pathogens and parasites (bacteria, microsporidia, viruses, mites)

Some diseases can be difficult to assess, especially in cases when time has passed and secondary and tertiary problems have developed. It can be what beekeepers are seeing in their colonies is the result of a secondary issue and not what started the initial decline. Learning about current, scientific-based assessments can help beekeepers improve beekeeping management, increase skills and improve the operations. Diagnostic tools for honey bee diseases is an learning online module that helps beekeepers learn visual identification and field tests for several honey bee ailments.

Diagnostic labs may offer testing for single, individual pathogens and parasites or offer panels that test for several pathogens at once. Note it is common for a declining colony to test positive for more than one stressor. Some labs and tests may report qualitative results (for example, yes/no or presence/absence), while others may report quantitative results that provide a level of infection or infestation. Similarly, some laboratories offer additional testing such as screening bacterial isolates from American foulbrood infections for their sensitivity to antibiotics or the species of microsporidia invading your honey bees’ guts. If interested in these specifics, confirm with diagnostic labs that they provide these measures in their tests and results.

Pesticides

Pesticide testing is a more costly service due to the complexity of testing materials for a panel of many chemical residues (not a single chemical). Beekeepers can report suspected honey bee kills due to pesticides to their state pesticide regulatory agency. In Michigan, beekeepers can review Michigan State University’s article on what to do if you suspect your honey bee colonies are harmed by pesticides.

To request a pesticide misuse inspection, contact the Michigan Department of Agriculture and Rural Development (MDARD) at 1-800-292-3939, MDA-Info@Michigan.gov or through the MDARD Online Contact Form. Pesticide complaints are handled by the Pesticide and Plant Pest Management Division.

The state pesticide regulatory agency may open an investigation to examine if the bee kill is due to pesticide misuse. Inspectors may collect samples and submit them for pesticide analysis. If the agency determines a pesticide misuse violation, it may issue the appropriate enforcement. Beekeepers can also collect and submit samples themselves; however, the results are unlikely to lead to enforcement outside of a formal investigation. Beekeepers who collect samples for pesticide analysis should be careful not to expose themselves to pesticide harm. Wear personal protective equipment, and do not eat, drink, chew gum or smoke in the apiary while inspecting for pesticide damage.

Queens

Lab assessments of characteristics associated with a queen’s quality provide a comprehensive and unbiased view of the queens you rear and keep. Morphometric measurements of reproductives indicate rearing quality, while mating success can be inferred by the number and viability of sperm stored in a queen. Patriline analyses of workers provide estimates of a colony’s genetic diversity, which has been shown to be important for colony health and functioning. Assessments of queens may destructive, meaning the queens will be killed before or during the testing process. Some labs may evaluate queens through genomic testing of their drone and worker offspring.

Assessments of queens may be destructive, meaning the queens will be killed before or during the testing process. Some labs may be able to evaluate queens through genomic testing of their drone and worker offspring.

Africanized honey bees

The first characteristic of an Africanized honey bee colony that beekeepers usually notice is extremely defensive behavior. Confirmation of Africanized honey bee genetics is required through standardized testing using molecular analysis. Please consult your state's regulatory policies to determine if you are required to report any suspected cases of Africanized honey bees. In such states, an apiary inspector may help assess the colony, collect and send off samples for diagnostic testing, assist in euthanizing colonies that test positive, and monitor nearby apiaries. In states without this reporting requirement and support, a beekeeper can submit samples to a diagnostic laboratory on their own.

Floral source of honey (or pollen)

Beekeepers may be curious to know what their bees are bringing in, but floral source testing is primarily performed for the purpose of labeling and selling honey as a specific variety based on the floral resource. These assays require sampling honey supers or at least extracted honey that has not been filtered or strained, which can remove some pollen grains. The honey sample is processed so the grains it contains can be analyzed with microscopy or molecular techniques. Proper packaging and shipping of honey is very important to help protect the integrity of the samples and to prevent a very messy and possibly contaminated package for the diagnostic lab.

Testing for adulteration of honey is costly and complicated due to different equipment and protocols required to test for different types of adulteration; contact your apiary inspector or other state regulatory agency personnel for questions regarding testing for adulteration.

Considerations

As already mentioned above, different diagnostic tests require different procedures. These differences in protocols, as well as the length of the queue of samples, can impact the turnaround time from submission to receiving results. Testing for the floral source of honey or for pesticide residues requires significant sample preparation by the diagnostic lab, so these assays may take more time (often over a month, sometimes over six months) than more targeted testing (for example, specific bacterial diseases). Cost of shipping can add to the overall expense. Shipping room temperature samples in small containers over a slower route is far less expensive than dry ice samples that need to arrive the next day.

Apiary inspectors provide several helpful services to the beekeeping community. The Apiary Inspectors of America have a helpful website that includes an inspection services page where you can easily find contact information for your state apiary inspector, their website and your state’s laws and regulations. Additionally, Table 1 has been adapted from the Apiary Inspectors of America’s webpage of honey bee diagnostic labs. Private labs may also be available in your area.

When contacting a diagnostic lab, there are several questions to consider before you start collecting samples from your colonies. Several labs have submission guides on their websites that will answer many of these questions. Please review these online materials before contacting lab personnel with questions. Considerations include, but are not limited to, the following questions.

Choosing a laboratory

• What type of results will I receive?
• What will I be able to do with the results/report? Does the report include interpretation of the data?
• What is the cost? Is there a discount for a large number of samples?
• What forms of payment are accepted?
• When can I expect results? How will results be sent?
• As a first-time user of your services, is there anything else I should know?

Collecting samples

• What type of sample is needed (adult bees, brood, pollen/bee bread, nectar, honey, swabs, etc.)?
• Should adult bees or brood be alive, dying or dead?
• When should samples be collected (immediately following an incident or event, seasonal, pre-treatment, post-treatment, etc.)?
• What quantity of the material is needed?
• Is there a minimum number of samples required?
• What kind of container should be used for the samples?
• Should a “control” sample be collected as well? For example, a sample from a colony that appears healthy when other colonies sampled appear sick.
• How should samples be labeled? What type of ink (or pencil) should be used?
• How should the sample be stored before submission?

Shipping samples

• What type of shipping container should be used?
• Do the samples need to be shipped with ice packs or dry ice? If so, much space should the ice packs or dry ice take up to keep the samples at the appropriate temperature throughout shipment?
• How should samples be sent? Do they require special packaging?
• Do they need to be sent at room temperature or on ice or dry ice?
• Do they need to be sent overnight?
• Should a particular carrier service (FedEx, UPS, USPS) be used?
• Does the lab have specific days when it receives samples?
• What is the address for receiving samples?

Honey bee diagnostic labs for analysis compiled by the Apiary Inspectors of America

Acknowledgements

This article was written collaboratively by the authors as part of the Managed Pollinator Protection Working Group, which is supported by the North Central IPM Center. A version of this article will be posted on multiple university websites.

This work is supported by the USDA National Institute of Food and Agriculture, Crop Protection and Pest Management Program through the North Central IPM Center (2022-70006-38001) and USDA ARS cooperative agreement 58-6066-9-046.

This work is supported by the Crop Protection and Pest Management Program [grant no 2021-70006-35450] from the USDA National Institute of Food and Agriculture.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.