Research & News

Researchers: Prof Claire Bethune (pictured), Prof Paul Turner, Prof Bernhard Gibbs

Institutions: University Hospitals Plymouth NHS Trust / University of Plymouth; Imperial College London; Canterbury Christ Church University

Dates: 2025 – 2028

Jointly sponsored by BDI Ltd and beekeeper associations

This three year research project investigates why beekeepers show such different immune responses to bee and wasp stings. Led by University Hospitals Plymouth NHS Trust, with partners at Imperial College London and Canterbury Christ Church University, the study aims to improve understanding of allergic reactions in the beekeeping community. The team will analyse blood samples from beekeepers with well documented sting histories to identify biomarkers linked to mild, moderate, or severe reactions. As the project notes, it seeks to “identify specific biomarkers or immunological signatures that may predict severity of response to Hymenoptera venom.”

A key focus is the growing threat of the Asian hornet (Vespa velutina), an invasive species now appearing more frequently in the UK. By comparing immune responses to bee and hornet venom, the research will help clinicians and public health teams assess risk more accurately as sightings increase.

This project supports safer beekeeping by improving diagnosis, risk stratification, and emergency preparedness. It also contributes to national resilience as climate change and invasive species increase sting related risks. The findings will benefit beekeepers, allergy specialists, and policymakers, offering new insights into venom tolerance and helping reduce anxiety and unnecessary withdrawal from beekeeping.

Lead Researcher: Maggie Gill

Organisation: PHIRA Science

Dates: 2026 – 2029

Tropilaelaps mites are emerging as one of the most serious global threats to honey bee health, and this project represents the fourth phase of BDI supported research by PHIRA Science. Building on extensive fieldwork in Asia and Georgia, the team has become the only research group worldwide to study Tropilaelaps mercedesae across both regions where the mite is now established. Their findings show that Tropilaelaps spreads faster, reproduces more aggressively, and causes colony collapse more rapidly than previously understood.

Earlier BDI funded work improved detection methods used by the National Bee Unit, examined mite survival on different materials, and assessed resistance to miticides. However, major gaps remain in understanding reproduction, dispersal, overwintering survival, and transmission between colonies. This three year project will investigate these unknowns through controlled field studies, brood biopsies, swarm monitoring, and overwintering trials.

The team will also test formic acid and biotechnical control methods to identify practical management strategies suitable for Western beekeeping. A strong outreach programme will expand beekeeper awareness through films, talks, and educational resources—critical because early detection is the only realistic defence against a Tropilaelaps incursion.

With the first established populations now reported in Europe, this research is urgent. It will help protect UK beekeeping, inform government policy, and strengthen global preparedness for one of the most dangerous honey bee pests.

Researchers: Dr Christopher Rodrigues, Dr David Chandler

Institution: University of Warwick

Dates:  2024 – 2028

American Foulbrood (AFB) is one of the most destructive honey bee diseases worldwide, caused by the spore forming bacterium Paenibacillus larvae. Once established, AFB leads to the death of infected larvae and often the destruction of entire colonies. This four year research project, led by Dr Christopher Rodrigues and Dr David Chandler at the University of Warwick, aims to deliver the most detailed molecular understanding to date of how P. larvae grows, infects, and spreads within honey bee colonies.

The project combines advanced molecular genetics, high resolution microscopy, and RNA sequencing to map the complete life cycle of the bacterium. As the agreement notes, the team will “establish an in vitro model for P. larvae growth, sporulation and germination,” providing a controlled system to study the pathogen’s development. Researchers will then build an infection model using honey bee larvae to observe how the bacterium behaves inside its natural host, including how it germinates, invades tissues, and forms new spores. 

By uncovering the molecular mechanisms behind AFB, this research will support better diagnostics, inform future treatments, and strengthen the UK’s ability to manage one of the most serious threats to honey bee health.

Photo: American Foulbrood (Paenibacillus larvae) infected larval remains of forming a drawn out, viscous string during a matchstick rope test.  Courtesy The Animal and Plant Health Agency (APHA), Crown Copyright

Project lead: Dr Richard Gill

Institution: Imperial College, London

Dates: 2023-2028

Jointly funded by BDI Ltd, CB Dennis Trust and the BBKA

The research addresses a critical gap in pollinator science: how climate change and pesticide exposure combine to influence bee metabolism, behaviour, and colony survival.

The project will use 3D printed assay chambers, thermal imaging, respiration measurements, and semi field observation hives to study how pesticide exposure affects metabolic rate, body temperature, walking behaviour, flight performance, and brood thermoregulation across a range of temperatures.

A novel aspect of the project is testing whether near infrared LED light can counteract pesticide induced metabolic disruption—offering a potential future mitigation tool for beekeepers. By linking individual level effects to colony level outcomes, the research will help identify when bees are most vulnerable, such as during cold snaps, heatwaves, or periods of high pesticide use.

The findings will support better risk forecasting, inform pesticide policy, and help beekeepers protect colonies under increasingly variable climate conditions.

Project lead: Prof Giles Budge

Institutions: University of Newcastle and the National Bee Unit (NBU)

Dates: 2025

Key findings:

• A Whole Apiary Shook Swarm (WASS) is 3.8 times more effective that not carrying out a WASS. 

• The larger the apiary size the greater the chance of reinfection.

European foulbrood (EFB) remains one of the most persistent bacterial diseases affecting honey bee colonies in England and Wales. This study analysed whether treating 'contact colonies' —healthy colonies within an affected apiary—reduces the likelihood of EFB returning after initial treatment.

Using inspection data from BeeBase between 2021 and 2023, researchers combined BDI’s original dataset with additional information on colony treatments, apiary size, local disease pressure, and the genetic clonal complex of Melissococcus plutonius, the bacterium that causes EFB. 

The results showed that treating contact colonies significantly reduced the probability of EFB returning, lowering the odds of reoccurrence by 3.8 times compared with leaving them untreated. Larger apiaries were more likely to experience reoccurrence. 

These findings will help refine national disease‑management strategies and support beekeepers in reducing the risk of EFB returning after treatment.

Photo: Courtesy The Animal and Plant Health Agency (APHA), Crown Copyright

Lead Researcher: Maggie Gill

Organisation: PHIRA Science

Dates: 2022 – 2025

Tropilaelaps research: strengthening the UK’s preparedness for an emerging global threat

Tropilaelaps mites are rapidly becoming one of the most significant emerging threats to honey bee health worldwide. Originally parasites of Asian honey bee species, Tropilaelaps mercedesae has now jumped to the western honey bee (Apis mellifera) and is spreading westwards at an alarming rate. Recent detections in Russia and Georgia highlight how close this parasite is to Europe, with modelling suggesting it could reach the UK within a decade. BDI has supported a series of research projects—led by PHIRA Science —to improve early detection, understand survival mechanisms, and develop effective control strategies.

These projects have revealed that Tropilaelaps mites survive far longer without brood than previously believed, tolerate extreme temperature fluctuations, and may resist commonly used synthetic miticides. Fieldwork in Thailand and Georgia has provided vital insights into mite reproduction, dispersal, overwintering behaviour, and the limitations of current surveillance methods. Researchers are now testing organic acid treatments, validating new detection techniques, and investigating how mites may spread via traded bees and equipment.

This work directly supports UK preparedness by improving diagnostic skills, generating new training materials for inspectors and beekeepers, and informing Defra’s ongoing Tropilaelaps pest risk assessment. Early detection and rapid eradication will be essential should this parasite reach the UK.

Researchers: Dr Thomas O’Shea‑Wheller and Ben Jones

Institutions: University of Exeter and Fera Science Ltd

Dates:  2024

This collaborative project examined how beekeeper adherence to Varroa destructor treatment recommendations influenced colony health across the UK. Drawing on one of the most comprehensive long‑term datasets available—annual records from around 1,500 beekeepers dating back to 2008—the research provided the first large‑scale, longitudinal analysis of how treatment behaviour shapes national honey bee health outcomes.

Building on previous modelling work by Dr Thomas O’Shea‑Wheller, the project combined Fera’s multi‑year monitoring data with advanced epidemiological modelling to quantify the level of treatment adherence required to maintain healthy colonies. The study also explored how climatic variables, such as temperature, affected treatment success—an increasingly important consideration as weather patterns shift and miticide resistance becomes more widespread.

The findings were designed to inform national policy and support evidence‑based guidance for beekeepers, particularly in relation to DEFRA’s recommendations for Varroa control. By identifying the practices most strongly associated with positive colony outcomes, the project aimed to help reduce losses, improve long‑term resilience, and support sustainable beekeeping across England and Wales.

This research directly addressed one of BDI’s core priorities: improving understanding of Varroa management to safeguard honey bee health at a national scale.

Click to read the final report.

PhD studentship: Ayman Asiri

Institution: Cardiff University

Dates:  2022-2024

This project investigated how honey bees used scent to detect disease within the colony, and how these chemical cues shaped social immunity behaviours. The research explored changes in volatile organic compounds (VOCs) produced by infected bees and examined how these odours influenced hive level responses such as hygienic behaviour and social distancing.

Honey bees rely heavily on chemical communication, and earlier studies had shown that infected individuals produced distinct chemical signatures. This project extended that work by focusing on volatile compounds capable of travelling further through the hive. As the proposal noted, VOCs were believed to act as early “smell signals” that alerted workers to diseased brood before visible symptoms appeared.

The team sampled 21 hives across Cardiff each month to link VOC profiles with infection status. They also conducted detailed behavioural studies using observation hives and tracking software to analyse how social networks changed when disease was present. Plans to expand to full colony monitoring included smart hive sensors, high resolution cameras, and advanced VOC sampling equipment.

The project provided new insights into how diseases spread through honey bee social networks and demonstrated the potential for sensor based early warning systems capable of detecting infections before they became established. This work contributed to the development of future diagnostic tools and strengthened understanding of honey bee disease resistance.

PhD studentship: Dr Hollie Pufal 

Institution: Newcastle University 

Dates: 2020 – 2023

Research included two projects examing individual EFB strains co-funded by Somerest BKA and Cambridge BKA. 

Hollie writes: Initially, I developed a whole genome sequencing pipeline that uses the buffer bottle samples from the European foulbrood (EFB) lateral flow devices that the NBU bee inspectors use in the field to confirm the disease. Each bottle contains a single infected larvae collected during an inspection. For chapter 2, the developed method was used to generate sequencing data from EFB positive samples collected in 2020. These data provided a higher resolution to the existing multi-locus sequencing typing (MLST) scheme, and I was able to identify genetic subgroups of M. plutonius within each sequence type. I also identified a strain of M.plutonius that was likely to have been imported. In my third chapter I investigated what other information could be gained from the sequencing data produced from the real-life infected samples, including other bacteria present and interesting genes. These genes included virulence genes, that help the bacteria cause disease, and antimicrobial resistance genes, that enable bacteria to become resistant to antibiotic treatments.  My final chapter stepped away from the lab and involved carrying out surveys. I sent surveys out to beekeepers in Cambridge and Somerset to investigate more about EFB and find out their views on EFB and some husbandry practices, swarm collection and biosecurity. I ran some structural equation models to highlight which beliefs or practices might be linked to an increase in disease risk. 

Lead researcher: Prof Stephen Martin

Institution: Salford University

Dates: 2021

Jointly funded by BDI Ltd and the BBKA

The researchers discovered why some honey bee colonies have become naturally tolerant to Varroa and to see if this information can provide beekeepers with a long-term solution to the problem. 

Early treatments for Varroa focussed on invasive chemical compounds and, whilst these still have a place, the emphasis is changing to biological methods of control, wherever possible. This latest research looked at ways in which bees and the mites can co-exist.

The Royal Society journal Proceedings B: Parallel evolution of Varroa resistance in honey bees: a common mechanism across continents? Isobel Grindrod & Stephen J. Martin

Journal of Apicultural Research 2021: Spatial distribution of recapping behaviour  indicates clustering around Varroa infested cells.  Isobel Grindrod & Stephen J. Martin

Varroa resistant Apis mellifera honey bees from the UK 2021. George Peter HAWKINS , Stephen John Martin 

BBKA Special Issue - Natural Varroa-Resistant Honey Bees

PhD studentship: Dr Monika Yordanova

Institutions: Imperial College, London &  Nottingham Universities

Dates: 2020 – 2023

This research project, supervised by Dr Peter Graystock and PhD student, investigated how pesticides and naturally occurring hive microbes affected the virulence of Melissococcus plutonius, the bacterium responsible for European foulbrood (EFB). Although M. plutonius can be present in colonies without causing visible disease, the triggers that shift it from harmless to harmful remained poorly understood. This project aimed to move beyond correlation and experimentally test whether co‑stressors—such as pesticides or beneficial microbes—altered disease severity in honey bee larvae.

Earlier work had identified candidate microbes that might suppress EFB, including Lactobacillus plantarum and L. kunkeei, as well as pesticides commonly found in bee bread. Samples collected with the National Bee Unit provided additional insight into UK‑specific patterns. 

An experiment involved exposing hundreds of larvae to combinations of M. plutonius, pesticides, and beneficial microbes to determine cause‑and‑effect relationships. By confirming whether these co‑stressors increased or reduced disease severity, the project aimed to provide valuable insights for beekeepers and researchers seeking to understand why EFB emerges in some colonies but not others.

This work contributed to a deeper understanding of brood‑disease dynamics and supported the development of more effective EFB‑management strategies.

PhD studentship: Dr Ben Rowland

Institution: Newcastle University

Dates: 2019-2021

Chronic bee paralysis virus (CBPV) has risen sharply in the UK over the past decade, yet the reasons behind this increase have remained unclear. Through a combination of laboratory experiments and computer‑based modelling, Ben’s research investigated how the virus spreads within colonies and which factors influence the severity of outbreaks.

In controlled lab studies, Ben examined key epidemiological traits of CBPV, including how the virus moves from bee to bee and how different levels of exposure affect disease progression. These experiments provided valuable insight into the mechanisms underpinning viral transmission and helped build a clearer picture of how CBPV establishes itself within a hive.

Alongside the laboratory work, Ben developed advanced computer models to simulate honey bee behaviour and CBPV epidemiology at the colony scale. These models allowed him to test multiple infection scenarios, explore how outbreaks might unfold under different conditions, and identify the points at which disease control is most effective.

Finally, the modelling framework was used to evaluate potential management strategies, with the aim of identifying practical steps beekeepers could take to reduce the likelihood or impact of CBPV outbreaks. This research has contributed to a deeper understanding of an increasingly important honey bee disease and supports the development of evidence‑based guidance for beekeepers. 

Researcher: Nicola Burns

Institutions: York University and National Bee Unit (Fera Science Ltd)

Dates: 2017-2020

Honey bees (Apis mellifera) are important because of their significant contribution to worldwide crop pollination. Colonies are under threat from multiple major pathogens including fungi, viruses, parasites, and bacteria. European foulbrood (EFB) is a bacterial pathogen of the honey bee, and is detected in hives globally. The causative agent Melissococcus plutonius is a gram-positive bacterium that infects the gut of the larva, resulting in death when the bee larvae is between 4-5 days old. Previously, isolates have been differentiated into strain types (STs) and clonal complexes (CC) which vary in virulence level (the severity of disease caused), but the genetic basis of this is still unknown.

Whole genome sequencing of more than 50 M. plutonius isolates, taken from UK EFB outbreaks, speculatively identified genes or genetic features related to increased virulence such as biofilm formation, toxin production, antibiotic resistance, and mobile genetic elements. Subsequently, laboratory-reared honey bee larvae were artificially infected with different M. plutonius strains, to gain further understanding of how the identified hypothetical genetic features may impact disease progression and severity in real EFB infections. M. plutonius isolates were also tested for their susceptibility to the antibiotic oxytetracycline, the only approved antibiotic treatment of EFB in the UK. If the presence or expression of specific bacterial genes can reliably predict disease severity or antibiotic resistance in the lab, then this may improve screening and management of EFB outbreaks in the UK in the future.

Researchers: Dr Declan Schroder, The Marine Biological Association (The MBA) based in Plymouth, and Prof Stephen Martin, The School of Environmental and Life Sciences, Salford University

Dates:  2015-2019

After the Varroa mite was first detected in the UK in 1992, many beekeepers used a range of chemical and biological methods to keep mite populations under control and minimise their impact on colonies. As a result, naturally resistant populations of bees did not have the opportunity to evolve, and widespread collapse of feral colonies followed. However, a small number of populations of European honey bees appeared around the world that were able to persist without any form of varroa treatment.

Initial research into a UK population of Varroa‑tolerant bees suggested that a new equilibrium between the honey bees, deformed wing virus (DWV) and Varroa destructor had been established, which may help to explain the long‑term survival of this mite‑resistant colony. 

This major project co-funded with beekeeper associations examined what happened when colonies of resistant bees were moved into other areas. Understanding this was important not only for identifying the traits that enabled these populations to survive untreated for Varroa, but also for determining how such traits might be incorporated into wider bee populations in the future.

Click to read the final report.

Photo: Signs of Parasitic Mite Syndrome due to severe Varroa infestation, with dead pupa and perforated cappings.  Courtesy The Animal and Plant Health Agency (APHA), Crown Copyright