Bee Pathogen Programme
Bee Pathogen Programme about NZ's honeybees
A large science and industry collaborative study, called the Bee Pathogen Programme, was undertaken by Biosecurity New Zealand from 2016 to 2018 to better understand the effects of disease, climate and apiary management on the health and productivity of New Zealand’s honeybees. Research and testing of samples are continuing as a result of the programme, and a further project has been developed.
Bees (and in particular honeybees) play a critical part in New Zealand’s biodiverse landscape and are an essential cog in our primary production machine. Aside from producing honey, they provide essential services to our pastoral and dairy farmers, and to the horticulture, arable and forestry sectors.
Because of the importance of bees to New Zealand’s primary industries, a significant body of work is undertaken by a variety of organisations to prepare for the most effective responses to any biosecurity threats that (inevitably) arise in New Zealand which may threaten bees. One example of this work is the Bee Pathogen Programme, undertaken by Biosecurity New Zealand. It was the forerunner to the ApiWellbeing Project.
From the spring of 2016 to spring 2018, on five separate occasions (six months apart) the largest and most detailed study of honeybee health undertaken in New Zealand was carried out by the Diagnostic & Surveillance Services of Biosecurity New Zealand. Samples from selected beehives were collected from around the country. Forty apiaries in the North Island and 20 apiaries in the South Island took part in the programme.
Bees were collected by experienced beekeepers acting on MPI’s behalf. They were trained to inspect hives for disease or exotic pathogens (such as varroa bee mite), collect data from the apiary managers and take samples from each apiary. The samples were then sent to MPI labs for further analysis.
Testing large samples can be challenging but there are ways results can be gained consistently and reasonable quickly. One of these methods is polymerase chain reaction (PCR), It involves identifying DNA and/or RNA from fungi, viruses, bacteria and parasites by crushing a sample of bees and placing them in a solvent to release any DNA and RNA present. The test is highly sensitive and selective and can quickly identity not only specific pathogens that might be in a sample but the amount in each bee.
Nosema spores were counted by eye, with technical staff using a similar method to that of getting human blood cell counts in the past. The study confirmed that the fungal parasites Nosema ceranae and Nosema apis, as well as the better-known varroa mite, were found to occur commonly in NZ bee populations.
Other health issues for bees are; chronic bee paralysis virus (CBPV), black queen cell virus (BQCV), deformed wing virus (DWV), Kashmir bee virus (KBV), and American foulbrood (AFB). Another potential pathogen problem is small hive beetle (SHB). It has not yet been detected in New Zealand, but it is being tested for, along with tests for rarer diseases and other exotic pathogens. This is part of improving preparedness for any future incursions.
All of the above can cause devastating impacts on a colony, so one of the aims of the research was to discover how widespread these pathogens are. Following that, to understand why some colonies are more resistant or less impacted.
Some colonies are more resistant to pathogens and disease and (unsurprisingly) good management practice appears to play an important role in minimising the harm caused by (and spread of) disease. Stress, overcrowding, under-nutrition, hive and equipment hygiene all affect the impacts of disease.
Some factors are more easily controlled by apiary management than others. For example, it was found that Nosema cerane was present in nearly half of all apiaries in the study in the spring of 2016. It can cause colony loss over winter or in early spring. As this organism originated in Asia, it can be killed by freezing. Management techniques that can reduce the impact of the N. ceranae parasite are; ensuring well stocked hives (with pollen and honey) going into winter, as well as placing hives in sunny locations to encourage cleansing flights during winter. Sterilising equipment between hives is also important to prevent the spread of disease.
Transfer of infection of a number of pathogens can happen by mites but also by foraging bees visiting flowers that have been previously visited by infected individuals and then returning to the hive.
The study has also provided opportunity for collaboration with other agencies. Working in conjunction with Gisborne-based diagnostic company, dnature, work is ongoing to produce a test that can identify the different types of American Foul Brood that exist, which will in turn improve the detection and traceability of the disease. New trapping methods, further molecular testing and more detailed analysis of the samples that have been taken are currently being worked on.
The ApiWellbeing Project is a combination of outreach and extension work on American Foul Brood. It began when the Bee Pathogen Programme finished. Dr Richard Hall, Senior Scientist at Biosecurity New Zealand, explains they are translating the scientific data and knowledge gained from the previous three years work and putting it into an accessible format that beekeepers can quickly and readily digest.
It also involves working with the American Foul Brood pest management agency and collecting further samples from hives affected by AFB. A genetic analysis will then be done to better understand the dynamics of how AFB might be moving between hives in New Zealand, or what is present now, and what pathogens are the disease-causing types of AFB.
Showdown Productions Ltd – Rural Delivery Series 15 2020