Golden Opportunity

There is an increasing buzz around the global decline of bees but University of Limerick is playing its part in taking the sting out of the problem.

The global collapse of bee populations is increasingly hitting the headlines but, as yet, no one has come up with a wholesale solution to stall the decline.

But, to cut to the buzz, while many land and marine species are also facing a similar fate, the loss of bees would have the most severe consequences for the human population’s food chain, posing an enormous threat to our very survival.

It is estimated that almost three-quarters of our wild plants rely on insect pollinators, of which bees are the most important, as well as being vital pollinators of food crops.

One estimate puts the value of bees to the Irish economy at €53 million per annum.

A 2015 report from a United Nations group found that populations for 37% of bee species globally are in decline, with 9% facing extinction.

The Irish situation

There are currently 97 species of bee in Ireland: one honey bee, which is mainly a managed species, 20 species of bumblebee and 76 of solitary bees. More than half of Ireland’s bee species have undergone substantial declines in their numbers since 1980, with 42 suffering decreases by more than 50%.

The Irish Bee Red List, published in 2006, notes 30% of Irish species are threatened with extinction: six are critically endangered, 10 are endangered and 14 species are considered vulnerable. Of the 20 bumblebee species, four are endangered and two are vulnerable. Two species have become extinct in Ireland within the last 80 years.

For example, the Great Yellow Bumblebee has suffered a serious decline in Ireland since the 1970s. It is now confined to small areas of high floral diversity, called machair, in the west of Ireland.

Locally, as an act of solidarity with the bees, the UL Environmental Society has initiated an Apiary Project, co-ordinated by Dr Adam de Eyto, which trains volunteers in beekeeping. It now has three thriving hives on campus. Furthermore, the meadow adjacent to the apiary is being managed as a “wild flower meadow” and the cuttings are timed to maximise floral biodiversity. 

What the findings showed is that of 29 countries surveyed globally, Ireland had the highest honeybee mortality rate, at 29.5%, over the winter of 2015-2016.


Pests and disease are the main threat to honeybees, particularly the parasitic mite varroa, which has been present in Ireland since the 1990s. It is implicated in transmitting a range of viruses, which have major health implications for colonies.

The National Apiculture Programme has been based at the University of Limerick for nine years, where the main researchers are Dr Mary Coff ey and Professor John Breen. Run by the Department of Agriculture, Food and Marine, with funding from the European Union, the latest programme, which runs until 2019, involves collaboration with Teagasc Oakpark in Carlow, NUI Maynooth, NUI Galway, the Federation of Irish Beekeepers Associations and the Native Irish Honey Bee Society.

Tackling the varroa problem is one of the programme’s primary aims, explains Professor John Breen. “Our research is mainly on colony health. As part of that, we run an annual COLOSS survey on mortality rates and about 450 beekeepers were surveyed last year in Ireland. What the findings showed is that of 29 countries surveyed globally, Ireland had the highest honeybee mortality rate, at 29.5%, over the winter of 2015-2016.

“We are testing various possible ways of controlling the mite, which will hopefully control the viruses,” he adds. “We are providing technical assistance to beekeepers, maintaining the research colonies and testing different ways of controlling mainly varroa.”

We need more toleration of untidy patches in gardens and on roadsides. Brambles, while maybe unsightly, are good for bees.

The programme is also trying to combat American foulbrood (AFB), one of the most threatening epidemic diseases in honeybee colonies. In the present study, a protocol to identify AFB in a colony, using bacteriological analysis of honey, is to be developed. “This task will also allow us to establish if it is practical to use this method as a diagnostic tool for AFB, rather than the traditional testing of brood comb.”

The pesticide curse

To meet global population growth and resultant food demand, the pressure on pesticides (insecticides, herbicides, fungicides) to deliver higher standards for crop protection has increased. These pesticides are applied to crops but reach bees through pollen, nectar, the air, water or soil. Although herbicides and fungicides may not have direct toxic effects on pollinators, herbicides reduce the amount of food available, and fungicides may interact with other pesticides and have negative impacts on bees.

In recent years, the use of neonicotinoid insecticides has been limited by EU regulation. ‘Neonics’ have been shown to reduce colony growth and queen production in bumblebees and possibly navigation in honeybees.

Habitat destruction

The availability of food plants and nesting sites has been drastically reduced through intensive farmland, forestry and industrial use. Those areas of habitat that do remain have declined in quality.

Research undertaken by Dr Veronica Santorum in UL’s Department of Biological Sciences shows there are very few bumblebees seen on County Limerick farms, compared to sites in the Burren in County Clare, which has more flower diversity.

One issue causing this is the intensification of farming, which has resulted in fewer flowers within the sward and in hedges.

The loss of natural and semi-natural habitats is another problem as, for example, removing hedges removes the sunny sites where solitary bees nest.

Our tendency to tidy up the landscape rather than allowing wildflowers to grow along roadsides, field margins and in parks and gardens is also playing a role in fewer of these resources being available, adds Professor Breen.

“We need more toleration of untidy patches in gardens and on roadsides. Brambles, while maybe unsightly, are good for bees. If you are into gardening, be mindful that single flowers are better for bees than double flowers,” he says.

Wildflower warning

There is a caveat on eff orts to introduce more wildflowers to the countryside however. A recent campaign by Cheerios to give away flower seeds was both wildly popular and controversial. The cereal maker’s move to distribute 1.5 billion seeds to the public to boost the ranks of North America’s bees drew praise from some quarters for trying to highlight the plight of the bees. However, others are fearful it could do more harm than good by introducing invasive species to ecologically-sensitive environments.

Professor Breen is an advocate of being mindful of the sensitive nature of ecology. “If you want to sow wildflowers, there are sources of Irish wildflower available here and they should be used. Be careful of the types of wildflower.

“If you want an example of a double-edged sword, the invasive species Himalayan Balsam is rampant on the banks of the River Shannon locally. Beekeepers consider that it is a valuable late source of nectar in September/October. So, while the honeybees love it and it looks pretty, it is absolutely an invasive species when it is out of control,” he concludes. 

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