Declining Bee Numbers Raise Concerns Over Plant Pollination
8 May 2007
A decline in bee diversity and abundance linked to habitat loss and disease in Europe together with a 50% drop in the number of managed honeybee colonies throughout North America are part of a global phenomenon known as the ‘pollination crisis’.
Over 80% of crops in Europe are pollinated by insects and the contribution of bumblebees to Irish agriculture is often underestimated. Bees are responsible for most crop pollination and are often actively introduced by farmers into crops to improve production. Each year, Irish growers import hundreds of commercial bumblebee colonies from mainland Europe to improve fruit quality and yield. However, without proper management, this could lead to the introduction of new diseases in native bumblebee populations. The nature of the bee pollination service in Ireland has changed quite dramatically over the last ten years.
Crops such as apples, pears and berries are entirely dependent on pollinators for fruit production, while in crops like oilseed rape, sunflowers, peppers and tomatoes, visits by pollinating insects like bees improve the quality and quantity of fruit and seeds produced. Recent intensification of agriculture in the United States has necessitated the direct and large-scale importation of honeybees to pollinate crops such as alfalfa and almonds.
Researchers at Teagasc Oak Park are working on the management of diseases in honeybees and the protection of native bumblebees through the proper management and containment of imported species. This research is featured in the latest issue of TResearch, Teagasc’s research and innovation magazine, and is particularly relevant considering the emergence of ‘Colony Collapse Disorder’, which is devastating US bee populations.
The Varroa mite (Varroa destructor) was accidentally introduced into Ireland and was first detected in Sligo in 1998. Early attempts at containment failed and it has now spread to most parts of the country. Teagasc has conducted research on Varroa since the mite was first found in Ireland. Varroa infestation has also been associated with an increased incidence of viral diseases in bees. Research at Teagasc is developing alternative Varroa management strategies that are suitable for Irish climatic conditions.
“By improving Varroa management and understanding the dynamics of bee
diseases, Teagasc research aims to contribute to increased honeybee densities in
the Irish countryside,” explains Dr Finbarr Horgan, Teagasc Oak Park
Crop Research Centre.
“The effective management of Varroa and associated diseases in
honeybees, as well as the protection of native bumblebees through the proper
management and containment of imported species, is expected to improve
pollination efficiency and contribute to sustained increases in crop