The caution comes as new data reveals the nation’s honey bee population has declined by almost 20% this year, a higher than average mortality rate.
“Over a number of years, colony losses in Ireland tend to be higher than the average in other countries,” said Mary Coffey from the national apiculture programme at UL.
“We in Ireland are definitely on the higher end of the annual losses. This underlines the need for making sure that stocks are strong enough for overwintering and that the varroa control is carried out in time — beekeepers are carrying out the control measures, but sometimes too late in the season.”
The varroa mite is one of the main parasites of honey bees — it is believed to be the single largest contributing factor in the decline of the honey bee due to its ability to transmit diseases such as deformed wing virus.
Recently, the Prevention of Honey Bee Colony Losses (COLOSS) carried out research on bees in 31 countries to determine the number of colony losses and beekeepers’ approach to disease control and management techniques.
About 10% of Irish beekeepers completed the questionnaire, providing information on 3628 colonies. Of these, exactly 700 colonies did not survive the last winter — representing a loss of 19.3%. This can be compared to a mortality of 13% the previous winter and a mortality of 37% for the winter of 2012/13.
It is believed that a number of factors contribute to these losses including disease, increased use of pesticides and possibly local factors such as climate and decreased floral diversity.
COLOSS experts said the decline in honey bees is traditionally higher in west and central European countries than the north of Europe.
“This can partly be explained by the later start of the breeding season of their honey bee colonies due to low temperatures in March/April, as was the case in 2014,” said Romée van der Zee, international data coordinator for COLOSS.
“This later start limits the number of brood cycles of the varroa mite.”