Can bottom boards help fight the mite? 07 Sep 2011

New research is being launched into a simple technology to help beekeepers manage the devastating bee pest Varroa mite, if and when it arrives on Australian shores.

A study aimed at measuring the impact of screened bottom boards on bee hive health and productivity is being undertaken over the next 12 months by the NSW Department of Primary Industries, led by honeybee specialist Dr Doug Somerville.

A simple wire screen rather than a solid base on the hive has the ability to separate mites from the colony when they drop off the bees as they’re unable to climb back up and re-attach themselves to another bee.

The research is being funded by the Pollination Program, a research partnership between the Rural Industries Research and Development Corporation (RIRDC), Horticulture Australia Limited (HAL) and the Australian Government.

Dr Somerville said the concept has been around for a long time in other countries where Varroa mites are already endemic.

“There are many designs available and they cost a little more than traditional closed hives, but they may possibly better prepare beekeepers to live with Varroa mite if and when they arrive on our shores.

“Alone a screened bottom board may offer 5-30 per cent control which can then be combined with an organic or synthetic chemical treatment program to acheive the greater than 90 per cent control needed to maintain hive productivity.

“This very simple technology is at work 24 hours a day, 365 days a year as a part of an integrated pest management program,” said Dr Somerville.

Australia is one of the last countries free of the mite which has wreaked havoc across the globe, and many scientists believe it will reach our shores sooner rather than later. It is likely to decimate wild European honeybee colonies and severely impact managed hives – not to mention the estimated 65 per cent of agricultural production in Australia that is reliant on honey bees for pollination.

“One of the reasons adoption of screened bottom boards has been slow in other countries is the perception by beekeepers that a screened bottom may leave the brood exposed to the elements. We are therefore conducting the study in some very cold regions in Southern NSW to test this concern.

“We are lucky to be free of mites at this stage in Australia, but if they do arrive the screened bottom has the added advantage of allowing beekeepers to monitor the population of mites in a hive as a part of an integrated pest management approach.

“Using a screen or a sliding board under the screen bottom board, beekeepers can count the number of mites that fall through and use this information to measure the threat to the colony from Varroa mites and judge the best time to treat the colony with miticides,” said Dr Somerville.