Screened bottom boards provide Varroa management option 10 Dec 2014

Beekeepers are being urged to consider the use of screened bottom boards, after a study revealed they had no impact on the productivity of the hive compared to conventional bottom boards.

The research has been conducted by the Honey Bee and Pollination R&D Program as part of efforts to prepare the industry for the Varroa mite, which is expected to devastate honey production and pollination efforts if it arrives in Australia, as it has in other countries around the world.

Screened bottom boards are considered an effective weapon in the management of Varroa and the project, run by Dr Doug Somerville from the NSW Department of Primary Industries, compared the two options in a variety of seasonal conditions and locations.

Spokesman for the R&D Program, James Kershaw, said many beekeepers have been concerned that screened bottom boards expose honey bee colonies to drafts and greater variation in hive temperature.

“The results of this research demonstrated no difference in the productivity of honey bee colonies. In fact, the screened bottom boards provide many advantages for beekeepers, not just in the management of Varroa,” Mr Kershaw said.

The bottom boards are a 3mm holed wire mesh. Where Varroa is present, they are often used in conjunction with sticky mats, stopping the blood sucking parasites getting back into the hive if they are dislodged and fall through the screen onto the ground.

“One of the main benefits right now for Australian beekeepers is the lack of build-up of debris on the floor of the hive with a screened bottom board. Excessive debris is an ideal haven for wax moth larvae and small hive beetles, which are major pests of bee hives.
“The ventilated bottom boards have shown no decrease in productivity from winter cooling, and they provide ventilation which can reduce humidity and mould within the hive.

"They also enable apiarists to lock the colony into the hive by using an entrance shutter. In an emergency, this allows for hive repositioning during the day, limits honey bee exposure to harmful chemicals and reduces the risk of the colony overheating in the hot Australian climate.

“To ensure Australia is prepared for a Varroa incursion it is important that beekeepers adapt to best practice and the research shows screened bottom boards can provide substantial gains in preparation for the mite’s arrival.

“The use of screened bottom boards alone will not control Varroa mites, but they can be a significant benefit in their management," Mr Kershaw said.

For more information about the Honey Bee and Pollination R&D Program, go to

The Honey Bee and Pollination RD&E Program is a jointly funded partnership with the Rural Industries Research and Development Corporation (RIRDC), Horticulture Innovation Australia Limited (HIA) and the Australian Government Department of Agriculture. RIRDC funds are provided by honey industry levies matched by funds provided by the Australian Government. Funding from HIA comes from the almond, apple & pear, avocado, canning fruit, cherry, dried prune, melon and onion levies and voluntary contributions from the dried prune and melon industries, with matched funds from the Australian Government.