Modified Bee Hive Bottom Board

Hi all

I thought I’d put something on the web about the modified bottom boards I use to control small hive beetle (SHB) in European honey bee hives. This makes the whole bottom board a beetle trap and I have found it so effective, I don’t use any traps inside the hive anymore. The design means I don’t need to open the hive to check or clean the trap.

This bottom board was first designed by Tibor Suto who was my bee mentor. Tibor was an engineer and made the bottom boards himself and he showed me how to. Now I buy them from the bee suppliers, as they can make them for the same price as it costs me for materials and I save my time.

Soon after I had made a few, I approached my local bee equipment supplier, who is also a timber yard, to see if they wanted to make and sell them. They now do. I advised on changes over about a year and they adopted my suggestions. They sell them for $62 or so including GST. They are Zenith Timber and Bee Supplies, 41-53 Greenbank Rd, North Maclean, Qld 4280, ph 07 5546 9777, 8am-4pm M-F.

The usual bottom board has two ‘legs’, solid pieces of wood the width of the hive, I think they’re called cleats. One is at the front and one is at the back, then there is a solid board. On top of that are three risers about one centimetre high. The end without a riser becomes the entry for the bees, once you put the brood box(es) on.

The modified bottom board uses a propolis mat, which bees can’t fit through, but beetles can, as the bottom of the hive. The bees chase the beetles, which try to hide in nooks and crannies and so they fall through the mat. Under that is a chamber for a tray to slide in from the back of the hive. In the tray you put something to catch the beetles, in which they die. You can use oil with a bit of vinegar, hydrated lime (~$12 for 20kg which would last me about a year for 10 hives) also called builders lime (not garden lime), or diatomaceous earth. I use hydrated lime, which is milder than garden lime and when I clean it out, I use the lime in the garden. Diatomaceous earth is more expensive, maybe $50 for 20kg. You put vinegar in oil to attract the SHB. You can sometime find SHB in your compost heap. They are attracted to the smell of rotten fruit. Thus the use of vinegar in the oil.

Here are pictures. First the front view. Maybe you can see the foot of the bottom board ~2cm thick, then above it is the usual board ~1cm thick, then is the chamber rixer ~3cm thick which becomes the lading pad for the bees. Onto of that is the usual riser ~1cm thick to create the entry.

Next is the view from the back. I add a bit of plastic to stop rain getting onto the tray.

Lifting the plastic up shows the extended end of the tray to form a kind of door. Propolis mats, are usually used under the lid. The bees seal us the gaps with propolis to regulate the flow of air: less in winter, more in summer. I try to seal this back door for the tray as much as possible, otherwise if there is a draft, the bees will seal the propolis mat up.