Our combination board should not be used by itself to combat Varroa mites. Currently we are recommending using powdered sugar brushed between combs. This treatment has demonstrated enormous mite falls (see insert) with our hives. We use a removable high-density plastic floorboard that can be applied in 4 different ways, used as a sticky board for observation and trapping by wiping vegetable oil (we keep canola in a old lemon squirt bottle), shortening or petroleum jelly or it can be used dry with powdered sugar.
The Combo Board can be used 4 different ways:
#1. Access at the rear of the hive allows you to observe and trap mites without disturbing your bees or risk being stung. In most cases, you do not need to smoke them or suit up just to observe or clean trap boards. The rear opening is large enough to remove mites, debris, and sugar without scrapping the substances and debris off onto the ground and allowing you to disposed of it easily into trash bags to avoid ants. Removable covers at both ends prevent bees from entering this cavity.
Notice the rain guard at the rear. Hives are traditionally tipped towards the front for drainage. Without protection rain would naturally be trapped and diverted into the hive via the sub-board.
And my favorite, the rear smoke hole with the closeable door. We found this addition easy and efficient to use, the smoke is funneled right into the hive. This is very effective with “Exotic Smoke,” such as dried grapefruit leaves or pipe tobacco.
#2. We recognize you might not always have rear access and have provided a front access to allow you to move your hives to pallets or on a fence line without changing your bottom board equipment. The front area also has a wide space to remove debris without scrapping it off the board.
#3. The floorboard can be moved to a slot above the screen board when you prefer a traditional hive with a closed bottom. This can be used to add warmth to weak hives, or where you cannot monitor the debris and would like the bees to do their own housekeeping. This function is not for trapping or observing Varroa mites, but it does lend itself to facilitate the use of fume type products such as Api-life Var and Oxalic Acid. You need a traditional type closed bottom board, as you are trying to keep the fumes in. Our Combo Board facilitates this with a board that can be slipped on top of the screen that makes it a natural floor. Wanting to use these fume products to control mites was preventing a lot of people from using screen boards because of the closed hive requirement.
#4. Remove the plastic floorboard entirely (store out of the sun) to allow for extra ventilation and no-hassle mite control. There have been lots of pros and cons on this method. Some beekeepers are reporting great success leaving their bottom boards off entirely with little or no mite problems, plus increased brood due to increased ventilation. Others are experiencing delayed brood hatching due to the additional chill. This allows the varroa mites to double their population during the additional time in the capped brood. Other research shows that mites can live over a week without a host and climb vertical and underneath horizontal ledges to get back to the bees, so they worry that without the floorboards in place, the mite can hit the ground and crawl back up to the bees
You decide your floorboard configuration to suite the health of your hive and varroa control methods.