Its that time of year when mite counts skyrocket. If you haven’t been doing mite counts over the course of the summer you may be a bit behind the curve, but there’s still time if you act now.
To win your battle against mites you must know how many mites are in your colonies. An easy way to do this is with a powdered sugar roll. Take a pint jar and replace the lid with hardware cloth. (Keep the ring to hold the mesh in place) The openings in the metal screen need to be small enough to keep the bees in the jar but large enough that you can drop in the powdered sugar.
Now, off to the beeyard. You will need to take with you a small shallow tub (white color works best), powdered sugar, some water and a tablespoon. Open the first hive and look for a frame of larva/brood. You are looking to sample the nurse bees that are caring for the larva and brood. Making sure the queen is not on the side of the frame you are sampling, then slide the jar (with the lid off) down the board, causing the bees to fall backward into the jar. You want half a cup of bees (approximately 300 bees) so mark your jar with a line measuring half a cup prior to going to the beeyard. (You can also shake bees from the frame into the plastic tub you brought with you and then pour them into the jar.)
Once you have half a cup of bees quickly put the mesh screen lid back on the jar. Then add two tablespoons of powdered sugar through the mesh. Roll and gently shake the bees for a few minutes until they are coated in powdered sugar and set the jar aside for one minute or so. While they sit, ready your tub. Pour in enough water to just cover the bottom of the tub – just enough to melt the powdered sugar when you pour it in.
When a minute is up, vigorously (but not hard) shake the jar over the water in the tub. The powdered sugar will melt and the dark colored mites will be easy to spot against the white background of the tub. Count the mites and return the bees to the colony unharmed.
Divide the number of mites by 300 (the number of bees in the jar) and you will have a percentage of adult bees that have mites. Anything under 5 percent is considered safe. If there are more than that you may want to consider treating your hive as the skyrocketing mite population needs to be knocked down fast. (Remember also that this only represents about 20 percent of the total mites. Approximately 80 percent of the mites are inside cells and not on the bees.)
If you have reached the conclusion that you must treat, probably the best option for this time of year is a product called Mite Away Quick Strips. This product contains formic acid. Its quick, effective and is said to leave no residue though it can harm queens and brood if applied when temperatures exceed 85 degrees. This product REQUIRES the use of gloves and a mask! So be careful to follow directions. But it is by far the most quick and effective product.
There are always trade offs when using chemicals in your hives and only you can decide if it is to be part of your hive management regimen. Proper management can reduce hive loses without using chemicals but part of managing your colonies is learning how to take mite counts and then doing the counts often enough to know what is taking place in your hives.