What is ‘alcohol washing' & why is it important for varroa mites?
The alcohol washing method is a quick and effective method for detecting the presence of varroa mites. It is also used in monitoring colony mite levels. Wash method can remove 70 to 80% of external Varroa mites present on adult honey bees. All beekeepers are encouraged to use this method since it is quick, easy, and low-tech, ideally while performing hive inspections. However, sadly this method kills the bees that are sampled.
However, considerable amounts of brood will give measurable data, especially when the sample bees are obtained from the centre of the brood nest. The wash approach is more successful when few brood are present.Here’s how to make an alcohol washing kit:
- Ready two identical plastic jars such as large peanut butter jars with screw top lids.
- Safely cut and remove the inner section of the closed-end of the screw-top lids to acquire the desired effect.
- Cut out a 3mm gauze wire mesh and place it between the two open screw-top lids and heat weld them together. Next, connect both of the jars to the lids. Make sure that the lid connection is strong.
- Place about 100ml of alcohol in one of the jars or more so that the bees will be covered. Then place a large sheet of newspaper or plastic beside the hive to be tested.
- Light a bee smoker, open the hive and remove a frame that contains a lot of brood.
- Make sure to look out for the queen bee. If the queen is present place her back in the hive before doing the hive. Shake bees from a brood frame onto the newspaper/plastic sheet/plastic tub.
- Pour about 1/2 a cup of bees into the jar containing around 100ml of 25% rubbing alcohol and cover the lid immediately to prevent bees from escaping.
- Invert the shaker so that the bees are now in the top jar then shake the jar for 20 seconds making sure the bees are all covered in alcohol.
- After 20 seconds, jiggle the jar so that the alcohol drains through the bees into the bottom jar. If you don’t, some of the mites may get stuck on the bees in the top jar.
- Once settled, raise the bottom of the jar to view any mites that have been dislodged from the bees.
Check out this video on how to do the wash method:
If you see varroa, use the online form at www.dpi.nsw.gov.au/hives, send an email to email@example.com or call the Exotic Plant Pest Hotline 1800 084 881 immediately.
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Varroa Mite Series
Learn more about Varroa Mites in our special 4-part series.
Part 1: What is a Varroa Mite and what does it look like?