Mason Bee cleaning for spring

Asked January 8, 2018, 2:27 PM EST

I understand that someone local makes a "sand blasting jar for cleaning the mites off of mason bees. Do you have contact information for that person? I would love to get a jar and possibly have a class with him. Rosalie Movius

Washington County Oregon

4 Responses

Dear Rosalie,
Hi and thanks for contacting Ask an Expert. We do not use sandblasting jars for the cocoon cleaning. It disturbs the bees and studies have shown that when they do hatch, they leave the area.
We remove them from the tubes or inserts, clean them for just two minutes in a cool water solution with 2 teaspoons of bleach. JUST 2 minutes. Swish them around, clean all the mud and debris off the cocoons. This kills the mites and anything on the outside of the cocoon. Drain thoroughly and rinse with cool not cold water for about 1 minute.
Lay them out to dry thoroughly on a paper towel. When dry, put them in a container lined with dry paper towels and with some wet paper towels in a small bowl in the middle of the container. The towels should be wet not dripping though. Lay the container top over the container leaving about 1/2 inch opening. Check the wet towels often as they can dry out quickly.
I have used this method very successfully for years. You can start putting the cocoons out when the weather warms and the fruit trees/flowers start to blossom around the first week in March. Bringing them in June 1st is recommended as that is when the parasatoid wasps start to hatch.
Putting them in a sandblaster also spreads the mites everywhere, some survive. If you have any further questions, please contact us. I hope this information helps you with the mites.

Sheryl - I imagine the concentration of bleach in the water solution is important. You mentioned 2 teaspoons of bleach but in how much water?

I do about 1/2 gallon of water to 2 teaspoons of bleach. However, I had over 1,000 cocoons. You can use 1 teaspoon in a quart if you have significantly less. Any cocoons that are smashed or dented are not likely to have viable bees, however, I keep them all just in case I am wrong. You can put the cocoons in the same bleach water if you need to do more than one batch due to amount of cocoons and gently swish them around. Just rinse gently but well to remove the bleach. I have a special collander with a handle that I keep for the cocoons to be rinsed in. Please feel free to contact me with other questions Rosalie.


Here's a new voice with a bit of additional information for you.

Sand cleaning is a viable alternative to using dilute bleach water to remove the damaging Krombein's hairy-footed mites (Chaetodactylus krombeinii) from mason bee cocoons. Mites can remain on the cocoons from either the wet or the dry method, depending upon the personality, precision, and dedication of the individual bee keeper.

Some years ago, Ron S., a Washington County Master Gardener, viewed a youtube video which used sand to clear damaging mites from mason bee cocoons. Since then, he has greatly refined the tools to enable a very effective cleaning method. Instead of blasting the mites off, gentle abrasive action by the sand simply dislodges the mites from the cocoons. Because Ron is so meticulous, he continues cleaning the cocoons until he verifies that all mites are gone.

Ron makes several presentation each fall. I suggest you contact the Washington County Master Gardener office during October to ask when and where the sessions are scheduled. Phone 503-821-1150, extension 2. Office hours are weekdays 9 to 11:45 am and 1 to 4 pm; closed holidays.

Enjoy your bees!