My name is Dr Margriet Dogterom and am the founder and owner of Beediverse. I write this blog for all who love bees and who want to learn more about these wonderful creatures.
I read in a blog the other day that washing cocoons is not necessary.
There are two good reasons for washing mason bee cocoons.
The first reason is to remove the majority if not most of the adhering mites. The washing process includes a soak in cold water to remove mud and feces. Then, cocoons are gently sprayed with cold water (while in a colander) to remove any excess mites. If excessive mites are present (even after washing) mites are removed by rolling the dry cocoons gently over a metal window screen (not plastic- it is not abrasive enough to remove mites).
The second is to remove debris and mud and feces from the cocoons so that cocoons can be candled for parasitic wasps. Candling Mason bees was first introduced and developed by Joe Sadowski from Burnaby British Columbia Canada. In a dark room, and over a bright light, parasitized cocoons can be identified, removed and destroyed. By removing these wasp parasitized cocoons, there is less of a chance for the wasp population to increase and potentially wipe out your bee population.
It is pretty neat to see what bees and other insects have been up to during the previous spring by candling cocoons and having a ‘closer look.
I recommend caring for your mason bees by harvesting and cleaning your mason bee cocoons in the fall.
|A little parasitic wasp with its ovipositor ready to insert into a
mason bee cocoon. The oblong object is a bit of bee feces
that is always on the outside of the cocoon. (photo by Hartley).
It is right in the middle of the mason bee season now. Stores have stocked up with product and individual customers buy from us direct. When it is so busy, I do collect stories with pictures on a daily basis for this blog. I have some catching up to do! Here is one of these stories from Larry.
We are cleaning our bee condo, and it appears as if we had a few of the
cocoons that had opened and there is larvae in them. Are they dead? Also, they seem to be larger that the the cocoons that are still intact (and which we have cleaned to remove mites, etc.)
My first response was to ask for a photo.
“Yes- please send a picture. It sounds like you have some beneficial wasps.”
Then I received this picture, it confirmed that this is a beneficial wasps. What is neat about these insects is that different species collect different live food items for their young. They either collect and feed their young with spiders, moth grubs or aphids. If one of the wasp eggs did not develop, there might be evidence of the kind of wasp is growing in the nesting tunnel.
This grub or pupae still has a lot of developing to go through before it is an adult. Further development starts when spring temperatures are on the rise.
These grubs are very fragile. I usually leave them in their nesting tunnel, remove mason bee cocoons in the remaining nesting tunnels, close the nest up and set it outside again.
|Beneficial wasp pupae. The brown part is the head capsule.|