Some folks don't advocate cleaning your cocoons at all but like weeding out your garden, it prevents an escalation of unwantable parasites and parasitoids associated with your pollinating bees that are found in your condos. Try this method instead, and remember you saw it here first. See the method that is growing a wide international audience. Norm Hutchings is the inventor of this method.
Beware of this:
"Hi Gord, We made an attempt at cleaning cocoons with sand as shown in your U-tube video. I used screened sand and 1/8" screen mesh. The result of cleaning can be seen in the attached photos. They don't appear to be clean enough! Should we use a finer sand? Comments?
I responded: "That is frass (excrement) stuck to the cocoons, not mites. That's normal and presents no harm.
On Overwinter Your Cocoons
What's the best way to winter over mason bee cocoons?
We currently have them in a paper bag tucked up against the outside of the house.
I looked on you website and didn't find notes on wintering.
We are trying to avoid the auto defrost fridge for wintering the cocoons.
Absolutely do NOT put them in the fridge until fairly close to the time that they historically emerge naturally in your area or unless you want to stall their emergence for some particular crop as it comes into early bloom. For instance, in my area the earliest recorded that we've noticed Osmia lignaria propinqua emerging was February 23, but of course, it highly depends on the weather for that particular year. One of my main clients who's crops come out in say late March/early April, then I'll put the cocoons in the fridge late February and release when the flowers commence blooming.
Fridges in your home are dessicating environmenets for the overwintering/diapausing bees and this can kill them in the final stages of their metamorphic stage before emergence. These are a native species and can handle their natural environment.
When I was cleaning out one of my bee barns, I came across this dead bumble bee stuck within the cells of a mason bee. Since this was spring when it happened and you can see clearly that it is stuck behind the first provisioned cell, this particular bumble bee decided to "sleep" within this channel. Because of the time of year, it most likely must have been a male who decided to depart the nest but I haven't checked the antennal segments yet but I will eventually as I kept the dead specimen. It is Bombus melanopygus.
Cleaning Cocoons Using Sand and Tube Method:
This method can also be seen on Youtube at http://www.youtube.com/watch?v=4tZu4o7nwj4
“How To Clean Orchard Mason Bees Using Sand” at http://www.youtube.com/watch?v=PrZkT9cC99k
And for Part 2, http://www.youtube.com/watch?v=KSr88h8iKQk&feature=related
So here's a selection of Open Tray System, and a condo that has routered holes that are split trays to open up.
Oh, and of course, you know to do this in outside temperatures. I'm doing this outside in my work shop. You'll see the pictures of snow in the background coming up. Yes, we had snow in Victoria (Nov. 2010).
Hole type split apart showing the contents within. The yellow fuzzy bits are left-over pollen and frass from the provisions left by the mother bee, that the mites have taken over and outcompeted the young bee larva that was there.
I'm going to use a clear tube here so you can see what goes on inside. One end has an accommodating union to bring the two halves together.
Pour in the clean sand. I start with the non-union end.
Pour in the appropriate amount of cocoons, faeces, extra mud, pollen etc., doesn't matter. You can pick out the big hunks later if you want.
Put the two halves together and rotate the tube end for end, allowing the sand to pass between and around all the cocoons etc. Shake, twist whatever it takes to scour the cocoons. I do this several times. If you have too many cocoons, the sand will hang up longer, caught in the middle. Adjust the amount of cocoons if need be.
Here's the sand passing through the middle screen section containing the cocoons.
Pour all contents out sieving one more time in a clean sieve, and put cocoons in an emergence box to put away for Spring. You can pick out the big hunks of mud if you want.
Photos from a recent class showing both the use of jars and shaking tubes.
First, cocoons are extracted from the condos, using appropriate toolage for this task. A whole range of condo styles come out at classes but of course, drilled hole blocks can't be cleaned, and we notice that plastic trays are prone to mould. The paper tubes have to be split to access, making for a replacement for next year. Here can be seen stacked trays, peek-a-boo trays and open tray styles filled with bee cocoons. Of course, some mites are living with the bees and these are what we're ridding the bees of.
This entire cleaning process has to be done in outside temperatures, which means you can do in the garage or cold basement. Here, we're lucky enough on this mid-November day to do it outside between snow and rain periods. Just make sure NOT to do in a warm environment. The bees can sense this warmth and may emerge thinking it's Spring and time to "wake up".
This is one of the double-ended tubes opened with the clean sand and extracted cocoons poured inside one half of the tube.
The two halves of the tube are put together and flipped end over end, passing the sand back and forth past the cocoons, scouring them in the process, held between the screens in the middle.
The cocoons are then poured out into a fine sieve and put into a dry, emergence box and placed next to your clean condos, ready for emergence next Spring.
Similar process is done using the jar.
Roll and shake your sand and cocoon mixture for a few minutes but not too vigourously, to knock the mites off the cocoons exterior.
Believe it or not, some non-entomologist thought that shaking your cocoons would make the bees not stay in the near vicinity of your emergence box since they incurred "shaken-bee syndrome". This is more to do with lack of poor returning habitat or where one puts up their condo, and lack of correct olfactory cues that the bees sense to entice them to return. This is what antennae are used for.
Cocoons being poured out one last time. Used sand can be saved, cleaned and dried in oven or stove to be used again and again. The high heat also kills any mites left in the mix.
Note the plastic trays here. These were the trays that had lots of mould covered cocoons and dead larvae inside. Plastic trays with paper tubes don't breath and the straws act as "sponges" to hold the moisture and the darkness and sugar combo makes for the possibility of mould more so than wood.