Six Inch Petri dishes and How to use them.

Six inch diameter petri dishes are very handy to have when keeping mason bees, especially when storing cocoons.  Winter storage of cocoons containing live bees can be problematic since you need humidity and air.  Petri dishes allow both air and humidity to pass under the lid and over the lip and into and out of the pretri dish.  Tiny strips keep the lid off the base and thus allowing air to pass.  All this means that living things can be stored in petri dishes.  Another good feature of a petri dish is that organisms can crawl around inside the petri dish, be safe and not escape.

About 100-200 mason bee cocoons can be stored in each petridish.  Petri dish are stackable and can occupy very little space. 

Here are a few ways to use  6" petridishes:

1.  Store cleaned cocoons inside a refrigerator that is a manual de-frost fridge)

2.  Each petri dish can be labelled according to location and other information.

3.  Store suspect cocoons-I call these DUDS!

When candling, cocoons that do not contain a bee can be set aside and left refrigerated until spring.  In spring, the petri dish is left on the counter.  If any bees emerge they can be released.

4.  Store unknown organisms until emergence
5.  Petri dishes are stackable and occupy very little space.

Stack of petri dishes with cocoons inside a manual defrost fridge.

A thermometer is an important tool to make sure the temperature
is right for keeping cocoons under hibernating conditions. 
In late Jan temperature is lowered to between 2-4C or 35-39F

Always keep a container of water inside the fridge. 
This is an easy way to make sure that humidity is above 60%.

Label each petri dish.

In a manual defrost fridge, there is a freezer compartment
that will require defrosting each year.

In spring, the occasional male will emerge even
though temperatures are low.

For spring emergence, cocoons can be placed into Starter
cottages or Emergence Cottages.  These can be temporarily
stored in the fridge, until weather conditions are reasonable.

Store cocoons inside Petri dishes that may contain parasitic wasps. 
Place on kitchen counter in spring.  If any bees emerge
 they can be released.  Parasitic wasps can be destroyed by freezing .