Re: 2012 Mason Bee Update
Originally Posted by Gyozu
looking at your pix of the wooden tray inner views...
Please remember that each nesting cavity will be filled with first several larger female larvae/cocoons in the innermost part of the tube, followed by about twice that many smaller male larvae. What you are seeing as 'smaller different' cocoons are simply the male bee cocoons. The males are positioned towards the outer/emerging end so that they emerge before the females and can wait around to mate as soon as the females emerge. The females sometimes emerge days or even as long as 2 weeks after the first males do, so be sure not to remove or discard the tubes until at least two weeks after the first males emerge- if you are too hasty, you might be discarding live female cocoons!
All your cocoons in the tubes and trays appear to be simply male and female mason bees, as they should be.
You do however seem to have a substantial pollen mite population that has destroyed a good number of bee larvae. The piles of bright yellow sandy pollen-like granules are all that remains where there used to be viable mason bee egg chambers.