Osmia californica by M. D Levin 1966

I had to go to my old stomping ground to get this article.  In 10 years Simon Fraser University did not seem to have changed much- although I did only go to the library.  It is a short ride from my home and so tonight I thought to chase up the 1966 article by Levin.  I wondered into the library, walked up to the 5th floor and found The Journal of Kansas Entomological Society.  Just like that!  I spent a lot of my time in amongst these rows and rows of journals.  So it was not surprising that I found the green volumes so quickly.  Unfortunately there was no volume number 39.  I went to information and a kind gentleman looked to see if the library had it hidden from my view.  No, but library did have it in digital format.  Perfect!  It was fairly simple to search for it on the computer and get it printed out.  Parking for 55mins was $3.25!  But enough about my adventure. 

Here is what Levin had to say about Osmia californica.  Levin compares Osmia lignaria with Osmia californica.  I will focus on the details of Osmia californica.

Osmia californica
-Restricts pollen collection from a few composites
-Does not always overwinter as an adult (lignaria overwinters as an adult)
-About half of 33 overwintering cocoons were prepupae and the remaining half were adult
-Uses a mixture of mud and small amount of leaf tissue (lignaria uses mud only)
-Leaves no vestibule at entrance to nest (lignaria leaves a vestibule)
-Seals last cell with a thicker partition and does not build an end plug
-Buries its egg within the pollen mass (lignaria lays the egg on top of the pollen mass).

I think the most interesting part of this information is that Osmia californica does not always complete their transformation into an adult bee by winter.  This means that some bees overwinter as prepupae and complete their development the following spring.