Finding anything written about Osmia californica is not easy. Although I found an article written on californica by M. D. Levin, his scientific article was published in the Journal of Kansas Entomological Society, 1966. Unless you are affiliated with a university, only the abstract is available. I will write a summary of the article when I get the full article. But I did find a great web site with good and very detailed photos of Osmia californica. Link to photos of Osmia californica
