This cardboard nest tube has been opened to show an egg of the blue orchard bee (Osmia lignaria) sitting on a provision made the purple pollen of the flower Phacelia tanacetifolia. (Photo credit: Derek Artz, Ph.D.) Leave a Reply Cancel reply Search Search for... Search Get New Posts in your Inbox! Enter your email address to subscribe to Entomology Today. You'll receive notifications of new posts by email. Email Address Get Certified!