Species Agapostemon texanus

An excellent resource with very detailed discussions of bee morphology, behavior, and biology---from identification to genus, to in-depth coverage of (a surprisingly diverse variety of) nest architectures. Many helpful diagrams throughout. Very readable, even though largely written at a technical level. I find it a very interesting and helpful reference...only wish it included all of western (and not just northwestern) America! Nevertheless, I think much of the utility and information in this book probably applies to areas beyond the northwest---especially to adjacent areas.

And as a very nice additional bonus...this book can be freely downloaded off the internet! The portal page for links to the PDF's is here.

This work (written in English and Spanish) describes 169 genera of the region. Two keys are inluded: to the families, and to the genera of each family of bees of North and Central America. I find the detailed, and labeled, anatomical drawings useful, even without a microscope. (Of course, specimen and microscope make the work far more useful!)

Available online at Internet Archive:
Volume 1
Volume 2
Volume 3 (index)