Here is a creature to add to your native bee list. Osmia aglaia is a small (about 3/8-inch long) metallic-green bee that is native to the west coasts of Oregon and California. Belonging to the same genus as the popular orchard mason bee, this bee is especially fond of Rubus varieties—particularly red raspberries and blackberries.
The adult bees—also known as “berry bees”—are active in the late spring just when the berries are blooming. The female lays her eggs in a wooden tunnel about 3/8- to 1/4-inch in diameter and provisions the nest with pollen and nectar collected from the berry flowers.
Cultivated red raspberries and blackberries are generally self-fertile plants, which means they can produce fruit without the aid of pollinators. But the fruits grow fuller and more robust in the presence of pollinators. In fact, James Cane of the USDA has found that red raspberries may be as much as 30% larger if they have been pollinated by bees—either wild bees or honey bees.
As the supply of honey bees has become more questionable, berry growers in these states are encouraging the berry bee by providing affordable housing—I mean appropriate housing—in the form of bee blocks and bundled reeds. In addition, experiments are underway to see if Osmia aglaia will live further north in the berry-growing regions of western Washington.
Although I couldn’t find a good photo that I could use on this site, if you follow this link to the Xerces Society you will see an Osmia aglaia in the header. Just ignore the text below the photo that refers to Osmia cascadica.