A Mining Bee, or Sand bee, Andrena
A Mining Bee, or Sand bee, Andrena is a very active little fuzzy bee that pollinates a wide range of flowers and food crops. There are hundreds of species of this bee, many subgenera, almost 80 pages of species and genus descriptions in "Catalog of Hymenoptera in America North of Mexico". So don't get too depressed if you don't figure out exactly what bee it is. Native bee research is underfunded to the point where I can't find a research program that is dedicated to it.
This page is meant to expose farmers and homeowners to the bees and help them plant native plants to provide nectar and pollen for the bees. The bees also need weed-free areas that are not cultivated for bee home sites.
It looks like a simple planting of A few manzanitas (Notably Austin Griffiths, Ian Bush, Sentinel, and Mama Bear) in one corner of the orchard and another patch of Salvia clevelandii Alpine in another corner of the orchard might be enough to sustain a population of Andrena in an orchard. You may have to add some other species of manzanita or Ceanothus to provide early nectar for the bees according to your target crop. Plums or other early flowing trees would probably be fine, but late flowering trees may need another species to provide a nectar bridge to keep the bees healthy until the crop flowers.
A Mining Bee, or Sand bee, Andrena, on an Arctostaphylos Ian Bush.
Andrena bee pollinating an Asian Pear, Pyrus serotin