Anthophora hololeuca
(By K. James Hung)
Today we feature some photos from my research associate, Jessica Davids, a promising young scientist and excellent photographer-in-training. On a recent bee survey trip to Anza-Borrego State Park, Jessica spent most of her day getting close-up shots of the many plant species in flower and the many insect species we came across.
The bee pictured above is a female Anthophora hololeuca, one of the smallest in the digger bee genus Anthophora. Whereas many Anthophora species are robust, intensely hairy, and comparable in size to our familiar western honey bee, Anthophora hololeuca (and several fellow members of its subgenus Heliophila) is barely the size of a small house fly. It has a very apt scientific name—“hololeuca” means “all white,” which is very evident in the photo. Even its eyes are very lightly colored.
Anthophora hololeuca, like a quite a few of its relatives in the subgenus Micranthophora of genus Anthophora, is a pollen specialist. In this case, it is the pea genus Psorothamnus, which includes the indigo bush in the above photo (P. schottii), its larger cousin, the smoke tree (P. spinosus), and its smaller cousin, the dye weed (P. emoryi), all of which occur in the Anza-Borrego Desert State Park. When these plants are blooming abundantly, one can often find over a dozen of these little bees zipping about an individual tree, with females collecting pollen (like the one in the first photo), and males chasing females. They are incredibly fast; their white coloration also helps them blend into the grey-white stems of the plant and the white sand on the ground. Thus, despite their high abundance in some areas, they are relatively difficult to closely examine.
Anthophora hololeuca Cockerell, 1923
Family: Apidae
Tribe: Anthophorini
Active season: March through June
Range: Baja California, northwestern Mexico, Southwestern USA
Floral preferences: Appears to be a specialist on plants in the genus Psorothamnus
Nesting biology: Makes solitary nests in the ground
