The month of June in my North American Native Bee Calendar purchased from the Great Sunflower Project, features the Wool Carder Bee, genus Anthidium. These bees emerge in summer and will nest in nesting blocks, preformed cavities in wood or hollow plant stems.
They are about 1/2-3/4 inches long depending on the species. Both the males and females have a black or brown abdomen with varying patterns of striking yellow or white markings.
The males are extremely territorial and will patrol a patch of preferred flowers jealously guarding it for potential female mates. They are easily recognized by their hovering, darting and ramming maneuvers. When other males or bees of another species attempt to land on the flower that's being guarded, the Anthidium male will hover for a moment near the trespasser and then forcefully bump him off.
I believe I've seen this in action and have several of these bees patrolling my sage, lamb's ear, and lemon balm. They truly do hover, dart and ram. This one I captured guarding my sage:
Wool Carder Bees are especially attracted to sage, lavendar, catnip and trefoil.