taylorford's Identifications

This Yellow Potentilla bush was buzzing with native bumble bees. This one has rust and black stripes on its abdomen, with yellow fuzz between the lower black stripes. There is yellow fur around the large black spot on its thorax. Overall it has fuzz rather than lush fur. Its head is black.

On the (very) shaded sunflower head in the evening. Had also seen same kind working this same sunflower head in the sun.
Black head, long yellow fur and round black dot on thorax, two scruffy yellow stripes and three black on abdomen. Wonder if length of fur and scruffy look indicates a male. Not positive re id.