I think this is a female, since I count 5 visible black abdominal bands...and the antennae look a bit shorter than in the males.

I didn't get enough resolution in this image to accurately count flagellomeres...though as best I could make out, there were 10. (In Colletes, as with most genera of bees, there are 10 flagellomeres for females, 11 for males. Recall the terminology: the 1st and 2nd antennal segments are called the "scape" and the "pedicel", the remaining segments collectively constitute the "flagellum", each segment of which is a "flagellomere".)

The antennal scapes (1st segment) in these bees seem to be longer on the females, but I may be wrong on that. The pedicels are short, appearing like little spherical beads between the scape and the flagellum.

Note the "cellophane"-like layers which appear laminated together in the turret for the burrow entrance. Colletes line their nests with a thin cellophane-like film derived from their saliva and spread by coordinated action of their mouthparts and forelegs.

(See remarks with the first image of this series for more info.)