This bee is one of a group of about one hundred leafcutters of the same species nesting underground in a gravelly path beside a pasture area. The bees have moved into holes occupied a month a go by a group of Colletes inaequalis bees.

Is this Megachile addenda?

M. addenda leafcutters have been found in the area in previous years, although only sporadically, never in such large numbers. This female bee is fairly hefty for a leafcutter – about 9 mm, with a broad abdomen, boldly striped, and the segments of its back legs are notably wide. Its scopal hairs are mostly white. Consistent with M. addenda, it has long jaws, with four teeth and a cutting edge between the third and fourth tooth.

Other info: (1) The bee also has a broad vertex (the distance between lateral ocelli is smaller than the distance from lateral ocelli to the back of the head). (2) T-1 through T-5 have white bands of hair and T-6 is entirely black. (3) There are white scopal hairs on S-1 through S-5 (with a few black hairs on the sides) and black scopal hairs on S-6. S-6 is entirely black.