What primary building material distinguishes mason bees from leafcutter bees?

Answer

Mason bees use mud, while leafcutter bees utilize neatly cut pieces of leaves

The primary difference in construction between these two closely related groups is that mason bees use mud to create cell partitions, whereas leafcutter bees use pieces of leaves for the same purpose.

What primary building material distinguishes mason bees from leafcutter bees?
insectbeeclassificationfamilyMason Bee