leaf cutter

 Any one of various species of wild bees of the genus Megachile, which cut rounded pieces from the edges of leaves, or the petals of flowers, to be used in the construction of their nests, which are made in holes and crevices, or in a leaf rolled up for the purpose. Among the common American species are Megachile brevis and Megachile centuncularis. Called also rose-cutting bee.  [1913 Webster]