These are the little grayish-black bees that cut circular notches out of the leaves of your rose bushes, bougainvillea, and other plants. It seems that once they decide on a particular plant, they can almost defoliate it by their cutting activities. I have seen bougainvillea plants completely denuded of flowers by leafcutter bees. Since these insects are very useful as pollinators for many plants, I suggest sparing the spray if at all possible. On the other hand, if leaf removal becomes so severe that the life of the plant is threatened, a spray of insect repellent should discourage further leaf removal.