The females lay up to 50 eggs on the underside of leaves. Moths fly at night and are rarely seen. They can be moved considerable distances on the wind, but usually spread with the movement of infested plants. The caterpillars are flat and yellow and 3 mm long when fully grown. When ready to pupate, the caterpillars pull over a leaf margin and anchor it with silk, forming a secure pupation chamber.
Moths emerge from the pupa case.
In summer it takes about two weeks from egg to moth so there can be many generations in a year and the population can explode rapidly if conditions are right. As caterpillars are protected within mines or pupal chambers, it is difficult to achieve good control with broad spectrum insecticides. These insecticides also kill beneficial insects and can cause pests such as red scale to increase in number. Petroleum oil sprays reduce leafminer numbers by reducing egg lay. The tiny moths avoid surfaces sprayed with oil, so sprays should be applied before too many eggs are laid.