Agromyzidae are small and usually dark flies.
Some species have yellow markings.
These flies are fairly similar and are more easily recognized by their host plant and the damage to the host plant than by the insect itself. Some leafminer maggots make serpentine tunnels that increase in size as the maggots grow. Other species make blotch mines or mines that are intermediate. Leafminer flies are pests of columbine, butterfly weed, chrysanthemum, cineraria, delphinium, gerbera daisy, holly, impatiens, mist flower, verbena, water lily and other ornamentals. The larkspur leafminer causes blotch mines in the leaves of delphinium, larkspur and aconite.