Growing susceptible plants under insect barrier netting will prevent female flies laying eggs on the foliage. However, crop rotation must be practised otherwise adult flies may emerge from overwintered pupae in the soil and be trapped under the netting.
On uncovered plants attempt to control infestations by removing mined leaves or squeezing the mined areas to crush the maggots. A careful search may also reveal the white eggs which are laid in small groups on the underside of leaves. Early summer damage is potentially the most harmful to the plants.
There are no pesticides available to home gardeners that are likely to give good control of beet leaf miner.