The way to prevent leaf miners is to prevent the flies that lay the eggs from getting access to the plants. That is done with yellow sticky traps and row covers. Once the eggs are laid - and they are injected in between the leaf tissues by the fly, not laid on top - there is little you can do about them other than removing affected leaves.

A systemic pesticide? No way. You'd be eating it. Commercially approved ones? Sadly, yes.

Dave

Here is a link that might be useful: Systemic Pesticides

Hi Dave,
Regarding those yellow sticky traps, do you experience problems with non target insects getting stuck to the traps? Like bees, hoverflies and parasitic wasps.

Generally no because I only place them in and among the leafy greens, no blooms that would attract the other insects. And the way my gardens are spread out helps too since those plants are so far removed from the blooming vegs.

In a small garden or one with leafy greens interplanted then yes, I can see how that could become an issue. Insect barrier covers would likely work best in that situation since no pollination is required anyway and miner flies have such a short season.

Dave

Thank you!
I never thought of the sticky traps and I didn't know that the eggs were actually injected into the leaves. Gross to think that there are pesticides that are 'approved' for use that are non-organic. The more I know, the less I want to eat from the store...but that means I gotta grow it so. Yah.

Between my poor, caterpillar, aphid-ridden brassicas and my greens, I suppose finding a place to grow them where I can actually PLACE the Agribon I did purchase is my next task. I started out doing this with the assumption that it was better to keep my plants spread around, but if I am to use the row covers I will need to lump them together a bit more next time.

Angie