What are these white things on my chard leaves? And what do I do about it?

Linda, You're sure keeping close eye on your chard! Glad to see that.

Those are probably the eggs of leaf miners, a bug that loves chard.

If you don't have too much chard you could crush the eggs. Spinosad is a natural insecticide but it also kills parsitic wasps. Tigard is effective against the larva, but only use two sequential applications.

For any insecticide, please carefully read and follow the instruction.

Susan, Yamhill County Master Gardener