A tell tale sign you have a leaf miner are squiggly white lines all over the leaf. If you see this, you probably have a miner.
A leaf miner is a larva of an insect that lives between the epidermal layers of a leaf. In most cases, they complete their life cycle within a single leaf. If they were removed from the leaf, they generally wouldn’t be able to survive and move to another leaf.
Like the gall-makers, they’re very host-specific.
For the most part when we see a leaf mine or a gall we need not start to panic, however are varieties are destructive.
The spinach and beet leaf miners eat the leaves and can do considerable damage in gardens and farms. If you happen to see these, remove them as soon as possible unless the plants is not wilting or crumpling. It is nothing to worry about if the plant still looks healthy.
But if you don’t see the plant wilting away or the leaves crumpling away, probably nothing to worry about.
Pay special attention to the oaks in your yard. Oaks are particularly popular with these insects. There are four orders of insects that mine leaves, and all four of them have species that mine oaks. So, beware of the mines when you have oaks.