Q. My potted Myer lemon tree has “wrinkles” on the leaves. The nursery told me that the leaves have an insect living inside the leaves.  I used whatever product was sold to me last spring and the leaves still look wrinkled. This is my second year having the tree and it has 12 lemons on it. Leaf miners on Myer lemon is usually a “greenhouse problem” with warmer temperatures. A. The nursery was right. The leaves of your Myer lemon have leaf miners inside of them. But the product you were using was wrong. Leaf miners are usually small flies that lays eggs on the surface of the leaves. these eggs hatch and the “maggot” of this fly tunnels between the outer surfaces of the leaves. Previous to yours, the only place I ever saw leaf miner on Myer lemon were in another country grown inside a plastic tunnel they called a “greenhouse”. Leaf miner infestation of tree leaves of Myer lemon is usually a greenhouse problem but here it was growing in a container. By the way, Myer lemon is a bit too large for container growing unless you use a very big container.            There is no insecticide I would use to control them. The usual method used is to hand remove or pick the infested leaves and immediately destroy them.  Leaf miners found inside tree leaves are usually a minor problem when growing citrus. Their life cycle can be easily interrupted by removing infested leaves. Leaf miners are more of a problem in leafy greens like spinach and lettuce.  A word of caution. These leaves must be destroyed soon after they are removed, or the leaf miner insect will emerge, mate and continue to infest other leaves.            I guess if you were to use an insecticide for controlling leaf miner then I would spray a systemic insecticide like imidacloprid if it is labeled for food crops. But in your case the easier and safer method is to remove infested leaves and immediately destroy them and interrupt the insect’s lifecycle.