The name “leaf miners” is a catchall term for certain moth, beetle and fly larvae that tunnel between the upper and lower surfaces of leaves. They usually feed inside the leaf. Developing mines will show up as tiny translucent spots of lighter green color than the rest of the leaf. The larvae tunnel through the leaf forming blotches and discoloration. As the miners move to the outer edge of the leaf, the leaf turns brown. The larvae finish feeding in late June or early July and then fall to the ground where they pupate. There are at least two generations per year.
Timely spraying for the first generation of leaf miners and larvae will help prevent greater numbers in any later generations.
Systemic insecticides that translocate through the plant are an excellent choice. Check out Optigard from Syngenta or Merit from Bayer Environmental Science. Or, go with a great residual insecticide such as Tempo, Talstar or Suspend SC. These odorless concentrates are mixed with water and applied with a pump sprayer. These are great products to use when you have large areas to treat and need something which works well so you don’t have to constantly retreat with something like an insecticidal soap. Use these products outside of the home on just about any plant or tree as well as around the home for general pest control.
– These concentrates are mixed with water and used in a compressed hand held sprayer to make your application.