Leaf Miner: What Is It and How to Treat It?

There are several different kinds of leaf miners, and the most common type tends to be non-descript black flies. The flies do not directly cause damage to the plant; instead, their larva is the root of the problem.

Although leaf miners are not usually fatal to larger plants, they can be destructive to young plantings and seedlings. If there is enough tunneling and damage to the plant’s leaf tissue, the planting may end up dying.

Leaf Miner’s Life Cycle

Mature larvae overwinter in the soil under host plants. As temperatures warm in the spring, the larvae passes to the pupal stage and appear as young adults in late April. Mated females lay up to 250 eggs just under the surface of the leaf epidermis, the outermost layer. Deposited eggs may appear as small raised spots on the leaf. Within 10 days, hatching larvae tunnel through the mid-leaf tissue, feeding as they go and leaving tell-tale blotches that are visible on the surface. Larvae mature in 2-3 weeks, leave the leaf and drop to the soil. Once on the ground, they dig 1-2 inches into the soil and pupate. Adults emerge within 15 days as adult flies. There are several generations per year.

Additional Facts About Leaf Miners:

• Lay up to several hundreds of eggs
• Have six development stages: egg, three larval stages, pupa and adult
• Development from egg to adult depends on the temperature and could take two weeks or more
• Adults females live for one to two weeks

Effectively Treating Leaf Miner

TreeAzin is a systemic insecticide produced from Neem tree (Azadiracta indica) seed extracts that is injected directly into the base of trees. It is effective against a variety of insects that consume tree tissues.

In Canada, TreeAzin (PCP 30559) is registered by Health Canada’s Pest Management Regulatory Agency (PMRA) for the control of: birch leaf miner and many others.

TreeAzin treatment is competitive with other treatment options, without sacrificing environmental safety. Typically, it costs less than tree removal, disposal and replanting.

Consult with ArborCare

Not sure what is wrong with your tree or uncertain if it could be leaf miner? Book a consultation with one of our experts in Calgary, Edmonton, or Kelowna.