What Do Leaf Miners Look Like?
Identification. Leaf miners are insects that tunnel through the foliage and needles of plants. Leaf mining is caused by the larval stage of several insects including moths, beetles, sawflies, and flies. The common leaf miners that are agricultural pests are citrus and vegetable leaf miners.
Citrus leaf miner: Tiny, light colored moths with a distinct black spot on the tip of each wing usually no bigger than 2mm long.
Vegetable leaf miner: Though there are different species, vegetable leaf miners are principally yellow and black appearing somewhat like a tiny yellow jacket and are generally smaller than 2mm long.
How Long Do Leaf Miners Live?
Lifespan. Leaf miners usually live for about one month.
How Do I Know If I Have Leaf Miners?
Damage. There are several telltale signs that leaf miners may be attacking your plants. Here’s what to look for.
Leaf miners create shallow tunnels on foliage known as mines, which gradually widen as the larva grows. In maturing plants, this damage can cause foliage to curl and become distorted. Mature plants are generally not affected.
Some leaf miners create blotches of irregular, round damage spots on the foliage.
Many times the visible damage is a combination of both blotches and tunnels.
How to Get Rid of Leaf Miners
Control. Leaf miner damage is for the most part superficial so insecticide use generally not necessary. If insecticides are decided upon there are two methods of attack to consider. The first involves the use of persisting contact insecticides, which are used to attack the egg stage of growth. The second involves an insecticide that is applied to the soil for root uptake.
Can I Get Rid of Leaf Miners Naturally?
Parasitic Wasps. These insects are important in the control of leaf miners worldwide. The parasites kill the leaf miners in the larval stages by laying their eggs inside or atop the leaf miner larva. When it hatches, it feeds on the leaf miner subsequently killing it.
Natural Enemies. In comparison to parasitic wasps, other natural enemies are not considered important. Leaf miner adults as well as larvae are susceptible to a wide variety of predators including ants.
Organic Methods. There are several sprays and oils on the market that are designed to inhibit leaf miner populations organically.
Can I Prevent Leaf Miners?
Prevention. Two cultural practices will help to limit and deter the leaf miner population; deter succulent growth and protect natural enemies.
Leaf miners lay their eggs in newly emerging leaves. The best prevention is to time new growth so that it happens once per year by avoiding pruning more than once per year. Remove suckers of new growth if leaf miners are a problem. Do not remove leaves that have been infested by leaf miners as the leaves still provide food for the plant.
To protect natural enemies, avoid using a broad spectrum insecticide as it may also harm beneficial insects.