Leaf miners are a pesky insect that this article will teach you to identify, and remove, should the burrowing bug attempt to feast on your Cannabis crop. Leaf miners, when ignored, can lead to health problems for your marijuana plants. They are a kind of insect that get between the two epidural layers of the leaves of your marijuana plants and consume plant cells as they burrow.
Surprisingly, the adults are not the source of the most damaging issues that come from leaf miners on your marijuana plants. It is their larvae that are the biggest problem, as they are the ones that actually burrow, and eat inside your plants’ leaves.
Adult leaf miners look similar to a house fly. Other types of leaf miners resemble the larvae of moths, beetles, and sawflies. The underside of plant leaves is where they lay their eggs, and when those eggs hatch, problems can arise.
Identifying leaf miners on your plants
Leaf miners are quite easy to identify, given the fact that they leave their signature burrowing path. This looks like white or brown squiggly lines on the leaves of your marijuana plants. They are hard to miss.
Generally speaking, leaf miners pose the greatest risk to the individual leaves of your plants. And only in rare cases, will they ever have a high enough population to cause serious overall damage to your plants. Still, any injury to a plant is best avoided, so if you can get rid of them, you should. More about identifying leaf miners in my free grow bible.
How to fix the problem
The best way to get rid of leaf miners is not pesticides. Remember, they live and eat within the leaf. So, they have total protection from methods like that. A better approach is more hands-on. Simply squish them inside their burrows, then gently remove the leaves with damage. This will encourage your plant to focus its energy on the leaves that are still healthy, rather than waste their resources on a dying leaf.
If the population of leaf miners is higher than is comfortable, introducing a parasitic wasp could help kill large numbers of them at the same time. Yellow sticky tape is also useful, as it attracts the adult flies and they stick to the tape and die before they can lay any eggs on your plants.
List of leaf miner symptoms
- Brown or white squiggly lines on the leaves
- Flies present
- Eggs on underside of leaves
- Larvae on underside of leaves
- Death of leaves
- Dry patches on leaves