Most Common Pests In Cannabis: Leaf Miners

Leaf miners are any species of bug whose larvae lives inside your cannabis plant, eating away the leaf tissue.
09 June 2020
3 min read
Most Common Pests In Cannabis: Leaf Miners

  • 1. What are leaf miners?
  • 2. What do leaf miners look like?
  • 3. Where are they found?
  • 4. Leaf miners symptoms
  • 5. What do leaf miners do?
  • 6. How to prevent them?
  • 7. How to deal with them?
  • 8. In conclusion

Leaf miners are larvae that leave a unique type of scar on your cannabis plant. Because they’re eating away the middle layer of your plant's leaves, they leave a “trail” that can be easily recognizable.

1. What Are Leaf Miners?

Leaf miners are any larvae that start as eggs which are located on the underside of the leaves and as soon as they hatch, these yellowish white worm-like insects go into the leaves of your cannabis plant, eating the plant tissue and leaving a trail behind.

Leaf miners are not actually a specific species of bug. It is a term used for the larvae of any bug (moths, flies, and beetles) that lays eggs on your plant’s leaves. 


Most Common Pests In Cannabis: Where Are Leaf Miners Found

Leaf Miners are the larvae of any bug (moths, flies, and beetles).

After the eggs hatch, they will eat their way into your cannabis plant's leaves.

2. What Do Leaf Miners Look Like?

Although they may differ when adults (because they are different bug species) all leaf miners are larvae.


Most Common Pests In Cannabis: What Do Leaf Miners Look Like

What do Leaf Miners look like.

Larvae look like small white or yellow worms, but it can be super hard to see them because they live inside the leaves until they are mature enough to grow wings or legs.

3. Where Are They Found?

Leaf miners are found inside your cannabis leaves. Their eggs are laid on top of the leaves and once they hatch they start eating their way under the second layer of a cannabis leaves “skin”.


Most Common Pests In Cannabis: Leaf Miners Eggs

Eggs of Leaf Miners laid on top of a Cannabis leaf.

And when they become adults, they can stick around and lay even more eggs if you don’t deal with them. 

4. Leaf Miners Symptoms

Although finding a couple of them eating away your leaves isn’t a super serious problem, a big infestation can reduce your plants' ability to grow and may ultimately decrease yields.


Most Common Pests In Cannabis: Leaf Miners on Cannabis plants

Leaf Miners eating their way under the second layer of a cannabis leaves “skin”.

The “trails” left behind can also start yellowing the leaves and if they get too affected, they can turn brown and fall, resulting in a less healthy plant.

5. What Do Leaf Miners Do?

The larvae eat the leaves cells, this means they eat what the plant needs to photosynthesize. These “tunnels” or trails can also be an entry point to diseases and can attract other bugs trying to feed on your plant.

6. How To Prevent Them?

There’s no other way to prevent these bugs other than maintaining a good growing environment. If you keep a good temperature, females won’t lay eggs.

Because females lay eggs in temperatures higher than 25 Celsius, keeping a lower temperature can effectively prevent these bugs.

7. How To Deal With Them?

It can be really hard to deal with leaf miners because they live inside the leaves and insecticides won’t reach them.

What you can do is press your leaves with your fingers to squish the bugs, this is a good way to deal with a low amount of miners while still keeping the leaves on your plants.


Most Common Pests In Cannabis: Symptoms of Leaf Miners

In order to get rid of leaf Miners press your leaves with your fingers to squish the bugs.

If you see the infestation is getting out of hand, the only way to remove them effectively is to pluck the leaves out. This will ensure all the bugs eating your plant are removed.

Obviously, this can stunt your plant’s growth but not doing anything will be way worse for your cannabis plants.

8. In Conclusion

Leaf miners aren’t that big of a problem in a small number. Of course, they are bad for your plant but won’t be a huge risk unless it’s a serious infestation.

If you’re having continuous problems with bugs, we recommend our new Gorilla Cookies Auto. 

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I got 134g off this gal growing in 3 gal pot with 24 hours of light. i'm stoked with the result! Smells like diesel. Was a great grow overall.
Verified customer
Reviewed 24 June 2020

Her high resistance will give you an advantage over any type of bugs.

Try to always take care of any bugs in the early stages so your plant doesn’t feel it too much.

09 June 2020