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Leaf miners are a type of insect that has a unique style of damaging your marijuana plants: they burrow between the two epidural layers of your plants’ leaves, eating the plant cells along the way. Adult leaf miners are a type of fly, and they look similar to a house fly.

They are not the culprits for the burrowing damage, however. Instead, they lay eggs on the bottom side of your plants’ leaves. Once those eggs hatch, the resulting larvae are what then begin eating and burrowing on the leaves.

Leaf miners are always the larvae version of their adult counterpart. While flies are the most common, you might also see leaf miners that come from moths, beetles, or sawflies.

Signs of leaf miners

Sings of leaf miners cannabis

Their presence is obvious because they leave a squiggly line the whole way that is white or brown in color. This pattern sits on top of the leaves of your marijuana plants, making it really clear what kind of problem you are dealing with.

Download my free marijuana grow guide at this link for more growing tips

Although you may lose a couple leaves here and there, leaf miners don’t pose too high of a threat to your plants’ total health. Generally their populations stay low and the injuries to your plants are quite minimal.

Not sure if leaf miners are causing the damage to your marijuana plants? Check the article Marijuana pest and bug control for a list with pictures of all pests and bugs

How to get rid of leaf miners

Get rid of leaf miners cannabis

Pesticides won’t work against these pesky creatures, simply because they are protected by the plant’s own skin. Your best bet is, therefore, to simply squish the little maggots within their burrow, then remove the leaves that were affected.

Download my free marijuana grow guide at this link for more growing tips

Another option to eradicate lots of leaf miners at once is to bring in a parasitic wasp that will consume these larvae. You can also purchase yellow sticky tape at your local garden center, which will attract the adult flies and they will then get stuck there and die. You can by the yellow sticky tape online at this link.

List of marijuana plant symptoms

– Squiggly gray or brown lines on leaves
– Presence of flies
– Eggs on leaf underside
– Larvae on leaf underside
– Leaf death
– Dry patches on leaf

While they are a bit of an annoyance and may damage some leaves, leafminers are generally not a huge threat to marijuana growers. You should take care of the problem as described above, but don’t panic about your crops and the end yield – they will probably be relatively unaffected.

Remember that plants with strong genetics have less change of getting sick and are less vulnerable for pests and diseases. So make sure you buy cannabis seeds from a trusted seed bank.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible

Robert

12 Comments

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  1. By Nick

    ,08 Jun 2015
    I really like this symptom checker. very informative. It really helps those question marks in the back of my head.
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  2. By Marijuana Pests & Bugs – Control And Identification

    ,10 Jul 2015
    […] Unfortunately, leaf miners are extremely difficult to get rid of. Pesticides are mostly ineffective against them, and the ones that do work aren’t safe to use on your plants: they’re more harmful than helpful. The only thing to do […]Read More
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  3. By Symptom Checker – Identify Marijuana Plant Problems

    ,24 Jul 2015
    […] Leaf miners […]
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  4. By marty

    ,25 Sep 2015
    be sides ,,B,T,,WHAT ELSE CAN I DO ABOUT THE GYPSY MOTHS THAT I HAVE HAD A PROBLEM WITH THE LAST 2 YRS,,,I SPRAY WITH NEEM OIL ALL DURING THE VEGATIVE STAGE,,,,,,,THEN I FING THE CATEPILLARS,,,,I GROW OUT DOORS,,,,,,,,
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  5. By latewood

    ,25 Sep 2015
    Try diatomaceous Earth
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    1. By Shalini Negi

      ,13 Aug 2017
      How would you apply the DE?
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  6. By pou

    ,12 Aug 2016
    caterpillars shrink and move on when youuse on them ,COMPO “Orchideendüngen” Orchid fertilizer.
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  7. By Shaun Leaman

    ,21 Aug 2017
    I downloaded the grow bible not so long ago after encountering a number of issues, be it from poor growth to nutrient deficiencies to pests and I have to admit that I will never regret my choice to download it…
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  8. By Theresa

    ,27 Aug 2017
    Thanks for the advice on the leaf miners. It worked
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  9. By forestfisherman

    ,29 Aug 2018
    I have A bad problem with Leaf Miners. Only thing that seems to help is, spray them every other day with Neem Oil. If I spray them in the morning, I see the egg layers on my plant by noon. […]Read More
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    1. By latewood_ILGM

      ,30 Aug 2018
      forestfisherman, Have you tried insecticidal soap safe for vegetables? A common remedy is to make a pepper spray. There are many recipes. (water a hot pepper, some citrus. Bugs hate citrus, and I am forgetting something but, you can do […]Read More
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      1. By latewood_ILGM

        ,30 Aug 2018
        sorry about the typo (no ) to close recipe)
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