What Causes White Lines on Tomato Plants

My tomato leaves have white lines on them. What causes this, and what should I do about it? -Bill

Those white squiggly lines are a trademark of leaf miners. Leaf miners are insect larvae (Liriomyza munda) which hatch from eggs deposited between the upper and lower surface of plant leaves. The hungry larvae munch their way around the leaf, leaving a telltale white trail or tunnel.

Leaf miners affect a host of edible and ornamental plants and are very difficult to control because they hide inside the leaf. Insecticidal sprays not only have a hard time reaching them, but such products kill off the beneficial wasps that would be happy to have your leaf miners for breakfast. Luckily, leaf miner damage is mostly cosmetic unless the leaves of the plant are going to be harvested and eaten (such as basil or chard). Extensive infestation with leaf miners can reduce the overall health and vigor of the plant, and the tunnels can provide an entry point for fungus or bacteria if the leaves are not removed.

Here are some tips for controlling the leaf miners on your tomatoes:

White trail left by a leaf miner.

  • Pick off and destroy any affected leaves and leaf miner larvae.
  • Grow your veggies organically, without the use of sprays or chemicals that could upset the balance of beneficial predator insects, since leaf miners can be largely controlled by natural predators.
  • Keep your plants healthy and well watered, so they can recover from the infestation (and the necessary leaf-plucking).
  • Keep your garden clean and free of weeds or debris that can harbor insects and diseases.
  • Some garden insecticidal sprays (such as those with carbaryl or pyrethrins) are labeled for use with leaf miners. Research gives mixed reviews on such products for leaf miners, and you certainly should consider whether you want insecticides on edible plants. Read the labels carefully before using.

Further Information



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12 Comments on “What Causes White Lines on Tomato Plants”

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  • Official Comment:

    Thomas Boni Says:
    March 9th, 2019 at 1:58 pm

    Hi, Anderson,
    Thanks for letting us know! Link removed. 🙂
    Take care!

  • Anderson Says:
    March 8th, 2019 at 12:46 pm

    “Photo of Leaf Miner on Tomato (Clemson University)”

    It gives me “server not found” error.

  • Mahesh Says:
    January 6th, 2019 at 10:16 am

    Please let us know how to control tomoto leaf miners…and which chemical is better..and in the wet months lots of leaf was burned…what is the cause…and precaution we should take prior

  • Paul W. Says:
    April 16th, 2018 at 11:56 am

    Best cure for leaf miners on tomato plants

  • T.Amudha Says:
    September 5th, 2017 at 6:43 am

    Good suggestion.luck will try to cut the leaf minor.

  • Bennett Says:
    August 15th, 2016 at 12:40 am

    thanks so much very helpful

  • christine Says:
    November 25th, 2015 at 1:38 am

    My tomato plant is smaller than the usual plant. How to make it bigger?

  • Sukhin Chawla Says:
    August 11th, 2014 at 12:36 am

    That’s a good advice! I have had cut down all the damaged leaves.Thank you

  • Mary Says:
    June 18th, 2014 at 4:06 am

    Why are my tomatoes growing with yellowish spots on them, and are they still edible ?

  • Vernice Says:
    February 21st, 2012 at 10:30 am

    I have leaf miner on most all leaves of tomato plants on our inclosed porch… Also on our citus trees.. what should do?

  • Kayla Says:
    October 16th, 2011 at 3:20 pm

    I have this disease all over the leaves. If I take them all of it will destroy the plant and u won’t have any leaves! What should I do?

  • Jeanne Briggs Says:
    March 28th, 2011 at 4:10 pm

    I seem to have leaf miners, and they are all over most of my tomato plant. Should I cut those leaves off which would drastically prune the plant? The top leaves about 5 inches down from the top are not yet affected but they become more profuse each day and will make their way to the top. Please help! Many thanks in advance

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What Causes White Lines on Tomato Plants