TheCronicGardener
Newly Registered
Posts: 2
Joined: Sun Dec 02, 2012 8:53 pm

Can someone help me identify this condition? => Leaf Mine

I've been growing tomato plants for years and for some reason I can never seem to identify or even get rid of this disease. White lines weave their way along the leaves and there is a smaller black line running through the white ones.
This condition never seems to affect my pepper plants but it does plague my radishes from time to time.
Other than this problem, my tomato plants are perfectly healthy.
If anyone else had this problem and cured it, I would appreciate the advice :)

Image

Image

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

That's an easy one, very distinctive. It is not a disease, it is a little insect larva called a leaf miner, that gets in between the layers of the leaf and burrows through it, eating leaf tissue and leaving those trails.

Because it is inside the leaf, it is not very susceptible to sprays. Easiest thing to do is at the first sign of squiggles, just remove and destroy (not in compost pile) the leaf. Hopefully if you catch it before the infestation gets so bad, you won't be defoliating your plant in the process.

In the meantime the plant can lose a fair amount of leaf tissue that way without suffering too much, so it's by far not the worst problem you could have.

For future reference, there's a wildflower called velvetleaf, that makes a great trap crop for them. It has very soft velvety leaves (hence the name) that the miners prefer to anything else. Grow a few of those and keep picking the squiggly leaves off them. I discovered that by accident. I planted a packet of mixed wildflower seeds. All the rest of the stuff died out, but the velvetleaf kept reseeding itself. So that would be a way you could obtain it.

If you don't remove and destroy the squiggled leaves, the larva eventually matures, leaves the leaf and drops down to the ground, pupates for awhile, and then metamorphosizes into a tiny fly like critter, that lays eggs inside more leaves (250 or so at a time). In favorable conditions the whole life cycle can occur in about a month, so they can multiply rapidly, as you have seen.

Since you have so many of them right now, another thing you can do is lay down plastic mulch under your plants, to help prevent the larvae from reaching the ground to pupate.

In the meantime, the healthier and more vigorous your plants, the less they will suffer from the tissue lost to miners. Are those plants growing in containers? As near as I can tell from the pics, the plants look crowded into small containers.

This is turning in to more than you wanted to know about leaf miners :) , but one more thing. Have you been using general insecticides in your garden? Sometimes when you see an outbreak of leaf miners like this, it is because the garden was sprayed with insecticide, which removed the beneficial insects that would otherwise help keep the leaf miners in check (tiny parasitic wasps and others).
Last edited by rainbowgardener on Tue Dec 04, 2012 5:47 am, edited 1 time in total.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

User avatar
ElizabethB
Super Green Thumb
Posts: 2109
Joined: Sat Nov 24, 2012 5:53 am
Location: Lafayette, LA

I agree with Rainbow on the need to remove the infected leaves and cover the surface of the soil. I also found this link which talks about spinosad - an organic insecticide to control leaf miners.

Hope this helps.

https://www.lsuagcenter.com/en/communica ... miners.htm

BTW your plants do look crowded.

LOL
Elizabeth - or Your Majesty

Living and growing in Lafayette, La.

When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant. ~Author Unknown

TheCronicGardener
Newly Registered
Posts: 2
Joined: Sun Dec 02, 2012 8:53 pm

Thanks for the advice , I appreciate it.
Just to be clear, they are not overcrowded; though it may look like many plants, there are but two, maybe three plants to 2 1/2' x 1' x 1' pots. what you're looking at are "support sticks". "LOL" is an interesting thing to say.


Happy Gardening.

DoubleDogFarm
Super Green Thumb
Posts: 6113
Joined: Mon Mar 29, 2010 3:43 am

TheCronicGardener wrote:Thanks for the advice , I appreciate it.
Just to be clear, they are not overcrowded; though it may look like many plants, there are but two, maybe three plants to 2 1/2' x 1' x 1' pots. what you're looking at are "support sticks". "LOL" is an interesting thing to say.


Happy Gardening.
I thought they looked like raspberries. :lol:

Eric

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Spinosad is completely organic and relatively harmless in the garden. It is a bacterial exudate. It is highly toxic to honeybees if sprayed directly on them, but the dried residues are not toxic, so just use it carefully, when bees are not out. But note from Eric's link:

Leaf miners are tiny insects that feed on the inside of a plant's leaf. They can feed on a number of plants and are difficult to control. Try spinosad before the insects burrow into the leaves. (italics added)

That is to be successful with any insecticide against the miners, you have to get the timing just right to get the adult flies. There actually is no before the larvae burrow in, because the fly lays her eggs inside the leaves and the larvae are born there.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

DoubleDogFarm
Super Green Thumb
Posts: 6113
Joined: Mon Mar 29, 2010 3:43 am

But note from Eric's link:
ElizabethB's :wink:

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Ooooops!! :oops: Sorry, Elizabeth, credit where it is due!
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

Return to “TOMATO FORUM”