idsjdpjodsfpjo
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How to deal with this cucumber disease?

Hi,

I live in Southern California and finally got into gardening. I am wondering if somebody can help me with dealing with this cucumber problem: Whenever I plant cucumbers they grow really well for a few weeks but then some kind parasite or disease attacks them and they die slowly. I have attached a few pictures of leaves that are just in the process of being attacked and others that are close to dying.

Any advice is welcome. I have attached a few pictures to illustrate the problem.
20150905-DSCF7147.jpg
20150905-DSCF7146.jpg
20150905-DSCF7145.jpg

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rainbowgardener
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Location: TN/GA 7b

Not a disease -- it's a bad case of leaf miner. They are the larvae of any of a number of different flies. The fly lays her eggs inside the leaf tissue . When the larvae hatch out , they chew their way around inside the leaf, leaving the squiggle trails .

In cold winter areas, they're usually not a very serious pest and don't tend to kill things . But I gather without a cold winter to slow them down , they can become a serious problem .

Type leaf miner into the search box top left of page to find lots more about them and how to control them .

idsjdpjodsfpjo
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Posts: 4
Joined: Sun Sep 06, 2015 10:31 pm

rainbowgardener wrote:Not a disease -- it's a bad case of leaf miner. They are the larvae of any of a number of different flies. The fly lays her eggs inside the leaf tissue . When the larvae hatch out , they chew their way around inside the leaf, leaving the squiggle trails .

In cold winter areas, they're usually not a very serious pest and don't tend to kill things . But I gather without a cold winter to slow them down , they can become a serious problem .

Type leaf miner into the search box top left of page to find lots more about them and how to control them .
Thanks! Just did some research. It seems this will be hard to deal with in CA where we never have winter.

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rainbowgardener
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But you can control them:

Remove the leaves with squiggles - as long as you are not defoliating your plants. If there is too much, try just cutting off the part of the leaves with the most tracks. If you get them soon enough, that helps prevent the next generation. When the caterpillars/larvae have eaten/ grown enough, they chew out of the leaf and drop down to the soil, burrow in a bit and pupate. Then they emerge as the adult moth (or sometimes flies) and start the cycle over. So if you remove the leaf while the caterpillar is still in it you prevent that. You can also help prevent it by mulching well around the tree - makes it harder for the caterpillar to get to the soil to pupate.

But the caterpillars are very protected inside the leaf and nothing much you can spray on the outside will do anything to them.

Prevention is to spray NEEM oil early on (late April-early May for me, maybe earlier for you), which repels the moth and keeps her from laying the eggs in the leaves. Do it again in July to protect from the next generation (since the moths fly, ones that hatched out in other people's yards can come lay eggs in your plants).

I have found trap crops work really well for them. Velvetleaf is a yellow flowering wildflower, which is named for its very soft leaves. The leaf miners love them and ignore everything else just to eat velvetleaf. Then I just keep pulling the squiggled leaves off of that. Columbine and lambsquarters are also reputed to work as trap crops for it.



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