Worms inside the leaves?

[soren]

Hi.

One of my plants is showing some strange markings on the leaves. The markings are visible on both sides of the leaves, and it looks like something is moving around inside the leaf.

Same leaf, less than 3 hours after the first photo. Trail has moved visibly closer to the edge of the leaf.


Any idea what this can be? Is it harmful to the plant? Can/Should I do anything about it?

Thanks for your comments.

Søren

[Oriax]

Just posted this on your other thread ...Leaf Miners methinks

http://en.wikipedia.org/wiki/Leaf_miner

[soren]

Excellent, thank you Oriax. It is nice to know what I am dealing with, at least.

Do you have any experience with those things on chili plants?

After reading your wikipedia link, I guess I'll have to get a trap crop, and maybe cut away the affected leaves on my plant.

Could I possibly squash them, without harming the leaf too much? It seems that once a leaf has been infected, the insects will notice the marks, and stay away from that leaf, thinking that it has probably already been eaten.

[Oriax]

To be honest I've only ever come across them literally while studying an Environmental OU course last year, the tracks seemed similar to holly leaf miners, so I can't really advise on the treatment... unless someone else has had first hand experience google may be your best friend with this one

[soren]

I have googled around a bit, and thought I would share the results of my research, for future reference.


Opinions seem to differ, regarding the impact of a leaf miner infection on plants.

Needless to say, they will destroy ornamental plants, as they will loose their visual appeal.

Edible plants, like spinach, will also be affected, as you will have to cut away the infected crop. The rest of the plant will be fine, though.

For a plant like Capsicum, the crop itself will not be affected, except to the extent that the plant's "handicap" limits production. It seems that you need quite a large attack, before you notice any reduction.

Conventional insecticides are not effective, as the miners are protected inside the leaves. A biological insecticide, Spinosad, is available, and even approved for organic gardening. Spinosad must be ingested by the miner, and will kill it by attacking it's nervous system.

Preventive methods include attacking adult miners with insecticides, attracting miners to trap crops, and letting wasps control the population of adult miners. There are many many types of miners though, and until you know the source of your problem, targeting it effectively is difficult.

Simply removing the affected leaves seems to be the simplest method, and this is the method I have decided to try first. I had about 10 miners on my plant, and most of them could be removed along with only a small part of the leaf. I don't think it will damage the plant at all. I have put all the affected leaves in a sealed plastic bag, hoping to identify the species once they leave their burrows.

Patient zero is probably still out there, so I doubt the problem will disappear with this simple operation. I will keep you posted on the progress!

Thanks for your help Oriax. Definitely a lot of interesting stuff about this topic out there. Google is our friend indeed!

[endorphine]

whip the effected leaves off, so they don't spread!

[Bobbber]

I agree... take the leaves off and throw them away... Miles away!

I go to a local pub - outside they have a cherry tree. A few of the leaves were like this, I wondered what it was until I saw this post. Now ALL of the leaves are like it.

Take a tough decision and cut your loses on the affected leaves. At the end of the day, chilli plants seem to recoup lost leaves very well.

B

[soren]

So far, no new bugs have appeared since the surgery, and the plant seems to be doing fine without the leaves. I agree that this must be the way to deal with leaf miners. Remove the leaves as fast as possible, before the problem grows larger.

[Bobbber]

soren, hopefully this is a good result!

[cherrybomb]

i got that tracking on all my Pak Choi plants, all now consigned to the bin!
couldn't eat that...

[Pierogi]

Really interesting thread. The leaf miners sound like a pretty nasty pest to have.

How are your plants doing now Søren, do you think you have stopped the miners?

I've also read that you can:

Quote:
Use yellow sticky traps to catch egg laying adults. Cover soil under infested plants with plastic mulches to prevent larvae from reaching the ground and pupating. Neem oil and Indoor/Outdoor IGR break the pests' life-cycle by preventing larva from reaching maturity. Neem oil may also have repellent qualities and interfere with egg laying activities.

Source: http://www.planetnatural.com/site/xdpy/ ... ntrol.html

[soren]

Great article Pierogi, i didn't see that one the other day.

The plant is doing well. It is continuing to grow fast, and no new miners have appeared. Looks like I caught them in time!

[tobrien1]

I've got some pea plants with these! Wondered what they were. I think I'll be cutting them right back seeing as how they share a home with my chilli plants!

[Bobbber]

I agree... take the leaves off and throw them away... Miles away!

I go to a local pub - outside they have a cherry tree. A few of the leaves were like this, I wondered what it was until I saw this post. Now ALL of the leaves are like it.

Take a tough decision and cut your loses on the affected leaves. At the end of the day, chilli plants seem to recoup lost leaves very well.

B

Interesting.,.. I've now held the leaves up to the sunlight and looked "through" the leaves. WOW!!!!! Horrid red strings in there!