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how to get rid of cirtus leafminer

Posted by nkt38238 Z9 CA (My Page) on
Mon, Sep 14, 09 at 21:11

Hi,

I have about 2 years old Meyer lemon tree (about 2 ft tall) planted in ground. I recently noticed that all new leaves had shallow tunnels on them and are mostly curled. After some research,

http://www.ipm.ucdavis.edu/PMG/r107303211.html#MANAGEMENT

I found that the plant seems to have been infected with Citrus Leafminer.

Question:

1. Is it possible to get rid of leafminer from lemon plant?

2. If so, what do you use (pesticide,etc.)to get rid of it in small backyard orchard setting?

I am in N. California (S. of San Fran).

Thanks.


Follow-Up Postings:

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RE: how to get rid of cirtus leafminer

spinosad is the recommended treatment for leafminer. i used malathion oil successfully as well.

its a very common problem, in larger trees its usually not detrimental to the tree unless its a large infestation.

wasps are a natural predator of leafminer so if you see them be nice to them and try to coax them onto your tree :)

if they come back im going to try to buy some lacewing eggs

Here is a link that might be useful: lacewing eggs mailorder


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RE: how to get rid of cirtus leafminer

If you were to use the Spinosad pesticide or the malathion, you'd harm any of the beneficial insects that may come around to aid in the control of the leafminers. Neem oil, however, has little affect on insects that do not feed on plants. Neem also acts as an anti-feedant, and has shown to keep the little moths that become citrus leaf miners from laying their eggs.

There are no wasps (that I know of) that can be called predators of leaf miners. Rather, there are a couple of teensy wasp species that are parasitic on the larvae of citrus leaf miners.

The only way to encourage them into doing their good work is to avoid the use of those pesticides mentioned earlier.

My advice is to try the neem to prevent further infestation, to squish any larvae that you can see in the leaves, and to pull off any of the worst leaves (as long as living larvae are still within).


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RE: how to get rid of cirtus leafminer

Rhizo, is there a particularly good neem product that you recommend to use on citrus? On the Cornell site, it sounds like a number of pesticides are manufactured from the neem tree. I want the one that does what you are saying - has little affect on insects that do not feed on plants. The one I've seen is from Green Light.

My citrus have swarms of little flying insects, and some others that look like little wasps. I wouldn't want to harm them since they might be the beneficials. Thanks, Chris


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RE: how to get rid of cirtus leafminer

100% pure pressed from Dyno-gro...That is if you want the best quality available to do a great job..:-)
Sorry rhizzo....;-)


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RE: how to get rid of cirtus leafminer

Dyna-gro is ONE manufacturer of cold-pressed neem oil. There are others, but I do not know if Green Light is one of them. Do some internet searching on cold-pressed neem, without any additives (like Pyrethrins). The label must state that the product is cold-pressed.

The citrus leafminer, by the way, is a teensy moth only about 2 mm in length.


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RE: how to get rid of cirtus leafminer

neem is useless against leaf miner. the smell will temporaily ward off insects but will do nothing to the leaf miner larvae themselves (i have personally tried repeatedly)

spinosad and malathion will ward off pollinators so dont use it during flowering season. i used malathion to kill my leaf miner and witnessed bees in the are of my citrus a few weeks later ( i too am very concerned with chemicals)

its really discretionary, many reputable sources consider leaf miner a "cosmetic problem" but my trees were young and small and my temple orange was obliterated by leaf miner.


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RE: how to get rid of cirtus leafminer

Thanks for the info everyone. The Green Light does not say cold pressed, it says Clarified Hydrophobic Extract of Neem Oil - glad I asked. I do get complete control of leafminers from Spinosad, but I would like to have another weapon in my arsenal that does not harm beneficials. Now what to do about the glassy winged sharpshooter...

Thanks, Chris


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RE: how to get rid of cirtus leafminer

I just bought a couple of grapefruit and lemon trees from Lowes and one of the trees had serious leafminer damage (but the trees were a bargain!). I put the trees on the North side of my house (awaiting when I will have time to transplant them) and in a day wasps were swarming it, feasting on the miners, presumably. Interestingly enough, I have other citrus trees in other warmer, sunnier parts of my yard and the wasps don't seem to be as interested. I don't know if it's a coincidence. Maybe the wasps prefer to eat miners in the shade.


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RE: how to get rid of cirtus leafminer

Regular wasps? They don't feed on leaf miners...they can't get to the tiny things. I've seen wasps swarm citrus because of scale insects (and their sweet honey-dew) and caterpillars.

If you've observed tiny wasps (gnat sized), they may be parasites of scale, aphids, or caterpillars.


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RE: how to get rid of cirtus leafminer

Attachment shows photos of the tiny wasps (pages 4 and 8).

Here is a link that might be useful: UC Pub


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RE: how to get rid of cirtus leafminer

Last year I started using these pheromone lures and sticky traps for the citrus leafminer and they seem to work pretty good. I have a Meyer's lemon tree that had leafminers all over it, so I put the traps up and they were loaded with the little buggers.

I still use Spinosad, but not as much. It's also nice to have a backup that doesn't harm beneficials.


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RE: how to get rid of cirtus leafminer

I've been battling this problem for about 5 years here in Southern California and have, after a lot of effort, gotten it under control.

The only way to effectively combat Citrus Leafminer is through judicious use of insecticides. I alternate between Spinosad and Malathion. They kill pretty indiscriminately, so they should only be applied when there are flushes of new growth. You'll get lots of new growth on younger plants if you apply high nitrogen fertilizers (as I do). You'll get less new growth on older, more mature plants, whether or not you apply fertilizer. You'll get less new growth during the winter, more during the summer.

What you have to keep in mind is that if you allow the new leaves on young plants to become damaged because you are worried about applying insecticides, then the tree won't grow. I want healthy, fruit producing trees, and am willing to put up with killing a few other insects along the way if that is what it takes.

I planted a very small (5 gallon) Blood Orange about 5 years ago. It was hit hard (and almost killed) by the leafminers almost immediately. Since I got on the Spinosad/Malathion regimen, it has grown to about 12-15 feet tall and doesn't have a single damaged leaf! New growth is mainly in the summer months. During this time, the tree needs to be sprayed about every other week. The rest of the year, it doesn't need much attention. Since the fruit (lots of it now) ripens in the winter, this is a good thing.

I have a mature Washington Naval Orange and a mature Bearss Lime. They get by on one or two applications of insecticide during the entire year - in early summer.

The real challenge though is with lemon trees. They are constantly sending out new growth, meaning that they constantly need to be sprayed in order to prevent the new leaves from being damaged. I have a Eureka Lemon and a Pink Lemonade Lemon. Both trees are about 4 years old. If I go more than 3 weeks without spraying, I notice leafminer damage.


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RE: how to get rid of cirtus leafminer

Anyone know where I can purchase the Spinosad treatment?


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RE: how to get rid of cirtus leafminer

I am getting it from our local ACE under the brand Fertilome (I think). Basically, any decent nursery should have spinosad-based insecticides.


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RE: how to get rid of citrus leafminer

Those of you opting for Spinosad. Please don't use it while your trees are in flower. If you do you may just kill every bee that comes to pollinate you're trees. Spray before they have flowered and after there are no more flowers on your trees.


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RE: how to get rid of cirtus leafminer

And please understand that the more frequently you use broad spectrum chemicals to 'control' a specific pest, the more likely you will have a rebound effect. It is well documented that the more you use those chemicals, the more likely you will be locked into major pest control for the life of the plant. Mites and scale insects are likely to enter the picture pretty quickly.

Has anyone tried 'Surround WP' for the control of leaf miners? Would seem a very worthy experiment, considering how useful the stuff is for a wide range of other plant-eating pests. As always, the timing of the application is important. Call your extension service to find out the approximate time for the emergence of the first leaf miner generation. That's the ideal window to apply Surround or Neem. Heck, any horticultural oil can deter leaf miners if applied at the right time.


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RE: how to get rid of cirtus leafminer

Myths about Asian Ctrus Leaf Miners, ACLEM

No Predators
We used to have some little flying critters that would catch white flies "on the wing". They looked a little like
flies but were more dainty and had swept wings and irredescent eyes and abdomens. Most of them were chartreuse color. Some had orangey streaks. Think they also were catching the adult moths. The miners were inactive when the flies had good numbers. One year that lasted through September. Then mosquito control to suppress West Nile Virus became the fad. I dont even have assassin bugs left.

Nothing can get them inside the leaf.
We also had an ant that rumages around on the trees and when it came to a miner inside the leaf it would cut it out and eat it. Hurricane Ike blew almost all them away.

Use Oil.
You can't use oils at ambient temps > about 92 deg F and you better have a highly purified one over 85 deg F. Our miners dont get active until I can't use oil.

ACLEM doesnt hurt your trees.
More love 'em to death nonsense. They are a catastrophy for young trees. They even get into the bark of tender shoots. Trees will be stunted. The wounds let in disease and stresses the trees in times of heat. This one is not as bad as Orange Dog catipillar though, which can destroy the proper shape of the tree.
by eating needed young branches.


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RE: how to get rid of cirtus leafminer

There are many parasitoids of leaf miners, a more accurate term than 'predator'. In an environment where these parasitoids can flourish, they are capable of keeping leaf miner damage to a minimum.

Parasitoids tend to be quite species specific. In other words, not all of them will use the citrus leaf miner as host. But there are many that DO!

Most parasitoids are tiny (gnat sized) wasps, which lay their eggs into the leaf miner larvae located in their little mines. Another important insect order for parasitoids is Diptera (the fly, mosquito, gnat order)

There are parasitoids for just about any pest insect, it seems, lol. 'Drilling' though a layer or two of plant cells to get to their quarry is nothing for these highly specialized little animals. There are species that go after larvae in woody branches and even tree trunks!

Of course, if you are interested in observing parasitiods at work, chemical sprays cannot be used. This includes organic products and oils, too.


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RE: how to get rid of cirtus leafminer

Rhizo:
While you're usually dead on, I used the term predator for citrus leaf miners spicifically since I have seen the "flies" catching mainly white fly and also saw them all over my trees when adult miners were in there. Because of the miner's erratic flight and dull grey/buff coloration I never saw one being caught in flight. But if I would shake a limb with the miners on it the "flies" would swoop in and act like they were trying to catch something. If they were not, they fooled me.

I also try to use some "organic methods" (it really is a stupid and misleading term). I keep as many tiny blossom plants on my grove as I can. Now I have hairy vetch which will be blooming and attracting bees in a few weeks. I dont know if it is small enough to attract the parasitic wasps or not but it will have primed my grove with swarms of bees by the time citrus begins to bloom in March. And the vetch adds nitrogen to the soil. After that wild carrot will take over. I use that instead of other carrot/dill family because it is naturally reseeding and only required that I try to leave as much of it as I can when weeding chickweed. That stuff will bloom till summer sets in. I used to add a little celantro growing among the trees just because I like the flavor but the carrot is enough now.

Then in summer is time for basil/mint family. Oh, Thai/Vietnamese purple top basil and cinimmony fragrant red leaf Perilla are so good in a salad,soup or spring rolls and they grow around the trees and bring in so many beneficials. Perilla reseeds also. Pull it up in the actual citrus beds, keep it around the edges since it attracts rootknot neematodes.

About oil. When I spray anything which is really rare, I shake my trees to get rid of the lacewings, assassin bugs and lady bugs. I also try to do it when they tiny beneficials population is down. I have not used oil on miners in so many years I cannot remember, but when I did, it was in late May or early June. I Do not use it in the fall since it is alledged to lessen citrus' cold hardiness. I think the wild carrot is the reason I don't need it much. I dont think the soybean oil kills my tiny wasps when applied as above. But who sees them anyway.


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RE: how to get rid of cirtus leafminer

I'm still 'dead on', lol. And so are you! I just didn't make myself clear. What you have observed catching the darn little moths are clearly predators, if they were trying to catch them in mid air. The little guys (er, gals) that lay the eggs into the leaf miner larva are the parasitoids.

A bit of a change of subject...several years ago I was sitting on my patio and noticed a swarm of little somethings attacking a nearby Camellia japonica. I got up to inspect closer and saw that they were tiny parasitic wasps laying eggs in a very small population of tea scale. The scale were clearly outnumbered by the tiny wasps.

I know what you mean about the term 'organic methods'. But I think that everybody knows what you're talking about when you use it. I often find myself using the words 'so called' in front of the word organic because I'm uncomfortable with it.

Whatever you call it, you've got the right idea, that's for sure!


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RE: how to get rid of cirtus leafminer

I have four year old kiffer lime tree in my yard. I was late on realizing that the tree has been infested by citrus leaf minersince april.

This morning, I cut off all the new young leaves because they're all have white "tunnels" and curled like crazy.

I have been trying to grow more leaves since I use kiffer lime leaves for cooking but it seems this year I have to wait a bit more. :(

On another note, I've noticed that there are lots of black ants near the young leaves. Anybody know if the ants are eating the citrus leaf miner or are they helping them ?

I am assuming they're eating the citrus leaf miners but I'm surprised the leaf miners are still alive with that many ants around.

Also should I buy ladybug to control the pests? It's already september, so I'm not sure if it's worthwhile to do so since the growth season has passed.


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RE: how to get rid of cirtus leafminer

I would LOVE to find a way to get rid of leaf miners. I have more than ever this year, probably because I have more citrus than ever but maybe because we had a really mild winter here. I read some of you are removing leaves with live miners in them. I have read you shouldn't remove the leaves since they still provide photosynthetic activity for the tree even if they do look awful. I have tried putting on magnifying glasses and squishing the larve in the leaves of a potted tree I have but I don't think I really helped in spite of the larvae I killed. I wonder if one could use a shop vac and just suck the adults out of the air on a daily basis for a while. The adults seem to be the weakest link and killing one adult means lots of eggs fail to be laid. I may look into the pheromone sticky traps. The good news is I think the leaf miner season is about over here because the new leaves are beginning to look better.


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RE: how to get rid of cirtus leafminer

I had bad infestations 2 years ago. The only thing I found that stopped them was Spinosad period. I tried oils to no avail. Not sure if the infestation was just too bad. I bought it a Lowes and Home Depot under the name Captain Jacks Dead Bug.


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RE: how to get rid of cirtus leafminer

John, I've posted on this so many times on the forum, I think at this point, I'm just going to refer you to any one of my many posts on CLM :-) Just search for CLM and you'll see my and many other posts. Two choices - Imidacloprid or Spinosad. Both work very well for me. Timing is essential, especially for a systemic.

Patty S.


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RE: how to get rid of cirtus leafminer

Patty, are you feeling like a broken record? I have seen many of your other posts on control of leaf miners and appreciate them. I have some trees that are at least a year from fruiting or flowering so I'm not as reluctant to use systemics on them. I looked for Spinosad at Lowes yesterday evening....gotta start carrying cheater glasses with me if I'm going to have to read those tiny labels.


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RE: how to get rid of cirtus leafminer

John, you aren't going to find it at bLowes or Home Dopey, at least based upon the ones in SoCal. They specialize in the mass market stuff and generally respond to the vendors pushing stuff at them at low cost. They tend to carry junk, with some notable exceptions of decent items that are are in good supply or readily available. The good is that when they do have something decent, it is generally inexpensive. Can you imagine trying to build something out of what they call lumber? That is just sad.

You should have no problem at any real nursery. The stuff I bought was Captain Jacks Dead Bug from Bonide. If your nursery has Monterey products that would be labeled Spinosad.

Patty deserves a reward for answering the questions over and over and over for people that don't search for previous answers.


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RE: how to get rid of cirtus leafminer

Well, I buy my Spinosad from amazon.com (Green Light), and if temps allow, I will mix it with Volck or Neem oil (not this summer, though, it's been brutally hot these last weeks). I do treat my citrus systemically with Imidacloprid twice to three times a year, which I hate to do, but, we have had sightings of the ACP here in N. San Diego county about 10 miles from me, so I have no choice, sadly. When I do spray with Spinosad, I do it after the bees have gone back to the hive, and I make sure to not spray any blossoms (sometimes hard to do, but I will use a little cup to cover up the flowers). The only reason I mix the Spinosad with hort oil is to allow it to stay stuck longer, not so much for the insecticidal effects of hort oils (although right now, I am seeing some spider mite damage here and there, so I could get a little double duty if I could use it!) I try very hard to stay as close to 100% organic as I can. I eat my fruit, and I want to know exactly what I'm eating, not so thrilled about having to eat Imidacloprid. But, until the "race for a cure" can come up with something to protect my trees from HLB, I'm having to treat for ACP, now, just to save my rather hefty citrus investment.

Patty S.


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RE: how to get rid of cirtus leafminer

Just to clarify though, I too have a CLM issue, but it's really hot here in San Diego now (expecting mid 90s tomorrow), and my tree is blooming, so this is NOT the time to use the spinosad, right? Wait another few weeks for temps to cool a bit and this flush of blooms to finish up?


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RE: how to get rid of cirtus leafminer

I've had no problem spraying Spinosad in the heat, it was 97 today & going to be 100 tomorrow. It is mixing it with Neem, and I assume any other oil, that will burn leaves in hot weather. I know I've used it in the evening when it was still high 80s and going to be 100+ the next day with no problems.

They do say to make sure you spray 3 hours before there would be any bee activity. I spray in evening after the bees go home and it will be 10 hours before the bees come back. I usually avoid the flowers just to be extra protective of the bees.


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