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.

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

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).

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

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

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.

Thanks, Chris

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

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

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.

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.

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.

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.

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.

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!