Author Topic: Can I cut citrus leafminer damaged leaves?  (Read 237 times)

EricSC

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Can I cut citrus leafminer damaged leaves?
« on: June 09, 2021, 02:00:01 AM »
Today, I found 4-5 citrus leafminer damaged leaves, not many.   Can I cut them? 

 The trees have most fully developed leaves, with a few of new growths.   If not many new leaves get CLM, can I continue monitoring and cutting?   I will also use insecticidal soap to spay on the new growths.

JakeFruit

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #1 on: June 09, 2021, 09:01:21 AM »
Removing leaves doesn't control CLM; unless the larvae/pupa are still within the leaves, you should leave them on the tree. Even if the leaves look completely mangled, the tree can get something from them and will abandon them on its own. Flipping a newly damaged leaf over, you should be able to see if the bug is still there. If you don't have young eyes, use a magnifying glass to make spotting them easier; they are tiny. Just pinch the flat leaf whenever you find one, you'll feel a tiny squish from the bug when you crush it.

I battled CLM all last year. The spot in my yard where I have the potted citrus is crazy with them. I gave up on timing fertilizers and using neem oil, spinosad sprays in the evening every 3-4 weeks has kept them under control so far this season. Also, I've given trees to my next door neighbor (maybe 50 yards from my trees) and a friend around a mile away; their trees don't get bothered by CLM at all. If you can move your tree(s), even a little, it might help.

EricSC

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #2 on: June 09, 2021, 01:01:57 PM »
JakeFruit,

Last a couple of years, I had so much of CLM.  Surely I didn't do much with them but they remembered my tree very persistently.

This year, all of my trees have healthy leaves with no CLM until this week, with small amount of new leaves emerge.   About 3-4 very young leaves were found with the CLM trails.

I will spray the young flush with soap plus peppers and rosemary extract.  If it does not work, will switch to use more powerful methods as yours.

Thanks.


Millet

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #3 on: June 09, 2021, 01:12:32 PM »
As Eric wrote above it would be a mistake to remove leaves that he miner has damaged.  Those leaves still produce energy for the tree.  Spinosad is a very helpful spray used by MANY citrus growers to control the insect.

JakeFruit

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #4 on: June 09, 2021, 03:17:26 PM »
New growth is what they like; if I can get new leaves through the first week or so, they seem to leave them alone.  I try to avoid using manmade toxins to control garden pests, but neem oil wasn't doing anything. Spinosad is organic, it originates from soil bacterium. Just be sure to use it close to sundown, when all the bees are done for the day (it is toxic to them and they can bring it back to the hive). From what I read, once it dries, it's harmless to the bees (you can avoid spraying it on any flowers, if you really want to be sure the bees don't encounter it). Also mix it with a little soap so that it adheres well and watch the weather, it'll wash off if you get much rain.

EricSC

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #5 on: June 09, 2021, 04:42:50 PM »
So far, it only happened to 3-4 leaves among about 50-100 of new shoots.   The flushes have been treated with soap water/pepper/rosemary every 3-4 days, so will closely monitor it in next a few of weeks.

Millet

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #6 on: June 09, 2021, 05:01:53 PM »
Although spinosad has low toxicity to most beneficial insects, initial acute laboratory tests indicated that spinosad is intrinsically toxic to pollinators. The hazard of spinosad to bees was evaluated using a tiered approach. Initial acute laboratory exposures were conducted, followed by toxicity of residues of spinosad on treated foliage, greenhouse studies to assess acute as well as chronic toxicity, confined field assessments, and finally full field studies using a variety of crops under typical use conditions. These data were used to assess the potential of adverse effects on foraging bees following the use of spinosad. This research has clearly demonstrated that spinosad residues that have been allowed to dry for 3 hr are not acutely harmful to honeybees when low-volume and ultralow-volume sprays are used. Further, glasshouse and semifield studies have demonstrated that dried residues are not acutely toxic, and although pollen and nectar from sprayed plants may have transient effects on brood development, the residues do not overtly affect hive viability of either the honeybee or the bumblebee.  (Copied from research trials)

SoCal2warm

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #7 on: June 09, 2021, 10:44:59 PM »
Can I cut citrus leafminer damaged leaves?
You can cut them off, if there are not too many of them. But keep in mind you will probably still have to give the tree a spray treatment.

It's debatable whether cutting off the leaves will really help. The deformed leaves can still be somewhat functional for the tree, but they may contain larvae inside of the leaves. The larva will hatch out of the leaves in about 25 to 30 days, and if the leaves have been saturated in spinosad spray at the time they emerge out, they should die. So there is not necessarily a need to remove the leaf.

The main treatment involves making sure the small newly formed leaves are sprayed, to prevent new leaves from becoming infested, because leaf miners prefer to lay their eggs in the smaller newer leaves.
« Last Edit: June 09, 2021, 10:46:32 PM by SoCal2warm »

John B

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #8 on: June 09, 2021, 11:44:42 PM »
Interestingly enough, leaf miners are only going after my Eureka. Right now they started showing. They only seem to make the tree look a bit off. Never seemed to affect production. I just go out and squish the larvae. My kids seem to enjoy it too. I try to avoid spraying if I can.

Laaz

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #9 on: June 10, 2021, 05:52:37 PM »
If the plant is not yet producing fruit, use Bayer Advance & the leaf miner are gone...

EricSC

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #10 on: June 11, 2021, 12:14:43 AM »
I only found them on 4-5 new leaves of Eureka.  Not much from other citrus trees yet.  I spay the new growth with soap/pepper/rosemary every week but these 4-5 leaves might be missed.   So will continue monitoring.

Yorgos

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #11 on: June 11, 2021, 09:52:36 AM »
Can I cut citrus leafminer damaged leaves?
You can cut them off, if there are not too many of them. But keep in mind you will probably still have to give the tree a spray treatment.

It's debatable whether cutting off the leaves will really help. The deformed leaves can still be somewhat functional for the tree, but they may contain larvae inside of the leaves. The larva will hatch out of the leaves in about 25 to 30 days, and if the leaves have been saturated in spinosad spray at the time they emerge out, they should die. So there is not necessarily a need to remove the leaf.

The main treatment involves making sure the small newly formed leaves are sprayed, to prevent new leaves from becoming infested, because leaf miners prefer to lay their eggs in the smaller newer leaves.
My experience is that once the leaves start to curl, the miner is no longer in the leaf, it having pupated.  So, removing the leaf seems counterproductive to CLM control and limits the trees ability to produce its food. 
Near NRG Stadium, Houston Texas. USDA zone 9a

EricSC

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Re: Can I cut citrus leafminer damaged leaves?
« Reply #12 on: June 11, 2021, 01:41:41 PM »
Thanks all for the valuable info.    Last two years it did a lot of damages to the young trees.  So, hopefully, I can manage it to some levels.