Preventing Leafminers and Citrus greening

[fyliu]

garlic is not an antibiotic. It can probably kill some bacteria on contact but that's it. Antibiotic generally refers to some substance produced by fungi to defend against bacteria invasion. Bacteria reproduce faster than fungi so fungi produce drugs to kill them or slow them down.

Antibiotics are not elements; they're molecules, so they may be broken down or rendered inactive by various things like water, light, ..., dilution. You can't just want to use a certain antibiotic and will it to remain intact and in a high enough concentration as it goes into soil and into plants.

Copper is used as a fungicide. It's at least more stable I guess.

[countryboy1981]

I knew it wasn't an antibiotic but has anti bacterial properties.  Copper does kill bacteria also but would not be healthy to consume the fruit after drenching the soil with it.

[Tropheus76]

CLM mostly leave my pummalo alone, but they love tearing up both my lemon trees and my mandarins. They aren't very nice to my key lime either but it is large and bushy enough I pretty much ignore them. They don't touch my finger lime and I do nothing preventative on it.

[fyliu]

What I meant was that many of the common substances are not stable enough to last the whole journey into the plant. That's maybe what makes them mostly harmless. The chemical companies figured out some compounds that do have this stability and a dosage that don't last until fruit harvest, and they make them into pesticides. So we really should follow the label directions so we don't end up poisoning ourselves.

[Doglips]

I don't believe copper gets ingested by plants, but if the roots touch it, they die.

[marklee]

The way I combat the leaf miners is force the flush early with nitrogen and by the time may or June rolls around with the leaf minor onslaught the leaves are already hardened off and there is no damage to the young leaves.

[fruitmentor]

For those in southern California in areas where eradication of ACP is no longer an option, there are some things that you can do to help short of using imidacloprid.

You can check your trees for psyllids. If you find psyllids, spray with soap or oil -- these do not harm the biocontrol efforts that are underway.

Argentine ants protect ACPs like they do other insects. If you keep the argentine ants off of your citrus trees, the biocontrol will be more effective. The parasitism rate is much higher when there are no ants on a tree. If there are ants on a tree, the psyllids have protection from the parasitic wasps.

[Millet]

In Texas, the general public are engaged directly in biocontrol by offering their own neighborhood lemon or lime trees for the mass production of a wasp variety (T. radiata) that kills the Asian Citrus Psyllid (ACP). Cages are being placed over their personal trees and then infested with the ACP, and the biocontrol wasps are then released into the enclosure.  USDA's Daniel Flores, Ph.D. developed this innovative approach that allows the biocontrol wasp to mass reproduce in the cage, by laying their eggs in the psyllids yielding up to 12,000 wasp per caged tree.  After the cage is removed, the biocontrol parasitoid wasps can freely move on their own to all the citrus trees in the area.   The entrepreneur who designed the cages, David Ways of Skeeta, Inc., worked with the USDA in Mission, Texas to create, test and redesign the cages to accommodate different tree sizes and to increase portability.  It resulted in two designs that can be adjusted for various tree sizes and fold up to the size of a king sized pillow.  The cages cost an average of $1,500 per unit and provide an effective, reusable tool most suitable for door yard citrus in urban areas.

Millet
This article was taken from  the Citrus Research Board's Citrograph Magazine.

[Samu]

I treated my citrus trees last February; and today none of my citruses have CLM attacks. (Unlike years 2014 and 2015, where by this time CLM were going wild in our house).

Per Rob's suggestion on another similar post (http://tropicalfruitforum.com/index.php?topic=19867.0) I need to do this 3x/year at label's strenght?!

Wow..., let me get up from my chair right now, and start mixing and drenching again! 

Thanks again guys!

[bsbullie]

I actually said that was for "our" or "my" area which is south Florida.  With our climate,  CLM seems to be prevalent year round.  You may be able to get away with treatments twice a year.

[Samu]

Yes, you are accurate, you did mention it's for your area (S. Florida) on that other post; I was just reading that too quickly.  Thanks for that clarification, Rob!

Anyway, I did my 2nd drench, that should do it for this year, I hope...

[laidbackdood]

Leafminer does not attack the first flush of the year, but starts their attach with the second flush. - Millet

Does this apply everywhere millet.......even down under?

[Millet]

laidbackdood, I'm not 100 percent sure about Australia, but I would think it would be true there also. - Millet

[bsbullie]

From an IFAS publication:

Citrus Leafminer

Adults of the citrus leafminer (Phyllocnistis citrella) are tiny moths that hide within the canopy during the day and emerge at night to lay eggs individually on young, expanding leaf flushes. The egg first appears as a tiny dew drop, usually alongside the midvein on the underside of an unexpanded leaf. The larva emerges directly into the leaf tissue, mining first along the midvein, then back and forth as it makes its way to the leaf margin, where pupation occurs.

Leafminer populations decline to their lowest levels during the winter, due to cool temperatures and the lack of flush for larval development. Populations of leafminer build rapidly on the spring flush, although their presence is not apparent until late spring, as populations increase while the amount of new foliage decreases. Throughout the ensuing warm season, leafminer populations vary with the flushing cycles, and subsequent flushes are often severely damaged. The summer period of high leafminer damage coincides with the rainy season when canker spread is most likely.

Citrus leafminer greatly exacerbates the severity of citrus canker caused by Xanthomonas axonopodis pv. citri. This insect is not a vector of the disease. Nevertheless, leafminer tunnels are susceptible to infection much longer than mechanical wounds. Tunnels infected by canker produce many times the amount of inoculum than in the absence of leafminer. Control of leafminer should be optimized in areas where infection by canker is high. Natural enemies already present in Florida have responded to leafminer infestations, causing up to 90% mortality of larvae and pupae. These natural enemies include the introduced parasitoid Ageniaspis citricola that has established throughout most of Florida and is responsible for up to 30% of this mortality, mostly later in the year.


As we in South Florida tend to have warmer winters, I have seen CLM attacks hit early year flushes.

[Samu]

Just an update:
this morning I noticed that some of my Valencia orange young leafs have Leafminers in them! My other citrus trees (6) appear to be Leafminers free, so far this year.
So, for the 3rd time this year, drenching with  imidaclropid mix (1.5G mix at 1.5oz/G) applied to this tree.
Will see what happens the rest of the year... 

[mrtexas]

From an IFAS publication:

Citrus Leafminer

Adults of the citrus leafminer (Phyllocnistis citrella) are tiny moths that hide within the canopy during the day and emerge at night to lay eggs individually on young, expanding leaf flushes. The egg first appears as a tiny dew drop, usually alongside the midvein on the underside of an unexpanded leaf. The larva emerges directly into the leaf tissue, mining first along the midvein, then back and forth as it makes its way to the leaf margin, where pupation occurs.

Leafminer populations decline to their lowest levels during the winter, due to cool temperatures and the lack of flush for larval development. Populations of leafminer build rapidly on the spring flush, although their presence is not apparent until late spring, as populations increase while the amount of new foliage decreases. Throughout the ensuing warm season, leafminer populations vary with the flushing cycles, and subsequent flushes are often severely damaged. The summer period of high leafminer damage coincides with the rainy season when canker spread is most likely.

Citrus leafminer greatly exacerbates the severity of citrus canker caused by Xanthomonas axonopodis pv. citri. This insect is not a vector of the disease. Nevertheless, leafminer tunnels are susceptible to infection much longer than mechanical wounds. Tunnels infected by canker produce many times the amount of inoculum than in the absence of leafminer. Control of leafminer should be optimized in areas where infection by canker is high. Natural enemies already present in Florida have responded to leafminer infestations, causing up to 90% mortality of larvae and pupae. These natural enemies include the introduced parasitoid Ageniaspis citricola that has established throughout most of Florida and is responsible for up to 30% of this mortality, mostly later in the year.


As we in South Florida tend to have warmer winters, I have seen CLM attacks hit early year flushes.

I thought the CLM pupates in the soil in the winter? I've had CLM appear as early as April 1 and as late as September 1 here hear Houston,TX. This year it was mid May. I hit them with spinosad and haven't seen another one yet.  The first flush here would be in March so they most likely wouldn't be active then.

[fyliu]

When do you spray the spinosad? Is it when the leaves are just growing or when they are curly? Or maybe for a few days?

[Tom]

One year I sprayed imadaclorpid early to 'clean up' lots of insects including leaf miners, aphids and scale insects in my citrus which is small scale <50 plants. I had the worse problem with scale and aphids ever. I'm guessing, and found some collaborative information, that I killed all the beneficials and the existing bad bugs too but the bad bugs came back with a vengeance. I've made a conscience effort to use horticulture oil more often or imadaclorpid as a soil drench. Spraying imadaclorpid did not work out well for me ! I've briefly read comparisons of Spinosid vs imadaclorpid that said Spinosid is more toxic on some things. I also read that imadaclorpid is the most used chemical to kill aphids all over the world but the aphids are getting resistant to imadaclorpid.

Bottom line, I don't know how to time a spray to effectively kill leaf miner months so with my experience I would have to drench imadaclorpid early IF I had a bad history of leaf minor damage. Most of my citrus is bigger now and leaf minor is not a major problem for me. I certainly have some damage and each spring I consider drench or spray but so far I have only drenched very small citrus plants. I would drench larger plants if necessary.

If using oil be careful of hot temperatures. I can't explain why oil doesn't seem as toxic on beneficials. It might be just as deadly ! When I use oil the additional benefit is it helps clean up sooty mold better than anything I've ever tried. With oil I've never had the huge rebound of bad insects that I experienced when spraying imadaclorpid. This was not a scientific experiment and I would not want to try to replicate the results !

We owned and operated the third largest pecan orchard in Alabama years ago (200 acres ). I let an extension agent use the back 10 acres for an experiment with chemicals and aphids. I can't remember if he did the whole test or just a portion in our orchard but his overall conclusion was spraying more often early causes the necessity of spraying more later. On our block or maybe just a small part he never had to spray! All that is fine but if you have a bad insect problem you better spray. Just be sure the initial spray is necessary meaning observe all threshold levels for IPM or you can cause worse problems that even money can't cure !

Tom

[buddinman]

I have minor leaf miner damage already this year. Normally they do not attack until July. We had a real mild winter. The small white moths are in the lawn and fly when the grass is mowed.

[Tropheus76]

I have a fair amount this year as well and I have been spraying spinosad every couple weeks. Guess I missed a stage. We had an extremely mild winter, even my coconut palm made it through without protection so I am not surprised the leafminers didn't get neutralized by winter this time around. Once again though, my pummalo and red finger limes have no sign of CLM, its really weird and my big no clue what it is orange tree (12 foot or so) has no sign as well and I do nothing to it, I don't even water it.

[Popo1984]

I had them mid april on my Meiwa but they just attacked my Cara Cara last week and got every leaf of the newest flush. I may try spinosad and see if that prevents any further damage.

I thought the CLM pupates in the soil in the winter? I've had CLM appear as early as April 1 and as late as September 1 here hear Houston,TX. This year it was mid May. I hit them with spinosad and haven't seen another one yet.  The first flush here would be in March so they most likely wouldn't be active then.
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