Lethal bronzing disease - Can we stop it?

[Maximum]

I read online that leafhoppers are the primary spreader of LBD. What are their natural predators? Birds? And what can we as individuals and as a community do to decrease the population of leafhoppers and protect our palms from getting LBD?! 

Edited December 24, 2023 by Maximum

[Silas_Sancona]

  On 12/24/2023 at 10:35 PM, Maximum said:

I read online that leafhoppers are the primary spreader of LBD. What are their natural predators? Birds? And what can we as individuals and as a community do to decrease the population of leafhoppers and protect our palms from getting LBD?! 

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Can't stop it, Only plant stuff that is resistant...

You'd have to kill any and every insect world-wide  that is considered a " sucking " insect, that is capable of transmitting the pathogen that causes Lethal bronzing ..or any other plant disease.. 

By killing .....a heck of a lot of insect species...., you throw things out of balance ( Lots of Birds, Lizards, other insects consume those " sucking " Bugs ) ..which will only cause more problems.

Typically,  " Pest " insects only become issues when the environment is ideal for them to thrive ..Often because there is a lack of predators to keep X pest insect's #' in check.  Often, it is plants that are already weakened by some other stress issue that end up a target of the " bad " bugs " / are more susceptible to infection by X plant killing pathogen. 

Dumping pesticides all over everything won't solve issues /eradicate X bug ..The Leaf Hoppers that can carry and transmit LBD in this case.. ..Many bugs just become more resistant to them..  Bacteria can also become resistant ( Not sure about Fungi though.. )  ..Look at the emergence of " Super Bugs " Caused in part by every paranoid person turning to antibiotics ..for a cold.. 

In the case of LBD, don't plant anything that is highly susceptible, and do everything possible to increase the #s of the birds, lizards / snakes / frogs ..and other bugs, that eat the bad bugs.. roaming  your yard. ...  Those are the Only  things that will lessen the chance(s) of LBD turning up in your garden.

FYI, Have Milkweed in your yard,, and see that is full of Gold- colored  Aphids?  Leave them alone..  Aphids that like Milkweed ..only like Milkweed.. Evolved together. 

[Silas_Sancona]

An interesting, fairly recent article that may offer some hope at management ..but not full eradication of LBD. 

Concept, which makes perfect sense, and would have far less of a negative effect -if any- on the environment compared to trying to get rid of all the present, ..and any other potential carrier(s) of the bacteria that causes LBD,   could be used to manage other significant plant diseases in the future too.. 

https://blogs.ifas.ufl.edu/news/2023/05/31/uf-ifas-study-leads-to-milestone-advances-in-understanding-lethal-bronzing-of-palm-trees/

[Maximum]

  On 12/25/2023 at 12:01 AM, Silas_Sancona said:

An interesting, fairly recent article that may offer some hope at management ..but not full eradication of LBD. 

Concept, which makes perfect sense, and would have far less of a negative effect -if any- on the environment compared to trying to get rid of all the present, ..and any other potential carrier(s) of the bacteria that causes LBD,   could be used to manage other significant plant diseases in the future too.. 

https://blogs.ifas.ufl.edu/news/2023/05/31/uf-ifas-study-leads-to-milestone-advances-in-understanding-lethal-bronzing-of-palm-trees/

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I read the article. Super interesting! Definitely gives me hope! 

[Looking Glass]

  On 12/24/2023 at 10:35 PM, Maximum said:

I read online that leafhoppers are the primary spreader of LBD. What are their natural predators? Birds? And what can we as individuals and as a community do to decrease the population of leafhoppers and protect our palms from getting LBD?! 

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Eliminate all turfgrass.  Lawn grass near the palms is requirement for this disease.  The nymph stage is exclusively grass feeders and live in the thatch layer.  If you truly are serious about doing something to help eliminate this disease, get rid of your lawn, especially if it is St Augustine grass.  

https://entnemdept.ufl.edu/creatures/orn/palms/palm_cixiid.htm

Edited December 25, 2023 by Looking Glass

[Maximum]

  On 12/25/2023 at 12:50 PM, Looking Glass said:

Eliminate all turfgrass.  Lawn grass near the palms is requirement for this disease.  The nymph stage is exclusively grass feeders and live in the thatch layer.  If you truly are serious about doing something to help eliminate this disease, get rid of your lawn, especially if it is St Augustine grass.  

https://entnemdept.ufl.edu/creatures/orn/palms/palm_cixiid.htm

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I can’t believe I’m saying this but I wish FL law would ban planting turfgrass to save the palms 😂 I have a lawn and I don’t want to have it removed because it’s a beautiful lawn. But if I were forced to remove it? Then I’d remove it and we’d be better off! Sometimes people (including myself) need extra incentive to do the right thing! I can’t stand seeing palms die from LBD! 

Edited December 25, 2023 by Maximum

[Merlyn]

I'm sure I posted this elsewhere, but I did hours of searching on the original Lethal Yellowing outbreak and Lethal Bronzing.  I could find no scientific studies that proved or disproved the transmission method of LY or LB.  There were studies that found the LY in the gut of the leafhoppers, so it's nearly 100% guaranteed to be one of the transmission vectors.  But there's no study where they took leafhoppers that fed on an infected tree, tested to prove the leafhoppers had LY phytoplasma in their guts, then stuck them in an isolated known-uninfected coconut and proved that it was then infected with LY by the leafhoppers.  That seems to be a very simple and easy thing to do.  But I couldn't find any study that did this, or anything like it.

There's a claim on UFL (and other websites) that LY and/or LB *cannot* be transmitted by pruning tools.  There appears to be precisely zero evidence that this is true, and no published studies on it.  Every other fungal and bacterial disease is known to be transmitted by infected pruning tools, so I have no idea why this particular disease is different?  Here's the statement on the UFL/IFAS site:

• The LB phytoplasma is limited to the phloem (sap) of the palm and cannot survive outside a plant or insect; therefore, it cannot be mechanically transmitted (e.g., by pruning tools or infected roots touching new roots).

I'd love to see an actual scientific study show that this is true.  But as far as I can tell, there has never been one done on LY or LB.  Maybe sunlight or exposure to oxygen kills the phytoplasma in milliseconds.  But if you clip a palm frond with loppers or chainsaw, that phloem is stuck in the chain or between the blades.  Absent some actual scientific proof, I'd still consider pruning tools as a possible transmission vector.

[Maximum]

  On 12/25/2023 at 3:02 PM, Merlyn said:

I'm sure I posted this elsewhere, but I did hours of searching on the original Lethal Yellowing outbreak and Lethal Bronzing.  I could find no scientific studies that proved or disproved the transmission method of LY or LB.  There were studies that found the LY in the gut of the leafhoppers, so it's nearly 100% guaranteed to be one of the transmission vectors.  But there's no study where they took leafhoppers that fed on an infected tree, tested to prove the leafhoppers had LY phytoplasma in their guts, then stuck them in an isolated known-uninfected coconut and proved that it was then infected with LY by the leafhoppers.  That seems to be a very simple and easy thing to do.  But I couldn't find any study that did this, or anything like it.

There's a claim on UFL (and other websites) that LY and/or LB *cannot* be transmitted by pruning tools.  There appears to be precisely zero evidence that this is true, and no published studies on it.  Every other fungal and bacterial disease is known to be transmitted by infected pruning tools, so I have no idea why this particular disease is different?  Here's the statement on the UFL/IFAS site:

• The LB phytoplasma is limited to the phloem (sap) of the palm and cannot survive outside a plant or insect; therefore, it cannot be mechanically transmitted (e.g., by pruning tools or infected roots touching new roots).

I'd love to see an actual scientific study show that this is true.  But as far as I can tell, there has never been one done on LY or LB.  Maybe sunlight or exposure to oxygen kills the phytoplasma in milliseconds.  But if you clip a palm frond with loppers or chainsaw, that phloem is stuck in the chain or between the blades.  Absent some actual scientific proof, I'd still consider pruning tools as a possible transmission vector.

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I agree! How do you like to disinfect your pruning tools?
A 70% isopropyl alcohol spray?
A water and bleach solution? 
Disinfectant wipes? 
Etc? 

[Hurricanepalms]

On the topic of disinfecting pruning tools, I use a small natural gas canister with a torch attachment. You can buy them at Ace and other hardware stores for around $10. It does a phenomenal job. A single canister has lasted me up to 2 years with quite a lot of use. 
 

On the bug issue, I don’t use any pesticides and haven’t for at least 10 years and the majority of my palm pests are eradicated by their natural predators. The only exception I have ,during our dry season, is spider mites. Thankfully, they seem fairly selectively on the palms they attack.  I remove them by hand and/ or with a jet of water from my garden hose. 

Edited December 25, 2023 by Hurricanepalms

[Silas_Sancona]

  On 12/25/2023 at 7:36 PM, Hurricanepalms said:

On the topic of disinfecting pruning tools, I use a small natural gas canister with a torch attachment. You can buy them at Ace and other hardware stores for around $10. It does a phenomenal job. A single canister has lasted me up to 2 years with quite a lot of use. 
 

On the bug issue, I don’t use any pesticides and haven’t for at least 10 years and the majority of my palm pests are eradicated by their natural predators. The only exception I have ,during our dry season, is spider mites. Thankfully, they seem fairly selectively on the palms they attack.  I remove them by hand and/ or with a jet of water from my garden hose. 

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Yep.. aside from keeping Black and Brown Widows away from highly used areas, bugs ...even the giant, flying cockroaches we have are left alone.. Have noticed that since i don't spray, other than a couple doorways where crickets like to wander in through, Hatchet Wasps ( Parasitize Cockroach egg cases ) Cricket Hunters ( another Wasp that captures both Cockroaches and Crickets ), and the local Lizards ( Introduced, ..but harmless..  Med Geckoes, and our ever present native Ornate Tree Lizards  ) #'s have been increased quite a bit.. Still Roaches around,  but kept in check ..Impossible to be completely Roach free in the subtropics..

May attempt to re introduce a couple pairs of Desert Spiny Lizards back into the neighborhood this year.. Were common before all the development, and still present in some neighborhoods nearby.  Absolute destroyer of adult Roaches / other big bugs.


Spider Mites are definitely a PITA at times here too, esp. during our fore-summer ..That late April / May.. to mid / late June  time period here when it is hot, bone dry, and can get quite dusty.. Once Monsoon season kicks in ( unless a total bust, which often = a much longer " spider mite " season 🤬 ) Spider mite issues generally wane ..or crash completely ( Did for me in '21,  which was quite wet here ).

  Since they blow around on the wind, forget  ever  being free of them.   To keep them away ..or numbers present as reduced as possible, keep highly susceptible plants in areas where there is as much gentle air movement as possible / can be provided, and any dust accumulation washed off the leaves.   Dusty / stale air conditions = Spidey Mite Heaven, ...X's 1000,  Haha..

[Tom in Tucson]

  On 12/25/2023 at 8:22 PM, Silas_Sancona said:

Yep.. aside from keeping Black and Brown Widows away from highly used areas, bugs ...even the giant, flying cockroaches we have are left alone.. Have noticed that since i don't spray, other than a couple doorways where crickets like to wander in through, Hatchet Wasps ( Parasitize Cockroach egg cases ) Cricket Hunters ( another Wasp that captures both Cockroaches and Crickets ), and the local Lizards ( Introduced, ..but harmless..  Med Geckoes, and our ever present native Ornate Tree Lizards  ) #'s have been increased quite a bit.. Still Roaches around,  but kept in check ..Impossible to be completely Roach free in the subtropics..

May attempt to re introduce a couple pairs of Desert Spiny Lizards back into the neighborhood this year.. Were common before all the development, and still present in some neighborhoods nearby.  Absolute destroyer of adult Roaches / other big bugs.


Spider Mites are definitely a PITA at times here too, esp. during our fore-summer ..That late April / May.. to mid / late June  time period here when it is hot, bone dry, and can get quite dusty.. Once Monsoon season kicks in ( unless a total bust, which often = a much longer " spider mite " season 🤬 ) Spider mite issues generally wane ..or crash completely ( Did for me in '21,  which was quite wet here ).

  Since they blow around on the wind, forget  ever  being free of them.   To keep them away ..or numbers present as reduced as possible, keep highly susceptible plants in areas where there is as much gentle air movement as possible / can be provided, and any dust accumulation washed off the leaves.   Dusty / stale air conditions = Spidey Mite Heaven, ...X's 1000,  Haha..

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You're absolutely right about the appetite of the desert spiny lizards. When I'm deep watering my palms, they hang out, and wait for our native desert roaches to emerge from the drenched soil, and make a "bee line" to snag them. Then they run off so the others can't steal their prey. They also have a fondness for huge caterpillars.

Hi 60°, Lo 34°

[Silas_Sancona]

  On 12/27/2023 at 6:25 AM, Tom in Tucson said:

You're absolutely right about the appetite of the desert spiny lizards. When I'm deep watering my palms, they hang out, and wait for our native desert roaches to emerge from the drenched soil, and make a "bee line" to snag them. Then they run off so the others can't steal their prey. They also have a fondness for huge caterpillars.

Hi 60°, Lo 34°

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Numerous YT videos of people here in the valley / other areas that hand feed their " Yard Spinys "  Some ( of the Lizards ) will even come to the back patio door at a specific time in the late  afternoon / early evening for  " Dinner " 

 

[kinzyjr]

A YouTube video with Dr. Bahder on Lethal Bronzing from 01/18/2024: https://www.youtube.com/watch?v=iiVP1rFXzIU

Some of the other threads on Lethal Bronzing:

• https://www.palmtalk.org/forum/topic/65161-lethal-bronzing-in-florida/
• https://www.palmtalk.org/forum/topic/74008-florida-lethal-bronzing-status-in-2022/
• https://www.palmtalk.org/forum/topic/61096-concerned-about-lethal-bronzing/