South American Palm Weevel MAJOR NEWS

[palmaddict]

I have not posted in about 10 years. I have a very well established 20 year old palm garden in the Bonita area of San Diego. For the last few years there has been a major infestation of the South American Palm Weevil. The Weevil has destroyed perhaps  85% of the local Phoenix canariensis. The Weevil crossed the border from Tijuana and and has been moving north. It was perhaps naive to think the weevil would only infect one species of palm. I am posting here as I just discovered  a Pritchardia that collapsed in the last few days. Performing a dissection on the collapsed part of the palm revealed the presence of weevils. So at this point it is clear that the weevils are capable of an infecting perhaps a host of palm species. Another concern which has surfaced is that the palm weevil was thought to be in Southern San Diego. However interacting with another collector who lives in Vista indicates they too have a Pritchardia infected with the same weevil. This suggests the weevil is moving much faster then previous thought. I have contacted UC riverside as they are conducting studies on the Weevil.  As I have numerous irreplaceable palms my plan is to treat each palm with a systemic pesticide as soon as possible. I will attempt to post images. Not good news at all.

[palmaddict]

Images

[palmaddict]

I speculate that the weevil is now infecting other palm species because it has run out of canariensis to feed on. It has already killed all the canariensis it can infect in my area and the remaining ones seem to be resistant. Therefore to avoid starvation it is now feeding on other palm species

Patrick

[palmaddict]

One more image

[Darold Petty]

Very sorry for your loss, and thanks for posting.

[LJG]

Yeah, it’s getting bad up in north county too. This is my neighbors tree in Vista. I now have someone come spray all my large non-crownshafted palms every 6 months.

[bubba]

That’s horrible. Get on it LJG.

[iDesign]

9 hours ago, LJG said:

I now have someone come spray all my large non-crownshafted palms every 6 months.

Does the spray need to be handled by a professional? My husband does his own pest control and I’m a little worried about my Sylvester palm and Pritchardia. We order from “domyown” if there’s something we can do?

No canary palms are close to our home, but I’ve sadly seen the canary carnage elsewhere in the city ☠️

[surfermatt]

I also have a friend in coastal La Jolla who lost a massive pritchardia to the weevil. The date palms down here have been hit so hard. 

[palmaddict]

So at this point I would assume all Pritchardia are subject to infection by this weevil. Here is a picture of the systemic pesticide I plan on using. My plan is to treat all non crown shaft palms. Probably 50 palms in total.  Does anybody have a recommendation for a better pesticide.

[ZPalms]

Is their a chance at this insect having a decrease in population due to the decline in CIDP? I know they can attack other palms but CIDP seem to be a favorite for them.

[Silas_Sancona]

16 minutes ago, ZPalms said:

Is their a chance at this insect having a decrease in population due to the decline in CIDP? I know they can attack other palms but CIDP seem to be a favorite for them.

Likely not ..they'll just move on to new specimens / other things. The species exploits " secondary hosts "  which includes stuff like Avocado, Citrus, Mango, Papaya, Sugarcane, Banana, etc.. All of those plants are widely cultivated in California, ...Southern CA. specifically so even if controlled in palms, they'll move onto something else ...while looking for new palms to attack. 

https://www.inaturalist.org/taxa/304994-Rhynchophorus-palmarum

As far as fully eradicating them, ..not gonna happen. Even if controlled,  species is native to / established throughout the Americas,  and is just expanding it's range further north atm.  They won't ever stop  exploring ideal, new territory.  If you look at pictures of feral/ cultivated date palms / other sp. on the weevil's menu in Baja / other areas where the Weevil is native, some palms drop dead, yes, but many more are still alive. Nature sorts out such things.


Use of systemics may work for awhile, but, like many insects subjected to long term use of pesticides,  the chance of the weevil developing tolerance to them is high.  At the same time, systemic pesticides kill pollinating insects like Bees,  ...so you can't use them on the above-mentioned " edible " crops these weevils might also attack..  I sure wouldn't anyway.  Too many chemicals in our food as it is.

[ZPalms]

26 minutes ago, Silas_Sancona said:

Likely not ..they'll just move on to new specimens / other things. The species exploits " secondary hosts "  which includes stuff like Avocado, Citrus, Mango, Papaya, Sugarcane, Banana, etc.. All of those plants are widely cultivated in California, ...Southern CA. specifically so even if controlled in palms, they'll move onto something else ...while looking for new palms to attack. 

https://www.inaturalist.org/taxa/304994-Rhynchophorus-palmarum

As far as fully eradicating them, ..not gonna happen. Even if controlled,  species is native to / established throughout the Americas,  and is just expanding it's range further north atm.  They won't ever stop  exploring ideal, new territory.  If you look at pictures of feral/ cultivated date palms / other sp. on the weevil's menu in Baja / other areas where the Weevil is native, some palms drop dead, yes, but many more are still alive. Nature sorts out such things.


Use of systemics may work for awhile, but, like many insects subjected to long term use of pesticides,  the chance of the weevil developing tolerance to them is high.  At the same time, systemic pesticides kill pollinating insects like Bees,  ...so you can't use them on the above-mentioned " edible " crops these weevils might also attack..  I sure wouldn't anyway.  Too many chemicals in our food as it is.

Very interesting, It seems so destructive even to stuff more than palms. Do certain palms have a resistance to the weevil or is it just by luck and do the weevils have predators like birds?

Seems like such a headache to palm growers because now you always have to be vigilant with your gardens.

Makes me worried they will reach filifera oasis and just wreck them

Edited October 13, 2022 by ZPalms

[Silas_Sancona]

1 minute ago, ZPalms said:

Very interesting, It seems so destructive even to stuff more than palms. Do certain palms have a resistance to the weevil or is it just by luck and do the weevils have predators like birds?

Seems like such a headache to palm growers because now you always have to be vigilant with your gardens

A lot of times, the " bad " insects that attack stuff are attracted by volatile compounds released by a sick or greatly stressed plant..  Over pruning, drought ( or being flooded ), nutritional needs out of balance are some things that create stress.. which in turn can attract everything from bad Aphid and/ or Mealy Bug infestations, to these darn Weevils.

I'm sure plenty of these beetles are being picked off by bug eating birds / other critters ( ..eaten by people in some areas as well -oof, lol ) but never enough beetle eaters to fully eliminate the weevils, especially when they explore new territory where the local birds might not yet be familiar w/ them.

While applying any pesticide may help knock down the pest you're after in the short term, that same stuff also effects other things which might help control X pest.  Less bug eaters, more bad bugs taking advantage of less things eating them. Too much pesticides, bad bugs can build up a tolerance ..which means having to use even more toxic stuff ..which effects the things that help control pest-y things even more.  Bad cycle.

Not just palms, but pretty much anything.. Agave have weevils that can attack them, same w/ yuccas ..and just about anything else.  For every plant out there, there's a list of bad bugs that can attack each of them under the right circumstances.  Keeping your plants as healthy and stress free as possible is all anyone can do with their gardens..  

[ZPalms]

3 minutes ago, Silas_Sancona said:

A lot of times, the " bad " insects that attack stuff are attracted by volatile compounds released by a sick or greatly stressed plant..  Over pruning, drought ( or being flooded ), nutritional needs out of balance are some things that create stress.. which in turn can attract everything from bad Aphid and/ or Mealy Bug infestations, to these darn Weevils.

I'm sure plenty of these beetles are being picked off by bug eating birds / other critters ( ..eaten by people in some areas as well -oof, lol ) but never enough beetle eaters to fully eliminate the weevils, especially when they explore new territory where the local birds might not yet be familiar w/ them.

While applying any pesticide may help knock down the pest you're after in the short term, that same stuff also effects other things which might help control X pest.  Less bug eaters, more bad bugs taking advantage of less things eating them. Too much pesticides, bad bugs can build up a tolerance ..which means having to use even more toxic stuff ..which effects the things that help control pest-y things even more.  Bad cycle.

Not just palms, but pretty much anything.. Agave have weevils that can attack them, same w/ yuccas ..and just about anything else.  For every plant out there, there's a list of bad bugs that can attack each of them under the right circumstances.  Keeping your plants as healthy and stress free as possible is all anyone can do with their gardens..  

That really explains why my trachy that isn't doing so well is experiencing terrible scale issues because it is so stressed. My chams had scale but now they seem to have figured out their transplant and seem happy and growing and the scale doesn't even bother them anymore. It's interesting how insects can figure out already valuable plants and attack them.

Why must they want to kill a plant just for reproduction or food. That seems so much overkill. Can't they just be normal and just enjoy a leaf or two😂

[kinzyjr]

20 hours ago, palmaddict said:

I have not posted in about 10 years. I have a very well established 20 year old palm garden in the Bonita area of San Diego. For the last few years there has been a major infestation of the South American Palm Weevil. The Weevil has destroyed perhaps  85% of the local Phoenix canariensis. The Weevil crossed the border from Tijuana and and has been moving north. It was perhaps naive to think the weevil would only infect one species of palm. I am posting here as I just discovered  a Pritchardia that collapsed in the last few days. Performing a dissection on the collapsed part of the palm revealed the presence of weevils. So at this point it is clear that the weevils are capable of an infecting perhaps a host of palm species. Another concern which has surfaced is that the palm weevil was thought to be in Southern San Diego. However interacting with another collector who lives in Vista indicates they too have a Pritchardia infected with the same weevil. This suggests the weevil is moving much faster then previous thought. I have contacted UC riverside as they are conducting studies on the Weevil.  As I have numerous irreplaceable palms my plan is to treat each palm with a systemic pesticide as soon as possible. I will attempt to post images. Not good news at all.

Terrible news for sure.

[Merlyn]

10 hours ago, iDesign said:

Does the spray need to be handled by a professional? My husband does his own pest control and I’m a little worried about my Sylvester palm and Pritchardia. We order from “domyown” if there’s something we can do?

I'd look at any Imadicloprid or Dinotefuran systemic.  I use Safari 20SG and Adonis 75WSP.   This place recommends pheromone traps and neonicontinoids like those two systemics: https://biocontrol.ucr.edu/south-american-palm-weevil

Hodel says the same thing here: https://ucanr.edu/sites/HodelPalmsTrees/files/247345.pdf

[Silas_Sancona]

11 minutes ago, Merlyn said:

I'd look at any Imadicloprid or Dinotefuran systemic.  I use Safari 20SG and Adonis 75WSP.   This place recommends pheromone traps and neonicontinoids like those two systemics: https://biocontrol.ucr.edu/south-american-palm-weevil

Hodel says the same thing here: https://ucanr.edu/sites/HodelPalmsTrees/files/247345.pdf

Any current recommendation for using Neonicotinoids for control may be about to change -soon.
https://www.northbaybusinessjournal.com/article/industrynews/common-pesticide-facing-ban-in-california/

 

[quaman58]

It's so interesting that the weevils taste seems to be toward canariensis, but not dactylifera or any other Phoenix. Their taste for Pritchardia is a major downer.

[Silas_Sancona]

4 minutes ago, quaman58 said:

It's so interesting that the weevils taste seems to be toward canariensis, but not dactylifera or any other Phoenix. Their taste for Pritchardia is a major downer.

P. dactylifera is one of the listed hosts.

[quaman58]

At least down here, I’ve yet to see an infected one; even ones in the midst of dying canariensis. Not saying that it can’t happen, but it seems clear they’re less affected

[Darold Petty]

different weevil, but this is what's happened in southern Italy.  The train platform at Amalfi had a perfect row of 6 or 8 P. canariensis,  by the time of our visit only the stumps remained. 

[Foxpalms]

I hope these never spread here and destroy all the CIDPs; the last one found was in 2016. Fortunately I have never seen any palm here infected by one. 

[Silas_Sancona]

1 hour ago, quaman58 said:

At least down here, I’ve yet to see an infected one; even ones in the midst of dying canariensis. Not saying that it can’t happen, but it seems clear they’re less affected

It is interesting Canaries appear to be the main target out there ..for now at least  considering the Weevil is likely attacking feral Dates not that far away in Baja..  Climate, at least in Northern Baja isn't all that much different than San Diego.  Intriguing. 

[UK_Palms]

7 hours ago, Foxpalms said:

I hope these never spread here and destroy all the CIDPs; the last one found was in 2016. Fortunately I have never seen any palm here infected by one. 

Make no mistake, the Red Palm Weevil will 100% survive and become a problem in London and the south coast if it gets established over here. It doesn’t get anywhere near cold enough to kill off the larvae, which will survive our winters easily in the trunks. The actual beetles would be active for about half the year here from May - October.

CIDP’s aside, there must be about 1-2 million Trachycarpus as well for them to feed on. I have criticised our palm import ban and strict regulations in the past, but at least it will help prevent the beetle spreading over here. It’s edging closer and closer though up the west coast of France. It may only be a matter of time, especially with us getting warmer and warmer each year.

[Foxpalms]

1 hour ago, UK_Palms said:

Make no mistake, the Red Palm Weevil will 100% survive and become a problem in London and the south coast if it gets established over here. It doesn’t get anywhere near cold enough to kill off the larvae, which will survive our winters easily in the trunks. The actual beetles would be active for about half the year here from May - October.

CIDP’s aside, there must be about 1-2 million Trachycarpus as well for them to feed on. I have criticised our palm import ban and strict regulations in the past, but at least it will help prevent the beetle spreading over here. It’s edging closer and closer though up the west coast of France. It may only be a matter of time, especially with us getting warmer and warmer each year.

The 2 year quarantine or only importing palms grown in protected greenhouses was added because of one found being in a shipment of palms to the uk. Aside from being accidentally introduced, could they fly across the channel? I'm not sure the distance these can fly without stopping. The problem with importing palms now is they need to make the system more clear and simplistic, whilst still checking documents and the palms.

[Tomas]

On 10/14/2022 at 4:01 PM, Foxpalms said:

The 2 year quarantine or only importing palms grown in protected greenhouses was added because of one found being in a shipment of palms to the uk. Aside from being accidentally introduced, could they fly across the channel? I'm not sure the distance these can fly without stopping. The problem with importing palms now is they need to make the system more clear and simplistic, whilst still checking documents and the palms.

The RPW is supossed to fly only 2km, but from observing some isolated palms, I would credit it with 5 km, still, there is no chance it could make it across the Channel on its own, but it is probable it will cross sooner or later trapped in a car or a freight wagon.

[Tomas]

On 10/14/2022 at 2:22 PM, UK_Palms said:

Make no mistake, the Red Palm Weevil will 100% survive and become a problem in London and the south coast if it gets established over here. It doesn’t get anywhere near cold enough to kill off the larvae, which will survive our winters easily in the trunks. The actual beetles would be active for about half the year here from May - October.

CIDP’s aside, there must be about 1-2 million Trachycarpus as well for them to feed on. I have criticised our palm import ban and strict regulations in the past, but at least it will help prevent the beetle spreading over here. It’s edging closer and closer though up the west coast of France. It may only be a matter of time, especially with us getting warmer and warmer each year.

The Trachycarpus are relatively at low risk, the female of the RPW will lay eggs in cracks of the petiole and the larvae has to gnaw through it to get to the heart. The Trachy's petiole is too hard for it. The mass death of Trachycarpus and Chamaerops here in Europe is due to the Palm Moth, it's larvae can "walk" at the petiole 😥

[Phoenikakias]

On 10/13/2022 at 6:00 AM, palmaddict said:

I have not posted in about 10 years. I have a very well established 20 year old palm garden in the Bonita area of San Diego. For the last few years there has been a major infestation of the South American Palm Weevil. The Weevil has destroyed perhaps  85% of the local Phoenix canariensis. The Weevil crossed the border from Tijuana and and has been moving north. It was perhaps naive to think the weevil would only infect one species of palm. I am posting here as I just discovered  a Pritchardia that collapsed in the last few days. Performing a dissection on the collapsed part of the palm revealed the presence of weevils. So at this point it is clear that the weevils are capable of an infecting perhaps a host of palm species. Another concern which has surfaced is that the palm weevil was thought to be in Southern San Diego. However interacting with another collector who lives in Vista indicates they too have a Pritchardia infected with the same weevil. This suggests the weevil is moving much faster then previous thought. I have contacted UC riverside as they are conducting studies on the Weevil.  As I have numerous irreplaceable palms my plan is to treat each palm with a systemic pesticide as soon as possible. I will attempt to post images. Not good news at all.

For us Europeans, no shocking news at all. It is well established that the red palm weevil (cousin of the siuth american one) attacks ALL NON CROWNSHAFTED PALMS WITH SOME STEM'S GIRTH. Like Bismarckia, Brahea, Livistona, Sabal too. That said, we have already recorded the kill of several Pritchardia spp.  Wait for the Paysandisia to come. That would be the ultimate nemesis, as it shows no mercy even to small palms, like juveniles or Rhapis and Chamaedorea...

[Josue Diaz]

I wonder if, when, the weevil might move north. Tejon pass might be a natural barrier with lack of host plants for them to travel between into the central valley - unless of course they can travel long distances between hosts. If the weevil moves north along the coast, I could see it expanding into the central valley from San Luis Obispo eastward. Would be sad to see the century old canariensis wiped out all throughout the valley.

[Silas_Sancona]

8 hours ago, Josue Diaz said:

I wonder if, when, the weevil might move north. Tejon pass might be a natural barrier with lack of host plants for them to travel between into the central valley - unless of course they can travel long distances between hosts. If the weevil moves north along the coast, I could see it expanding into the central valley from San Luis Obispo eastward. Would be sad to see the century old canariensis wiped out all throughout the valley.

Unfortunately highly doubt they'd be stopped at the pass.. Though maybe slowed by any cooler winters / far fewer vulnerable palm sp.  to seek out / hibernate in up there. 

If they can't reach the C.V. via Tejon, moving up the coast, then spreading east through the coast ranges / coastal valleys, esp. after reaching the Bay Area,  would be the next, most likely route.


Being large beetles, they are capable of long distant flights, let alone survived moving north from the drier areas of mainland Mexico and ..even drier Baja.

[TropicalGardenSpain]

In Spain we have the red palm weevil which in my area close to Elche we have a big problem and here they are also killing palms like R. Regia and they get in at the bottom of the trunks. I have all my palms sprayed every 6 weeks in the warmer months. Last year they got one of my R.Rivularis. I know people who have lost Pritchardia and if they go for Roystonea it worries me that foxtails and archontophoenix will be next. 

[Phoenikakias]

3 hours ago, TropicalGardenSpain said:

In Spain we have the red palm weevil which in my area close to Elche we have a big problem and here they are also killing palms like R. Regia and they get in at the bottom of the trunks. I have all my palms sprayed every 6 weeks in the warmer months. Last year they got one of my R.Rivularis. I know people who have lost Pritchardia and if they go for Roystonea it worries me that foxtails and archontophoenix will be next. 

I thought that at least crownshafted palms are safe...

[TropicalGardenSpain]

I've not lost a crownshafted palm yet so I hope the same but I get them sprayed all the same. last year I used the pheromone traps but it was bringing a lot of weevils to my garden so I didn't bother this year. 

[Than]

Any natural predators? 

[Little Tex]

6 hours ago, ego said:

Any natural predators? 

unfortuantly not, well not any practical

[GoatLockerGuns]

6 hours ago, ego said:

Any natural predators?

Humans I guess.  I hear they are a delicacy in some parts of the world (https://www.graphic.com.gh/lifestyle/palm-worms-delicacy-catches-on.html).  Watched the dude on the Primal Survivor TV show open up a downed palm with his machete, and then grab a hand full of palm weevil larvae out of the trunk.  He held them by their heads, and bit off/ate the rest of the body.  He said he didn't eat the head because they have sharp teeth.

[Silas_Sancona]

5 minutes ago, Little Tex said:

unfortuantly not, well not any practical

Not true.

6 hours ago, ego said:

Any natural predators? 

Beetles, ..and all other insects... are the Pizza, Candy, and Potato Chips of the Animal food chain,   so yes.. Insectivorous Birds, Reptiles / Amphibs., bigger Insects, and Mammals that eat bugs will eat them and the Grubs, just like they do where the Weevil originated in Central and South America.  

That said, as mentioned, if not already familiar w/ them, it takes time for locally native insect eaters to recognize new insect prey when those insects first colonize new areas.

One thing i'm curious about, regarding a legit and, most importantly,  environmentally friendly, human-devised strategy to help control them is if Palm Weevils would be a good candidate for using S.I.T.  ...AKA the Sterilized Insect Technique.

Same thing that has helped subdue / stamp out periodic outbreaks of the Mediterranean, Mexican, and Oriental Fruit Fly,  ...Let alone a far more dangerous insect that once caused all sorts of problems in the U.S. and Mexico.. The New World Screwworm  whose Latin name, Hominivorax  literally translates to: " Man Eater "  Don't know what it is?  do some research ..and be prepared to be grossed out, if blood and gore turn your stomach. Find it fascinating myself.

Another thing that could be done is modifying the Weevil's genome / Immune system so it can't carry or transmit the Nematode that causes Red Ring ..Which causes further destruction.  That hasn't been detected in California -yet..

[Silas_Sancona]

8 minutes ago, Silas_Sancona said:

Not true.

Beetles, ..and all other insects... are the Pizza, Candy, and Potato Chips of the Animal food chain,   so yes.. Insectivorous Birds, Reptiles / Amphibs., bigger Insects, and Mammals that eat bugs will eat them and the Grubs, just like they do where the Weevil originated in Central and South America.  

That said, as mentioned, if not already familiar w/ them, it takes time for locally native insect eaters to recognize new insect prey when those insects first colonize new areas.

One thing i'm curious about, regarding a legit and, most importantly,  environmentally friendly, human-devised strategy to help control them is if Palm Weevils would be a good candidate for using S.I.T.  ...AKA the Sterilized Insect Technique.

Same thing that has helped subdue / stamp out periodic outbreaks of the Mediterranean, Mexican, and Oriental Fruit Fly,  ...Let alone a far more dangerous insect that once caused all sorts of problems in the U.S. and Mexico.. The New World Screwworm  whose Latin name, Hominivorax  literally translates to: " Man Eater "  Don't know what it is?  do some research ..and be prepared to be grossed out, if blood and gore turn your stomach. Find it fascinating myself.

Another thing that could be done is modifying the Weevil's genome / Immune system so it can't carry or transmit the Nematode that causes Red Ring ..Which causes further destruction.  That hasn't been detected in California -yet..

Here's a snippet from UC Riverside's site on potential bio controls that i'm sure are being evaluated:

[DoomsDave]

I’ve witnessed “bugopalypses” over the decades, and it seems that natural controls are going to be key in the long run. Chemical insecticides cause problems of their own and the bugs often develop resistance to them over time. 

One example is the Eugenia Psyllid which came on the scene in the mid 1980s. It’s an aphid type of critter that lays eggs in the new shoots of Eugenia, a popular shrub, particularly beloved for making topiaries at Disneyland. The shoots looked like someone melted them in a flame. Acephate (“Orthene”) controlled it, but that stuff STUNK! Eventually my old alma mater UCR found a parasitic wasp that keeps it under control, though it didn’t eradicate the psyllids.