Weevil sighting in the garden... Any suggestions?

[quaman58]

Hey all, 

I was wandering around the yard last week and see what appears to be a dead palm weevil on the ground.  I have a lot of moderate size Pritchardia in the yard, so I knew this day would come. The next day, one of the little bastards flies right by me and does a quick landing on a Pritchardia and crawls down into one of the leaf bases. But by the time I get back with a nuclear chemical to murder her, she's gone. (Less than a minute). So, here we are. No infected palms that I can see yet. All of the Pritchardia, Bismarkia and others high on their menu are still short enough to access visually. But I do have a couple way overhead Thrachycarpus and Becarriophoenix, which make me nervous. So, I'm looking for suggestions on what to look for. I've been pretty vigilant looking for signs of them like holes, wounds; etc. Is there a foliar spray that might be useful for the crown? How about systemics? I'm sort of working blind here, so any or all suggestions are appreciated! 

[Phoenikakias]

Quaman58 I am really sorry for you. Suffice saying that today I finished the monthly preventive spraying of all palms wearing a hazmat suit and mask in air temperature of over 37 C and in full sun. I was nearly in hyperthermic shock. As you have already pointed out Pritchardia and BIsmarckia are among prefered targets of the weevil. Generally any palms of some trunk size and not having a crownshaft such as Ravenea, Beccariophoenix, Phoenix, Livistona, Trachycarpus etc. You have unfortunately ushered in a new palmy era, where only the most resolved palm aficionados will eventually manage to keep safe their palm collection. I strongly recommend monthly preventive spraying of imidacloprid 20% at a rate of 2ml per lit water. I do not spray crown only directly in to the apex of the palm. It really works considerably.

[Merlyn]

@quaman58 if CA hasn't banned it yet, Imadicloprid soil drench is a good systemic.  Just cut off any flowers to avoid any potential bee risk.

[MJSanDiego]

It's my understanding that their main or preferred host is the Canary Island Date palm. Do you see any of that species nearby? It's my understanding that the weevils burrow in the crown so inspecting the crown is the only way to determine if there is any infestation. Once the fronds show symptoms it's too late. They have taken out so many Canary Island Date palms all over San Diego it is very sad. I see many homeowners who leave the massive trunks still standing with the crown gone 

[MJSanDiego]

https://cesandiego.ucanr.edu/Palm-Weevil-Featured-Story/

[DoomsDave]

Oh dear holy God.

Praying for you @quaman58. Pray for me and the rest of us back, including @Phoenikakias.

For an effective natural control to those vile grubs.

[WaianaeCrider]

Sounds as nasty as the CRB here in the islands.  PLEASE don't send any here.

 

[Phoenikakias]

3 hours ago, MJSanDiego said:

It's my understanding that their main or preferred host is the Canary Island Date palm. Do you see any of that species nearby? It's my understanding that the weevils burrow in the crown so inspecting the crown is the only way to determine if there is any infestation. Once the fronds show symptoms it's too late. They have taken out so many Canary Island Date palms all over San Diego it is very sad. I see many homeowners who leave the massive trunks still standing with the crown gone 

One other symptom of infestation may be (many will dispute this but I am nevertheless sure about my observation at least with regard to Pritchardia) epinasty. It is documented in Pritchardia and may also apply in some cases on Livustona.

[quaman58]

Well, here’s a depressing update. I have been nervously watching a Pritchardia “blue moon“ for a while now. This is the poem that I saw a weevil actually land on a couple months back. But the other issue, as I’ve posted before is just a god-awful case of sooty mold throughout the yard, which appears to be an abating, but which this is still covered with. So I’ve been looking feverishly for signs of weevil, but since the growing point is still at about the soil line, it’s not like I can see any visible holes or anything. Here is the palm in question.

[quaman58]

So as I’m winding down yesterday, I noticed that Pritchardia kaalae about 10 feet to the left. Looks like the leaves are beginning to appear desiccated. When I get home today, one of the leaves is actually bending down. So I go up and begin pushing against the plant and I can tell that the integrity of the trunk is all gone. so with a couple pushes, it simply breaks off above the soil line with the help of the sawsall. I cut it off at the base, and can immediately smell a sweetish fermented smell. So, here’s what my afternoon is consisted of.

[quaman58]

You’re actually looking at the inside of the trunk right at and just below the soil line. It was like I was scooping ice cream until I found one of the little effers. I then started cutting the growing point section of the “trunk“, would split them down the middle and then unroll them like a roll of toilet paper. Pictures are worth 1000 words.

[quaman58]

I guess the good news is that none of them had begun cocooning yet, and I found no evidence of any other cocoons

[quaman58]

Thanks for looking…

[quaman58]

By the way, they have all been successfully composted into the garden soil at this point. The circle of life… A hollow victory perhaps, but I feel better…

[D. Morrowii]

Aww that sucks condolences.. Thanks for the photos and video.

[Kim]

That is SO depressing. 😫 

Had you tried the imidacloprid application previously?

[quaman58]

Kim, I applied it about 4 weeks ago around the growing point (not as a drench, at least yet). I suspect that the infection was probably already pretty far along, as I had already seen a dead weevil or two not too far from this particular plant. I am guessing the blue moon is also infected. ☹️ 

[Tracy]

55 minutes ago, quaman58 said:

Kim, I applied it about 4 weeks ago around the growing point (not as a drench, at least yet). I suspect that the infection was probably already pretty far along, as I had already seen a dead weevil or two not too far from this particular plant. I am guessing the blue moon is also infected. ☹️ 

Bret, I feel your pain.  I also want to thank you for sharing this update of how they attacked your Pritchardia.  It has me motivated for a Labor Day project now to pre-treat my Pritchardia.  Only one of them here in Leucadia is at the flowering stage and it is still easily accessible to remove the inflorescence before the flowers open.  Earlier this week, I was walking down the street and could see yet another neighbor on the street behind me has lost a tall old CIDP to these evil weevils.  Your experience has nudged me away from my optimism that my garden would be safe with so many CIDP's going down nearby.

Along those lines, I hope you are being proactive with your other Pritchardia as well as your Ravenea.  If I recall you have a nice size Ravenea julietiae that is at risk too.  Wishing you the best with the rest of your beautiful garden.

[quaman58]

9 hours ago, Tracy said:

Bret, I feel your pain.  I also want to thank you for sharing this update of how they attacked your Pritchardia.  It has me motivated for a Labor Day project now to pre-treat my Pritchardia.  Only one of them here in Leucadia is at the flowering stage and it is still easily accessible to remove the inflorescence before the flowers open.  Earlier this week, I was walking down the street and could see yet another neighbor on the street behind me has lost a tall old CIDP to these evil weevils.  Your experience has nudged me away from my optimism that my garden would be safe with so many CIDP's going down nearby.

Along those lines, I hope you are being proactive with your other Pritchardia as well as your Ravenea.  If I recall you have a nice size Ravenea julietiae that is at risk too.  Wishing you the best with the rest of your beautiful garden.

Thanks for the encouragement, Tracy. For some reason, I assumed these were too young to be affected. I seldom see adolescent CIDP's affected; it's usually the ones with trunks. So I was paying close attention to those in mine & Terry's garden. Guess I was wrong. I'll pay close attention to the Ravenea, Bismarkia and Beccariophoenix. Guess those are on the menu as well. ☹️ I think I'll take up stamp collecting..

 

[Tomas]

20 minutes ago, quaman58 said:

Thanks for the encouragement, Tracy. For some reason, I assumed these were too young to be affected. I seldom see adolescent CIDP's affected; it's usually the ones with trunks. So I was paying close attention to those in mine & Terry's garden. Guess I was wrong. I'll pay close attention to the Ravenea, Bismarkia and Beccariophoenix. Guess those are on the menu as well. ☹️ I think I'll take up stamp collecting..

 

Pritchardias are aesy victims, small trunks and very soft inside. And there is no time to show any damage. I also know many people lost Ravenea glauca to RPW

[Phoenikakias]

Have you reached the soil below the trunk basal plate? Perhaps you could find there cocoons.

[quaman58]

Pretty much everything down to the root structure has been cleared.  This palm had no real discernable trunk yet, so the area they were in was perhaps 1 foot long, more or less. I think that maybe the impact on a plant that small was so obvious and dramatic, I simply caught it before their full life cycle could play out.  

[Phoenikakias]

12 hours ago, quaman58 said:

Pretty much everything down to the root structure has been cleared.  This palm had no real discernable trunk yet, so the area they were in was perhaps 1 foot long, more or less. I think that maybe the impact on a plant that small was so obvious and dramatic, I simply caught it before their full life cycle could play out.  

It occured to me with a still trunkless CIDP. It was infested in the stem base, a very sneaky kind of infestation. One can not observe any chewed newly emerging leaves or sawdust and tunnels on petioles and leaf axils. Just gradually desiccating leaves, which could be also a symptom of fungal infection in the roots or lack of water. And then despite ample irrigation, fungicides and pesticides, rapid deterioration and total collapse. Only difference is that I had found quite few cocoons and many adults all dead. Shocking fact that some larvae inside the cocoons were still alive, despite the application of 20 kg of organophosphate solution through soaking wet of the whole plant two times with two weeks interval.

I have managed to save my trunking Pritchardia though heavily wounded by injecting 1 part dimethoat to two parts water in to the tunnels.