Strategus Aloeus: Tis the season for the ox beetle.

[Swolte]

I hear you. I am in a similar boat but I don't have electricity out there so I am more reliant on solar. I put a few solar spot lights out last year and will see if that helps at all this round. I had ZERO beetle attacks last year due to the extreme drought (prefer the beetles to that drought!). It looks we'll have a "normal" summer this time around so I am getting ready for them starting June

[Cindy Adair]

Hi Ed! I am so glad to hear you are making some progress with your strong barriers and your secret weapon!

Thanks so much for all your great information over years!

Although I have made a substantial effort to reach out to those in authority positions in PR response as been limited. 
 

Before seeing your post I was taking photos of a leaning palm and documenting the cause-you guessed it, a beetle.

I also had put a note on my old fashioned dry erase board on my refrigerator to update PT on my own beetle battle so yes, tis the season.

[Ed Askew]

Yeah, sure thank you Cindy.  Yeah, Swolte, I think we pretty much had normal precipitation in Mississippi last season.  I forgot to mention that the pheromone baits, light trap, and pit trap all failed.  I have some hopes this year will not be bad, since it has been a beautiful, cool, and dry spring so far.  Plus, we had this Christmas Arctic Outbreak, where it got down to 18F two nights in a row, remained below freezing for almost 48 hrs, and the ground froze.  I was surprised I actually had some freeze damage on what apparently were actively growing spear leaves of many of my large, mature Sabals, but S. Palmetto and S. Louisiana.  Normally, they are unfazed.  They're ok now, but those fronds have light colored areas and are withered a bit.  I have about 50 potted S. Palmettos and their pots froze solid, but it didn't bother them at all.  I bet it bothered those grubs.  We'll see.

[Ed Askew]

Just a follow up from last season: zero beetle attacks.  We did have a severe drought during beetle season, and bad enough I even lost an azalea.  That could be why.  They always dig the night after a hard rain.  My mortality rate is 20% for these palms I used the palm fortress on.  I have something like 30 palms I have to plant this year.  These palms I used the palm fortress on are all big enough (except for the 4 I planted last year) that I don't think I have to worry about beetles anymore with them, but still I have to make quite a few new palm fortresses.  One thing I found out is that some of the beetle attacks are coming from underground probably through established tunnels.  I have not been able to get one to survive in this high attack area I have, and I think that's why.  So I have a plan to try a few palms in that area again, and I'm going to dig a 2 foot deep hole, put some granular insecticide to be determined in the bottom of the hole, cover that with pond rocks, fill the outer part of the hole with pond rocks and the inner with dirt until the hole is the right depth to plant the palm, and then do as I did before.  We'll see what happens. 

[Swolte]

Same here. Another (devastating) drought season here in Central Texas with months without any significant rain and triple digit temperatures on a daily basis. Haven't seen a beetle! Given that the drought last year didn't produce any sign of beetles, also, I didn't even put insecticide out last year. Who'd thought we'd find an upside to these droughts, eh?! 

[Cindy Adair]

It’s true that I don’t want a drought in PR! Glad at least that you all have gotten a break from rhino destruction. 
 

I have finally gotten it straight in my head that although the photos look similar and both kill palms, the coconut rhino beetle in Guam and HI is a totally different creature. 

I guess that explains why the coconut rhino beetle (CRB) and the Ox beetle attack different parts of the palms. 
 

Ox beetles go low and CRB go high is the way I am thinking of it now. 
 

I guess I should be happy that if I can get my palms to the trunking stage they MIGHT be of no interest to the rhino beetles in PR. 
 

My barrier methods have not been sufficient so in 2024 I am trying April 1 (maybe even March 1 if our current trends continue) and August 1. 
 

It will be impossible to apply systemic imidocloprid granules to all my young palms in one day. Maybe it will take two weeks or more. 
 

Good luck to us all!

[Ed Askew]

I'm thinking termite poison.  I'm at the early stage of figuring out what insecticide I will use.  The problem with insecticide is that it kills friendlies, and you have to do all you can to limit the collateral damage there.  Friendlies are lady beetle larvae, and I imagine that they are not large enough to get 2 feet below a palm.  So, I'm thinking they will not be affected by poison applied at that depth. 

[Ed Askew]

O.K., here is my plan for 2024, and I am beginning to carry it out:  I have some areas where I have had next to no luck growing palms due to the beetle.  These are the areas where the fortress failed.  Examining these dead palms, I see that the beetle came up under the palm from deep burrows.  Something I didn't understand before:  these beetles have extensive underground tunnels that survive one season to the next.  I can see one now that at least one has been maintained recently with new dirt on top of an old, dead palm burrow,  and we are just at the cusp of spring here.  I found one tunnel complex that had collapsed creating a big hole.  Multiple tunnel intersections.  So, beetles can kill the palm from any direction in areas where they have been breeding.  In these areas, I have re planted and have a 360 degree protection of the palm heart from the beetle.  I dig an 18" hole, then add rocks about 3" thick, the I put in this very sticky thick clay we have here that is nearly waterproof on top of those rocks to about 4".  I make a little hill in the middle of those rocks.  Then I add more rocks around that hill.  Then I flatten the hill a bit and pour permethrin 0.25% granules on top, add a bit more clay, then compact the hill with a section of 4x4 post.  At that point, the permethrin is at 14" from the surface.  Then I add more dirt and rocks around it until the palm I'm planting will rest on it so it's upper roots are at about the surface of the hole.  Then I pour in rocks all around the palm.  Then I put in the palm fortress on top, making sure that the fortress is at least 1" underground.  I have a bunch of pictures but don't have time to upload them right now.  My thinking is the beetle always digs a drain hole that is 20" deep and when he does that, he's going to find the permethrin, and hopefully this permethrin in this  thick clay that is below the aerobic layer will not wash out and will not be degraded for a long time.   I planted so far 10 palms and I have another 12 to plant.  I'm only doing the extensive beetle protection for areas I know are the worst, which will be 10 palms.  These are 5 year old cabbage palms I've grown from seed.  Also, where I find old beetle tunnels, I fill them with permethrin granules, being very careful not to allow any of the permethrin to stay on the surface.  I know that my best friend is a close relative of Strategus: Chilorchorus Stigma, the twice stabbed lady beetle who eats scale.  I don't want to hurt her and I suspect she never gets into the anaerobic soils.  

[Ed Askew]

17 palm fortresses ready for deployment.

[Ed Askew]

18” hole rocks in bottom 

[Ed Askew]

Little clay hill

[Ed Askew]

I have to go with chemical weapons at this point, but underground hoping to limit collateral damage.

[Ed Askew]

Permethrin with compacted clay on top is at roughly 14 inches from the surface.

[Ed Askew]

Palm in.  Rocks all around.

[Ed Askew]

Finished product.  Fingers crossed.  We’ll see what happens.

[Ed Askew]

Actually, that was almost the finished product.  I added thick clay and rocks all around the fortress and watered it in.  I have learned that this beetle is a determined enemy.  You cannot give him any chance.  You have to make so he can't move the fortress, and he can't go underneath it either.  Even then, he will get some of them.

Edited March 25, 2024 by Ed Askew

[Ed Askew]

P.S. don't do any of this at home.  This is just my little experiment!  I don't know what will happen. 

[Swolte]

Dangit Ed, here I am trying to grow kidney-weed at the base of palms...

I am following this with increasing amazement. Do I spot of hint of joy in your posts? These bugs certainly have gotten to your head. Sure hope this works!

[Cindy Adair]

Ed you are the one who helped identify my demon ox beetles and I really appreciate all of your posts about your trials! 

I hope your current plan works!!!
 

My question for you (and everyone with these pests) is have you had palms who have actual trunks to be attacked?

If so were the trees killed?

So far after 7 years of observation (not nearly enough) I have seen no holes nearby nor evidence of damage to any genera of trunking palms (of any diameter)

even plants that were attacked once or twice a year and had to regrow after losing spears etc. 

It would make all my efforts with the juvenile palms worth it if it is only until they trunk.
 

I am not going to keep them in pots on benches until they trunk as that is just not practical for me, but still am hoping you have had the same experience about ox beetle’s lack of interest once trunking??

Still strange to me with coconut beetles which look so similar attacking from above…
 

 

[Ed Askew]

Yeah they did kill this one cabbage palm that had a 2 foot trunk.  It was in this heavily infested area I referred to that is riddled with tunnels.  All other fatalities have been small palms.  I have well over 100 palms, maybe 200.  My big palms seem unaffected even though they have multiple tunnels at their base sometimes.  One thing I believe is helping the beetles in the area is landscape fabric applied over 10 years ago that now has a layer of soil and a thick mat of Asian jasmine on top.  They are running wild under that.

Edited March 25, 2024 by Ed Askew

[Ed Askew]

 No joy; determination, Swolte.  I have been fighting this bug 15 years now.  He wins some, and I win some.

[Cindy Adair]

Thanks so much Ed for adding to my hope that at least most trunking palms are no longer vulnerable. 
 

Gives me hope that maybe, just maybe, my collection might outlive me.

[PR00636]

  On 3/25/2024 at 6:55 PM, Ed Askew said:

 No joy; determination, Swolte.  I have been fighting this bug 15 years now.  He wins some, and I win some.

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Hey thanks for posting.  We have been fighting these KILLERS for a couple of years since we finally figured out WHAT was killing the palms.  We have lost Joey Magnifica, lots of Phoenicophorium borsigianum, various Areca species, Veitchia species, and lot more!  You name it, it's probably been at least attacked if not killed.   

This year we decided to make cylinder-style cages of 1/2" wire mesh that we bury 8" and cover the top with mesh, too.  We realize that we will probably have to make vertical extensions to these cages as the palms grow and until they reach a safer size less appealing to the beetles.   And even though it is time consuming to make the cages, they are somewhat easy to assemble with zip ties, and using an angle grinder we saw off the excess mesh on the covers.  While the cages are not a pretty sight in the garden, we just want to eventually enjoy the mature palms.

So far we have only protected newly-planted coconuts as we plant an avenue of them on the property.  And so far, knock on wood, the beetles have not seemed to "recognized" the palms due to the wire and even if they did should not be able to penetrate the mesh.  We have received occasional downpours in the dry season of more than 2.5" each storm so this is bringing on the beetle breeding season earlier than usual.

[Cindy Adair]

Hope it works PR00636! Dreadful to lose all those beautiful palms.

[Ed Askew]

I hope it works out, of course.  I think we, as above ground beings fall to understand the subterranean world of the beetle.  Your defenses need to extend below the organic layer of the soil to be effective.

[Ed Askew]

Alright:  it's mid summer and it has been raining a good bit here, so, more or less this is the peak of beetle season.  I had one of the 19 palms I planted that has been hit, although there is some evidence that it was an aborted burrow.  I put permethrin in the soil at 14" when I dug that hole to plant this palm, but this one doesn't have rocks at the bottom of the hole.  Another larger palm, that I planted a few years ago was attacked before and hit again, right next to the other one above.  Right now I have 34 palms of 39 I planted with the palm fortress.  The older ones are really too big now for the beetle.  2 attacks at this stage is not bad.  I poured permethrin granules in the holes, and sprayed a little Bengal roach spray down them.  I've been busy and have not looked at these palms for over 2 months.  They're pretty much on their own back there.

[PR00636]

I can happily say that any protected palm with a cage has not been attacked.  The cages are buried eight inches into the ground at the lowest point as a number of the palms are planted on a steep grade.  Perhaps if a beetle lands on the fine mesh, it just doesn't recognize it as an easy food source.  We have found no holes surrounding the mesh of the imprisoned palms. 

We tested one coco palm outgrowing a second tier and removed the lid in August, and just yesterday it was attacked.  We found the hole today, ejected the beetle, trimmed the mesh down to eight inches above the ground and added mesh ring around the palm.  Let's see what happens

 

 

 

 

[PR00636]

  On 3/27/2024 at 12:15 AM, Ed Askew said:

I hope it works out, of course.  I think we, as above ground beings fall to understand the subterranean world of the beetle.  Your defenses need to extend below the organic layer of the soil to be effective.

Expand  

I failed to mention that the cages are buried 8 inches at the lowest point, so if they are on a steep hill the back side of the cage may be more than 18 inches below the soil line.

[Cindy Adair]

It has been great to have a “beetle break” with the normal for PR dry season since January. 
 

Fall was rainy here and lots of beetle attacks. 
 

I have failed so far attracting any beetles into my traps as I have not found an effective obtainable lure. 
 

I have stopped using the layered barriers as overall they seemed ineffective.

PR00636 has very different barriers that I hope work great!

At least I finally have trunks on some species and they seem to be uninteresting to the ox beetles even if the trunks have diameters less than an inch. 
 

And as noted before, clumping palms get attacked but generally survive. 

Tiny seedlings seem of no interest either. So this year I guess I will try using imidocloprid granules every 4 months with a break for the dry season and only on susceptible size palms.
 

I may try a slightly higher dose than the lower one I used last year, especially on palms that are hit every year like Asterogyne and Syagrus and Licuala grandis.
 

Plus working hard to improve my paths and steps so I can check for holes more frequently and use dawn dishwashing liquid and water to get any beetles out. 
 

I finally have an electric cart which could make it possible to start imidocloprid treatment just prior to the rainy season.
 

I could at least get water in bottles closer to the sites far from irrigation rather than waiting for rain since water is supposed to be used after granule application to minimize chemical burn. 

[PR00636]

Cindy,  with existing palms with no barriers we are now simply placing 48" fine mesh all the way around the palm stem.  It was suggested this may not take into account the subterranean nature of the beast but we also feel their instinct is to find a way into the ground near the palm, not two feet away from the stem.  I have lost 5  of 6 Hydriastele begunii v Obi Island.  This is our last-ditch effort to save the remaining one.  Sad my hillside of the species is gone but they are fast growing in Puerto Rico 🇵🇷.  Hopefully, we are successful with this barrier.  And we monitor growth and adjust the collar as needed.

[happypalms]

I work in horticulture industry and we use a product called Suscon to control the African black beetle. It’s slow release and very affective in control of the beetle and other soil insects. Not sure what’s available in other countries but it is basically Chlorpyrifos aka lorsban. We would add about a tablespoon to the planting hole or top dress with it. Iam personally not a fan of such chemicals for home gardening but if it was my palms being destroyed I know how I would feel about the situation and use it. Perhaps it may help control the beetle and being a slow release it has its advantages. Could be worth a try. Good luck. 

[Cindy Adair]

Thanks so much for the information happypalms. 
 

I can’t say what I will do in the future as I lose young palms here. 
 

Before better and safer products became available I dealt with this chemical used in flea control products and sadly saw reactions. 

It was a very hard decision to use imidocloprid, but at least if I never use it on flowering palms to protect bees and it seems less dangerous. And I never saw toxicity in the dogs and cats and many other species who used it in my veterinary practice. 
 

I continue to look for the safest options, but definitely appreciate all ideas!!!

This morning I will remove 2 or 3 more palms which were not well observed and are beyond help.

Maybe some pieces of these palms could be chopped and used as a lure?? And the rest sealed in a plastic bag rather than tossed on a debris pile?

Keep in mind that this is not easily done as it involves climbing some steep hills acres away from real accessible paths/roads. However it is great exercise!