Causes for palm weevils.

[JoshuaTilaranCR]

I recently had my only coconut that was just starting to flower get broken from high winds. I thought it weird for a palm so strong to basically crack at the base but when I brought it down I saw the whole center was mush and there were huge grubs eating basically everything. Even the young leaves had strips eaten right up the center of the leaf stem.

I had the plant mulched at the bottom with wood chips and then throughout the year I would toss grass clippings around it too. It was never piled up at the base but it was touching the trunk. My wife believes from having it mulched it brought the weevils, could that be the case? The damn things would fly into the house at night and since I thought they were just beetles I would toss them back outside and leave them be.

[achetadomestica]

Is the weevil native or introduced?

Is it possible the weevil entered a lesion?
I cut the boots too close one year and had a native beetle
kill my bismark palm. They entered an area that was
stressed by me. If it is a non native insect only time
will tell the damage it may cause your trees

[Chandramohan]

Did the beetle have a 'horn' like a Rhinoceres?

[JoshuaTilaranCR]

From the adult weevils I've seen, they are native. American palm weevil, Rhynchophorus palmarum. It has a horn yes! Here's a picture of one I found my dog grabbed and was playing with. For people with weak stomachs maybe you shouldn't look, it's been decapitated haha




It may have entered a lesion, now that you mention it I remember taking out some leaves with a machete close to the stem. I may very well have gone into the trunk a little.

Are these a pest I should be worried about with my other fruit trees? The only other palms I have at the house are pygmy date palms but I have a lot of other fruit trees all around where the coconut was.

[Galatians522]

Here is an interesting read about Coconut Palm Weevil. I hope it has not made its way to Costa Rica. Other than palms it can damage bananas, sugarcane, pineapple, and papaya according to this.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://entnemdept.ufl.edu/creatures/orn/palms/Oryctes_rhinoceros.htm&ved=2ahUKEwiy1em_19_0AhXESjABHek1D1sQFnoECDAQAQ&usg=AOvVaw0dUvNx6ASwgFlmSFNjr-WY

The damage done by our native palm weevil here in Florida has been greatly increased by the introduction of Lethal Bronzing. It used to only attack weak or really old trees that were basically already dying. As LB has spread (and along with it weakened trees) weevil populations have exploded.

[JoshuaTilaranCR]

Thanks for that. I've never seen one here that is covered in that link.

[Finca La Isla]

Called locally ‘picudo’.
Keep it clean right around the trunk and routinely check for a hole that will be covered with fresh mud. They tunnel under the young palm, then come up, eating as they go, into the heart.
We pour soapy water in the hole and kill the picudo when it comes out. Sevin will work well if you use that sort of stuff.
Peter

[JoshuaTilaranCR]

Thanks for the info Peter! That was our only coconut and I'm not sure I'll plant another one. If I ever do I'll keep an eye out for those holes. I had no idea they had these pests. I'll use the soap water method, I won't use chemicals here at all. I'm actually struggling with scale on my citrus and a couple other things because my homemade white oil won't kill them thoroughly.

[fliptop]

Which soap do you use? Aren't a lot of soaps derived from chemicals?

[Finca La Isla]

The soap we are using is powdered laundry detergent that we mix with water in a strong solution. My farm is certified organic and the inspectors say it’s ok.
I heard of another solution from the Dominican Republic. Place about 4” of sand around the palm. When the picudo tries to dig then the hole keeps caving in!
Peter

[fliptop]

Thanks, Peter! I hope one day to be able to visit your farm. When I first started gardening, I followed some advice I read somewhere about mixing up a solution with dish soap. I erroneously thought because it was homemade, it was "safe" for the environment 😝

[Finca La Isla]

It’s common to use a bit of dish soap as an adherent to foliar sprays or alone to control aphids.