I have a bug that is eating and killing my cocnut trees and the ornamental bamboo plants .

Supposedly something like that caused several thousand Rai of trees to be cut down in the South .

Looks like a leaf / stem borer that is attacing the leaves , which turn brown and die off.. Is there anything I can do to kill that pest ?

do you see anywhere on the stems, or near the trunk, clumps of fibrous material ?

looks like coconut fiber in a ball !

if yes or not sure, you probably are being visited by a relative of the rhino beetle.

a dark brown, hard shelled beetle about 1" long, comes out at night to forage.

it looks just like the rhino beetle minus the horns.

they chew the stems close to the trunk, or even higher up leaving behind the fiber clumps.

very hard to get rid off, after experimenting, the only thing working for me is:

in a 10 liter spray bottle, put one espresso size cup of Chaindrite liquid & about 20 ml of Cypermethrin.

mix good and spray directly on top of the trunk, where the leaves emerge from the tree, especially straight up, where the young shoots are coming out.

spray in the evening, if successful, in the morning you might see a couple of the beetles laying around the tree trunk.

do not spray this mixture on regular plants, highly toxic you will kill them.

good luck

I think Soidog2 probably has it right, the coconut rhinoceros beetle, Oryctes rhinoceros (duang maprao) is one of the 3 common beetle pests of coconut palms. There is another pest that often follows it, the red palm weevil, Rhynchophorus ferrugineus, that uses the holes that the larger rhino beetle bores, and furthers the damage. (Coconut hispine beetle is the third, not necessarily associated with the others).

Sanitation, prevention and early detection/treatment is key, a heavy infestation is bad news. You will lose trees one by one; concentrate on protecting the trees that are not yet infested.

Cypermethrin, like SD2 has found, is the pesticide of choice for a local coconut grower foreman that I quizzed, but there are other controls used too. (A Chiang Mai ag shop recommended chlorpyrifos.) Drench the base of the frond stalks so that the pesticide solution rolls down into the cracks and crevices and existing holes that may have been formed. This is a contact pesticide, not a systemic, it may have a residual effectiveness of up to about one month (in dry season; rains will leach it out faster) and will have to be repeated. Some growers use fine sand pored into this same area, it apparently is abrasive to the borers and limits their activity. Sand may be an alternative for strict organic growers. There is a biological control of a virus that attacks the beetles, but I've only read about it and don't know if it's available.

Don't underestimate the value of sanitation, cleaning up of fallen trees and tree parts, heavy mulch and manure piles where the pest harbors.

I think Soidog2 probably has it right, the coconut rhinoceros beetle, Oryctes rhinoceros (duang maprao) is one of the 3 common beetle pests of coconut palms. There is another pest that often follows it, the red palm weevil, Rhynchophorus ferrugineus, that uses the holes that the larger rhino beetle bores, and furthers the damage. (Coconut hispine beetle is the third, not necessarily associated with the others).

Sanitation, prevention and early detection/treatment is key, a heavy infestation is bad news. You will lose trees one by one; concentrate on protecting the trees that are not yet infested.

Cypermethrin, like SD2 has found, is the pesticide of choice for a local coconut grower foreman that I quizzed, but there are other controls used too. (A Chiang Mai ag shop recommended chlorpyrifos.) Drench the base of the frond stalks so that the pesticide solution rolls down into the cracks and crevices and existing holes that may have been formed. This is a contact pesticide, not a systemic, it may have a residual effectiveness of up to about one month (in dry season; rains will leach it out faster) and will have to be repeated. Some growers use fine sand pored into this same area, it apparently is abrasive to the borers and limits their activity. Sand may be an alternative for strict organic growers. There is a biological control of a virus that attacks the beetles, but I've only read about it and don't know if it's available.

Don't underestimate the value of sanitation, cleaning up of fallen trees and tree parts, heavy mulch and manure piles where the pest harbors.

To my dismay, they were having a party with the date trees, it is correct, you have to spray quite often in order to control the buggers.

Attached is a picture you will enjoy. (for the good doctor)

Best regards.