What's eating our palm trees?

[Thailand Garden]

A photo is attached of a Champagne palm completely eaten out inside.  Last year something similar happened to a Caribbean Royal Palm. 

Could be we have more than one problem.  We often have very stunted palms (Betel nut and others) which appear to be infested with ants inside the crown shaft and coming out of the growth point, but from what I read the ants are generally not the root of the problem (but can’t see what is).  In other places I’ve seen little insects or these white deposits like in the last photo (hard to see, used zoom). 

I’d like to get a good pesticide regiment to use annually that would take care of most of these problems so we don’t lose palms.  We are in Thailand and have to source product here, so active ingredients or organic solutions are more useful than brand names. 

Any input you have would be most appreciated.  Thank you.