I am not very good when it comes to babying palms. I have way too many, and a very large garden for one guy to keep up on. So, I generally plant more than one of each species (if available), and let Darwinism rule. So when two of my favs started getting sick, I let them be. A lot of times the center of a smaller palm may rot out, but here in Hawaii they can just push on through with some quick growth. So I let my Dypsis sp. 'mealy bug' (my only one) fend for itself. And I let my Dypsis lastelliana var. 'mealy bug' fight it off. But after a year, and the palms going into a bad funk, with no sign of a new spear pushing through, I tried some Hydrogen Peroxide. I mixed up half and half of the common strength and just poured it into the growing point. A week later I noticed some green in both palms, so I did it again at a two week interval. It only took a second to pour half H2O2 and half H2O into a large glass, and another second to pour it in the center of each palm - and no clean up but a quick rinse of the glass. Fast, cheap, and easy. Here's a pic of the D. lastelliana. First a pic of the large ones. Then the sick palm. Then a close up of the new growth, that hadn't been apparent for a year, yet within a week of the H2O2 - there it was peeking through. This is about a month later.