Kaktus said:I also need some guidance on how to take care of this H. Magnifica.
These 2 are the same species, freebies from the same seller. The one the right is just arrived yesterday, the one on the left is 2 - 3 months under my care, I keep it in the place where it is very bright but no direct sunlight at all, because last time I let it have some sunlight and it immediately turn black and dry. And somehow it is in dormant stage eversince. It is shrinking, looking dull and dry, don't know what to do, any suggestion ? 
Tx.
I have two versions of this species and both of them are in my south-facing nursery area where they receive 50% overhead shade during the spring and summer but full sun during fall and winter (when the sun hits more from the side than overhead). You being equatorial I can understand how the sun may have caused problems. If there's any way you can get a little sideways action or filtered light, that would be good. I honestly don't have any more insight about this plant, provided it's getting some sort of wet-dry cycle (to the extent that's possible in your climate).
Regarding the general question about ways to kill insects without insecticides (per se)... I use insecticidal soap for most mealy infestations. I have heard that mild dish soap at 1-2% in water does the same thing. You have to repeat the spray after a few days to make sure you got everybody. For some plants I prefer 70% alcohol (either ethanol or isopropanol), especially for scale problems. Neither of these products has ever burned my plants or required rinsing, but I never spray while the sun is out (ie. only at dusk or only when it's cloudy).
