I have been fighting an up hill battle with mealybugs since I got my first Den. moniliforme back in March.
When I got it it was fine then after a fey waterings I started to see white fuzzie things close to the joints of the leaves. I assumed mealybugs. I took action in trying to rid myself of the invaders but with no luck. I tried everything from organic pesticides to inorganic pesticides that I can get locally, but with no luck.
Spray with alcohol. Buy 70% isoproyl alcohol (rubbing alcohol from the drug store) and put it in a spray bottle. Then spay these little buggers. It won't hurt the plant. Be sure to peel back any dry sheaths where the critters can hide.
Isolate your plant and check all your others - you never have just one!
I find the alcohol spray very effective if you keep after it.
I use the rubbing alcohol too. When you use it try and use it to dab every crevice where you can see any sign of the white fluff. Check it every day after that for a couple of weeks and as soon as they re-appear treat again in the same way. If when the next batch hatch you can get them before they lay more eggs then you should get rid of them.
I agree with everyone who posted above about using alcohol. I would also go one step further and repot in new media and give the plant a good bath in water to remove as many of the mealys at all stages as you can. Good luck!
Rosie...your photos are spectacular! These are all your orchids? I see sev. that I also have and will strive to get them to look as lovely as yours.With all the bad news these days,it has brought a big grin to my face to see such beauty at my fingertips.
Thank you all for the advice on using the alcohol. Its lowering them in numbers. Yay!!
I looked at all the others in my collection and haven't found any yet.
Now I have another problem....its another white fuzzy thing that keeps eating my Den. and my coconut orchid...its my cat how do I keep him from chewing on them??