Can anyone help me with this? It seems to be affecting several of mine now. They are still blooming and growing well, but they get a white, sticky, powder type substance on the leaves and flower stems.
The sticky stuff only appears to be at the base of the new leaves. The white powder stuff is on the back and front of the leaves.
Is there a cure?
Mealy Bugs without a doubt and it is curable. I clean them off carefully with rubbing alcohol using a swab to get in the crevices and corners and then rinse off the plant. As badly as you have it you can also use a systemic insecticide but make sure that it's usable on orchids. If you clean them off you'll have to watch the plant carefully for a while to make sure you don't get them back and that you've gotten all of them.
"Orchids are universally acknowledged to rank among the most singular and most modified forms in the vegetable kingdom" - Darwin
If you want to use a systemic pesticide, I used Imidacloprid without side effects on Phalaenopsis hybrids. Mealy's also can feed on the roots and when you spray the plant only it's likely youd don't kill the eggs. If you spray the plant you'll need multiple treatments.
If you spray the plant, do it early in the day and make sure you remove excessive 'water' from the crown afterwards.
Sheena, I use rubbing alcohol often (70%) but I mix it half and half with water. Works great on mealie bugs. Use a cotton swab for the larger areas but to get down into the crevices I find that a student's paintbrush with a fine point works best. Good luck!