At the beginning of the summer, I noticed that one of my orchids (a phanaelopsis) had developed some tiny bumps (less than 1mm in diameter). On the floor at the end of the leaf there was a shiny sticky substance. The leaves invaded by this "thing" turn yellow and die. These things come off when you scrape them w/ your nail. I watched them under a not so powerful microscope(pocket microscope) and there were no moving limbs, which leads me to suspect it is not an insect. The underside is shiny. Now I have seen the same growth in my masdevalia, oncidium, anthurium and another phanaelopsis. I have puctures but do not know how to upload them? Can somebody help me determine what it is and how to get rid of it? Thanks a million for any help.
Sounds like scale. Disgusting and persistent pest. Q-tip moistened with rubbing alcohol will take them off individually. More than one treatment will likely be necessary.
Something else that will work very well is Horticultural Oil. I use Green Earth brand, which is the only one I've seen in Ontario, but it is labelled for use on some green growing plants, during active growth. It will kill scale, mites, mealy bug, even fungus gnats, both on leaves and stems and in potting media if you water the pot with the solution. it smothers all life stages, and I have had excellent results with it, on everything from various orchids, other leafy tropicals, cacti, even some ferns and sensitive succulents. Just keep out of direct sunlight when the spray is still wet, and make sure you shake frequently. There is nothing in this to force it to remain mixed, so it separates from the water quickly. Small price to pay for one of the safest and most effective products I've found so far. Don't breathe the spray of course, no spray is good to breath, nor dust either.