A friend gave me a B.nodosa about a week or two ago,and today I see this on the tip of one leaf. First of all what are they? Are they harmful? Should I quarantine the plant? How do I get rid of them? This is my first sign of any pest! Thanks for your help
It's a bit difficult to tell, But the way they cluster up ... look like aphids. You might also want to check for ants in the media, since they farm them.
I would pick them off then follow thru with spraying of Soap dish and water.
Definetly qurantine them from other plants. If the bugs are moving rapidly then they may be ants (they may be those dangerous red ants that I heard infest much of Florida? I am not sure if ants eat plants, but there does seem to chew marks on the leaf next to it) otherwise they could be aphids. I would first try to wash them off with strong jets of warm water, if this doesnt work then try neem oil or horticultural oil. If this doesnt work then try a low toxic insecticide like pyrethins. If this doesnt work use a potent insecticide. Usually the insecticides that are meant for roses are safe for orchids. Good luck