Is this black scale or fungal spores on my Brassocattleya Maikai Louise?
I have found three of these black spots on my orchid. They look similar to black scale, but are very rounded in shape. They also remind me of Bird's nest fungal spores in appearance. They are adhered tightly to the leaves. When removed and smashed between finger nails, they seem very waxy in substance and appear to be kind of reddish brown in coloration. Any identification ideas and treatment suggestions would be appreciated.
Scale. And under those shells are eggs. So if you squish them and the bits fall in the medium, you're helping them to propagate. You'll want to drench the medium as well as treat the leaves where you see it.
That works, but be sure to treat the plant once a week for 3 weeks at least. You may also want to immerse the whole plant (pot and all) in the soapy water for a half hour or so to drown what my be living in the medium.
This works by drowning the pests (which breathe through pores in their bodies) so it only works by contact, and only on the adults. That's why the repetition is so important... you need to kill the next generations that may hatch from eggs.
I'd start with the soap, but then something like Bayer's Advanced (or whatever the new formulation is called) Yes, systemic for the longer term would be a good idea.
This made me wonder if neem oil is safe on orchids (particularly phalaenopsis in my case).* I searched and it appears the answer is yes. True?
* I used it on scale on a Curly Sue (epiphyllum guatemalense monstrose) once and it was effective. Scale hasn't been a problem otherwise, but I have seen it, so I expect I will see it again someday.