Small clear circles with brown dot on cereus

[sha]

my night blooming cereus has these small clearish circles with brown dots in the middle on its leaves. what is that? i had a powdery mildew problem in the surrounding mother of a thousand plants but it doesn't look like mildew.

 

[oneeye]

Take a strong magnifier and get a close-up of the spots and make sure they are not bugs. Queen of the night plants are desert orchids and do best with dry conditions. If you overwater the plant they will suffer. I only give mine 1/4 a cup or 250 ml of water one time a week in a one-gallon pot.

 

[Tetters]

They are bugs. Scale insects which like cacti and succulents. They need to be dealt with.