black sooty mold and insects

[VickiC]

I just noticed this morn. that 4 of my orchids had a very small infestation of scale....maybe 2 or 3 scale....no more than 6 or so on all 4 plants combined. I also noticed that these 4 plants had black sooty mold (once again, not a large amt., but nevertheless some) The plants were all in approx. the same area....3 on mounts, 1 in a basket, near the end of one of my benches. If any area of the greenhouse gets less humidity and airflow than the others, it would be this area, although I think the entire greenhouse in general is sufficient in both from what I have read in past posts (2 large fans--1 under each bench, approx. 55-75% humidity in the summer, and much less in the winter, so I have to work harder then to control it). Also, the temp. is hot in the summer (approx. 90-95 degrees). I have sometimes read conflicting answers about various problems on the internet, so I would rather have your opinions and advice. Is there a connection between the mold and scale (insects, in general), humidity and/or airflow or was it just coincidental that I found both problems on all 4 plants? Once again, I would appreciate your help.
Vicki