Question
I have one cymbidium that have black spots on the leaves. I pulled some of those leave off then I also found like white scale/spots on some of the leaves. Are these some kind of bugs or decease?

Answer
Hello Elvie,

If the black spots are on the small (tiny) side and near the end of the leafs, it probably is okay.  Some cymbidiums are susceptible to leaf spotting especially when exposed to temperatures below 40F.  It also could be caused by a fungus, if the spots are visible on both sides of the leaf it could be fungus damage which is not normally fatal.  But, fungus damage at the base of the leaf can be fatal as it can cause the pseudobulbs to rot slowly.  

White spots on the leafs, especially near the leaf bases could be boisduval scale which needs to be taken care of soon.  Use an insecticide that contains imidiclod as the active ingredient, mix it in water and drench the entire plant and pot.  It will take a minimum of three applications spread over 3 weeks to get rid of them.  Scale, once established, can be very difficult to eradicate so keep a wary eye for their reappearance in the future.  

Hope this helped.

Jim Kawasaki
San Jose, Ca.