Plz help!! Masd "Cheryl Shohan" has perfectly round, tiny black spots

[sbriz]

Hello! This is my first time posting and I need some advice, please. My Masdevallia "Cheryl Shohan" has started to develop tiny dark, blackish, perfectly round spots on its leaves. Looks like something might be boring thru the underside of the leaves, but haven't spotted anything. Used an insecticide w/neems oil on it and water it about twice a week. It is kept on antique pillow or shoe rack with other orchids in a west window in my home. Circulation is standard central heat/air. My home is about 80 years old and on pier and beam. Any advice? I recently moved this plant from my bathroom, where it sat in a northern window--moved it because the bathroom tends to be colder. Please help--I'm fairly new to growing different types of orchids other than phals, but have recently added oncidiums, cattleyas, a vanda, and dendrochilum. Thanks.
-Susan