Okay, Sarah, a chick is responding...
in the past, yes, I tend to clean up at the end of the night after folks. But I also make sure the cushions on the couch are straight, because it's my OCD kicking in. But I do explain to my cast/crew that use of a kitchen is a privledge (even the daily coffee... no where does it say that the theatre/SM is responsible to provide coffee) and they are expected to clean up after themselves. If things are left out, unless I want to keep it, I tend to just throw them away.
However, it's one thing to take this responsibility on yourself and another for the theatre to tell you that it's YOUR responsibility. If the theatre were to truly say it was my job (as in, if not done there are repercussions) then I would make the rule that there is to be no food in the green room - won't be popular but if the cast/crew can't clean up after themselves then that would be the rule I'd throw down.
(Last LORT theatre I worked at I had huge battles with the company manager who, during tech, to be nice, would leave trays of fruit and pastries, etc which was lovely - but then after tech notes, at 1am, I found myself in the green room, cleaning it all up. When she would clean it up, she'd leave dirty dishes in the sink and they'd stay there for days or until I washed them. Came to a head after one night a just threw it all out, trays and all.)
The bug issue has me baffled. Does the theatre not have a maintenence crew?