Flies! Help!

Seakay

if you are prepared to sacrifice the orchid anyway then it might be worth repotting it outside and getting rid of all the previous potting material without bringing it back into the house; scrub the pot clean, give everything a good hoover before you return and enclose the pot and plant in a big plastic bag for a few days (clear so plant gets light) to make sure it doesn't get reinfected.

Chris25

I think seakay's suggestion is a good one; I remember now that we found little flies in the potting material around an orchid once - It seems to be mostly ground bark.

If that is the cause of your infestation, perhaps some flies flew in through the window and laid eggs under the compost and have now hatched?

Pipkin

The orchid is now outside (sob), will see if that makes a difference.