Flies circling yucca

[Courtjobby]

Hi,

So I had two yucca plants on my windowsill. 1 is thriving, one basically died becoming hollow on the inside. There are now little tiny flies circlingy healthy yucca and am afraid they are what killed the other one? Any advice. They seem the size of fruit flies. There is also a orchid on the windowsill, could the damp from that be causing issues?

Thanks

I've got these. I ordered fly sticky paper on amazon next day delivery. I've placed one on each plant. They can't lay their eggs if they're stuck to the paper. It's gross but I'm hoping they're almost all on the paper now. I'll gve it a few more days.

Small black flies with pointy abdomens? They might be fungus gnats. Iirc they lay their eggs in damp soil and the larvae feed on fungus growing in the compost. I don't think they do much harm but can be a nuisance if you get lots and might finish off an ailing plant. I think they can be dealt with by a top dressing that stops the adults laying their eggs, decorative gravel, etc. I put a small bowl of water and malt vinegar with a drop of washing up liquid which attracts them and they drown in it. Currently I've got a spider living over my plants who seems to be controlling them.

However, they might be something else, have you got a picture?