What have I caught and do I need to take any action?
This is the result of one of my sticky traps. I lay them flat on top of the soil. The trap is 2 sided which is why you see the shadows of other insects.
In addition to (I think fungus gnats) I have caught these critters. Out of the 4 places where I placed sticky traps only 2 have these. And only 1 is covered in these things.
The picture I took is from the most infested trap. This particular trap is about 10cm/3" square. It puzzles me since they appear to be wingless.
My plants sit in pots on my balcony. There is no other foliage around.
I set new traps today. As an experiment I set the traps vertically rather than laying them down on the soil. Minutes later I started to see these small insects jump onto the bottom of the traps. So they are definitely not dropping from somewhere.
This small section is representative of the entire trap. It's literally covered in them.