When one of my lettuce plants started wilting, I pulled on it and found I could just pull it straight out of the soil with no resistance. On the roots, I found these maggots. (You may need enlarge the picture a bit.)
Does anybody know what these are?
How likely is it that those are why the lettuce started dying?
Can they spread to other nearby potted plants?
What can you do against these?
I don't buy this. I just caught them going through the roots of a plant with severe root damage visible. Granted, this was in combination with overwatering, but still. There are also plenty of voices in the Internet saying that, if those larvae run out of other organic material in the soil, they will start eating plant roots.
Right, they're infesting the plant because of the root damage. You gave them a great food source. But if they run out of damaged roots, they won't start in on the healthy ones.