I'd appreciate it if you could help me indentify the larvae from the below YouTube video.
They look like some sort of sawfly larvae. What plants have you had in the pot in question? Keep some of them on that plant, enclosed and see what the end result is. This can be very interesting watching and photgraphing their developement and at the end of the day you will be certain of the species, have a good photographic record and plenty to place on i-Spot.