Hey wormmad
I can only give my humble but uninformed opinion

if you can see the cocoons it would be my guess that they are from your worms - I have never seen anything that looked like a cocoon of a pot worm - I use dampened bread crusts to attract the pot worms @ then trash 'em. It could be, too, that your bedding is a little wet.

imho
bruce

I would think that pot worm cocoons would be very small. If you are seeing a lot of pot worms, that should be telling about conditions in your bin. (Conditions that a favorable to pot worms). Look at what you are adding as feedstock and check your moisture. I see loads of pot worms when my bins become more acidic and wet. The key to your success is in your observation.

Bruce's humble, uninformed opinion just happens to be based in good science and fact! You cannot see pot worm cocoons with the unaided eye.

Kelly S

What's wrong with Potworms.
I would think they would add to the micro-ecosystem.
They are usually the first to attack food, that and the nemetodes.

Thanks all. I guess I should have realised that the cocoons would have been minuscule given the size of a potworm. Silly me. But am happy now to be reassured that all the cocoons I've picked out will, hopefully, turn into large worms and not more potworms. Actually, I dont mind the potworms, their population waxes and wanes depending, like others have said, on the conditions.