Sorry, but I don't get a "long sheet of silk" in your post. Might you mean a long THREAD of silk?

Sorry, I don't know any worms, clear or otherwise.

Did you just buy the plant? Could it have come home w/ you in the pot?

Oops, forgot to add that part! Yes, the plant was just bought. By a sheet, I don't mean a thread. It was like a layer of silk kind of like the funnel-web spiders, except without the funnel, and thinner...

The soil is kind of peaty, I guess. The worm hasn't come out again, but the flowers are dropping now... :(

Oh, well, if it were me, I'd be taking it right back to the store. I live in an apartment, can't risk unknown living creatures.

If it was pretty tiny it might be a nematode worm. Not sure they make webbs but they do eat the plants' roots. I would take the plant out, examine the roots for webbs and / or rotting and perhaps you can catch the worm. You could rinse off the old soil and repot in new soil.

It was said "If it was pretty tiny it might be a nematode worm."

Umm. Nematodes *not* visible to naked eye. Also don't have an obvious head. Also, they don't make webs.

HelloPandaNF, I thought that I had posted this. See if the worm in the picture on the following site matches what you have.

http://www.opalexplorenature.org/Redheadworm

To fend off all the guessing, we need pictures. Pictures, puhleeeeze.

jean001a: I would have taken a picture, but it hasn't come back to the surface...should've snapped one when I had the chance!

Wouldn't changing the soil stress the plant? It doesn't look like there is any damage other than no flowers, and I don't want to change soil for a worm that may be harmless...

ronalawn82: From my memory, it was at least half an inch long, and looked nothing like the redheadworm. I appreciate your help, though!

Have no idea what it is but if you see no signs of distress on your plant than there's not likely any need for immediate concern.

There is a possibility that it is damaging the roots so you should pay attention to it for any signs that something is going wrong. You could re-pot it and be done with it and if your cactus is in good condition to begin with then it won't hurt it at all to give it new soil.

It's also possible that the web and the worm have nothing to do with each other and you have two different homesteaders living in there.

Caitlin

You said:
For this plant, I used organic soil and had been watering frequently when I started to notice the worms

I think that you can see, in organic soil there is more 'life' - they have lots to feed on, so no surprise - together with plenty of organic matter & moisture, you always get some 'bugs' - good or bad.
Your photos look like a larvae I would not want to have in the pots. Just my opinion.

Panda

I would either take the plant back, or change all of the soil. As dellis mentioned, there could be couple of different creatures there.

Rina

Had this same problem in my indoor growing space with organic growing medium. Found this thread when I searched for my problem and boy was the beginning depressing. How can you come in all hot with "Sorry, but I don't get a 'long sheet of silk' in your post. Might you mean a long THREAD of silk?"

Then go on to say "Sorry, I don't know any worms, clear or otherwise."

So you only replied to this question for the first part. Well thanks.

Caitlin82328, you have restored my hope in humanity. I am going to take care of the worm I found in mine and see what it becomes.

It is quite probably the larva of a fungus gnat or sciarid fly. I found some among my cactus seedlings and they have been eating them up from the inside after starting with the roots.
Google "fungus gnat larvae" and there should be some remedies for large plants.