I looked at that and wondered the same thing, but the netting doesn't look to be deteriorating at all. Sorry I couldn't get a better picture of it. The weird thing about it is that it almost appears to be growing from the cardboard onto the netting itself.

The only reason I was using the cardboard was because I couldn't find the lid to the container. I think I'll go digging for it now, and see if that makes any difference. Thanks for the non mold-ish reassurance. That already has got me feeling better!