Guthay is where the Silk Wyrms come from. So says Uncle Tantor.
Since hearing that story (and no doubt influenced by Nijineko’s cystalsinger idea) I’ve been thinking about them dropping from the sky like Pern Thread.
Inspired by this, in my last session the players ran into a storm with greenish thunderheads that rained burrowing insects wrapped in a comet tail of acidic filaments.