NOTES ON THE POEM CHOICE:
The translator has included a link above to a very informative and enjoyable site, whose commentary on this poem I won't duplicate here. It's well worth checking out!
I wonder if there were originally two answers to this riddle--one a literal, universal bookworm, and the other a metaphorical, individual bookworm. ("Pfft! That's Godric! All that study, and no whit wiser!")
NOTES ON THE TRANSLATION:
The pun of "moth" and "myth" in the verse translation is magical, and I immediately share the narrator's sense of wonder. That wordplay also captures some of the flavor of the "word'/wyrd/wyrm" series in the original.
Despite Roger's assurances of the broader meaning of "bug" in the
"Insect-themed poems NOT in translation" thread, I do miss the worm idea. For that reason, I think I'd prefer something like "worm"/"wordsmith" to "bug"/"bard" in L3. But I can live with "bug"/"bard."
I like "of a poem's power," even though this seems quite a departure from the praise of lore as "the foundation of the strong". Then again, as both a poet and a weakling, I may be a wee bit biased.
Two more quibbles, both small: First, I'd like a "had" before "chewed," to make that phrase more parallel with "had swallowed." Second, I'd like to see L2 end with a full stop, so that "Pilfering guest" doesn't immediately follow a sentence beginning "A marvel, I thought." Currently, I find myself wishing there were a "But" or "Yet" or something punctuational before "Pilfering guest," to contrast the narrator's early wonder and later contempt, but making "a cheat in darkness / chewed on the glory / of a poem's power" a stand-alone sentence would solve that for me.