It's true that bigger bugs can cause some problems! Perhaps the solution is huge, betentacled, foul-smelling carnivorous plants that are full of teeth? They could eat the bugs.

"Have you?" Hythlodaeus seems to perk up some more at the revelation; after all, it's still relevant to his work. "Did they not acclimate to their environment properly, or was there some error in their introduction?"

Well, he sure sounds as though he expects people to have put bugs in the world, instead of them always being there. Weird how that happens.