Prismatic Lacewing Jar

The lacewing is the one critter you cannot casually display, because killing it at the wrong moment starts a boss fight you were not ready for. Bottling it removes that risk. Once placed it is furniture, it glows the way the live bug does, and nothing you do to it will summon anything.

The flip side is that a jarred bug is out of play. It cannot be used as a summon under any circumstances. If you change your mind, shimmer breaks the jar apart and gives the lacewing back as an item, and from there you kill it the usual way. Worth remembering before you bottle your only catch on a night when nothing else is spawning.