Prismatic Lacewing

The Prismatic Lacewing is a rare flying Critter that resembles a butterfly and spawns in the Surface Hallow from dusk until midnight after Plantera has been defeated. Killing it summons the Empress of Light boss.

The Prismatic Lacewing can be caught with a Bug Net, and be used to craft a Prismatic Lacewing Jar. Releasing it from the inventory in any Hallow biome and then killing it will still summon the Empress of Light. Only one Lacewing can be naturally spawned at a time. Because it can only spawn between dusk and midnight, its spawn is limited to between the times of 7:30PM and 12:00AM.

It is one of the few critters that can be detected by the Lifeform Analyzer.

Contrary to popular rumors, wind does not seem to affect rarity or spawn rates.

Tips

 * Keep the Guide to Critter Companionship with you so you may farm the Hallow without having to worry about you or a minion accidentally killing it.
 * A Lifeform Analyzer can be used to see if one is nearby.
 * The spawn rate is increased in Hallow biomes in the outer 2/3 of the world.
 * Using a Battle Potion and Water Candle increases its spawn rate, like other monsters.
 * Similarly, because it is considered an enemy the spawn rate is increased during the Blood Moon event and can be easily farmed using a Bloody Tear.
 * Building a platform roughly 35 tiles above a hallowed biome, and being under the influence of a Water Candle, you can expect 3-8 Lacewings to spawn, provided you are there from 7:30 to 12:00.
 * It seems to only spawn in normal hallow biomes, therefore if you have snow hallow it likely won't spawn there. If you don't have a normal hallow in your world then you can use a Clentaminator with Blue Solution in a forest biome in order to create one. It can be found in a hallow desert.