Ultra-poison spray

Ultra Poison Spray is dropped by Black Unmarked Spectralids, Burgeoning Spiderwort, and Iridescent Glint Beetle Larva(IGBL), more commonly known as 'strange bugs' or 'Wistful Wild Bugs'. It is grayish-black colored. It is a poisonous spray that deals half as much damage as eating a White Pikmin to all enemies caught in the spray's radius. It will not kill an enemy, at most it will bring the creature down to where one-hit will kill it.

The Oasis

 * There is a swarm of IGBL in the alcove behind where you find the Tan Pikmin.
 * On a random day a single Black Unmarked Spectralid will appear in the landing site.

Flooded Abyss

 * On the island in the center of the lake are two Burgeoning Spiderworts, one with black berries and one with red berries.
 * Talking to Sir Pikmin after unlocking every area except for the final will yield two doses of this spray.

Ancient Forest
You cannot find any Ultra Poison Spray doses here.

Bald Mountain

 * At the top of the mountain are five Black berries.

Dawn Lake
There are no traces of Ultra Poison Spray here.

The Facility
There are no traces of the spray here, you are in a factory.

The Wilderness
No traces of the spray here.

Olivert
It is the first level, no sprays here.

Merged Nothingness
Final level, almost nothing is here. Hence the name.