Bonesaw- Test Tube Bug Killer

Few of the bugs were getting past that spray, and even the droplets of the spray that had settled lingered on Bonesaw’s skin, hair and clothing were enough to kill or incapacitate them on contact.
...

I could feel my bugs congregating on her as she put the aerosol down and fumbled around inside her pockets.  Test tubes: I could feel the long, smooth glass. She dropped something into each, then stabbed the aerosol can.  The smoke that plumed out killed most of the bugs in the area.  I couldn’t follow what she did with the can and the test tubes.

“It’s interesting,” she said.  I felt small hands on me, and she heaved me over so I was staring at the ceiling, and at her.  Clouds of what looked like steam were rising around her.  From the test tubes?  It was having the same effect on my bugs that the aerosol had.  She’d erected some kind of gaseous barrier.

- Worm, Snare 13.9