Not sure this is the same wasp you are talking about but...

"The velvet ant has multiple defensive strategies, but is best known for its extremely painful sting, earning it the nickname of "cow killer". Its defenses include a thickened exoskeleton, the ability to run fast and evasively, warning coloration, stridulatory warning sounds, a chemical secretion, and venom"
[link to en.wikipedia.org (secure)]

Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects... and this ant calls for recruits when it's in danger. That's fucking amazing.