Patch 9.0.1 (2020-10-13): Re-added and effects and icon changed.
Previous version: The moth's wings produce a cloud of dust that interrupts the enemies spellcasting and preventing any spell in that school from being cast for 4 sec.
Hotfix (2011-04-29):Some interrupts were still incorrectly missing targets. Wind Shear, Spell Lock, Counterspell, Mind Freeze, and hunter pet abilities Nether Shock and Serenity Dust should no longer miss.
Patch 4.0.1 (2010-10-12): Redesigned. No longer increases the attack power of or heals the moth. Now interrupts spellcasting of nearby enemies.