Locust Swarm

Locust Swarm is a secondary Poison Witch Doctor skill.

In-game
The Locust Swarm creates a 20 yard-ranged cloud of green insects that affects one enemy (the closest one) in a narrow cone in front of the Witch Doctor. Upon dealing one tick of damage, the locusts spread to one additional enemy within 20 yards, refreshing the duration to full on that target (but not on the old ones). Each enemy can only spread locusts to one additional enemy, and the swarm cannot jump to a target already affected by that specific cast. If there are no suitable targets in range to jump, the locusts will stop spreading.

It is thus a useful skill to use against clustered enemies. Damage per second of the split swarm remains the same, therefore the total damage may be greater than 1040%. The Swarm may not roll Critical Hits, but the damage increases proportionally to Critical Hit Chance / Damage ratio.

While the Locust Swarm deals significantly less damage than Haunt, it can affect more enemies at a time. Multiple Swarms on a single target, however, do not stack. The Swarm also has a very considerable Mana cost, but in most battles, it is enough to cast it once to ensure all enemies present will suffer from it.

Skill Runes

 * Pestilence: the swarm jumps to two enemies per tick instead of one (unlocked at level 27).


 * Devouring Swarm: damage type changes to Cold, and regain Mana per second as long as the original target (first one to be hit) is still under the Locust Swarm effect (unlocked at level 33).


 * Cloud of Insects: damage type changes to Physical, and affected enemies deal less damage (unlocked at level 37).


 * Diseased Swarm: enemies killed while under the Locust Swarm effect leave behind a cloud of locusts that deal 750% damage as Poison over 3 seconds to enemies who stand in the area (roughly 5 yard radius) (unlocked at level 42).


 * Searing Locusts: damage type changes to Fire, damage increases to over  seconds. (unlocked at level 59).

Non-rune enhancements

 * Hwoj Wrap (Legendary Belt): affected enemies are also Slowed by 60-80%.
 * Swamp Land Waders (Legendary Pants): deals 300–400% additional damage against enemies affected by Locust Swarm.
 * Bakuli Jungle Wraps (Legendary Belt): Firebats deal 250-300% increased damage against enemies affected by Locust Swarm.
 * Vile Hive (Legendary Mojo): adds Pestilence rune to any other and increases damage by 45-60%.
 * Ring of Emptiness (Legendary Ring): enemies that suffer from either Haunt and/or Locust Swarm take 250-300% more damage.
 * Quetzalcoatl (Legendary Voodoo Mask): halves the duration of Locust Swarm, but doubles the damage per second.
 * Wormwood (Legendary Staff): every second, casts Locust Swarm on a random nearby enemy.
 * Raiment of the Jade Harvester Set (Set Bonus for 4 items): when casting Locust Swarm, also reduces the remaining cooldown of by 1 second.
 * Raiment of the Jade Harvester Set (Set Bonus for 6 items): Soul Harvest consumes up to 10000 seconds of Locust Swarm and instantly deals the damage of that duration.
 * Spirit of Arachyr Set (Set Bonus for 6 items): increases damage by 17500%.
 * Zunimassa's Haunt Set (Set Bonus for 6 pieces): pets deal 15000% more damage to enemies damaged by Locust Swarm for 8 seconds, the effect does not stack.

Passives

 * Creeping Death: increases duration of Locust Swarm to 19800 seconds (with same damage per second).