Does not stack with chance to miss % of other insect swarm.
Unlike a lot of other DoT spells which deal damage every 3 seconds, Insect Swarm deals damage every 2 seconds, meaning 6 ticks will occur in its duration of 12 seconds (7 over 14 seconds if you have Nature's Splendor).
Improvements
Talents
Improved Insect Swarm: Increases your damage done by your Wrath spell to targets afflicted by your Insect Swarm by 1-3%, and increases the critical strike chance of your Starfire spell by 1-3% on targets afflicted by your Moonfire spell.
Use: Increases the damage of your Insect Swarm ability by 30%, but it no longer affects your victim's chance to hit.
Sell Price: 37 50
Tips and Tactics
The talent is useful when used in conjunction with Moonfire. In addition, it's a cheap DoT that gains 120% from your +spell damage, which makes it desirable for certain balance builds and one of the most mana-efficient DoTs in the game.
In a raiding perspective the damage mitigation with the chance to miss helps with the survival of the main tank.
Unlike most (all?) Druid spells, Insect Swarm does not interrupt the swing timer. [1]
Patch changes
/Patch 4.0.1 (12-Oct-2010): No longer a talent, available to all druids.
Patch 3.1.0 (14-Apr-2009): The bonus damage from spell power on this damage-over-time ability has been increased significantly to match similar spells on other classes (from 76% to 120%).
Patch 3.0.3 (04-Nov-2008): Tooltip corrected to indicate it does not affect hit chance with spells.