Insect plague

Insect plague is a conjuration spell that conjures an insect horde to limit vision, inflict damage, and cause weak creatures to flee.

Effect
A horde of creeping, hopping, and flying insects swarm in a thick cloud when you cast this spell. The insects limit vision to 10 feet, and spellcasting within the cloud is impossible. Creatures inside the insect plague, regardless of Armor Class, sustain 1 point of damage at the end of each round they remain within, due to the bites and stings of the insects. Invisibility is no protection. All creatures with 2 or fewer HD are driven from the cloud at their fastest possible speed in a random direction and flee until they are at least 100 feet away from the insects. Creatures with 3 to 5 HD flee as well, though a Will save negates this effect. (This urge to flee is an extraordinary fear effect.)

Heavy smoke drives off insects within its bounds. Fire also drives insects away. For example, a wall of fire in a ring shape keeps a subsequently cast insect plague outside its confines, but a fireball spell simply clears insects from its blast area for 1 round. A single torch is ineffective against this vast horde of insects. Lightning, cold, and ice are likewise ineffective, while a strong wind (21+ mph) that covers the entire plague area disperses the insects and ends the spell.