Insect plague

Insect plague was a conjuration spell that could summon swarms of locusts to attack all creatures in an area.

Effects
The summoned insects blanketed the area of effect, biting and stinging every creature relentlessly, reducing visibility down to 10 ft (3 m), and preventing all spellcasting. Armor did not protect and invisibility was useless to avoid the swarms. Small creatures and anything with failing morale would move at top speed in a random direction until they were well away from the plague. The insects did not pursue fleeing targets but remained in the spot they were summoned for the duration of the spell. Sustained large fires and smoke, or strong winds were effective in driving the insects away but a blast from a fireball would only clear an area briefly.

Components
Newer versions of this spell require only verbal and somatic components plus the priest's divine focus or holy symbol. Older versions also required a pinch of sugar, a few kernels of grain, and a smear of fat.