[el_kalkylus]

Thanks. I copied the information about spell immunity from the link. Here it is:

Spell Immunity Most enemy spellcasters use spells from too many different schools for this spell to be any good as a conventional spell protection, but it is incredibly powerful in specific instances. Especially solo mages can put its immunities to great use. The spell offers the following choices: Abjuration: Will protect you against Dispel Magic, Remove Magic and Imprisonment (including the demilich variant Trap the Soul). Will not protect you against Breach, Lower Resistance or any conventional spell protection removal (use Improved Invisibility for that). Conjuration: Will protect against Melf's Acid Arrow, Flame Arrow, the Power Words, Maze, the Symbols and all of the nasty insect spells. Will not protect against summons in any way. Divination: Protects your illusions from all illusion removal spells. Will prevent Projected Images from being killed by True Sight if they cast it themselves. Enchantment: Will protect against some nasty level 1-5 spells, such as Dire Charm, Hold Person, and Feeblemind. Illusion: The only illusion that affects others is Blindness... Evocation: Protects against every Evocation spell in the game (though only partially against Melf's Minute Meteors). While that may seem impressive, don't forget Mirror Image will probably protect you even better. This is the best protection against stationary area damage, though. Necromancy: Protects against Skull Trap, Abi-Dalzim's Horrid Wilting and a few spells too sad to mention. Since enemies cast these spells only very rarely, you're probably better off using Mirror Image, (Minor) Spell Turning and/or Improved Invisibility instead. Alteration: Protects against a small number of save-or-else spells. Again, try (Minor) Spell Turning or Improved Invisibility instead. In solo play, where enemy True Sight or Remove Magic triggers can wipe out all of your precious protections in one go, immunity to both Abjuration and Divination is essential. Won't protect you from your own spells (only those of others).

Nice to know that protection from conjuration will protect you against insect plaque!