I did this at Level 64, Arcane Specced Mage, I got so busy in Outland, nearly forgot about Silithus. The wasps are in swarms up to 5, and they inflict a poison, that stacks up to 8 times. Which deals 350 damage each tick if 8 are stacked up. I soloed it no problem, make sure each swarm your health and mana are 100 percent, keep health potions handy and if you have any pots to neutralize poison, I went herb/alch so I can make em myself. Also pack some food. Eating after the fight if you got afew DOT poisons stacked against you can prevent you from dieing, bandages wont help, once you take damage the next tick, bandage loses its effect. You can solo this, just stock up on pots, food, and make sure you are at full health and mana before taking on each swarm. I pulled one with icebolt, followed up by arcane missiles and fireblast, hit frost nova, backed up, took another out, then I AOE'd with Arcane Explosion to take out the remaining 3 mobs. AOE is nice, if you dont have AOE, might be wise to bring someone along that can, or that can neutralize the poisons and heal you.