Paladins: Can hunt larvas with spears and a shield from a low level, perhaps dragging spears to a spawn would be helpful.
Mages: Should use low level wands/rods to save mana unless you are using Mana Potions. If you did, then a level 19+ wand/rod will help kill these much faster, if you don't care about the waste. You can also wear any item from the Terra Set or a Silver Amulet to avoid the damage from their poison. Mages could also use a melee weapon while rune making or spend mana on hasting to get to the larva faster, as the cave's ground makes you walk slowly.