If you are specialized, try Icestorm or Firestorm. They are quite expensive in Mana, but effective. I killed all 4 Mantraps (I play Hard) with 3 Firestorms (and a few Spectral Ravens). The JungleLilies I killed with 3 Icestorms in the Boogre Caves. No big Deal.
If you play Solo (much more Fun) these Spells are truly wonderful.
(I levelled from 5th to 9th by killing these Mantraps
)