A cankerworm is a pest of fruit and shade trees both in larvae and moth form. The Bible refers to cankerworms as the devourer.
Positive: Dreaming of a cankerworm could represent God fighting your battles and devouring your enemy before you even have to fight.
Negative: In a dream, cankerworms destroying crops could represent that the enemy is trying to steal your harvest.
(Joel 2:25; Joel 1:4; Nahum 3:15,16).