Definitions for dobsonˈdɒb sən
Random House Webster's College Dictionary
Ref: hellgrammite .
large brown aquatic larva of the dobsonfly; used as fishing bait
dobson, dobsonfly, dobson fly, Corydalus cornutus(noun)
large soft-bodied insect having long slender mandibles in the male; aquatic larvae often used as bait
the aquatic larva of a large neuropterous insect (Corydalus cornutus), used as bait in angling. See Hellgamite