Source : Webster's Revised Unabridged Dictionary (1913)

Larval \Lar"val\, a. [L. larvalis ghostly. See {Larva}.]
   (Zo["o]l.)
   Of or pertaining to a larva.

Source : WordNet®

larval
     adj 1: immature of its kind; especially being or characteristic of
            immature insects in the newly hatched wormlike feeding
            stage; "larval societies"; "larval crayfishes"; "the
            larval stage"
     2: relating to or typical of a larva; "the larval eye"