Larval growth of L. eurinus is studied in detail on a laboratory culture. The occurrence of several growing types (13, 14, 15 and 17 instars) is discussed. The growth of the laboratory reared larvae is compared to that of larvae caught in the field; this gives an evaluation of the efficiency of our rearing technique. Finally, an allometric study underlines the existence of two distinct growth phases in the life-cycle of this species.