Proc. Proc. Ar thropod. Embryo l. Soc. Jpn. 41 , 1-9 (2006) l (jJ (jJ 2006 Ar thropodan Embryological Society of Japan ISSN ISSN 1341-1527 [REVIEW] Character Phylogeny in Lepidopteran Embryogenesis: It s Revaluation and Issues to Be Resolved * Yukimasa KOBAYASHI Departme 四t 01 Biological Science , Graduate School 01 Sciences and Engineerin g, Tokyo Metropolitan University , Minami-ohsawa Minami-ohsawa 1-1 ,Hachioji , Tokyo 192-039 7, J4 μn E-mail: E-mail:
[email protected] 1. 1. Introduction The order Lepidoptera is the insect group whose embryogenesis has been well investigated. Until about 30 years ago ,however , the materials had concentrated on the highest group of this order , or the former suborder Ditrysia , and nothing nothing had been known of the embryogenesis of primitive ,non-ditrysian Lepidoptera. In several ditrysian species , for example , Orgyia antiqua , Chilo suppressalis ,Pieris rapae , and Epiphyas pωtvittana ,it had been known that their embryonic embryonic membranes (serosa and amnion) are formed independentl y, not by the fusion of amnioserosal folds to be described described later ,and their germ bands or embryos grow in the submerged condition under the yolk until just before hatching hatching irrespective of the shape and size of eggs (Christensen , 1943; Okada , 1960; Tanaka , 1968; Anderson and Wood ,1968). Since such developmental processes are not common to other insects ,it had been speculated that these processes processes are characteristic not only of the Ditrysia but also of the whole Lepidoptera until the time when Ando and Tanaka Tanaka (1976 , 1980) found out a di 妊erent mode of ea r1 y embryogen 巴sis in the hepialid moths ,Endoclita , belonging to the the non-ditrysian Lepidoptera.