Embyonic movement during development of the light brown apple moth

Abstract

A complete time-lapse cinematographic record of the embryonic development of the tortricid moth Epiphyas postvittana has provided data on the movements of the embryo. Exposures were made every 32 sec during the 6.5 days development at 28°C. There are 11 contractions of the blastoderm indicative of synchrony in cell division. Pulsations of the developing embryo which begin about the 49th hour of development become progressively more rapid until the 74th hour when the caudal lobe begins its movement over the ventral side of the embryo. During the 40 contractions involved in this migration the embryo doubles in length. A prolonged period of quiescence lasting 14 hr precedes sudden filling of tracheae after which the developing embryo proceeds to ingest the yolk remaining in the egg. Eclosion occurs at 160 hr. The film on which these details are based is available and should be a useful aid in teaching embryology.