Number of Larval Instars of the Gypsy Moth in Japan (Lepidoptera:Lymantriidae)

Individual rearing of the gypsy moth, Lymantria dispar (L.), was carried out for over a quarter of a century (1956-1981) on 86 egg batches collected at 73 localities in Japan. Six and 7 larval instars in female and 5 and 6 instars in male were obtained for almost all races. In some races 5 and 8 instars in female and 4 and 7 instars in male were obtained. Any discussion of racial differences in morphological or physiological characters should terefore be made after the sorting of experimental records based on the number of larval instars and sexes.