SEASONAL POLYMORPHISM OF THE ADULT RICE-PLANT SKIPPER, PARNARA-GUTTATA-GUTTATA(LEPIDOPTERA, HESPERIIDAE) AND ITS CONTROL

Larvae and pupae of Parnara guttata guttata were reared under various temperature and photoperiodic conditions. The adult morphology varied manifoldly with temperature and photoperiodic conditions during larval period. Longer photoperiod induced paler wing coloration and smaller size but independent of each other. Temperature exerted threefold effect: lower temperature inducing larger size, stronger melanization and more conspicuous silver spots on wings. Higher density combined with shorter day seemed to equalize adult size. Because of such complicated control of morphological features, the polymorphism in this species seemed to have different implications, including its role in connection with migration, from well known seasonal forms in other Lepidoptera. © 1979, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.