A Multivoltine Strain of the Nymphalid Butterfly, Libythea lepita, Found from the Main Island (Honshu) of Japan

Abstract

A female of Libythea lepita (Nymphalidae), captured at Minamiechizen in Fukui Prefecture on May 25, 2018, laid eggs on sprouts of Celtis sinensis (Cannabaceae) several days later in an outdoor cage (6.5 m×12.5 m, height, 3.5 m) equipped with various flowers as a nectar source. Larvae were reared on potted plants of C. sinensis placed in the shadowy area of the cage under natural conditions. Adults (1st generation) that emerged late in June were kept in the same cage where they were allowed to freely perform daily activities such as foraging and mating. Surprisingly, oviposition took place by females of the 1st generation, though we failed to confirm their copulation. Many neonates were found growing on young leaves of the plant in early July and the 2nd generation emerged in late July. Subsequently, the 3rd and 4th generations occurred in the latter part of August and September, respectively. No additional broods were observed since then, probably due to low temperature and short daylength. To the best of our knowledge, this is the first confirmed record of the occurrence of four generations/year in L. lepita in Japan.