Abstract
Given are the results of observations for adult behavior, life cycle and natural enemies of Nymphalis xanthomelas japonica (Stichel) based on the 26-year field surveys chiefly made in Nagano Prefecture. The newly emerged adults seem to become either residents near habitats or migrants to the high altitude mountains. Residents seem usually to pass the mid-summer inactively in the suitable spaces. Migrants seem to return to the low to middle altitude places for hibernation, since the hibernated adults were not observed in the high mountains. A copulating pair was found in the end of March, and the flight manner in copula was confirmed as "←♀+♂" for the first time in Japan. Ovipositions were observed in April in low to middle altitude places to willows, elms and nettle trees. The larvae grow toward the end of May to June, and the adults emerged from June to the middle of July. The larvae were observed to be attacked by ten or more sparrows and two larvae were bitten by spiders. In one case, the parasitic flies escaped from 39 out of 53 pupae produced from the larvae in the field.
