抄録
Eggs, larvae and pupae of Narathura bazalus (Hewitson) were reared at constant (17, 20, 23, 25 or 28°C) or fluctuating (14–20, 17–23, 20–26, 22–28 or 25–31°C) temperatures superimposed on a photoperiod of 12L : 12D (12 h light : 12 h dark) and 15L : 9D. When insects were reared under lower temperature conditions (mean temperature of 17, 20, 23 and 25°C under 12L : 12D, and 17°C under 15L : 9D), the developmental period (egg to adult emergence) was significantly shorter than that at constant temperatures corresponding to the mean of fluctuating temperatures. This mechanism permits rapid development completion even at low temperatures during autumn, helping to increase the number of adults in the overwintering stage in this species. Based on the developmental zero and the total effective temperature for development obtained in this study, the number of generations per year in N. bazalus in Tsukuba, central Japan, was estimated to be four on the assumption that oviposition by overwintered females takes place in early April.
