暗期干扰对环带锦斑蛾滞育诱导的影响

在短日照条件下，环带锦斑蛾Pseudopidorus fasciata以4龄幼虫进入冬季滞育，其滞育诱导的临界暗长为10.5 h。本文系统测试了暗期干扰实验［即在暗期采用单一的光（亦称光脉冲）干扰光周期反应的实验］对环带锦斑蛾幼虫滞育的抑制影响。幼虫孵化后在25℃，短日照L9∶D15(光9 h∶暗15 h)，L10∶D14、L11∶D13及L12∶D12暗期的不同时段给予1 h或30 min光脉冲干扰。结果表明： 滞育是否被抑制主要取决于暗期的长度，当光脉冲干扰前的暗长（D₁）或光脉冲干扰后的暗长（D₂）超过临界暗长（10.5 h）时，100%的幼虫被诱导进入滞育；当D₁和D₂都短于（或等于）临界暗长时，滞育不同程度被抑制，抑制的效果则取决于所干扰的光周期、光脉冲的长度和光脉冲落入的位点。结果说明该虫滞育诱导的暗期干扰反应是基于临界暗长的时间测量。

Night-interruption response of diapause induction in Pseudopidorus fasciata (Lepidoptera: Zygaenidae)

The zygaenid moth Pseudopidorus fasciata enters winter diapause as the 4th instar larvae under short daylight with a critical night length of 10.5 h. In the present study the effects of night-interruption experiments, in which the scotophase of a photoperiod was interrupted by a simple light, on diapause-averting were systematically investigated in P. fasciata. The experiments were carried out by using 1 h or 30 min light pulse to interrupt the scotophases of short photoperiods of L9∶D15 (Light 9 h∶Dark 15 h), L10∶D14, L11∶D13 and L12∶D12 at 25℃ at different phases. The results showed that whether diapause was averted by light pulse mainly depended on whether the pre-interruption (D₁) or the post-interruption (D₂) scotophase exceeded the critical night length (10.5 h). When D₁ or D₂ exceeded the critical night length, diapause was always induced. When both D₁ and D₂ were shorter than critical night length, diapause was averted at different degree, mainly depending on the photoperiod applied and the length and position of light pulse. The results revealed that the night interruption response of diapause induction in P. fasciata was based on a time measurement of the critical night length.