高温对环带锦斑蛾幼虫滞育的抑制作用

The role of high temperature in diapause inhibition in larvae of Pseudopidorus fasciata (Lepidoptera: Zygaenidae)

本文报道了高温 (31℃ )对环带锦斑蛾幼虫滞育发生的抑制作用。当幼虫暴露于 31℃时 ,所有个体都继续发育 ,与光周期无关。在诱导滞育的光周期条件 (L12∶D12 )下 ,光期的高温配合不同的暗期低温 (15～ 2 8℃ ) ,导致几乎所有个体滞育 ,但当暗期为 5℃时 ,滞育率反而下降 ;相反 ,当光期的低温配合不同持续时间的暗期高温 (31℃ )时 ,则几乎所有的个体都继续发育 ,这说明高温在暗期发挥着重要的作用。在暗期给予不同时间长度 (2、4、6、8、10、12h)的高温处理 ,结果表明一个 2h的高温处理就能有效地抑制滞育的发生。在暗期的不同时间给予 4h高温处理 ,显示了幼虫在暗期开始后的第一个 4h (18:0 0～ 2 2 :0 0 )对高温最敏感 ,完全抑制了滞育的发生。最后讨论了高温调节滞育机制在该虫生活史上的适应意义。

The role of a high temperature of 31℃ in diapause inhibition in Pseudopidorus fasciata was investigated. All larvae developed without diapause regardless of photoperiod when they were exposed to a high temperature of 31℃. Under a diapause-inducing photoperiod of L12∶D12, nearly all individuals entered diapause when high temperature in the photophase was combined with relatively low temperatures (15-28℃) in the scotophase. However, the incidence of diapause significantly declined when the high temperature in the photophase combined with a much low temperature of 5℃ in the scotophase. Nearly all individuals developed without diapause when the high temperature in the scotophase was combined with relatively low temperatures in the photophase, indicating that the high temperature plays an important role in the period of darkness. The effect of durations (2, 4, 6, 8, 10, 12 h) of high temperature on the incidence of diapause showed that a 2 h high temperature exposure was sufficient to inhibit the incidence of diapause. When a 4 h high temperature exposure was used to interrupt the scotophase at different stages, the results showed that the first 4 h in the darkness was the most sensitive part to high temperature exposure and completely inhibited the incidence of diapause. Finally, the adaptive significance of the mechanism of high temperature regulation in life history of P. fasciata was discussed.