马尾松毛虫越冬代滞育与非滞育幼虫过冷却点的研究

测定了在恒温和自然温度处理下饲养的马尾松毛虫滞育与非滞育幼虫的过冷却点。结果表明 ,2 7℃恒温饲养的滞育幼虫的平均过冷却点较非滞育幼虫的平均过冷却点低 ,但无显著差异 ;而自然温度下饲养的滞育幼虫的过冷却点较非滞育的过冷却点也低 ,然而 ,滞育开始时差异不显著 ,之后差异显著。相应滞育状态下 ,自然温度下饲喂的幼虫较 2 7℃恒温下饲喂的平均过冷却点低 ,但在滞育开始阶段和结束阶段两者之间的差异显著。自然温度下滞育和非滞育幼虫的抗寒能力都随气温的降低而增强 ,而 2 7℃下滞育与非滞育幼虫的抗寒能力均出现先增后减的趋势

The super-cooling point of diapause and non-diapause larvae of the masson pine caterpillar, Dendrolimus punctatus

The super cooling points of diapause and non diapause larvae of the masson pine caterpillar Dendrolimus punctatus (Walker) at different diapause stages and different temperatures were studied. Results show that the mean super cooling point of diapause larva were lower than that of non diapause larvae at 27℃. However, there was no significant difference between the two groups of larvae at 27℃ in all development stages. Meanwhile, the mean super cooling point of diapause larva was lower than that of non diapause larvae at room temperature. A significant difference in the mean super cooling points of diapause and non diapause larvae was observed in all stages, except in the first stage at room temperature. The mean super cooling point of the larvae reared at room temperature was lower than those of larvae reared at 27℃. There were significant differences between first and third stage. The cold tolerance of diapause and non diapause larvae changed greatly when they were reared at different temperatures.