短时高温对意大利蝗存活和生殖的影响

Effects of short-term exposure to high temperature on the survival and fecundity of Calliptamus italicus(Orthopera:Acrididae)

【目的】明确短时高温对意大利蝗Calliptamus italicus(L.)存活和生殖的影响,为气候变暖趋势下意大利蝗灾害的预测预报及综合防治提供理论依据。【方法】采集初羽化24h内的意大利蝗雌雄成虫,于30℃光照培养箱中饲养。设置4个温度处理组,分别为33、36、39、42℃,每日处理4h,之后放回30℃光照培养箱中继续饲养。未经过短时高温处理的意大利蝗为对照组。观察记录各组意大利蝗存活率、寿命、产卵前期、产卵期、单雌产卵量、卵巢发育情况及卵巢中卵黄蛋白含量,并分析变化规律。【结果】短时高温对意大利蝗成虫存活率无显著影响,但对其寿命有显著影响(P<0.01),其中33℃处理4h,意大利蝗雌雄成虫寿命显著延长(P<0.01),而36~42℃范围内处理4h,意大利蝗雌雄成虫寿命显著缩短(P<0.01)。短时高温对意大利蝗产卵前期有显著影响(P<0.05),随温度升高,产卵前期缩短,但对产卵期没有显著影响(P>0.05)。短时高温对意大利蝗单雌产卵量有显著影响(P<0.01),其中33℃处理组单雌产卵量为(57.6±2.4)粒,显著高于对照组(P<0.01),36~42℃范围内,随温度升高单雌产卵量显著降低(P<0.01)。短时高温对意大利蝗卵巢长度、鲜重及发育历期有显著影响(P<0.01),但对卵巢宽度没有显著影响(P>0.05),且随温度升高,卵巢长度、宽度、鲜重及发育历期均呈下降趋势。短时高温可使卵黄蛋白在卵巢中提前沉积,并对其含量(峰值)有显著影响(P<0.01),其中33℃处理组卵黄蛋白含量(峰值)为(49.795±6.253)mg/mL,显著高于对照组(P<0.01),36~42℃范围内处理4h,卵黄蛋白含量(峰值)显著减少(P<0.01)。【结论】33℃处理4h,意大利蝗存活及生殖特性显著提高,而36℃及以上高温对意大利蝗生长繁殖产生不利影响。

[Objectives] To clarify the effects of short-term exposure to high temperature on the survival and fecundity of Calliptamus italicus in order to provide a theoretical basis for forecasting and prevention of outbreaks of this pest under global warming conditions. [Methods] Newly-eclosed C. italicus adults （within 24 h of eclosion） were reared in a phytotron at 30℃, and exposed to temperatures of 33, 36, 39 and 42℃ for 4 h every day, respectively, after which they were returned to the phytotron which was kept at 30℃. The control group were not exposed to high temperatures. The survival rates, longevity, female oviposition rates, ovary development, and vitellin content of the ovary of each treatment group were measured. [Results] Brief exposure to higher temperatures did not affect survival rates but did a significant effect on longevity （P〈0.01）; 4 h exposure to 33℃ significantly extended the longevity of male and female adults （P〈0.01） but exposure to temperatures within the range of 36-42℃ significantly reduced longevity （P〈0.01）. Higher temperatures had a significant effect on female oviposition rates （P〈0.01）. The average fecundity of females was increased by exposure to 33℃ for 4 h, but was reduced after exposure to 36-42℃. The length, width, fresh weight and developmental duration of ovaries tended to decline with increasing temperature. Higher temperatures had a significant effect on the length, fresh weight and developmental duration of ovaries （P〈0.01）, but no significant effect on their width （P〉0.05）. High temperature had a significant effect on the vitellin content of the ovary （P〈0.01） which increased after exposure to 33℃, but decreased following exposure to temperatures in the range of 36-42℃. [Conclusion] The survival and fecundity of C. italicus significantly increased after exposure to 33℃, but was negatively affected by exposure to temperatures 〉 36℃.