幼虫密度和温度对水芹叶象甲未成熟阶段生长发育的影响

Effect of larval density and temperature on immature developmental stages of Hypera sp.

【目的】为明确不同幼虫密度和不同温度条件对水芹叶象甲Hypera sp.未成熟阶段生长发育的影响。【方法】在室内条件下对不同幼虫饲养密度和不同温度条件饲养的水芹叶象甲未成熟阶段(卵、幼虫、预蛹和蛹)的存活和生长发育进行研究。【结果】幼虫密度对水芹叶象甲幼虫、预蛹和蛹的存活和生长发育均具有显著影响。水芹叶象甲幼虫、预蛹和蛹在50头/盒的密度条件下的存活率均显著高于其它密度条件,且发育历期显著短于其它密度条件。此外,各密度条件下的雌蛹重均显著重于雄蛹重,但性比(♀/♂)不受密度条件的影响。温度条件对水芹叶象甲卵、幼虫、预蛹和蛹的存活和生长发育亦均具有显著影响。27℃条件下的幼虫和蛹的存活率均显著高于其它温度条件,1龄幼虫在30℃条件下的存活率显著高于其它温度条件,而3龄幼虫在27℃条件下的存活率显著高于其它温度条件,但温度条件对2龄幼虫的存活率无显著影响。水芹叶象甲各龄期幼虫及各虫态的发育历期随着温度升高而显著缩短。【结论】幼虫饲养密度和温度是影响水芹叶象甲种群变化的重要因子,这将为分析水芹叶象甲种群动态变化规律,以及提高该虫的预测预报和综合防控水平提供依据。

[Objectives] To clarify the influence of larval rearing density and temperature on immature developmental stages(eggs, larvae, pre-pupae and pupae) of Hypera sp. [Methods] The survival, growth and development of the above immature developmental stages were measured and compared under different larval densities and temperatures. [Results] Larval density had a significant effect on survival and growth;survival was significantly higher, and the developmental duration significantly shorter, at a density of 50 larvae per box than that at other densities. The pupal weight of females raised at any of the larval densities tested was significantly greater than that of males. Sex ratio(♀/♂) was not affected by larval density but temperature had a significant effect on survival and growth. The survival rates of larvae and pupae were significantly higher at 27℃ than at other temperatures. The survival rate of 1 st instar larvae was highest at 30℃, whereas that of 3 rd instar larvae was highest at 27℃. Temperature had no significant effect on the survival rate of 2 nd instar larvae. The developmental duration of different developmental stages and instars was significantly shorter at higher temperatures. [Conclusion] Larval density and temperature significantly affect the population demographics of Hypera sp., a finding that contributes to better forecasting, prevention and control of this pest.