恒温和温室波动温度下异色瓢虫种群生命表

Life Tables of Harmonia axyridis Pallas Under Laboratory Constant and Greenhouse Fluctuating Temperatures

【目的】异色瓢虫(Harmonia axyridis Pallas)是一种重要的捕食性天敌昆虫,广泛应用于害虫生物防治。生命表是研究外界环境因子对昆虫发育、繁殖、存活及种群动态影响的工具。室内恒温下异色瓢虫生命表研究已有报道,但是在田间释放时经历的是昼夜波动温度。与恒温相比,波动温度能显著改变昆虫的生物学特性。论文通过构建室内恒温和温室波动温度下异色瓢虫种群生命表,比较分析异色瓢虫在两种条件下的生活史和生命表参数,为规模化生产、释放提供技术支撑,充分发挥其在生物防治中的作用。【方法】利用年龄-龄期两性生命表分析室内恒温和温室波动温度下异色瓢虫发育历期、存活率和繁殖率数据,并利用统计软件SPSS17.0t-test比较两种温度下生活史数据间的差异;应用Bootstrap方法计算种群参数的平均数和标准误,并利用TWOSEX-MSChart的t-test比较两种温度下种群参数间的差异。【结果】温室波动温度下异色瓢虫发育历期延长、成虫寿命缩短,繁殖力降低。由年龄-阶段特定存活率(sxj)和年龄-特定存活率(lx)可知温室波动温度下异色瓢虫各发育阶段存活率明显降低。由繁殖力曲线(fx、mx)可以看出室内恒温下异色瓢虫产卵时间长,产卵量高。两种条件下异色瓢虫期望寿命(exy)均随年龄增加而缩短,且温室条件下其期望寿命更短。生殖价值(vxj)是个体对未来种群的贡献,随着异色瓢虫雌虫的羽化生殖价值增加,当雌虫产卵生殖价值达到最大,温室波动温度下异色瓢虫的生殖价值要明显低于室内恒温下的。室内恒温和温室波动温度下异色瓢虫内禀增长率(r)分别为0.1395和0.0613 d-1,周限增长率(λ)分别为1.150和1.062 d-1,净增殖率(R0)为257.3和13.3后代/个体,种群平均世代周期(T)为39.7和42.7 d。【结论】室内恒温和温室波动温度下异色瓢虫生活史特性和种群参数存在显著差异,恒温可能过高或过低的估计许多生命表参数,依据恒温下得到的生命表数据进行田间释放应用存在一定误差,从而影响其防控效果。

【Objective】 The ladybird beetle Harmonia axyridis Pallas is a well-known aphid predator and plays an important role as a biological control agent in its native regions. Life table can provide a comprehensive description of the development, survival, and fecundity of a population. The life history of H. axyridis has been studied using the traditional life table in controlled laboratory conditions. However, when released, H. axyridis were exposed to fluctuating temperatures which can significantly change the biological characteristics of insects. The objective of this study is to build life tables for H. axyridis both at constant temperature in the laboratory and at fluctuating temperatures in the greenhouse, and to facilitate the effective use of this species as a biological control agent.【Method】Developmental, survival, and fecundity rate data were analyzed by using the age-stage, two-sex life table under laboratory and greenhouse conditions and the significant differences were compared with t-tests at a 5% significance level by SPSS17.0. Means and standard errors of population parameters were calculated by using the bootstrap method and the significant differences were compared with t-tests by the TWOSEX-MSChart computer program. 【Result】 H. axyridis at constant temperature in the laboratory developed more quickly in the pre-adult stage and were longer-lived compared with those in the greenhouse. Moreover, significant reductions in survival and reproduction of H. axyridis under greenhouse conditions were observed in the curves of sxj, lx, fx and mx. The life expectancy of H. axyridis decreased gradually with age while the life expectancy were shorter and varied significantly at fluctuating temperatures in the greenhouse. The contribution of an individual to the future population was described by the reproductive value（vxj） which under greenhouse conditions was lower and more varied than that in the laboratory. According to the age-stage, two-sex life table, the intrinsic rate of increase（r）, net reproductive rate（R0）, finite rate of increase（λ）, the mean generation time（T） were 0.1395 and 0.0613 d^-1, 257.3 and 13.3 offspring, 1.150 and 1.062 d^-1, 39.7 and 42.7 d, respectively, under laboratory and greenhouse conditions. 【Conclusion】 It revealed significant differences of life history and population parameters between life tables collected under laboratory and greenhouse conditions. The results indicated that at constant temperature, one could under- or over-estimate the values of numerous life-history traits compared to the fluctuating temperatures. There exist some definite errors in the field release application according to life table data obtained by constant temperature, which affects the control effects.