稻纵卷叶螟成虫日龄的判定指标

Parameters for the determination of adult age of the rice leaf roller, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

本研究旨在明确稻纵卷叶螟成虫生化和形态指标与其日龄之间的关系,为建立稻纵卷叶螟成虫日龄判定的数学模型和预测预报提供理论依据。通过提取稻纵卷叶螟成虫头部生化物质和解剖其生殖器官,研究了羽化后1~6日龄雌雄成虫头部褐脂质、蝶啶含量的变化以及雌蛾卵巢小管和雄蛾精巢的发育状况。研究表明:(1)不同日龄间雌、雄成虫头部褐脂质、蝶啶含量均无显著差异。(2)不同日龄间雌蛾卵巢小管长度、雄蛾精巢大小均具有显著差异(P<0.05)。雌蛾1~3日龄、3~6日龄卵巢小管长度与日龄的线性相关系数(R 2)分别为0.615 2和0.128 4。雄蛾精巢长半轴、短半轴长度与日龄的线性相关系数(R 2)分别为0.578 4和0.579 6。(3)利用卵巢小管长度对低日龄雌蛾日龄的估计表明:1 d估计误差平均为±0.56 d,2 d估计误差平均为±0.47 d。利用精巢长半轴对雄蛾日龄的估计表明:1~6 d估计误差平均为±1.28 d、±1.48 d、±1.43 d、±1.32 d、±1.53 d和±1.29 d。利用精巢短半轴对雄蛾日龄的估计表明:1~6 d估计误差平均为±1.15 d、±1.04 d、±0.97 d、±1.12 d、±1.46 d和±1.21 d。综上,头部褐脂质和蝶啶不能准确反映稻纵卷叶螟成虫日龄的变化,不能作为其日龄判定的指标。而雌蛾卵巢小管和雄蛾精巢形态稳定,其大小变化与日龄具有一定的对应关系,卵巢小管和精巢在稻纵卷叶螟成虫日龄的判定中具有较大的应用潜力。

This study was carried out to clarify the relations of the age to biochemical and physiological indexes of Cnaphalocrocis medinalis,so as to establish a mathematical model for the determination of the adult age and provide a theoretical basis for the prediction and forecast.The lipofuscin and pteridine were extracted and the internal reproductive organs were dissected to study the lipofuscin and pteridine concentrations and the morphologies of the ovaries and testes in 1-6-day-old moths.The following results were obtained:(1)There were no significant differences in lipofuscin and pteridine concentrations between ages.(2)The length of ovariole of the females and the size of testis of the males had significant differences between ages(P<0.05).Linear relationships of ovarioles and testes between different ages were also analyzed.The correlation coefficients of ovarioles were 0.615 2 in 1-3 day-old females and 0.128 4 in 3-6 day-old males.The correlation coefficients of the length of testes were 0.578 4 in semi-major axis and 0.579 6 in semi-minor axis.(3)The analysis of age estimation determined by the length of ovarioles showed that the mean errors of estimated age were±0.56 d in 1 day-old females and±0.47 d in 2 day-old.The mean errors of estimated age determined by the semi-major axis length of testes were±1.28 d in 1 day-old males,±1.48 d in 2 day-old,±1.43 d in 3 day-old,±1.32 d in 4 day-old,±1.53 d in 5 day-old and±1.29 d in 6 day-old.The mean errors of estimated age determined by the semi-minor axis length of testes were±1.15 d in 1 day-old males,±1.04 d in 2 day-old,±0.97 in 3 day-old,±1.12 d in 4 day-old,±1.46 d in 5 day-old and±1.21 d in 6 day-old.It is concluded that lipofuscin and pteridine in the head can not accurately reflect the age of C.medinalis.Stable morphology of female moth ovariole and male moth testis is related to the adult age and has great potential for application in determination of adult age of C.medinalis.