马铃薯甲虫自然种群生命表的组建及影响因子

应用作用因子生命表方法,组建了马铃薯2代马铃薯甲虫自然种群生命表,并采用排除分析法分析了作用因子对马铃薯甲虫种群数量的控制作用.结果表明:马铃薯甲虫卵期和1龄幼虫期的存活率分别为79.1％和69.3％,显著低于其他虫态的存活率,表明该阶段为马铃薯甲虫种群生存的脆弱阶段,是马铃薯甲虫防治的关键时期.“自然死亡”的排除作用控制指数最大(1.87);其次为“捕食及其他”,排除作用控制指数为1.51;寄生性天敌对马铃薯甲虫没有控制作用.如果排除所有天敢等因子的作用,马铃薯甲虫自然种群趋势指数将增长2.8倍.表明天敌等自然因子虽对马铃薯甲虫种群数量有一定的控制作用,但控制能力较弱.

Life table of Leptinotarsa decemlineata (Say) natural population and related affecting factors

In this study, the life table of the 2nd generation of Leptinotarsa decemlineata (Say) natural population on potato plants was constructed based on functional factor life table method, and the control effects of different factors on the population were analyzed by exclusion analysis method. It was shown that the survival rate of eggs and first instar (79.1% and 69.3%, respectively) was rather lower than that of the L. decemlineata at other growth stages, suggesting that the eggs and first instar larvae were the key stages to control L. decemlineata. Among the controlling factors, "natural death" was the most effective factor, its exclusive index of population control (EIPC) being 1.87, "predators and others" was in the second place, with the EIPC being 1.51, while "parasitism" had no control effect. The index of population trend of L. decemlineata would be increased 2.8 times if all natural factors were excluded. It was concluded that natural factors had a certain but weak action on the L. decemlineata population.