斜纹夜蛾天敌作用的评价

通过组建斜纹夜蛾第４代和第８代自然种群生命表，运用排除作用控制指数分析了生物因子对斜纹夜蛾种群的自然控制作用．结果表明，低龄（１～３龄）幼虫的捕食性天敌是影响斜纹夜蛾种群数量动态的重要因子．对第４代和第８代种群的排除作用控制指数分别为１３．９０４和１２．９４６．如果没有捕食性天敌的作用，下代种群数量将分别增长到当代的１５．１２０６和７４．６７８倍．病原微生物是影响第４代斜纹夜蛾种群数量的另一重要因子，其排除作用控制指数为２．４７２６．

Effectiveness of natural enemies on Spodoptera litura.

The 4th and 8th generation life tables were applied to evaluate the effectiveness of natural enemies on common cutworm ( Spodoptera litura ) population by exclusion index of population control (EIPC). The results showed that the predatory natural enemies of the 1st, 2nd and 3rd instar larvae were the important factor influencing the population dynamics of common cutworm. The EIPC values of the 4th and 8th generation common cutworm were 13.904 and 12.496 respectively, which means that the next generation of common cutworm population would increase 15.1206 and 74.678 times of current generation if the predators were excluded. The pathogenic microbes were another important factor affecting the 4th generation population, and its EIPC was 2.4726.