十字花科蔬菜对小菜蛾实验种群的影响

通过组建4种十字花科蔬菜上小菜蛾实验种群生命表发现，在菜心、芥蓝、芥菜和小白菜4种蔬菜上繁殖的小菜蛾实验种群增长趋势指数分别为41．0、69．5、38．2、52．4，影响种群增长的重要因子为幼虫的自然死亡，不同蔬菜种类对小菜蛾雌蛾的总产卵量和寿命无影响，但芥蓝繁殖的小菜蛾日平均产卵量显著高于其它几种蔬菜。在芥蓝和小白菜上繁殖的小菜蛾幼虫具有较高的存活概率，是其种群具有较大增长潜力的重要原因。试验结果表明，在4种蔬菜中，芥蓝提供的营养最适宜于小菜蛾种群生长、发育和繁殖，是最佳的寄主，其次为小白菜、菜心，而芥菜尽管被报道为小菜蛾成虫最喜欢产卵的寄主，由于所繁殖的小菜蛾种群在幼虫期有较高的死亡率，是最不适宜于小菜蛾生长发育的寄主。

Effects of cruciferous vegetables on experimental population of diamondback moth Plutella xylostella

The impact of four species of cruciferous vegetables on the experimental population of diamondback moth (DBM) Plutella xylastella was evaluated in the laboratory. The results showed that there was no significant difference in total fecundity and longevity of DBM female moths reared on different crucifers. The population increase index of DBM reared on flowering Chinese cabbage, Chinese kale, leaf mustard, and pak-choi was 41.0, 69.5, 38.2 and 52.4, respectively, and the natural death at larvae stage was the most important factor influencing the population increase of DBM. The relatively lower natural death rates of larvae on Chinese kale and pak-choi contributed a higher increasing potential of DBM populations. It was concluded that among four species crucifers, Chinese kale could provide the most suitable nutrients for the development and reproduction of DBM population, and thus, it was considered as the best host of DBM. However, although leaf mustard has been reported as one of the most preferable host for DBM adult oviposition, it was not as better as three other crucifers for DBM development due to the higher natural death rate of larvae.