甜菜夜蛾在四种寄主植物上的生命表参数比较研究

在控制条件下对甜菜夜蛾Spodoptera exigua(Hübner)在白菜、大葱、甘蓝和豇豆上的生命表参数进行了比较研究。结果表明,甜菜夜蛾幼虫在4种寄主植物上均为5个龄期。幼虫和蛹在大葱上的发育历期最长,在白菜上最短。甘蓝叶片饲养的甜菜夜蛾生殖力最高,单雌产卵量为1015.8粒,豇豆叶片上饲养的生殖力最低,为496.1粒。甜菜夜蛾在甘蓝上的内禀增长率和净增殖率最高,分别为0.237和287.82,在大葱上最低,分别为0.172和173.90。在大葱上甜菜夜蛾幼虫存活率较低,在其他3种寄主植物上较高。甜菜夜蛾的特定年龄生殖率在甘蓝叶片上最高,第22天单雌产卵量高达453.6粒。研究结果表明,在选取的4种植物中,甘蓝是甜菜夜蛾的最适寄主。

Comparative life table parameters of the beet armyworm, Spodoptera exigua, on four host plants

The effects of four host plants on life table parameters of beet armyworm, Spodoptera exigua （Htibner）, were studied in the laboratory at（27 ± 1 ）℃ , relative humidity of 65% ± 5% and photoperiod of 18L： 6D. The host plants tested were Chinese cabbage （Brassica campestris L. ssp. pekinensis （Lour.） Olsson）, Chinese onion （Alliumfistulosum L. var. giganteum Makino） , cabbage （ Brassica oleracea L. var. capitata L. ） , and bean （ Vigna unguiculata W. ssp. sesquipedalis （L.） Verd）. The results show that five larval stages of S. exigua occur on the four host plants tested. The larval and pupal periods were longest on Chinese onion, and shortest on Chinese cabbage. Among the different host plants, S. exigua exhibited the highest fecundity on cabbage, with 1 015.8 eggs/female and the lowest on bean, with 496.1 eggs/female. The intrinsic rate of increase （r~） ranged from 0. 172 to 0. 237, with the highest rate on cabbage and the lowest on Chinese onion. The highest net reproductive rate （Ro） was on cabbage, with 287.82 female/female/ generation and the lowest was on Chinese onion with 173.90 female/female/generation. Larval survival was lower on Chinese onion than on the other three host plants. Age-specific fecundity rate of S. exigua was higher on cabbage than the other plants. It is concluded that cabbage is the most suitable host plant for S. exigua of the four plants tested in this study.