寄主植物对双斑恩蚜小蜂的发育、存活和繁殖的影响

研究了茄子和扶桑两种不同寄主植物对烟粉虱寄生性天敌双斑恩蚜小蜂Encarsia bimaculata发育、存活和繁殖等特性的影响。在26±0.5℃的条件下，在扶桑上，双斑恩蚜小蜂卵至成虫的发育历期为13.6天，2龄幼虫至成虫的存活率为93.2%；而在茄子上双斑恩蚜小蜂卵至成虫的发育历期和2龄幼虫至成虫的存活率分别为12.1天和91.1％。扶桑上双斑恩蚜小蜂雌性成虫的平均寿命为8.0天，平均单雌产卵量为35.9粒；而在茄子上雌性成虫的平均寿命为6.6天，平均单雌产卵量为27.6粒。双斑恩蚜小蜂在扶桑和茄子植物上的种群内禀增长率分别为0.2081和0.892。两种不同寄主植物对双斑恩蚜小蜂在若虫发育历期和存活率、成虫寿命和平均产卵量以及内禀增长率等方面均存在着显著差异。研究结果表明，寄主植物对双斑恩蚜小蜂的发育、存活和繁殖有较大的影响。

Effect of host plants on the development, survivorship and reproduction of Encarsia bimaculata ( Hymenoptera :Aphelinidae), a parasitoid of Bemisia tabaci ( Homoptera: Aleyrodidae)

Encarsia bimaculata Heraty & Polaszek, a parasitoid of Bemisia tabaci (Gennadius) biotype B, was recently discovered in South China. The development, survivorship, longevity and reproductive biology of E. bimaculata parasitizing B.tabaci on eggplant and hibiscus at 26 + 0.5 ℃ were studied in the laboratory. The developmental time of E. bimaculata from egg to adult was longer on hibiscus (13.6 d) than on eggplant (12.1 d), and its survival rates from 2nd instar to adult emergence were 93.2% and 91.1% on hibiscus and eggplant, respectively. The mean longevities of E. bimaculata female adults ranged from 6.6 d on eggplant to 8.0 d on hibiscus, and the mean lifetime fecundities on the two plants were 27.6 and 35.8 eggs, respectively. The intrinsic rate of increase ( rm ) of E. bimaculata population at the tested temperature was higher on hibiscus (0.2081) than on eggplant (0. 1892). The results indicated that E. bimaculata performed better in development,survival and reproduction on hibiscus, a glabrous plant, than on eggplants, a hirsute plant.