在受重金属Zn^(2+)胁迫的斜纹夜蛾幼虫寄主上双斑侧沟茧蜂的生存与发育

Survival and development of Microplitis bicoloratus Chen on larvae of Spodoptera litura Fabricius stressed by heavy metal zinc

通过在植食性昆虫斜纹夜蛾SpodopteralituraFabricius幼虫人工饲料中添加不同浓度的Zn2+,测定了连续3代取食含不同Zn2+浓度饲料幼虫的血淋巴中Zn2+含量,并研究了被Zn2+胁迫的斜纹夜蛾幼虫对寄生性天敌双斑侧沟茧蜂MicroplitisbicoloratusChen生存与发育的影响。结果表明,斜纹夜蛾幼虫血淋巴中Zn2+含量随饲料中Zn2+浓度和幼虫取食世代数的增加而增加;Zn2+胁迫斜纹夜蛾幼虫对双斑侧沟茧蜂的寄生率、从寄生到结茧的时间、蛹期长短、成虫羽化率和成虫寿命等都有不同程度的影响,其中以第2代的寄生率和第1代的羽化率受影响最大,均随着Zn2+浓度的增大而降低。因此,寄主饲料中高浓度的Zn2+能通过食物链影响双斑侧沟茧蜂的生存和发育。

By feeding the host, Spodoptera litura Fabricius, larvae with artificial diets treated with different concentrations of zinc for 4 generations, the side effects of zinc on the survival and development of Microplitis bicoloratus Chen, a larval parasitoid of S. litura, were estimated. The results indicated that the zinc contents of S. litura hemolymph increased with the increase of zinc concentrations in diets and generations of the phytophagous insect. The parasitism rate, time from parasitism to pupae, pupal duration, adult emergence rate, and adult female longevity of M. bicoloratus wasp were influenced to some extent. Specially, the adult emergence rate of the first generation and the parasitism rate of the second generation decreased significantly with the increase of the zinc concentration in their host diets. It was so concluded that high dose zinc in the diet of herbivorous insects affected the survival and development of their larval parasitoid M. bicoloratus through food chain to some extent.