Abstract:
Heavy metals are defined as an abiotic factor that affects the efficiency of biological pest control. This study constructed a cadmium (Cd)-polluted artificial diets-Hyphantria cunea-Arma chinensis food chain to analyze the effects of Cd exposure on the ability of A. chinensis to control H. cunea. The results revealed that Cd was transferred through the artificial diet to H. cunea larvae and A. chinensis nymphs via a biological amplification effect. After feeding on Cd-accumulated H. cunea larvae, the body weight of A. chinensis nymphs reduced, mortality increased, developmental duration prolonged, and the expression of growth regulatory genes (EX, cycE, and MER) decreased. Cd activated the antioxidant defense system of the nymphs, accompanied by a significant enhancement in the contents of H2O2 and MDA, marked damage to the midgut sub-microstructure, and a remarkable induction in the expression of genes crucial for the mitochondrial pathway/ER stress-apoptosis pathway. Cd significantly diminished the contents of total amino acids, glucose, free fatty acids, and expression of the genes (HK2, PFK, IDH1, and IDH2) essential for the TCA cycle and glycolysis in the nymphs. The preference of the A. chinensis nymphs to Cd-treated H. cunea larvae was evidently reduced. Cd diminished the search-ability, food intake, instantaneous attack rate, and maximum theoretical daily food intake but prolonged the feeding time of the nymphs. Taken together, Cd exposure reduces the ability of A. chinensis nymphs to control H. cunea and provides a new challenge for the efficiency of insect pest control using natural enemies. These findings have important reference value for optimizing pest control strategies in heavy metal polluted areas.
摘要:
重金属被定义为影响害虫生物防治效率的非生物因素。本研究构建了镉(Cd)污染的人工日粮-美国白蛾-中国白蛾食物链,以分析Cd暴露对中国紫菜控制H.cunea能力的影响。结果表明,Cd通过人工饮食通过生物放大作用转移到山葵幼虫和若虫中。以Cd积累的H.cunea幼虫为食后,中国若虫的体重减少了,死亡率增加,发育持续时间延长,和生长调节基因的表达(EX,cycE,和MER)下降。Cd激活若虫的抗氧化防御系统,伴随着H2O2和MDA含量的显着增加,中肠亚微观结构明显损伤,以及对线粒体途径/ER应激-凋亡途径至关重要的基因表达的显着诱导。Cd显著降低了总氨基酸的含量,葡萄糖,游离脂肪酸,和基因的表达(HK2,PFK,IDH1和IDH2)对于若虫的TCA循环和糖酵解至关重要。中国若虫若虫对Cd处理的H.cunea幼虫的偏好明显降低。Cd降低了搜索能力,食物摄入量,瞬时攻击率,和最大的理论每日食物摄入量,但延长若虫的摄食时间。一起来看,Cd暴露降低了中国若虫的防虫能力,并为利用天敌控制害虫的效率提供了新的挑战。研究结果对优化重金属污染区病虫害防治策略具有重要的参考价值。