农药对家蚕(Bombyx mori L.)的亚致死效应研究进展

Research advance in sublethal effects of pesticides on silkworm,Bombyx mori L.

明确农药对家蚕的影响对综合评价农药的生态效应与合理使用农药具有理论和实践意义。从生长发育、经济性状和食物利用方面综述了农药对家蚕的亚致死效应;从生理代谢、组织器官亚显微结构和培养细胞方面介绍了亚致死效应产生的机制,并结合杀虫剂对其它鳞翅目昆虫亚致死影响方面的研究结果对其进行了讨论,提出了今后加强研究的重点。总的来说,亚致死剂量农药的胁迫可使家蚕幼虫眠性不齐,眠蚕体重和蛹重减轻,发育历期延长,严重者结茧(上蔟)时间推迟,且吐丝营茧功能失常,最终导致蚕茧质量下降。桑叶上残留的农药在一定程度上还会对家蚕的取食行为以及食物摄入后的消化吸收产生影响。农药对家蚕亚致死效应产生的机制目前主要有3个:家蚕体内正常生理水平和代谢平衡受到扰动、家蚕的一些重要组织器官如中肠和后丝腺等微形态结构受到损伤和家蚕卵巢细胞出现凋亡现象。农药对家蚕的亚致死效应因农药种类、试验剂量和家蚕受药时间而异,产生的机理也十分复杂。今后应着重开展新农药对家蚕亚致死效应研究,特别是对生化和分子机制方面的研究以及农药复合污染对家蚕影响的研究。

Understanding the effects of pesticides on silkworms is important for both evaluation of pesticides ecological effects and rational application of pesticides.In this paper,effects of pesticides on growth and development,economic characters and food utilization of silkworm were reviewed.In addition,the mechanisms of sublethal effects of pesticides on silkworm,in terms of physiology and metabolism,tissue ultrastructure and cultured cell,were introduced and discussed by considering research results of sublethal effects of insecticides on other order lepidoptera.Overall,sublethal doses of pesticides result in inconsistent molting,reduced weight of both dormant larval and pupa and prolonged developmental duration.Sometimes,cocoon-making time of larvae affected seriously is delayed,and functions of cocoon-making or spinning are impaired.All of those in turn may influence cocoon quality and silk production.Food consumption and utilization of silkworm are also affected when exposed to sublethal doses of pesticides.Disruption of normal physiological and metabolic equilibrium,dramatically adverse changes in important tissues,such as midgut and silk gland,and damage of ovary cells are primary mechanisms for sublethal effects of pesticides on silkworm.sublethal effects of pesticides on silkworm are variable,and depend on pesticide types,experimental concentrations and treatment duration.Since the mechanisms of sublethal effects of pesticides on silkworm are complicated,it is necessary,further,to investigate sublethal effects of new pesticides on silkworm,in terms of biochemical and molecular mechanisms,and effects of combined pollution of pesticides on silkworm.