溴虫氟苯双酰胺对小菜蛾的毒力及相关酶活性的影响

溴虫氟苯双酰胺是一种全新的双酰胺类杀虫剂,主要用于防治鳞翅目、鞘翅目、白蚁以及蚊蝇等害虫。为了明确溴虫氟苯双酰胺对小菜蛾的生物活性及解毒酶活性的影响,本研究选择氯虫苯甲酰胺为对照药剂,采用叶片药膜法测定了溴虫氟苯双酰胺对小菜蛾的生物活性,并测定了亚致死剂量(LC20、LC40)的溴虫氟苯双酰胺和氯虫苯甲酰胺对小菜蛾多功能氧化酶、谷胱甘肽S-转移酶和羧酸酯酶活性的影响。结果表明,溴虫氟苯双酰胺与氯虫苯甲酰胺对小菜蛾的生物活性相当,两者对小菜蛾的LC50分别为0.042和0.056μg/mL。与氯虫苯甲酰胺相似,亚致死剂量的溴虫氟苯双酰胺能够诱导小菜蛾体内羧酸酯酶活性升高,但溴虫氟苯双酰胺对多功能氧化酶和谷胱甘肽S-转移酶活性没有显著影响。

Toxicity of broflanilide to Plutella xylostella and its influence on the activities of related enzymes in P.xylostella

Eggs, larvae and pupae of Sitophilus zeamais Motschulsky all survive and develop in the wheat kernel, which can affect fumigant penetration into seeds and killing of hidden insects. The exposure time and concentration are important to the mortality of insects under fumigation conditions, especially for the immature stages. The resistance of three strains of S. zeamais was monitored, and the mortalities of egg, larvae, pupae and adults of the insect were assayed at the concentrations of 100, 200, 300, 400 and 500 mL/m3 of phosphine. The results indicated that there was no resistance to phosphine among the three S. zeamais strains. The mortality of adults changed from 59% at 100 mL/m3to above 91% at 500 mL/m3for 6 h. The mortality of adults was 100% after 12 h, while the mortalities for egg, pupa and larva were below 100% for all concentrations in 12 h. The mortalities of eggs, larvae and pupae were achieved in 24 h under fumigation with 400 mL/m3 or more phosphine. Fumigation for 36 h was lethal to the eggs, larvae and pupae of the strain BJXNSz but not to the other two strains. Fumigation for more than 48 h at all tested concentrations of phosphine could completely kill all insects of any stages. The results indicated that phosphine at more than 100 mL/m3 could kill all stages of S. zeamais in the exposure time tested. The lethality to all stages of S.zeamais could be achieved by fumigation with phosphine of 100 to 500 mL/m3 in the exposure time from 48 h to 24 h accordingly. The tolerance of eggs, larvae and pupa of the insect to phosphine was similar and stronger than that of the adult.