四种杀菌剂对两种赤眼蜂的毒性分析及敏感性比较

Analysis and evaluation of four fungicides toxicity and sensitivity against two Trichogramma spp.

采用药膜法分别测定了95%三唑酮、99.5%肟菌酯、96.2%咪鲜胺和95%申嗪霉素4种杀菌剂对玉米螟赤眼蜂Trichogramma ostriniae和松毛虫赤眼蜂Trichogramma dendrolimi Matsumura的急性毒性。结果表明,4种供试杀菌剂对玉米螟赤眼蜂的直接接触毒性LC50值分别为0.822 0、48.70、12.94和24.25 mg/L,对松毛虫赤眼蜂的LC50值分别为10.55、180.3、218.1和240.3 mg/L。即4种杀菌剂对两种赤眼蜂的风险性存在差异,供试药剂对松毛虫赤眼蜂相对较为安全。由于玉米螟赤眼蜂比松毛虫赤眼蜂对供试杀菌剂更为敏感,因此以玉米螟赤眼蜂作为评价农药对赤眼蜂风险的供试生物更为适宜。

Four fungicides,triadimefon,trifloxystrobin,prochloraz and phenazino-1-carboxylic acid were tested to determine their toxicity to parasitoid Trichogramma ostrininae and Trichogramma dendrolimi by using dry film bioassay.The results showed that the toxicity of all the fungicides tested to the parasitoid were different.The toxicity of triadimefon to T.ostrininae and T.dendrolimi was the highest one（with LC50 of 0.822 0 and 10.55 mg/L respectively）,followed by prochloraz（12.94 and 218.1 mg/L）.The LC50 values of trifloxystrobin and phenazino-1-carboxylic acid were 48.70 and 24.25 mg/L to T.ostrininae,180.3 and 240.3 mg/L to T.dendrolimi,respectively,exhibiting low toxicity when compared with others tested.The results suggested T.ostrininae was more sensitive to the fungicides than T.dendrolimi,and the risk of four fungicides exposed to the two Trichogramma was different.It indicated that T.ostrininae was more representative to assess the risk of pesticide to Trichogramma spp..