نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه گیاهپزشکی، دانشکده کشاورزی، دانشگاه شهید مدنی آذربایجان، تبریز، ایران
2 گروه شیمی، دانشکده علوم پایه، دانشگاه شهید مدنی آذربایجان، تبریز، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Potato tuber moth, Phthorimaea operculella is a serious insect pest of potato that infects its host plants in fields and stored conditions. In this study the biological activity of n-hexane, dichloromethane and acetone extracts of Ageratum houstonianum, Xanthium strumarium were evaluated against larvae of PTM. Insects reared on potato tubers in controlled condition. Maceration method were used for extraction. Fumigant and oral toxicity of extracts studied according to standard bioassay methods. In addition, effects of three sublethal concentrations including LC20, LC50 and LC80 on some biological parameters such as larval life span and adult’s emergence were studied. The results revealed that, all extracts of X. strumarium did not affect first instar larva of potato tuber moth by fumigant application. However, A. houstonianum dichloromethane and hexane extracts with LC50 values of 0.546 and 0.236 mg/l air showed the lowest and highest fumigant toxicity against PTM 1st larval instars respectively. About oral toxicity, the results showed that dichloromethane and acetone extracts of X. strumarium with LC50 values of 96.98 and 14.30 mg/l have the least and most toxicity against 1st larval instars of PTM respectively. The hexane and dichloromethanolic extracts of A. houstonianum with LC50 values of 13.24 and 27.01 mg/l respectively showed the most and least oral toxicity against first larval instars of PTM. The life span of PTM larvae statistically was not affected by extracts. However, about adult’s emergence the results were different and in the application of LC80 and LC50 concentrations of A. houstonianum only 6.67 and 33.33% adult emergence recorded. Application of LC80 concentration of X. strumarium extracts reduced adult emergence by 74-87% in comparing with controls. Acording to acute and chronic toxicity of extracts it is possible to use them in management of PTM with compelimentary studies and formulation of extracts.
کلیدواژهها [English]
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