Larvicidal and irritant activities of hexane leaf extracts of Citrus sinensis against dengue vector Aedes aegypti L.  

作　　者：Radhika Warikoo Ankita Ray Jasdeep Kaur Sandhu Roopa Sanial Naim Wahab Sarita Kumar 

机构地区：[1]Department of Zoology,Acharya Narendra Dev College,University of Delhi

出　　处：《Asian Pacific Journal of Tropical Biomedicine》2012年第2期152-155,共4页亚太热带生物医学杂志（英文版）

基　　金：supported by University Grants Commission[grant No.F.35-74/2009(SR)]

摘　　要：Objective:To assess the larvicidal and irritant activities of the hexane extracts of leaves of Citrus sinensis(C.sinensis)against the early fourth instars and female adults of Aedes aegypti(Ae.aegypti).Methods:The larvicidal potential of the prepared leaf extract was evaluated against early fourth instar larvae of Ae.aegypli using WHO protocol.The mortality counts were made after 24 h and LC_(50)and LG_(50)values were calculated.The efficacy of extract as mosquito irritant was assessed by contact irritancy assays.Extract-impregnated paper was placed on a glass plate over which a perspex funnel with a hole on the top was kept inverted.Single female adult,3-day old unfed/blood-fed,was released inside the funnel.After 3 min of acclimatization time,the time taken for the first take-off and total number of flights undertaken during 15 min were scored.Results:The citrus leaf extracts from hexane possessed moderate larvicidal efficiency against dengue vector.The bioassays resulted in an LC_(50)and LC_(90)value of 446.84 and 1370.96 ppm,respectively after 24 h of exposure.However,the extracts were proved to be remarkable irritant against adults Ae.aegypti,more pronounced effects being observed on blood-fed females than unfed females.The extract-impregnated paper was thus proved to be 7-11 times more irritable as compared with the control paper.Conclusions:The hexane extracts from C.sinensis leaves are proved to be reasonably larvicidal But remarkably irritant against dengue vector.Further studies are needed to identify the possible role of extract as adulticide,oviposition deterrent and ovicidal agent.The isolation of active ingredient from the extract could help in formulating strategies for mosquito control.Objective:To assess the larvicidal and irritant activities of the liexane extracts of leaves of Citrus sinensis(C.sinensis) against the early fourth instars and female adults of Aedes aegypti dp.aegypti).Methods:The larvicidal potential ol the prepared leaf extract was evaluated against early fourth instar larvae of Ae.aegypti using WHO protocol.The mortality counts were made after 24 h and LC_(50) and LC_(90) values were calculated.The efficacy of extract as mosquito iiritant was assessed by contact irritancy assays.Extract-impregnated paper was placed on a glass plate over which a perspex funnel with a hole on the top was kept inverted.Single female adult.3-day old unfed/blood-fed,was released inside the funnel.After 3 min of acclimatization time,the time taken for the first take-off and total number of flights undertaken during 15 min were scored.Results:The citrus leaf extracts from liexane possessed moderate larvicidal efficiency against dengue vector.The bioassays resulted in an LC_(50) and LC_(90) value of 446.84 and 1370.96 ppm.respectively after 24 h of exposure.However,the extracts were proved to be remarkable irritant against adults Ae.aegypti,more pronounced effects being observed on blood-fed females than unfed females.The extract-impregnated paper was thus proved tn be 7-11 limes more irritable as compared with the control paper.Conclusions:The liexane extracts from C.sinensis leaves are proved to be reasonably larvicidal but remarkably irrilant against dengue vector.further studies are needed to identify the possible role of extract as adulticide.oviposition deterrent and ovicidal agent.The isolation ol active ingredient bum the extract could help in lormulating strategies for mosquito control.

关 键 词：CITRUS HEXANE Larvicide Irritancy Take-offs CITRUS sinensis Aedes aegypti LARVICIDAL activity IRRITANT activity DENGUE VECTOR Mosquito control 

分 类 号：R184[医药卫生—流行病学] S853.7[医药卫生—公共卫生与预防医学]