title: Eco-friendly larvicides from Indian plants: Effectiveness of lavandulyl acetate and bicyclogermacrene on malaria, dengue and Japanese encephalitis mosquito vectors.
abstract: Mosquitoes (Diptera: Culicidae) are a key threat for millions of people and animals worldwide, since they act as vectors for devastating pathogens and parasites, including malaria, dengue, Japanese encephalitis, filiariasis and Zika virus. Mosquito young instars are usually targeted using organophosphates, insect growth regulators and microbial agents. Indoor residual spraying and insecticide-treated bed nets are also employed. However, these chemicals have negative effects on human health and the environment and induce resistance in a number of vectors. In this scenario, newer and safer tools have been recently implemented to enhance mosquito control. The concrete potential of screening plant species as sources of metabolites for entomological and parasitological purposes is worthy of attention, as recently elucidated by the Y. Tu's example. Here we investigated the toxicity of Heracleum sprengelianum (Apiaceae) leaf essential oil and its major compounds toward third instar larvae of the malaria vector Anopheles subpictus, the arbovirus vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. GC-MS analysis showed that EO major components were lavandulyl acetate (17.8%) and bicyclogermacrene (12.9%). The EO was toxic to A. subpictus, A. albopictus, and C. tritaeniorhynchus, with LC50 of 33.4, 37.5 and 40.9µg/ml, respectively. Lavandulyl acetate was more toxic to mosquito larvae if compared to bicyclogermacrene. Their LC50 were 4.17 and 10.3µg/ml for A. subpictus, 4.60 and 11.1µg/ml for A. albopictus, 5.11 and 12.5µg/ml for C. tritaeniorhynchus. Notably, the EO and its major compounds were safer to three non-target mosquito predators, Anisops bouvieri, Diplonychus indicus and Gambusia affinis, with LC50 ranging from 206 to 4219µg/ml. Overall, this study highlights that H. sprengelianum EO is a promising source of eco-friendly larvicides against three important mosquito vectors with moderate toxicity against non-target aquatic organisms.
authors: Unit of Vector Control, Phytochemistry and Nanotechnology, Department of Zoology, Annamalai University, Annamalainagar 608002, Tamil Nadu, India. Electronic address: drgovind1979@gmail.com.
authors: Marimuthu
authors: M
authors: Govindarajan
authors: Insect Behavior Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy. Electronic address: benelli.giovanni@gmail.com.
authors: Giovanni
authors: G
authors: Benelli
mesh_terms: D000085:Acetates / Q000633:toxicity; D000330:Aedes / Q000187:drug effects; D000818:Animals; D000852:Anopheles / Q000187:drug effects; D009033:Culicidae / Q000187:drug effects*; D003715:Dengue / Q000517:prevention & control / Q000635:transmission; D004672:Encephalitis, Japanese / Q000517:prevention & control / Q000635:transmission; D004777:Environment; D030002:Heracleum / Q000737:chemistry; D006801:Humans; D007194:India; D007306:Insecticides / Q000032:analysis / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D008288:Malaria / Q000517:prevention & control / Q000635:transmission; D039821:Monoterpenes / Q000633:toxicity; D009032:Mosquito Control; D000072138:Mosquito Vectors; D009822:Oils, Volatile / Q000737:chemistry / Q000633:toxicity*; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D045788:Sesquiterpenes, Germacrane / Q000633:toxicity; D000071243:Zika Virus Infection / Q000517:prevention & control / Q000635:transmission
chemical_list: D000085:Acetates; D007306:Insecticides; D039821:Monoterpenes; D009822:Oils, Volatile; D010936:Plant Extracts; D045788:Sesquiterpenes, Germacrane; C492922:lavandulyl acetate
keywords: Apiaceae; Biosafety; Gambusia affinis; Heracleum sprengelianum; Mosquitoes; Non-target effects