783 Original article https://doi.org/10.12980/apjtd.7.2017D7-175 ©2017 by the Asian Pacific Journal of Tropical Disease. All rights reserved. Larvicidal effcacy of Scabiosa arenaria Forssk. (Dipsacaceae) organs extracts against Culex pipiens L. Malek Besbes Hlila 1* , Ali Lamari 2 , Amel Omri Hichri 1 , Hichem Ben Jannet 3 , Maha Mastouri 1 , Mahjoub Aouni 1 , Boulbaba Selmi 4 1 Laboratory of Transmissible Diseases and Biological Active Substances, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Avenue Avicenne, 5000 Monastir, University of Monastir, Monastir, Tunisia 2 Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir 5019, Tunisia 3 Laboratory of Heterocyclic Chemistry, Natural Products and Reactivity, Team: Medicinal Chemistry and Natural Products, Department of Chemistry, Faculty of Sciences of Monastir, University of Monastir, Monastir, Tunisia 4 Laboratory of Bioresources: Integrative Biology and Exploiting, Higher Institute of Biotechnology of Monastir, Department of Molecular Biology, Cellular and Biotechnology, University of Monastir, Monastir, Tunisia Asian Pac J Trop Dis 2017; 7(12): 783-787 Asian Pacific Journal of Tropical Disease journal homepage: http://www.apjtcm.com *Corresponding author: Malek Besbes Hlila, Laboratory of Transmissible Diseases and Biological Active Substances, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Avenue Avicenne, 5000 Monastir, University of Monastir, Monastir, Tunisia. Tel: 216 97663356) E-mail: angelkm2007@yahoo.fr Foundation Project: Supported by the Ministry of High Education and Scientific Research of Tunisia (Grant No. 11/TM06). The journal implements double-blind peer review practiced by specially invited international editorial board members. 1. Introduction Insect vectors, particularly mosquitoes (Diptera: Culicidae) are among the most dangerous and serious insect pests of medical significance. There are about 2 700 species of mosquito worldwide; the three more important genera are the Culex, Anopheles and Aedes. They are well-known vector borne illness, a few of which result in millions of fatal, epidemic diseases such as yellow fever, dengue fever, West Nile virus, Japanese encephalitis, Louis encephalitis, malaria, Zika virus, chikungunya and filariasis causing deaths in animals and humans in the world each year[1-4]. The species Culex pipiens L. (C. pipiens) has a large geographic distribution and may be found through the world in all urban and sub-urban tropical and temperate zones. The principal larval developmental or breeding sites of this mosquito are artificial containers, septic tanks, water irrigation channels, animal watering basins and temporary pools[5], where they play significant roles in the transmission of parasite and many illnesses that infect human, like the West Nile virus, Louis encephalitis virus, bird malaria (Plasmodium spp) and filarial worms[6,7]. We found many preparations and apparatuses designed to prevent or decrease such vectors, comprising microbial formulations and pesticides[8] such as, the conventional insecticides, pyrethroids and organophosphates. The pyrethroids are nowadays the most extensive insecticides for the indoor fight against mosquito adults ARTICLE INFO ABSTRACT Objective: To determine the larvicidal activity of sixteen extracts of Scabiosa arenaria Forssk. (S. arenaria) against the third instar larvae of Culex pipiens L. (C. pipiens). Methods: Larvicidal activity of S. arenaria extracts was determined according to World Health Organization. Twenty third instars of the C. pipiens were exposed to different concentrations (15 µg/mL to 60 µg/mL) of extracts. Mortality was recorded after 24 h of exposure. Results: The roots ethyl acetate fraction of S. arenaria had a significant toxic effect on larvae of C. pipiens, with high mortality percentage (100.0% ± 2.2%) at 60 µg/mL, and 50% lethal concentration value of LC 50 = (15.00 ± 0.09) µg/mL. Conclusions: Results show that roots ethyl acetate could be used for the production of natural bio-pesticides which could decrease our dependence on chemical pesticides. Article history: Received 20 Jul 2017 Received in revised form 24 Aug 2017 Accepted 10 Sep 2017 Available online 29 Nov 2017 Keywords: Scabiosa arenaria Forssk Culex pipiens L Larvicidal activity Mosquito