author(s)
Saud Talaq Alerwi, Naser Alkenani, Jazem A Mahyoub, Mahmoud S Ahmad, Habeeb M Al-solami, Abdullah Alghamdi, Hanan S Alyaha and Yasir Anwar

abstract
Each year millions of peoples die to due mosquito's related diseases. Resistance of these mosquitoes towards chemical pesticides is one of serious issue. Bio-control is one of the safe ways to control these vectors. The aim of our study was to evaluate three different plant extract against the 4^th instar larvae of Culex quinquefasciatus mosquitoes. Two ethanolic plants extract and one plant essential oil (EOs) was used for the larvicidal activity ranging from concentration of 0 to 900 ppm against the 4^th instar larvae of Culex quinquefasciatus. To determine the LC₅₀ and LC₉₀ value, data was subjected to probit analysis. Mosquito larvae's used during this study was identified using COI gene sequencing. Among them Argania spinosa oil showed moderate larvicidal effect at low concentration but Thevetia peruviana extract and Saueda monoica extract shows high larvicidal activity at low concentration respectively. The LC₅₀ and LC₉₀ values for Thevetia peruviana extract was 105.95 and 243.36 (ppm). In case of Saueda monoica extract the LC₅₀ and LC₉₀ value was 104. 04 and 282.26 respectively. But the Argania spinosa oil shows activity with almost double the concentration of the other two plant extracts. It is concluded from our data that Thevetia peruviana and Saueda monoica has the potential to control Culex quinquefasciatus in an eco-friendly way.