Determination of the larvicidal activity of benzoyl thiosemicarbazone and its Ni(II) complex against Aedes aegypti and Anopheles darlingi larvae in Amazonas, Brazil

Abstract

Due to the resistance of some mosquitoes to pyrethroids insecticides, new synthetic compounds are of great interest for the development of new insecticides against vectors of tropical diseases, especially in the Amazon region. Our aim was to synthesize and evaluate the larvicidal potential of benzoyl thiosemicarbazone and its Ni(II) complex against larvae of Aedes aegypti and Anopheles darlingi  . The compounds were synthesized from thiosemicarbazide according to the literature, and the larvicidal potential was evaluated in triplicate at concentrations of 7 to 500 µg/mL. Benzoyl thiosemicarbazone and its Ni(II) complex showed an LC50 of 42.09 and 42.28 µg/mL, respectively, against . Ae. aegypti larvae. For .An. darlingi larvae, the LC50 values of benzoyl thiosemicarbazone (4.77 µg/mL) were lower than its Ni(II) complex (7.33 µg/mL). Benzoyl thiosemicarbazone presented satisfactory results against the larvae, and due to the insecticidal potential of this substance, the development of new chemical insecticides may be possible.   Key words: Benzoyl thiosemicarbazone, nickel (II), larvicidal activity; Aedes aegypti, Anopheles darlingi.