Larvicidal activity of synthesized copper(II) complexes against Culex quinquefasciatus and Anopheles subpictus

Abstract

Malaria and lymphatic filariasis are two of the most common identifiable mosquito-borne parasitic diseases worldwide. Mosquito-borne disease is believed to be responsible for approximately 1 million deaths per year. Such diseases are controlled by use of insecticides; however, these may have undesired effects on non-target organisms. We therefore sought a suitable larvicidal compound that could replace insecticides by evaluating copper(II) complexes for larvicidal activity against Anopheles subpictus and Culex quinquefasciatus.Larvicidal bioassays were performed with five batches of 20 mosquito larvae in 249mL water and 1.0mL of complexes of the precursor [Cu(phen)(l-Thr)(H2O)](ClO4) with semicarbazide, thiosemicarbazide, urea or thiourea; the control was dechlorinated tap water. The number of dead larvae was counted after 24h of exposure. Dose–response assays were performed at concentrations ranging from 10.0 to 0.625mg/L of the complexes. The complex with urea had the best larvicidal activity against C. quinquefasciatus and A. subpictus at all concentrations.Copper(II) complexes have potential larvicidal activity, and that with urea had dose-dependent activity.