THE EFFECT OF CADMIUM AND LEAD ELEMENTS ON THE MORTALITY OF CULEXQUINQUEFASCIATUS

Abstract

Present study was carried to evaluate the toxicity of the Pb and Cd elements on the larvae of Culexquinquefasciatus. In the laboratory 5 concentrations of lead nitrate and cadmium nitrate , namely 10, 20, 30, 40, and 50 mgl and 1, 1.5, 2, 2.5, and 3 mgl of Pb and Cd respectively in each concentration 10 larvae were introduce beside there was a control (0mg/l).Statically analysis results declare that 1st and 2nd instars effected significantly in comparison with the control .Mortality percentage reached 28, 38.7, 48, 58, and 73.5 % in concentration 10, 20, 30, 40, and 50 mgl respectively of lead nitrate. On the other hand, cadmium nitrate mortality percentage reached 44, 55, 65, 74.5, and 79.5 % in concentration 1, 1.5, 2, 2.5, and 3 mgl respectively.Also, LC50 was going higher as the larva going older, measured 14.7, 16.9 for 1st and 2ndinstars and 22.3 and 41.4 for 3rd and 4th instars. On the other hand, cadmium nitrate appeared more affect than Leadnitrate with LC50 of 0.9, 1.05, 1.3, and 1.8 mgl for 1st, 2nd, 3rd, and 4th instars respectively.