[Effect of 3 organophosphates on the reproduction of Culex quinquefasciatus Say 1823].

An experiment was carried out with a Culex quinquefasciatus strain with resistance genes called "Quibú", this strain was pressured with 3 organophosphorous insecticides: malathion, chlorpyriphos, and pyrimiphos-methyl. The most toxic for this species was the chlorphyriphos (LC50 = 0.000009 mg/L), followed by pyrimiphos-methyl (LC50 = 0.00026 mg/L), and malathion (LC50 = 0.0035 mg/L). Larvae surviving the effects of the LC30 and LC70 of the three insecticides were selected to test their effect on fecundity, fertility and sexual index. Fecundity was not affected by the employed doses of chlorpyriphos and pyrimiphos-methyl, while a significant decrease was observed with the LC30 and LC70 of malathion. The employed doses of malathion did not affect fertility but there was a slight decrease with the LC70 selections of chlorpyriphos and pyrimiphos-methyl. The proportion of adult females showed a significant increase with the doses of chlorpyriphos and pyrimiphos-methyl; sexual index was not affected by malathion.