EFFECTS OF 3 ORGANOPHOSPHORUS INSECTICIDES IN THE REPRODUCTIVE POTENTIAL OF CULEX-QUINQUEFASCIATUS

A Culex quinquefasciatus Say 1823 strain with resistant genes to organ ophosphates was tested in the laboratory to know the reproductive pote ntial after exposure, as larvae, at the LC(30) and LC(70) (mg/l) of th ree organophosphorus insecticides: malathion, chlorpyrifos and methyl- pirimiphos. Data showed that fecundity was decreased significantly by malathion at LC(30) = 0.0025 and LC(70) = 0.0075, whereas fertility ha d a no significant decrement by chlorpyrifos and methyl-pirimiphos at the LC(70) (0.000016, 0.00043). The sexual index was affected by chlor pyrifos and methyl-pirimiphos showing a greater number of adult female s.