[Effect of cypermethrin on some reproductive factors in Culex (C) quinquefasciatus Say 1823].

An experiment was carried otu with a Culex quinquefasciatus strain with resistance genes called "Quibú", and with a susceptible strain provided by the WHO; they were pressured with different lethal doses of cypermetrine. Time-mortality regression lines of the 2 strains were estimated following WHO methodology and the "Quibú" strain showed tolerance to the insecticide. TL30 and TL70 were selected to test their effect on fecundity, fertility, sexual index, and egg eclosion time. A significant reduction in fecundity and fertility was observed in the "Quibú" strain after it was pressured, no effect was detected on the sexual index and egg eclosion time in this strain.