The choice of an oviposition site by gravid females is the principal factor responsible for the distribution of the mosquitoes in breeding sites and it is of great relevance for the dispersion of the species in the nature. Therefore, accurate monitoring of Culex abundance is critical in forecasting the risk of disease outbreaks. Previous studies have demonstrated the atractiveness of natural oviposition pheromone in some Culex quinquefasciatus strains. Our objective is to determine the effects of natural pheromone as oviposition attractants for C. quinquefasciatus from in endemic area of lymphatic filarioses in Recife, Brazil. To examine the effects on mosquito oviposition behaviour, six cages (30x22x20cm) were used; two glass cups (200ml) were placed inside the cage, with one containing 10 egg-rafts and the other containing tap water as a control. The positions of treatment and control cups were alternated between replicates. Twelve replicates of 20 gravid females per cage were used. The egg-rafts were counted 24:00h after the beginning of the experiment. The results of this oviposition bioassay have shown that 76% females oviposite in the test site and 24% in the control site. These bioassays demonstrated that natural pheromone strongly attracted oviposition by C. quinquefasciatus gravid female. These data are of great usefulness to improve the atractiveness of an oviposition traps model under development. Supported by FACEPE and FIOCRUZ

Index terms: Culex quinquefasciatus, oviposition attraction, vectors control, pheromone.

---