Diel oviposition patterns of Anopheles albitarsis in Trinidad, West Indies

The diel pattern of oviposition of wild-caught Anopheles albitarsis derived from rice fields in Frederick Settlement, Trinidad, was studied in the laboratory by recording the performance of egg-laying individuals and a colony at 2-h intervals. Oviposition was almost exclusively nocturnal, with 79.3% of the eggs being laid during the scotophase. During the rest of the day and during evening twilight, 7.8 and 12.9% eggs were laid, respectively. Wild-caught parous females allowed to engorge on human blood matured, on average, 71.1 +/- 12.4 follicles (range 53-106). These findings provide vector control personnel with the opportunity to maximize the impact of insecticides on An. albitarsis populations by restricting their operations to the time of peak activity.