Observations on the seasonal incidence and diel oviposition periodicity of Haemagogus mosquitoes (Diptera: Culicidae) in Trinidad, W.I. II. Haemagogus equinus Theobald.

Diel patterns of oviposition of sylvan Haemagogus equinus in the field in Trinidad, West Indies, were monitored weekly for 53 consecutive weeks using standard ovitraps. During the wet season (September to November 1981 and May to September 1982) a large well-defined unimodal peak (comprising 97% of all eggs laid and 89% of occurrences) occurred at 12.00-14.00 hours, four to six hours before sunset. During the dry season (December 1981 to May 1982), two small less-well-defined peaks occurred at 10.00-12.00 and 14.00-16.00 hours (comprising 4.9% of eggs laid and 14% of occurrences). A diurnal oviposition pattern was observed when the wet and dry season data were combined. The number of eggs and occurrences found during the wet season was significantly higher (P greater than 0.001) than that observed during the dry season.