Biting rhythms of some Pakistan mosquitoes (Diptera: Culicidae)

Abstract

A total of 18 873 mosquitoes comprising 18 species in 4 genera was collected during a series of 12 monthly all-night collections on bovid baits near the village of Sattoki, Punjab Province, Pakistan. Anopheles pulcherrimus Theo. and usually An. Culicifacies Giles and An. Stephensi List. had unimodal biting rhythms. Mansonia uniformis (Theo.), An. Annularis Wulp and An. Nigerrimus Giles had essentially unimodal rhythms, with most feeding occurring early in the evening but with occasional very slight morning increases.Aedes caspius (Pall.), Culex pseudovishnui Colless, C. tritaeniorhynchus Giles and usually An. Subpictus Grassi had distinctly bimodal biting rhythms, with well-defined early evening and predawn peaks. An. culicifacies, An. Stephensi and An. Subpictus occasionally had multimodal rhythms or were arhythmic. Some species exhibited more than one type of biting curve. In species having a distinct bimodal curve, the amplitude of the predawn or dawn increase varied considerably from month to month. The anophelines, especially An. culicifacies, An. Stephensi and An. Subpictus, exhibited a marked seasonal shift in feeding times, with most biting occurring at dusk during the cold period and late at night during the warm period. However, all components of the biting curves for these species were maintained at varying magnitude throughout the year, perhaps suggesting seasonal variations in the relative frequency of more than one behavioural genome. The remaining species exhibited little or no seasonal change in biting rhythms