Some aspects on biting cycles of Culex quinquefasciatus in Bangkok.

The indoor and outdoor biting cycles of Culex quinquefasciatus were studied in Bangkok. The biting cycle was nocturnally periodic and preferably endophilic in character. There were two minor peaks on top of the nocturnally periodic peak. The first peak was between 2200 and 2300 hours, the latter peak was after midnight being at 0100 and 0400 hours. Parous mosquitoes formed 0%-20.0% of hourly total population. More parous mosquitoes were collected indoor and also during in the latter half of the night. Comparisons made between Bangkok, the none endemic area for Wuchereria bancrofti and Sri Lanka the endemic area, revealed that Bangkok has a lower survival rate of Culex quinquefasciatus, based on parous rates and that the older mosquitoes, which are potentially infective vectors were collected late in the night. This evidence could explain why Bangkok is not endemic area for periodic Wuchereria bancrofti.