Host preference and nocturnal biting activity of mosquitoes collected in Dhaka, Bangladesh

摘要

Knowledge of host preference and activity periods of a mosquito species provides valuable insight into the dynamics of disease transmission and allows vector control authorities to design and implement efficient strategies for vector management. In this study, we determined what mosquito species be attracted to humans and their times of biting both indoors and outdoors in Bangladesh. Adult mosquitoes were collected for every first and third week of the month from January to December 2011 in Garua village, Bangladesh. Mosquito trapping was conducted inside, outside the house and in the cattle shed using human-bait (HB), cattle-bait (CB), and light traps. Each team of collectors captured adult mosquitoes between 1800-0600 h. A total of 14,788 adult mosquito samples consisting of 16 species belonging to 4 genera were captured during a year. Culex quinquefasciatus (5673/38.36%) was the dominant species followed by Cx. hutchinsoni (4644/31.40%), Cx. tritaeniorhynchus (3203/21.66%) and Ar. subalbatus (506/3.42%). All these dominant species were found throughout the year with a peak in July. The biting activity of various mosquito species in different hours of night varied from each other. The biting activity also varies in different months. Culex quinquefasciatus starts to bite human after sunset and gradually increase the density and attain peak at 2300-2400. After 2400 the biting density decreases gradually. Culex hutchinsoni start biting soon after the sunset and progressively reach the peak at 2400h and then decline slowly. Species diversity was higher in cattle shed compare to the human house. A significant difference (p0.01) of the mosquito density were found between the cattle bait and human bait catch. Culex vishnui mosquito strongly prefers to feed on cattle. Armigeres subalbatus, Cx. hutchinsoni, Cx. sitiens, Cx. tritaeniorhynchus, and Mn. annulifera were found to feed both on human and cattle. The majority of the Mosquitoes species were seeking hosts between 2400-0300 h. The main filarial vector Cx. quinquefasciatus peak biting time was between 2400-0300 h. It seems advisable that during this period, people should be advised to take precautions like the use of appropriate repellents, and proper clothing as well as sleeping under a bed net to avoid vector-host contact.