Abstract
This study was conducted in Al Bahah Region, Kingdom of Saudi Arabia during the period from March 2004 to February. 2006, to determine mosquitoes fauna and their abundance. Results showed that there are 19 mosquito species belonging to four genera. The identified species include Aedes vexans arabiensis, Ae. caspius, Ae. aegypti, Anopheles cinereus, An. d'thali, An. stephensi, An. subpictus, An. turkhudi, Culex laticinctus, Cx. perexiguus, Cx. pipiens, Cx. quinquefasciatus, Cx. sinaiticus, Cx. theileri, Cx. tigripes, Cx. torrentium, Cx. tritaeniorhynchus, Cx. univittatus and Culiseta longiareolata. Most larvae identified belonged to Culex sp. (50.35%), followed by Anopheles spp. (38.41%) and Culiseta sp. (11.24%). The results showed no significant correlation between total dissolved salts (TDS) and pH of the water and the distribution of different mosquito larvae species. Adult mosquitoes were collected throughout the year, but at different magnitudes, depending on prevailing climatic conditions. Adult population began to increase in April to May with the increase in temperature at the end of the winter season, reaching a peak in June, with an average temperature of 29 degree C and average monthly rainfall below 10 mm. However, the population density of adults declined gradually in the period between August and September, reaching minimum density in November with an average temperature of about 18 degree C. This study confirmed the presence of Cx. tritaeniorhynchus, the main vector of Rift Valley fever, in Al Bahah Region for the first time. The presence of this disease vector constitutes a major health problem, and every effort should be made to control it. The results of this study have shown that mosquitoes are widespread in Al Bahah Region. Further studies on their medical impact and vectorial capacity in disease transmission are required.