Ecology and habitat characterization of mosquitoes in Saudi Arabia

The Kingdom of Saudi Arabia (KSA) contains many of the world's mosquito vectors of parasitic and arboviral diseases. However, few studies addressed their geographic distribution and larval habitat characteristics. We carried out a 14-months mosquito survey in three KSA regions: Makkah and Al-Baha (western) and Jezan (south-western). Larvae were collected by dipping from various water habitats and adults by CDC light and BG sentinel traps. Climatic conditions and physicochemical characteristics of collection sites were recorded. We collected a total of 3331 mosquitoes {larvae (n= 2766, 83%) and adults (n= 565, 17%)} of 21 species from six genera (8 Anopheles, 8 Culex, 1 Aedes and 3 others). Larval water habitats included streams, rocky pits, seepage, leakage and containers (plastic and concrete). Of the total larvae collected, 52% (n= 1439) were Anopheles, 44.3% (n= 1226) were Culex, 0.51% (n= 14) were Aedes aegypti and 3.1% (n= 87) were from four other species. The most abundant species were Culex tritaeniorhynchus (n=1008, ~36.3%) and Anopheles dthali (n= 976, ~35.3%). The medically-important species were Anopheles arabiensis (n= 128) and Anopheles sergenti (n= 58), vectors of malaria and Culex tritaeniorhynchus, Culex quinquefasciatus (n= 53) and Ae. aegypti (n= 14), vectors of arboviral diseases. Three species are new records in KSA and all from Jezan: Anopheles superpictus (n= 3), Culex duttoni (n= 1) and Culex mimeticus (n= 1), however the numbers were very low, which requires further investigations. Only two species were collected in the adult stage, Cx. quinquefasciatus (n= 561: 551 females and 10 males) from Makkah and Culex theileri (n= 4, all females) from Al-Baha. Only 3.8% (n= 21) of Cx. quinquefasciatus females were blood-fed. This study provides new information on the bionomics of 21 mosquito species in KSA including six dominant vector species and thus adds to the scarce data available on them. This information is essential to better understand mosquito population dynamics in relation to disease transmission and control.