~ 34 ~ International Journal of Mosquito Research 2021; 8(3): 34-43 ISSN: 2348-5906 CODEN: IJMRK2 IJMR 2021; 8(3): 34-43 © 2021 IJMR www.dipterajournal.com Received: 04-03-2021 Accepted: 12-04-2021 Mohammed H Alzahrani General Directorate of Vector-Borne & Zoonotic Diseases, Ministry of Health, Riyadh, Saudi Arabia Yousif Eldirdiry Elamin General Directorate of Vector-Borne & Zoonotic Diseases, Ministry of Health, Riyadh, Saudi Arabia Mohammed Abdullah Al Helal General Directorate of Vector-Borne & Zoonotic Diseases, Ministry of Health, Riyadh, Saudi Arabia Abdelmohsin MO Abdoon General Directorate of Vector-Borne & Zoonotic Diseases, Ministry of Health, Riyadh, Saudi Arabia Waleed M EL-Motasim Ibrahim Vector Borne and Zoonotic Disease Administration, General Directorate of Health Affairs in Riyadh Region, Riyadh, Saudi Arabia Faris ahmed Alqarni Vector Borne and Zoonotic Disease Administration, General Directorate of Health Affairs in Riyadh Region, Riyadh, Saudi Arabia Hasabelrasol FA Elhaj Vector Borne and Zoonotic Disease Administration, General Directorate of Health Affairs in Aseer Region, Abha, Saudi Arabia Mo’awia Mukhtar Hassan (1) Department of Biology, Faculty of Science, University of Tabuk, Tabuk, 71491, Saudi Arabia (2) Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Ministry of Higher Education and Scientific Research, Sudan Corresponding Author: Mo’awia Mukhtar Hassan (1) Department of Biology, Faculty of Science, University of Tabuk, Tabuk, 71491, Saudi Arabia (2) Department of Parasitology and Medical Entomology, Tropical Medicine Research Institute, National Centre for Research, Ministry of Higher Education and Scientific Research, Sudan Distribution of mosquitoes and the first record of Aedes ( Stegomyia ) aegypti (Linnaeus, 1762) (Diptera: Culicidae) in the Riyadh Province, Kingdom of Saudi Arabia Mohammed H Alzahrani, Yousif Eldirdiry Elamin, Mohammed Abdullah Al Helal, Abdelmohsin MO Abdoon, Waleed M EL-Motasim Ibrahim, Faris ahmed Alqarni, Hasabelrasol FA Elhaj and Mo’awia Mukhtar Hassan Abstract Mosquitoes are among the most important vectors that transmit several parasitic and viral diseases in different regions of the world. Mosquito surveillance was carried out from 2012 to 2017 to determine the occurrence and distribution of mosquito species in five places in the Riyadh Province (Riyadh city, Al- Kharj, Ad Dilam, Al Majma’ah, and Al Duwadimi) in the Kingdom of Saudi Arabia (KSA). Larval collections were carried out using standard dippers and adult collections with Bio traps. The mosquito collection comprised Anopheles dthali, An. pretoriensis, Culex pipiens, Cx. quinquefasciatus, and Aedes aegypti. The presence of Ae aegypti is considered to be the first record in the mentioned places. The occurrence of Ae. aegypti represents a serious risk of transmission of Ae. aegypti-borne diseases in the region. Therefore, active entomological surveillance and proper vector control are needed to prevent the further spread of this vector and the transmission of Ae. aegypti-borne diseases in the region. Keywords: mosquitoes, Aedes aegypti, first record, Riyadh province, KSA 1. Introduction Mosquito-borne diseases (MBD) such as malaria and dengue fever are endemic in the southwestern and western regions of the Kingdom of Saudi Arabia (KSA), respectively [1,2] . During the last three decades, the KSA had s witnessed major epidemics of mosquito arboviral diseases which were Rift Valley fever (RVF), and dengue fever (DF). The outbreak of RVF occurred from August 2000 to September 2001in the southern regions of KSA and resulted in 1500 infected human cases and 215 deaths [3] . Furthermore, several outbreaks of DF were reported from the western coastal region in the country [4] . The first documented outbreak of DF in KSA was in 1994 in Jeddah, where 289 confirmed cases were recorded [5] . Thereafter, sporadic outbreaks of DF have been reported in the western region of the KSA [6,7] . More recently, local transmission of DF in the KSA has been reported in different cities including Jeddah, Makkah, Al Madinah, Jazan, AL Taif, and Najran [8, 9, 10] . Mosquitoes comprise the most important vectors of human diseases in the Kingdom of Saudi Arabia (KSA). Studies on the fauna and distribution of mosquitoes in the country revealed about 49 species, that include 18 anophelines and 31 culicines [11] . Among these species, Anopheles arabiensis, An. sergentii and An. stephensi are currently considered as the potential vectors of malaria parasites [11, 12] , Culex pipiens, and Cx. quinquefasciatus, probable vectors of human filariasis and West Nile virus [13] , Cx. tritaeniorhynchus and Aedes vexans arabiensis are proposed to be vectors of RVF in KSA [14, 15] , Aedes aegypti the main vector of dengue fever in the country [16] . Most of these mosquito species are recorded in almost all surveyed regions in the Eastern [17] , Western [18, 19] , and Southern areas of KSA [20, 21] , including the Riyadh Region [22] . However, Aedes agyepti was recorded only in the western and southern regions of the country [19, 20] . Hence, studies on the identification, fauna, and distribution of vector species are important requirements for disease control.