West Nile Virus
Last reported: July 2025
low risk
Mosquitoes in Riverside, California
5 active species · Season May–Oct · Mediterranean/Desert climate · Low standing-water risk
Active disease alerts
Species active in Riverside
Yellow Fever Mosquito
Aedes aegypti
Small, dark mosquito with white markings on legs and body. Highly adapted to urban environments. Found indoors and outdoors, prefers shaded areas. Active during daylight, especially dawn and dusk.…
Carries: Zika Virus · Dengue Fever · Yellow Fever
Asian Tiger Mosquito
Aedes albopictus
Striking black mosquito with white stripes on legs and thorax. Originally from Southeast Asia, now widespread in North America. Known for aggressive, persistent biting behavior.…
Carries: Dengue Fever · Zika Virus · West Nile Virus
Western Encephalitis Mosquito
Culex tarsalis
Medium brown mosquito found primarily in western US. Important vector for encephalitis viruses. Breeds in clear water.…
Carries: West Nile Virus · Western Equine Encephalitis (WEE) · St. Louis Encephalitis
Northern House Mosquito
Culex pipiens
Brown mosquito with banded legs. Common in temperate climates. Often enters homes at night. Prefers standing water with organic matter.…
Carries: West Nile Virus · St. Louis Encephalitis · Avian Malaria
Western Malaria Mosquito
Anopheles freeborni
Medium brown mosquito with spotted wings. Found in western US. Historically important malaria vector but now very rare.…
Carries: Malaria