Bug FAQAedes nigromaculis
Aedes nigromaculis · Order: Diptera · Family: Culicidae
Source: Wikipedia
Aedes nigromaculis is a mosquito species in the Aedes genus, subgenus Ochlerotatus. Its larvae are commonly found in groups along the edges of grassy areas. It occurs in the western United States, such as California, and in Canada’s Northwest Territories.
Source: Wikipedia
How to recognize it
Commonly called the irrigated pasture mosquito, it belongs to the Culicidae family.
Source: Wikipedia
Does it bite or sting?
Laboratory studies show it can carry western equine encephalitis, St. Louis encephalitis, and Japanese encephalitis viruses, and wild populations have natural western equine encephalitis infections.
Source: Wikipedia
Where it lives
Larvae tend to cluster along the margins of grassy habitats.
Source: Wikipedia
Where it is found in the US
Recorded in 20 of 51 states and DC. Most records: Idaho, Iowa, Montana, Colorado, North Dakota, Texas, Kansas, Oklahoma.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
Can Aedes nigromaculis spread diseases to humans?
Yes, it can transmit western equine encephalitis, St. Louis encephalitis, and Japanese encephalitis viruses.
Source: Wikipedia
Where is Aedes nigromaculis found?
It lives in the western United States, such as California, and in Canada’s Northwest Territories.
Source: Wikipedia
Where do the larvae of this mosquito live?
The larvae often gather along the edges of grassy areas.
Source: Wikipedia
Same family (Culicidae)
Asian Tiger MosquitoAedes albopictusCan spread germs or disease
House Mosquito ComplexCulex pipiensCan spread germs or disease
Yellow Fever MosquitoAedes aegyptiCan spread germs or disease
Inland Floodwater MosquitoAedes vexansCan spread germs or disease
Asian Bush MosquitoAedes japonicusCan bite
Southern House MosquitoCulex quinquefasciatusCan spread germs or diseaseSources
- Wikipedia: https://en.wikipedia.org/wiki/Aedes_nigromaculis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.