Why is Anopheles quadrimaculatus important in Maryland?

• A. It is not important
• B. It is the most important vector of human malaria in the eastern United States
• C. It transmits West Nile virus
• D. It is not a vector for malaria

Answer: (B)

Anopheles quadrimaculatus is a key malaria vector in the eastern United States, including Maryland. Anopheles mosquitoes are the group that can transmit human malaria parasites to people. In Maryland’s historical context, this species has been identified as the primary vector because it is common, tends to bite humans at night, and breeds in water sources near human activity. That combination makes it the main carrier of malaria risk in that region. West Nile virus, by contrast, is transmitted by Culex mosquitoes, not Anopheles quadrimaculatus, so this species is not a vector for West Nile. So, while malaria isn’t currently endemic in Maryland, this species’ role in past transmission explains why it’s regarded as the most important malaria vector in the eastern United States.