Which species is primarily associated with the transmission of malaria?

The species primarily associated with the transmission of malaria is Anopheles quadrimaculatus. This mosquito belongs to the Anopheles genus, which is specifically known for its role as the primary vector for the malaria parasite, Plasmodium spp. Anopheles mosquitoes have particular biological and behavioral traits that make them effective at transmitting malaria, including their feeding habits and breeding preferences, usually in clean and slow-moving water sources.

Other mosquito species listed, such as Aedes vexans, Aedes triseriatus, and Culex pipiens, do not play a significant role in malaria transmission. Aedes species are more commonly associated with the transmission of viruses like dengue and Zika virus. Culex pipiens is primarily connected with the transmission of West Nile virus and other similar pathogens. Therefore, while these other species are important vectors for different diseases, Anopheles quadrimaculatus is uniquely tied to the spread of malaria, making it the correct answer in this context.