In the Arctic summer, the mosquito population explodes-there are records of men driven mad by swarms of mosquitos. how come these mosquitos never transmitted malaria? As far as I know, the disease is unknown in the arctic.
The malaria-transmitting mosquito lives only in tropical and subtropical regions. That’s why.
In order for a mosquito to transmit malaria, it must be infected with the parasite. The mosquito can get this infection when it drinks the blood of an infected animal. The parasite multiplies and migrates to the mosquito’s salivary glands, which inject the parasite into the next animal that the mosquito bites.
Most species of mosquito are immune to malaria. There are 41 genera of mosquitos - only one of these, Anopheles, includes species that transmit malaria. There are about 460 species in Anopheles, and about 100 of these transmit human malaria (there are type of malaria that infect other animals).
Anopheles mosquitos seem to prefer middle latitudes to northern and southern latitudes. Here’s a map showing the range of various species. I don’t know why the Anopheles genus hasn’t spread to places like the Arctic.
There’s also a pretty specific time-table for different strands of malaria: it takes a set period of time for each strand to multiply in the mosquito’s salivary glands to the point that it is contagious. The mosquito season in the arctic is only a few weeks. There simply wouldn’t be time for the mosquitos to become contagious.