Mosquitoes (Culicidae) are a family of insects within the order of diptera. There are more than 3600 species of mosquitoes worldwide.
With the help of specialized mouthparts, the biting sucking trunk, female mosquitoes can pierce the skin of their hosts and suck blood. The proteins (especially from haemoglobin and albumin) and iron (from porphyrin compounds such as haematoma) taken up with the blood meal are essential for the production of eggs. Otherwise, female mosquitoes, like males, feed on nectar and other sugary plant juices. Different species of mosquitoes may be specialised for different hosts or host groups. Certain mosquitoes are important vectors of infectious diseases such as malaria or dengue fever.
Mosquitoes are common worldwide, they are only absent in Antarctica and on some isolated oceanic islands, such as Iceland. Especially large swampy areas like in the tundra and taiga are ideal breeding grounds for the mosquito. However, the different species have very different ranges of distribution.
Laboratory and field experiments have shown that mosquitoes find their blood hosts mainly through exhaled carbon dioxide and body scents (for example, various fatty acids and ammonia). Depending on the species and host specificity, individual substances can be of particular importance. For example, in the yellow fever mosquito (Stegomyia aegypti), which specialises in humans, the lactic acid found on the human skin is a central stimulus for finding a host.
In finding a host, the mosquitoes follow the scent of their host to its source. Apparently, not only the chemical composition of the scent plume but also its size, structure and shape provide important information about the host and its removal. At close range, visual cues and body heat also play a role.