QUESTION
Why is it only the female anopheles mosquito alone can cause malaria but not the male anopheles mosquito or any other mosquitoes?
ANSWER
Malaria is actually caused by a single-celled parasite called Plasmodium—it is transmitted via the bite of a female mosquito, of the genus Anopheles, as she takes a blood meal from a human (or other mammal) host. Male mosquitoes do not feed on blood (they only feed on nectar), whereas females need the nutrients from blood in order to produce their eggs; as such, only female Anopheles transmit mosquito.
Why only Anopheles are able to transmit malaria to humans is interesting—birds and reptiles also can get Plasmodium (though different species than those that infect humans and other mammals), and these kinds of malaria can also be transmitted by other kinds of mosquitoes, such as Aedes and Culex. Other closely related blood parasites can even be transmitted by other flying insects, such as sand flies and black flies. However, it is true that only Anopheles can transmit human malaria.
you didn’t answer the question… why can this particular genus transmit plasmodium falciparum and other mosquitoes cannot?
It is a matter of evolutionary compatibility. There are other types of Plasmodium, which only infect birds or reptiles, which can actually be transmitted by other genera of mosquitoes, such as Culex. Other related parasites, such as Leucocytozoon, another parasite of birds/reptiles from which Plasmodium probably evolved, can also be transmitted via black flies.
The species of Plasmodium which infect mammals (and there are many dozens, infecting all manner of primates and rodents; of these, only five are considered parasites of humans) seem to have evolved from the types which infect birds and reptiles, and appear to have crossed over into mammals only once. Presumably this cross-over occurred with a type of bird/reptile Plasmodium which was transmitted by Anopheles, hence why all mammal Plasmodium species known today are transmitted by this genus, including the types which infect humans.
Does the Anopheles mosquitoes have an effect on birds?can birds disappear from their host because of mosquitoes?
That’s a great question. Birds can get malaria, although different species to those that infect humans. However, the types of mosquito which usually transmits avian malaria are from the genus Culex, rather than Anopheles. Avian malaria has devastated bird populations across the world, particularly on islands which were previously free of malaria, and then it was introduced by humans – the Hawaiian Islands are a classic example, and the Galapagos Islands are also now exposed and vulnerable. Climate change is exacerbating the situation, by allowed the mosquito and the avian malaria parasites to travel to higher and higher latitudes; avian malaria has now been detected as far north as Alaska, suggesting even more bird populations are now at risk.