Anopheles

Anopheles (/əˈnɒfɪliːz/) is a genus of mosquito first described by the German entomologist J. W. Meigen in 1818, and are known as nail mosquitoes and marsh mosquitoes. Many such mosquitoes are vectors of the parasite Plasmodium, a genus of protozoans that cause malaria in birds, reptiles, and mammals, including humans. The Anopheles gambiae mosquito is the best-known species of marsh mosquito that transmits the Plasmodium falciparum, which is a malarial parasite deadly to human beings; no other mosquito genus is a vector of human malaria.

The genus Anopheles diverged from other mosquitoes approximately 100 million years ago (mya), and, like other mosquitoes, the eggs, larvae, and pupae are aquatic. The Anopheles larva has no respiratory siphon through which to breathe, so it breathes and feeds with its body horizontal to the surface of the water. The adult mosquito hatches from the surface and feeds on the nectar of flowers; the female mosquito also feeds on blood, which animal diet allows them to carry and transmit parasites between hosts. The adult's feeding position is head-down, unlike the horizontal stance of the culicines. Anopheles are distributed almost worldwide, throughout the tropics, the subtropics, and the temperate regions of planet Earth. In hot weather, adult Anopheles aestivate, which is a state of dormancy that enables the mosquito to survive in hot dry regions, such as the Sahel.

Fossils of the genus Anopheles are rare; only two had been found by 2015. They are Anopheles (Nyssorhynchus) dominicanus Zavortink & Poinar in Dominican Republic amber from the Late Eocene (40.4 million years ago to 33.9 million years ago), and Anopheles rottensis Statz in German amber from the Late Oligocene (28.4 million years ago to 23 million years ago).

The ancestors of all flies including mosquitoes appeared 260 million years ago. The culicine and Anopheles clades of mosquitoes diverged between 120 million years ago and 150 million years ago. The Old and New World Anopheles species subsequently diverged between 80 million years ago and 95 million years ago. Anopheles darlingi diverged from the African and Asian malaria vectors ~100 million years ago. The cladogram is based on an analysis of mosquito genomes by Heafsey and colleagues in 2015:

The genus name Anopheles was introduced by the German entomologist Johann Wilhelm Meigen in 1818. He described two species, A. birfurcatus and the type species, Anopheles maculipennis. He stated that the name meant beschwerlich, "burdensome". The name comes from the Ancient Greek word ἀνωφελής anōphelḗs 'useless', derived from ἀν- an-, 'not', 'un-' and ὄφελος óphelos 'profit'.

The taxonomy of the genus was greatly advanced in 1901 when the English entomologist Frederick Vincent Theobald described 39 Anopheles species in his 5-volume monograph on the Culicidae. He was provided with mosquito specimens sent in to the British Museum (Natural History) from around the world, on the 1898 instruction of the Secretary of State for the Colonies, Joseph Chamberlain.

Anopheles (with a nearly worldwide distribution) belongs to the subfamily Anophelinae alongside two other genera: Bironella (restricted to Australia) and Chagasia (restricted to the Neotropics). The taxonomy remains incompletely settled. Classification into species is based on morphological characteristics – wing spots, head anatomy, larval and pupal anatomy, chromosome structure, and more recently, on DNA sequences. In the taxonomy published by Harbach and Kitching in 2016, it was shown that three species of Bironella (B. confusa, B. gracilis, and B. hollandi) are phylogenetically more similar to A. kyondawensis than other Bironella species. That phylogeny argues that, based on genetic similarity, A. implexus is divergent from the common ancestor of Anopheles.

Like all mosquitoes, anophelines go through four stages in their life cycles: egg, larva, pupa, and adult. The first three stages are aquatic and together last 5–14 days, depending on the species and the ambient temperature. The adult stage is when the female Anopheles acts as malaria vector. The adult females can live up to a month (or more in captivity), but most probably do not live more than two weeks in nature.