Taxonomy of Anopheles
Anopheles is a genus of mosquitoes comprising over 500 recognized species. These mosquitoes are the primary vectors responsible for transmitting malaria to humans.
The genus is taxonomically divided into several subgenera, including Anopheles, Baimaia, Cellia, Kerteszia, Lophopodomyia, Nyssorhynchus, and Stethomyia. Notably, only about 30 to 40 of these species are commonly involved in malaria transmission.
Classification
The classification of this genus began in 1901 with Frederick Vincent Theobald. Despite the passage of time, the taxonomy remains incompletely settled. Classification into species is based on morphological characteristics - wing spots, head anatomy, larval and pupal anatomy, and chromosome structure, and more recently on DNA sequences.The genus Anopheles belongs to a subfamily Anophelinae with three genera: Anopheles Meigen, Bironella Theobald and Chagasia Cruz. The genus Bironella has been divided into three subgenera: Bironella Theobald, Brugella Edwards and Neobironella Tenorio. Bironella appears to be the sister taxon to the Anopheles, with Chagasia forming the outgroup in this subfamily.
The type species of the genus is Anopheles maculipennis.
Subgenera
The genus has been subdivided into seven subgenera based primarily on the number and positions of specialized setae on the gonocoxites of the male genitalia. The system of subgenera originated with the work of Christophers, who in 1915 described three subgenera: Anopheles, Myzomyia and Nyssorhynchus. Nyssorhynchus was first described as Lavernia by Theobald. Frederick Wallace Edwards in 1932 added the subgenus Stethomyia. Kerteszia was also described by Edwards in 1932, but then was recognised as a subgrouping of Nyssorhynchus. It was elevated to subgenus status by Komp in 1937; this subgenus is also found in the Neotropics. Two additional subgenera have since been recognised: Baimaia by Harbach et al. in 2005 and Lophopodomyia by Antunes in 1937.One species within each subgenus has been identified as the type species of that particular subgenus:
- Subgenus Anopheles - Anopheles maculipennis Meigen 1918
- Subgenus Baimaia - Anopheles kyondawensis Abraham 1947
- Subgenus Cellia - Anopheles pharoensis Giles 1899
- Subgenus Kerteszia - Anopheles boliviensis Theobald 1905
- Subgenus Lophopodomyia - Anopheles squamifemur Antunes 1937
- Subgenus Nyssorhynchus - Anopheles argyritarsis Robineau-Desvoidy 1827
- Subgenus Stethomyia - Anopheles nimbus Theobald 1902
The number of species currently recognised within the subgenera is given here in parentheses: Anopheles, Baimaia, Cellia, Kerteszia, Lophopodomyia, Nyssorhynchus and Stethomyia.
The subgenus Baimaia may be elevated to genus level, as it appears to be a sister group to Bironella and all other Anopheles''.
Divisions below subgenus
Taxonomic units between subgenus and species are not currently recognised as official zoological names. In practice, a number of taxonomic levels have been introduced. The larger subgenera have been subdivided into sections and series, which in turn have been divided into groups and subgroups. Below subgroup but above species level is the species complex. Taxonomic levels above species complex can be distinguished on morphological grounds. Species within a species complex are either morphologically identical or extremely similar and can only be reliably separated by microscopic examination of the chromosomes or DNA sequencing. The classification continues to be revised.The first species complex was described in 1926 when the problem of nontransmission of malaria by Anopheles gambiae was solved by Falleroni, who recognised that An. gambiae was a complex of six species, of which only four could transmit malaria. This complex has subsequently been revised to a total of seven species of which five transmit malaria.
Subgenus Nyssorhynchus has been divided in three sections: Albimanus, Argyritarsis and Myzorhynchella. The Argyritarsis section has been subdivided into Albitarsis and Argyritarsis groups.
The Anopheles group was divided by Edwards into four series: Anopheles, Myzorhynchus, Cycloleppteron and Lophoscelomyia ; and two groups, Arribalzagia and Christya. Reid and Knight modified this classification by subdividing the subgenus Anopheles into two sections, Angusticorn and Laticorn and six series. The division was based on the shape of their pupal trumpets. The Laticorn section was created for those species with wide, funnel-shaped trumpets having the longest axis transverse to the stem, and the Angusticorn section for species with semitubular trumpets having the longest axis vertical more or less in line with the stem. The earlier Arribalzagia and Christya groups were considered to be series. The Angusticorn section includes members of the Anopheles, Cycloleppteron, and Lophoscelomyia series, and the Laticorn section includes the Arribalzagia, Christya, and Myzorhynchus series.
Cellia is the largest subgenus: all species within this subgenus are found in the Old World. It has been divided into six series - Cellia, Myzomyia, Neocellia, Neomyzomyia, Paramyzomyia and Pyretophorus. This classification was developed by Grjebine, Reid, and Gillies & de Meillon based on the work by Edwards in 1932. Series definition within this subgenus is based on the cibarial armature - a collection of specialized spicules borne ventrally at the posterior margin of the cibarium - which was first used as a taxonomic method by Christophers in 1933.
Kerteszia is a small subgenus found in South America whose larvae have specific ecological requirements; these can only develop within water that accumulates at the base of the follicular axis of the epiphytic Bromeliaceae. Unlike the majority of mosquitoes, species in this subgenus are active during the day.
Within a number of species, separate subspecies have been identified. The diagnostic criteria and characteristic features of each subgenus are discussed on the own page.