About Anopheles arabiensis

Range

Anopheles arabiensis belongs to the An. gambiae species complex, and is one of the most important vectors of malaria in sub-Saharan Africa and surrounding islands.

Habitats

Anopheles arabiensis is considered a species of dry, savannah environments and sparse woodland yet it is known to occur in forested areas, but only where there is a history of recent land disturbance or clearance. Its larval habitats are generally small, temporary, sunlit, clear and shallow fresh water pools, although An. arabiensis is able to utilize a variety of habitats including slow flowing, partially shaded streams and a variety of large and small natural and man-made habitats. It has been found in turbid waters and, on occasion, in brackish habitats. It readily makes use of irrigated rice fields where larval densities are related to the height of the rice, peaking when the plants are still relatively short and then dropping off substantially as the rice plants mature. Such density fluctuations are also reflected in the adult population, which also peak when rice stalks are small and decline as the plants mature. These patterns may be due to a preference for sunlit areas of water with relatively limited emergent vegetation, with densities decreasing as shade from the growing plants increases.

Resting and feeding preferences

An. arabiensis is described as a zoophilic, exophagic and exophilic species. However, it is also known to have a wide range of feeding and resting patterns, depending on geographical location. This behavioural plasticity allows An. arabiensis to adapt quickly to counter indoor residual spraying control showing behavioural avoidance of sprayed surfaces depending on the type of insecticide used. The behavioural variability of An. arabiensis is clearly evident with reports of both anthropophilic and zoophilic behaviour. An east-west behavioural cline has been suggested where populations found in western Africa display higher levels of anthropophily, and preferentially feed and rest indoors, whereas those in the east exhibit greater zoophily and rest outdoors. Overall, however, biting patterns tend to be exophagic. Blood feeding times also vary in frequency but biting generally occurs during the night. Peak evening biting times can begin in the early evening (19:00) or early morning (03:00). This species, demonstrates a predisposition to exophilic (or partial exophilic) behaviour regardless of where it has blood fed or the source of its meal, a behavioural trait considered to be depend on location.

Vectorial capacity

Anopheles arabiensis is considered to be a dominant malaria vector species.

This text was modified from Sinka ME et al. (2010) The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis Parasites & Vectors 3:117.

Dongola strain

Strain used for sequencing. Originally isolated from Sudan the colony has undergone isofemale selection, and is available from the BEI resource center.

Source: VectorBase

Picture credit: James Gathany, CDC Public domain via Wikimedia Commons (Image source)

Taxonomy ID 7173

Data source Broad Institute

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