Biology Reference
In-Depth Information
Anopheles arabiensis
tends to be found in drier climates within Africa and
larval habitats are typically small, temporary, clear, sunlit freshwater pools
similar to those of
An. gambiae s.l.
However,
An. arabiensis
larvae have also
been sampled from large or small man-made water bodies, including rice
fields, as well as flowing or even brackish waters.
There is less variation observed in the bionomics of
An. funestus s.l.
relative to
An. arabiensis
. This species is known to be highly anthropophilic
and endophilic and have a late biting time (after 2200), making IRS or
ITNs highly effective interventions (although pyrethroid resistance has now
been reported (
Hargreaves et al., 2000
;
Coetzee and Fontenille, 2004
)). The
larval habitats of the Funestus Complex tend to be large, permanent (or
semi-permanent) bodies of freshwater such as a pond, lake edge or rice
field, where the larvae use emergent plants as protection against predation.
There is some variation in the behaviour of members of the complex and
further investigations using molecular identification methods are needed
to determine the distribution of the different subtypes and the bionomics
they exhibit.
Anopheles gambiae s.l.
is perhaps the most well-known vector of human
malaria and the most studied. It occupies a wide geographic range and is
considered to be a highly efficient vector because of its highly anthropo-
philic biting behaviour and relatively long adult life stage. Females gen-
erally feed late at night indoors and also rest indoors, again making IRS
and ITNs successful intervention strategies. However, in studies com-
paring feeding and resting location preference,
An. gambiae s.s.
exhibited
both indoor and outdoor feeding and resting habits (
Sinka et al., 2010a
).
This is likely ascribed to different chromosomal and molecular forms now
identified within the species (
Bockarie et al., 1993
). The larval habitats of
An. gambiae s.l.
were long thought to be restricted to clear sunlit, temporary
pools such as puddles or hoof prints, however, larvae have been reported
from turbid and even polluted water and from large semi-permanent water
sources such as rice fields. The variation of larval habitats is again attributed
to divergences of the chromosomal or molecular forms.
The vector species of
P. vivax
in Africa occupy wide geographic ranges
across the region and exhibit variation in behaviours both among and
within individual species or species complexes. This may present challenges
for control, yet, the tendency for these species to bite and rest indoors at
night makes control methods such as ITNs effective control strategies.Vivax
malaria is not currently the main focus of malaria research in this region and
incrimination studies on wild populations have yet to be performed on half
