| Anopheles mosquitoes are found worldwide except Antarctica. Of nearly 430 Anopheles species, 30-40 transmit
the four species of malaria parasites, depending on the region and the environment.
Anopheles gambiae is best known for its role in the transmission
of
P. falciparum in Africa. Some species of Anopheles also can serve as the vectors for canine heartworm
Dirofilaria immitis, the filarial worms
Wuchereria bancrofti and
Brugia malayi, and
O'nyong'nyong fever virus.
Anopheles
stephensi
Source:
http://en.wikipedia.org/wiki/Image:Anopheles_stephensi.jpeg |
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Structure
and Habits
Anopheles mosquitoes can be distinguished from other mosquitoes by the palps,
which are as long as the proboscis, and by the presence of discrete blocks of
black and white scales on the wings. Adult Anopheles can also be identified by
their typical resting position, with their abdomens sticking up in the air
rather than parallel to the surface on which they are resting. The degree to
which an Anopheles species prefers to feed on humans (anthropophily)
or animals such as cattle (zoophily) decides its efficiency as a disease vector;
anthropophilic Anopheles are more likely to transmit the malaria parasites and the primary
malaria vectors in
Africa, A. gambiae and A. funestus, are strongly
anthropophilic and, consequently, are two of the most efficient malaria vectors
in the world. Most Anopheles
mosquitoes
are
active at dusk or dawn or
at night. Some Anopheles mosquitoes feed indoors while others feed outdoors.
After obtaining a full blood meal, the female rests for 2-3 days while the blood
is digested and eggs are developed. The adult females can live up to a month but most
probably do not live more than 1-2 weeks in nature.
Breeding
Adult females lay 50-200 eggs per
oviposition. Eggs are laid singly, directly on water and are unique in having
floats on either side. Eggs are not resistant to drying and hatch within 2-3
days, although hatching may take up to 2-3 weeks in colder climates. The larvae occur in a wide range of habitats but most species prefer clean,
unpolluted water - fresh or
salt water marshes, mangrove swamps, rice fields, grassy ditches, the edges of
streams and rivers, and small, temporary rain pools. Mosquitoes can develop from
egg to adult in as little as 5 days but usually take 10-14 days in tropical
conditions.
Sources
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