Monday, November 7, 2011

Anopheles vector graphic

A small contribution to the public health community from InHouse Design Studio:  new vector graphics for the female Anopheles mosquito, a.k.a the malaria mosquito.  This image has been vetted by entomologists and given their (conditional) stamp of approval - it is a drawing, after all.

Anopheles spp.  Please click on the appropriate link below for the vector graphics version
The most notable characteristic of the Anopheles mosquito is the way it holds its body at an extreme angle and how it holds its back two legs up in the air.  Other distinctive characteristics are the light stripes or bands on its legs and it’s spotted wings (not seen in this image, which does not show wing detail).  With a really close look you’d also see that the female has slightly ‘feathered’ antennae and that the palps on either side if the probiscus (what it sticks in you to ‘bite’ you) are almost the same length as the probiscus. (the male has ridiculous looking antennae-the mosquito equivalent of huge feathery moustaches!)

Anophelines are brown (dark or light brown, depending on the species and the individual) with light markings (legs and wings).  I’m including several versions here so that you can ‘grab’ the one that suits your printing/design needs:

all images subject to copyright Anne Jennings 2011

In addition to these distinctive markings, Anopheles mosquitoes are identifiable by their habits/behavior, i.e. the tendancy to rest on an indoor wall after feeding (which makes indoor residual spraying, IRS, a reasonable intervention) and their habit of feeding in the late evening hours and early morning (a good argument for sleeping under a mosquito net and screening-in sleeping areas).  When we are in the US we are always surprised at the mosquito activity during the day - unthinkable in Zambia.  There are plenty of strange bugs here in the daytime but hardly ever biting mosquitoes.



Here is some background on malaria and the Anopheles from the World Health Organisation:
"Malaria Entomology and Vector Control" (WHO/CDS/CPE/SMT/2002.18REV.1)


Malaria is caused by the Plasmodium parasite which spends its life in both humans and certain species of mosquitoes.  Four species of Plasmodium cause malaria in humans:  Plasmodium falciparum, P. vivax, P. Malariae and P. ovale.  Of these, Plasmodium falciparum is the most important in parts of the tropics and is responsible for the most severe illnesses and deaths.

Malaria parasites are transmitted by female mosquitoes belonging to the genus Anopheles.  Male Anopheles mosquitoes only feed on plant juices and nectar and cannot transmit malaria.

There are 400 species of Anopheles mosquitoes.  Approximately forty species worldwide can transmit malaria and of these only 15 are vectors of major importance.  Some anophelines prefer to bite animals and transmit malaria parasites to humans rarely.  Other do not live long enough for the parasite to develop in the mosquito or the parasite does not seem to be able to develop.

Malaria control involves the diagnosis and treatment of malaria cases, preventing mosquito bites, eliminating breeding sites, and killing mosquitoes.


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