The Mosquito –My 'Femme Fatale'

Mosquitoes do have a beautiful side too. You just need to look closer at themOn World Mosquito Day (August 20), we can all read how deadly mosquitoes are. And yes, they are –by far– the number one killer, so I guess that is why they deserve their own special day. But today I would also like to give them some credit. I have been working with them for the past 15 years or so (although "working with" is not really the right wording, as they are rarely cooperative). Mosquitoes do have a beautiful side too. You just need to look closer at them.

The obvious beauty is on the outside. Looking closer at e.g. the tiger mosquito that we have in our own backyards in Barcelona, you can easily spot their beautiful black and white stripes and dots (see the figure below). You have to agree with me that she is not a dull mosquito. But there are –as always– exceptions; I personally find the Culex mosquito a highly unattractive and boring mosquito to look at.

A hungry tiger mosquito. Image: Centers for Disease Control and Prevention's Public Health Image Library (Wikipedia).

And just watch her movements as she tries to get to you (or maybe better: when she is going after one of your friends or colleagues). They sense you from afar, zoom in on you, and try to get closer and closer to you in a sort of zig-zag movement, keeping inside that attractive odor plume you release. And while you watch your legs to kill her once she comes back, she already approached you in stealth-mode and bit you in the finger! Ha!

They rapidly become resistant to our insecticides, making vector control very difficultAlso the process of blood-feeding is mesmerizing. How they get to your blood with their set of highly specialized tools. It’s not just a single needle! Just have a look at this video! After that she will slowly fill up with your bright red blood, squeezing out a tiny drop containing the stuff she doesn’t need from you. After that she flies off, in an uncoordinated fashion, like an airplane that is heavily loaded with a pilot that had a few drinks too many...

Observing a malaria mosquito feeding on my hand in southern Guyana. Image: Silvie Huijben

It is the pathogen (malaria, filarial, dengue, zika) that makes you sick, not the mosquito itself!And she is clever by adapting very quickly to us. Just have a look at the tools we use to target them… They rapidly become resistant to our insecticides, making vector control very difficult. And Aedes mosquitoes (the ladies responsible for the transmission of Zika, dengue, Chikungunya and yellow fever) have completely adapted to our lifestyle: they live very close to us in our homes, and breed in the little bits of water that we –often unintentionally– leave lying around outside. All very clever ways to survive.

Aedes aegypti breeding in beer bottles with a bit of rainwater, discovered by a mosquito surveillance team of the Vector Control Service in Guyana.

There are –of course– many other reasons why I am fascinated by these creatures, but I will save those for another time. But remember, it is the pathogen (malaria, filarial, dengue, zika) that makes you sick, not the mosquito itself! She is simply the messenger. But one that annoyingly follows you around, bites you and leaves you behind with an itch…