Opinion Sur Joven

Sunday, March 11 Buenos Aires is besieged. Though not by armed forces or tanks. The enemy is less visible but much greater in number: an immense wave of mosquitoes (belonging to the ochlerotatus albifasciatus species, more exactly) desperately aims at sucking the sweet blood of our bodies and reproducing as fast as they can. We may think they’re invading us from some far Northern rainforest and that the best thing is to fumigate them or kill them one by one with a shoe. However, the movement of the mosquito troops had started ten days before...

Mosquitoes are insects whose development depends on environmental temperature. Unlike humans and the rest of the mammals, they’re not cold blooded, but their body temperature is the same as the environment’s. Besides, their life cycle is different. Their shape is not always the same, but they undergo metamorphosis: from egg they turn into larva, pupa and adults.

Nicolás Schweigmann is the director of the Study Group of Mosquitoes in the Exact and Natural Sciences School at the Buenos Aires University. Concerned about this mosquito invasion, Opinión Sur Joven interviewed him.

-Why have we suddenly been invaded by mosquitoes?
-It’s not a sudden event. Mosquitoes are always there. They’re present in winter, but in form of eggs. The mosquito is not only the insect that flies and bites you, but it’s also the larva –which is in the water- and the egg. When the spring comes, the eggs get wet after some rain and the temperature is higher, so they turn into adults.

Be fruitful and increase in number

Mosquitoes are very respectful, and that’s why they follow the biblical command. Once they become adults, each female lays 50 eggs, out of which only 15 remain alive. Therefore, in three weeks, for example, their population may be quintupled. This process is remarkably accelerated when the temperature rises.

-So mosquitoes don’t invade us, but they’re always there and, if anything, their population grows in some circumstances…
-The word “invasion” makes it look like they’ve come from another planet. That’s not right. The mosquito population is in its own place; the egg bank is distributed all over the containers in Buenos Aires homes… It’s a population explosion, but we can’t call it “invasion”.

The word “containers” is referred to baskets, tanks, bottles, tires, gutters and whatever holds water. These water-filled containers turn into mosquito-breeding places which, at the right time because of humidity and temperature, eclose and start bothering us.

To your health!

Although nobody likes being harassed by insects, this issue is more complicated than we may think: apart from biting, they are a problem for public health because they transmit several diseases. That is why scientists and governments are devoted to eradicate them.

In the case of Buenos Aires and its surroundings, the most abundant species are Aedes aegypti (notoriously famous for being the vector of the dengue virus, which still hasn’t emerged within this region), Ochlerotatus albifasciatus and several belonging to the Culex type.

Although everyone agrees on eradicating them, there is no agreement in the media. Governments usually make unclear and poorly explanatory campaigns, and they use mass fumigation as a solution.

Schweigmann disagrees and emphasizes the importance of prevention. “Finding a solution for mosquitoes is much harder than finding one for AIDS”, he asserts without fearing exaggeration. “With AIDS, the message is that you must take car of yourself, and if you do, you’re taking care of the rest of the people. In the case of the mosquitoes that grow at home, if you don’t take care of yourself, mosquitoes also bite your neighbor. The key is to find out how we can make all people living in the same block take care of themselves. Because if one doesn’t, it all fails. It’s very complex because it implies unity”, he says.

Phone... home...

Now let’s go back to that bloody Sunday, March 11. The header in La Nación newspaper read: “Heat and humidity bring mosquito cloud to Buenos Aires” And the article described how medical consultation had increased in hospitals due to the bites and the people’s fear of a dengue epidemic (which didn’t happen) regarding the worrisome news arriving from Paraguay and the north region of Argentina.

“What happened on March 11 was due to very strong rains on March 1. On March 11, there was an eclosion of the silvestre ochlerotatus albifasciatus mosquito, typical of the humid pampas, which lays its eggs on puddle edges. When the puddle floods those eggs get wet, and that’s what they need to eclose. If it hadn’t rained much before, they accumulate because the puddles gather little water and don’t get to wet them. But if it rains heavily afterwards, causing floods, then said egg bank around the puddle ecloses and turns into a great amount of mosquitoes”, the mosquitologist explains.

“Thus, there is a simultaneous generation reaching adulthood at the same time, because the environmental temperature is the same. People have the feeling that there weren’t that many mosquitoes yesterday. Nevertheless, they’re unnoticed beings that are actually around us”, he adds.

You can be one of them

Mosquitoes, then, are not invaders but arch-enemies all around us: increase of temperature and humidity favors the exponential growth of their population. Now, are we supposed to get used to their harassment? Maybe.

It is caused by the same reason as many other problems: Climate change, the mother of all battles in 21st century. “The subtropics are becoming tropical, so all “bugs” will start to multiply faster. Heavy rains and humidity in Buenos Aires enable mosquitoes to live longer, so it could result in an epidemic”, Schweigmann points out. As we may see, global warming has a stronger influence in our day-to-day lives than we think. In fact, a World Health Organization report forecasts an increase of deaths all over the world as a consequence of the diseases derived from this scourge. (See More Info)

The climate change process is structural and many times its consequences seem to be unmanageable. However, we can always make an individual contribution with results in society. The mosquitoes issue is an example of the necessity to start prevention at home, from an early age and along with education.

“It’s an educational problem; we have to work really hard, along with teachers and schools, and making the students be interested in projects involving their families”, Schweigmann concludes.