07.08.2017 change 07.08.2017

Mosquitoes find their victims from the distance of several dozen meters

Mosquitoes - equipped with advanced smell detection system - can find the victim from a distance of several dozen meters. Although those living in Poland are mostly harmless, worldwide mosquitoes contribute to around 750,000 deaths each year. they spread malaria, dengue and yellow fever.

Mosquitoes are very well adapted to the conditions in which they live. They are equipped with antennae with olfactory receptors and the brain specialized in the analysis of the aroma. This allows them to find their victims from a distance of several dozen meters.

Male mosquitoes feed on nectar from flowers and vegetable juices. We get bitten only by females that need the blood of vertebrates to reproduce. "They usually attack from dawn to noon, and then they re-activate just before dusk, and hunt until 21-22. Unless the weather is favourable for them - on cloudy and humid days they are active all day. They do not like the wind, which effectively prevents them from finding the smell of a potential victim" - informs the Warsaw University of Life Sciences in a release.

Female mosquitoes give lay eggs only once in their lifetime. After about six weeks after laying eggs in the water larvae are hatched, and before they become adults, they are in a pupa stage that lasts a few days. Males live only 2-3 months and can not survive the winter.

"Although it may be hard to believe, for us mosquitoes are the most dangerous animals in the world" - write the WULS-SGGW experts. According to WHO data, they contribute more than 750,000 deaths per year. For comparison - according to WULS-SGGW - crocodiles and alligators kill about a thousand people, hippopotamuses - 500, venomous snakes - several dozen thousand.

Of course this statistic does not apply to all places in the world. It is not the tiny insect that really kills, but even smaller bacteria, viruses and protozoa with which the insect infects its victims. In some parts of the world, mosquito-borne diseases are widespread, and in other parts they are practically non-existent. Statistically, the biggest threat to human life is malaria, but dengue fever, yellow fever, meningitis, and recently Zika virus also take its toll.

Fortunately, according to WULS-SGGW, none of the dozens of Polish mosquito species carry diseases that endanger the lives and health of people. The situation is similar in most European countries. This does not mean, however, that we are completely safe.

At least one species of mosquito living in Poland may be a vector of malaria. There have already been cases of this disease, the last ones were recorded in the 1960s. We dealt with malaria by completely destroying the population spreading this terrible disease. But this does not mean that it will never return. Besides, there is a risk that mosquitoes carrying dangerous bacteria, viruses, protozoa and parasites from Asia and Africa will also be appear in our country. In the south of Europe, there have already been cases of insects carrying dengue and West Nile virus" said Prof. Stanisław Ignatowicz from Department of Applied Entomology at SGGW-WULS, quoted in the release.

There are several ways to fight mosquitoes. The most effective method is the mass use of pesticides, but this method is not recommended, as the experts point out. "It is important to remember that pesticides destroy not only mosquitoes and ticks but also beneficial insects. They also kill ladybugs, butterflies, bees and many other species. Such actions are not necessary or advisable, as we have many other methods. First we should think about personal protection measures and ensuring that home gardens are not a hatchery of these annoying insects" emphasised Prof. Ignatowicz.

In his opinion, the most effective means of protecting us from mosquito bites are repellents that contain high concentrations of organic chemical - DEET. They prevent mosquitoes from detecting us. We can also do a lot to get rid of mosquitoes in our neighbourhood - without harming other living organisms.

"It is enough to ensure that there are no sources of standing water in our environment. Abandoned tire, clogged gutter, metal can filled with water - these are perfect places to live for mosquito larvae. This does not mean that we cannot have garden pools or ponds. In this case, it is enough to use a bacterial agent that harms only mosquito larvae" - said Prof. Ignatowicz.

When fighting mosquitoes, it is important to remember that they are an important part of the ecosystem. "If we were to bring them to extinction, which is unlikely, we would deprive many species of animals, especially fish and birds, of food. Total war, mass use of pesticides, is not going to work out for us. Besides, we should not worry too much. Dangerous diseases carried by these insects might not reach us at all. For now, we should remember that mosquitoes are the most dangerous animals in the world especially during foreign travel" - concluded Prof. Ignatowicz.

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