The nights short, the days long // the morning full of birdsong / the sharp high buzz of a mosquito† Yes, before you know it all summer is long gone, but until then many nights are rudely disturbed by that damn mosquito. At the dawn of the annual mosquito peak: everything we know about the mosquito.
Insight 1: The mosquito is the most dangerous animal on earth
The lion, the venomous snake or the shark are sweet little creatures compared to the mosquito. In any case, the insect makes many more victims than all known feared ‘wild animals’. It can spread parasites and viruses. Malaria, yellow fever, dengue, Zika and chikungunya viruses are transmitted to humans by the mosquito. The result: about two million deaths every year. That is considerably more than man himself has realized: he makes about 475,000 victims worldwide every year.
Of the 108 billion people who ever lived on Earth, 52 billion may have died from mosquito bites, historian Timothy Winegard writes in his book mosquito† The insect has profoundly influenced the course of history. A well-known example is the fall of the Roman Empire. One of the explanations for this is the mosquito: the swamps around the city of Rome were a breeding ground for the malaria mosquito. The advance of Alexander the Great to the Far East would also have failed because of the mosquito. He himself probably died of West Nile fever or malaria.
Due to the climate effect and international traffic (through trade and tourism), there is a chance that mosquito species that are dangerous for humans will also occur more often in the Netherlands.
Insight 2: One mosquito is not the other
About 3,500 species of mosquitoes live worldwide. There are about 35 species in the Netherlands. From (rather large) ringed winter mosquitoes to the (smaller) house mosquitoes. About 2 percent of mosquitoes in the Netherlands are mosquitoes. It has six long thin legs (and not eight, like harvestmen) and a clear, long snout. In contrast to, for example, dance mosquitoes or crane flies, which do not have a snout and do not drink blood. In addition, midges or gnats and tickling mosquitoes fly around, which do drink blood, even if they do not have a long snout.
Mosquitoes literally have a nose for blood and that has evolved evolutionarily. Only the females sting. They need blood (from humans, but also from other vertebrates) for proteins and to lay their eggs. They do this in standing water and that can be anything: bird baths, buckets of water, a puddle in the gutter, the rain barrel. The eggs and larvae grow into adult mosquitoes within a few weeks.
Males have only one goal in life: to fertilize the females. Their sad fate: they die soon after the act.
A mosquito weighs an average of 5 milligrams, is between 3 and 6 millimeters in size, and reaches (very briefly) top speeds of 1 kilometer per hour. The animal needs two to five minutes to suck on (human) blood. A serving of 3 milligrams, or 0.003 milliliters, is sufficient.
Insight 3: Your bumps may be bigger than someone else’s
According to research mosquitoes are attracted to body odor and CO2exhalation emissions. The composition of microbiota (bacteria) on the skin provides more specific information and determines the mosquito’s preference. Food like garlic or other ingredients has no influence on this, despite popular belief. Some people are less bothered by mosquito bites and develop fewer or no mosquito bite(s) after a bite, so they seem to be bitten less.
Insight 4: Scientists can kill mosquitoes with bacteria
Many who, after a sleepless night and three itchy mosquito bites, can drink the blood of those critters, will have wondered, blinded by impotent rage: can’t we just exterminate them all?
That is possible, as everything can break. Chinese researchers published in scientific journal in 2019 Nature a method to combat and even eradicate the tiger mosquito, which transmits dreaded diseases such as dengue fever (dengue) and chikungunya. Eggs from this Asian mosquito are also increasingly common in the Netherlands, arriving here via car tires or via imported bamboo. The researchers developed a method by which about 90 million mosquito males were infected with a bacterium that prevented the females from laying viable eggs. Due to this massive distribution, the tiger mosquito has virtually died out locally.
Insight 5: Eliminating all mosquitoes is a bad idea
As unimaginable as it may be to some, mosquitoes have their own function in the grand scheme of the earth’s ecosystem. If only because they are food for other animals. The swift that brightens up our summer evenings by whizzing through the air in large groups is constantly nipping at insects such as mosquitoes. Other bird species, as well as fish, spiders, frogs, toads and bats, like to feast on the mosquito.
Mosquito larvae grow up in standing water. There they eat bacteria and therefore have a cleaning function. Finally, many people owe their lives to the mosquito, especially when they have been stung. Scientists use the anticoagulant that the mosquitoes inject with their bite in research into medicines against blood clots. This is used, among other things, in the fight against thrombosis, where blood vessels can become blocked by a blood clot, sometimes with serious consequences such as pulmonary embolism, myocardial infarction or cerebral infarction.
Insight 6: There are many weapons against mosquitoes available
Clear up some misunderstandings first. Citronella or ‘mosquito plants’, the variety’s scented geraniums Pelargonium citrosum for sale in garden centers every year, repel very few, if any, mosquitoes, the authors write in the newly published popular science collection The mosquito† The effect of citronella scented candles on mosquitoes is unknown.
Mosquitoes never come from far. It is therefore wise to investigate the immediate vicinity for suitable breeding grounds. So look in your own garden or balcony to see if there are places with standing water where they can lay their eggs. A puddle in the gutter, a birdbath, a bucket, also pay attention to water that remains in the tarpaulin over garden furniture. Change standing water regularly. Put a lid on the rain barrel.
A garden pond? A fountain keeps the water moving; fish eat mosquito larvae. Place a nest box: tits and other familiar gardeners eat insects. When they have young in the spring, they collect many dozens a day.
Install screens in windows and doors. Wear covering or thicker clothing. Sleep under a mosquito net. A fan can cause air currents, mosquitoes don’t like that.
Anti-mosquito creams work especially if they contain the insect repellent deet or icaridin contain.
Spreading lemongrass oil on the skin has been proven to be effective, the scientists write. Practical problem: the skin has to be reapplied every thirty to sixty minutes. Then the night is just as sleepless as with a buzzing mosquito around your head. Another quote from that annoying buzz The mosquito: ‘Furthermore, the burden of the buzzing can be solved by wearing earplugs at night, but of course that does not help against bites.’ So much for science.
Insight 7: Preferably don’t hit a mosquito with a towel
That too has been investigated. Researchers from Wageningen University & Research (Wur) tried with a mechanical fly swatter more than ten thousand (malaria and yellow fever) mosquitoes and recorded the flight behavior on high-speed cameras. Only in 8 percent of the cases did the swatters hit, in all other cases the mosquitoes managed to escape, the researchers described in March in the journal Current Biology† Their aim was to study the escape routes of the mosquitoes, in order to develop better mosquito traps or improve existing traps.
Mosquitoes active during the day use visual cues to recognize attacks, was one of their conclusions. More surprising was another finding: malaria mosquitoes that fly in the dark have an extremely irregular flight pattern. This makes it much more difficult for an attacker such as humans to predict the precise location of the mosquito.
What to do when a mosquito ruins the night’s sleep again? Jeroen Spitzen, one of the researchers, answers. ‘When a mosquito flies in the air, it is best to ‘clap’ it with both hands. If you only use one hand, you are, as it were, waving the mosquito away with the air current that causes it.’ That is why hitting the wall or ceiling with a towel has no chance: the airflow almost automatically pushes the animal away.
According to the researcher, it is better to wait until the mosquito settles on the skin to bite. It takes some self-control, but once in that position the mosquito is less mobile and takes longer to take off.
Spitzen himself achieves the best results with an electric fly swatter of cheap Chinese manufacture, in the form of a tennis racket. ‘They don’t work very well for flies, but they do for mosquitoes. Due to the mesh-like pattern, they hardly move any air, so that the mosquito is not driven away either.’
Insight 8: You can make scientists happy with your dead mosquito
In February last year, scientists from Wageningen University via mosquitoradar.nl an appeal to send dead mosquitoes for research, including into possible infection of the West Nile virus via a mosquito. In a short time, about six thousand came in. The call was repeated in October, but then received less response. According to Arnold van Vliet of Mosquito Radar.nl the research results have not yet crystallized. But if dangerous mosquitoes had been found, alarm bells would undoubtedly have ringed in the lab.
For this article, grateful use has been made of, among other things, the newly published collection The mosquitocompiled by the Biosciences and Society foundation and published by Lias publishers.