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Now tell me what is it?

A lion? A Tiger? A Cheetah? A snake? A Crocodile? A Shark? A Human being?

No, none of these! Surprised? And you will be more surprised when I say it is extremely small!

Yes, and yes. Most of the people of science think a small insect called mosquito is the most dangerous animal on Earth.

Why? Because they are the primary vectors (an organism, typically a biting insect or tick, that transmits a disease or parasite from one animal or plant to another) for major human diseases such as Yellow fever, Malaria, Dengue fever, Zika, West Nile, and Chikungunya, which together infect hundreds of millions of humans worldwide and kill millions each year. None of the above mentioned animals - not even humans - can match this mosquito-menace! The World Health Organization reports that more than 50 percent of the world’s population is presently at risk from mosquito-borne diseases.

As the mosquitoes fly, they can also spread a disease more quickly than some other illnesses.

What is more disheartening is they are very difficult to fight, i.e., control or eradicate.

Mosquitoes spread disease-causing agents, not the disease.

Mosquitoes go through four stages in their life: egg, lava, pupa and adult (imago). Adult females lay eggs in stagnant water, for example reservoirs or in containers such as plastic buckets or pools.

Male mosquitoes generally feed on nectar and plant juices, whereas the females often feed on blood, including the blood of humans. This is because they need the nutrition from the blood before they can lay eggs. Mosquitoes feed from their mouth-parts which are adapted to pierce the skin and then "suck" the blood. Prior and during blood feeding, the females inject saliva into the bodies of the blood source. This serves as an anticoagulant, meaning that it stops the blood from clotting.

That is the reason why it itches when a mosquito bites. The bumps and itchiness that follow come from an anticoagulant that the mosquito injects to prevent our blood from clotting, which triggers a mild allergic reaction that includes the typical round, red bumps.

When feeding, a mosquito pierces the skin like a needle and injects saliva into a person’s skin. This allows the disease-causing agent into the site.

Mosquitoes get attracted to certain things. If you want to avoid them, you must know what they are....

If you are wearing dark-cloured clothes, it will attract these insects more!

And the more you move, the easier you are to identify as a living, breathing, being full of blood.

Visual clues allow the mosquito to locate you from relatively far away, but as she approaches, it's your body heat that draws her in. This puts pregnant women, who average about 1.26 degrees Fahrenheit warmer than others, at a particular risk — a fact which has been substantiated by a number of studies (1).

Mosquitoes can detect carbon dioxide using a special organ called a maxillary palp from as far as 164 feet away. Since everyone emits CO2 simply by exhaling, it comes down to relative amounts. Unfortunately for mothers-to-be, pregnancy causes women to emit 21 percent more CO2. This is also why kids are often safe from bites, when bigger, more CO2-emitting adults are around.

Recent research has since shown that over distances of many feet, mosquitoes rely on the carbon dioxide we exhale, the odors we give off, and visual cues to find us. But when they get within a few inches, it's our bodies' temperature that plays a major role in guiding them (2).

Alcohol is another thing that magnetizes mosquitoes!. Studies show that drinking even just 12 ounces of beer will significantly increase the attention you receive from these pests.

The composition of your skin and sweat , the make up of your skin bacteria — the kind that naturally and healthily exists there — can serve as a attractors. As can the levels of lactic acid, uric acid, ammonia, and other substances present in your sweat.
Because strenuous exercise increases the buildup of lactic acid and heat in your body, it likely makes you stand out to the insects. Meanwhile, genetic factors influence the amount of uric acid and other substances naturally emitted by each person, making some people more easily found by mosquitoes than others.

Blood type is a factor you just cannot control. And it stands to reason that, if the mosquito is there to suck your blood, she cares what kind she's getting. People with blood type O are more prone to mosquito bites than those with type B, with type A folks are least attractive to these insects.

It is also important to prevent mosquito bites, which can be done by using the following techniques:

Use an insect repellent on your bare skin and clothes. Remember to reapply every couple of hours
Limit your exposure to wide areas of still, open water, particularly at dawn and dusk when mosquitoes are most prevalent
Keep your body covered where possible (e.g. long sleeved tops), and stick to light colours.
Use mosquito netting on beds and make sure you aren't touching any part of the net whilst you sleep
Use unscented hair shampoo and deodorant
Remove all water pooling areas from around the house to remove breeding grounds. If you have water bowls, aquariums etc. either inside or outside your home , replace the water frequently.

The technique of a mosquito bite .... the action that sometimes is just a pricking but sometimes has a deadly consequence ....

References:

1. http://www.sciencedirect.com/science/article/pii/S0140673600023345?...

2. https://phys.org/news/2020-02-mosquitoes-humans.html?utm_source=nwl...

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https://phys.org/news/2020-05-malaria-mosquitoes-lab-all-male-popul...

Malaria mosquitoes eliminated in lab by creating all-male populations

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How this mosquito, one of nature's greatest killers, evolved its taste for human blood

New research suggests some mosquitoes could prove especially difficult to eradicate, and that the diseases they spread could get even worse as more people move from rural environments into cities.

new research suggests some mosquitoes could prove especially difficult to eradicate, and that the diseases they spread could get even worse as more people move from rural environments into cities.

The latest research, released in the journal Molecular Ecology, focused on the Aedes aegypti mosquitoes from around the world, including Madagascar and other islands in the Indian Ocean. They're most easily identified by the white stripes on their legs.

Although most of the roughly 3,500 mosquito species don’t feed on human blood, the Aedes aegypti is one of the worst. Its bite infects millions of people – especially young children – with yellow fever, dengue and Zika, causing tens of thousands of deaths each year.

By comparing their genes, the researchers determined that the Aedes aegypti mosquitoes probably evolved from an ancestral species on islands in the southwest Indian Ocean about 7 million years ago.

And the research indicates the mosquitoes spread from the islands to the African mainland quite recently in evolutionary time, possibly within the last 25,000 to 17,000 years, lead author John Soghigian, an evolutionary biologist at North Carolina State University, said.


the Aedes aegypti was traditionally seen as a forest species that had adapted to human settlements, but the new research suggested it first adapted to survive the varied environmental conditions of the islands.

This is a mosquito that may have already been highly adaptable to diverse habitats when it reached Africa, and so that could explain why [it] became such an important vector and pest to humans,” he said.

The research by Soghigian and his colleagues comes just a few weeks after another study of the Aedes aegypti mosquitoes published in the journal Cell Biology.

Most populations of Aedes aegypti prefer the blood of animals such as rodents and monkeys to human blood. But the researchers found urban mosquitoes in sub-Saharan Africa were more drawn to the smell of a human forearm than to a guinea pig, compared to mosquitoes from rural areas.

The study also found that mosquitoes from the dry Sahel region of Africa – the semi-arid zone between the Sahara desert and wetter regions further south – consistently preferred biting humans.

That suggested they evolved to feed on human blood after they were exposed to drier conditions than they were used to, Carolyn McBride, an evolutionary biologist at Princeton University and the lead author of the study, said.

Those two factors indicated the Aedes aegypti had evolved in densely populated areas in a dry region like the Sahel to bite humans – and so some mosquito-borne diseases could increase if the climate became drier and as more people moved to live in cities, she said.

https://www.nbcnews.com/science/science-news/how-mosquito-one-natur...

https://www.cell.com/current-biology/fulltext/S0960-9822(20)30978-7

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