Category Zology

How can we prevent mosquito bites?

Why mosquitoes bite and what to do:

  • According to studies, mosquitoes prefer blood type O over A, B or a mix of any of them. So if your blood type is O, you find more of the insects buzzing around you.
  • Mosquitoes are attracted to bright colours.
  • Mosquitoes like the smell of beer in beer drinkers.
  • When you exercise, you let out a lot of carbon dioxide. Mosquitoes thrive on CO2.
  • Our skin usually keeps us safe from mosquitoes, but you know they attack your legs. That is because of the bacteria on your feet.
  • All this information about what is good for them is genetically coded into the mosquito brain. So the insect knows where to find food.

What you can do:

  • Sleep under a net if your area is mosquito-prone.
  • Keep surroundings clean to prevent them from breeding.
  • Keep your feet covered in places like the park, bus stands, railway stations, movie halls.
  • Wash your feet well when you reach home after school, before sitting down at the table to study.

 

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How to determine if mosquitoes are ready to feed?

Mosquitoes buzzed around even when dinosaurs roamed the earth. By sucking blood and carrying parasites of crippling diseases, these creatures have ravaged human populations, especially in Africa. Mosquito bites have caused the death and disability of millions of people, ruining the economy of some countries:

Weaponized

Mosquitoes have been used as a biological weapon during wars. According to Winegard, the Nazis purposely re-flooded the Pontine Marshes around Rome and Naples in Italy to reintroduce mosquitoes, and they spread malaria in that part of Italy during World War II. The soldiers fighting the Nazis got malaria and had to be sent back.

With all the science and technology we have now, why are we not eradicating mosquitoes?

Here is why:

They’re everywhere

Mosquitoes are everywhere – in swamps, forests, fields and homes – 110 trillion of them. They are global, and have been around for 100 million years. They are great survivors, “masters of evolutionary adaptation.” They are resilient, which means they can adapt to different weather conditions and terrains. They withstood “global showers” of DDT spray, and five types of mosquitoes are now immune to this pesticide. We all have defences in our body against disease. In the same way, mosquitoes have developed immunity to survive our attempts to kill them off.

Untiring work

Still, a lot of work has been done to tackle this relentless insect. Funding is available for research on mosquito-borne disease. Mosquito nets are given out in large numbers to people. Insecticides and malaria drugs are distributed in counties that cannot afford them. Doctors say death from malaria, the major disease caused by mosquitoes, has decreased across the world. However, there is an increase in the incidence of Zika, West Nile, and dengue.

Governments are low trying biological control of mosquitoes. This is to avoid use of pesticides. In this method, fish are bred in ponds where mosquitoes lay eggs. The fish eat the larvae. There are also plants that kill mosquito larvae. But these have had only limited success in keeping down mosquito numbers.

Climate crisis

Mosquitoes thrive when we create the right environment for them – by rearing animals and plants close to our homes, cutting down trees, letting water stagnate and keeping sewage channels open. Climate change, which is now a serious crisis, also helps breed mosquitoes. “Increased temperatures mean a longer breeding season for mosquitoes,” said Winegard in an interview.

“Canada has seen a 10% increase in mosquito-borne disease in the last 20 years. In the southern US, we’ve seen domestic cases of Zika, chikungunya, and even dengue in the last 10 years. So if temperatures rise around the planet, which increases the risk of spreading disease.”

 

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Why is the mosquito deadly?

The mosquito transmits or carries more diseases than any other insect. The six major ones spread by it are: malaria, dengue fever, chikungunya, zika fever, lymphatic filariasis and Japanese encephalitis.

Different species of the mosquito cause different illnesses. Research into human civilisation shows that mosquito-borne diseases throughout history have killed more people than man-made weapons.

In the book: The Mosquito: A Human History of Our Deadliest Predator, historian Timothy Winegard gives us this startling fact: over the course of 200,000 years, 108 billion people have lived on Earth. Of these, 52 billion have been killed by mosquitoes. Since 2000, an average of 2 million people have died due to diseases caused by mosquitoes. And so, it is safe to sat, the insect has had a disastrous effect on our civilisation.

 

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What makes the snow leopard an endangered animal?

               A snow leopard is a large cat that is native to the mountain areas of Central and South Asia. These wild cats can be spotted sporadically in the alpine and subalpine zones of China, Bhutan, Nepal, India, Pakistan, Afghanistan, Russia, and Mongolia, at heights between 3000 to 4500m.

               In size, snow leopards are slightly smaller than others of its family. They have stocky bodies with thick fur and small, rounded ears, all of which together, help the animal to minimize heat loss.

               Although the animals are agile and powerfully built, their population is in great danger. The main reasons for such falling numbers are hunting, habitat loss, and retaliatory killings. With the reduction in the number of its prey like the Argali sheep, ibex, and hares, these leopards are forced to hunt domestic animals in its nearby areas.

               As a result, locals kill them in retaliation. The leopards are also poached for their skin for making fur coats.

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Why is the sei whale an endangered animal?

            The sei whale is one of the fastest whales in the world that inhabits all oceans and adjoining areas, except those in polar and tropical regions. They are the third largest rorquals, followed by blue whales and fin whales.

            Sei whales are sometimes seen travelling alone, or in pods of up to six individuals. A normal individual is about 14 to 20 metres long, with a weight up to 26 tonnes. Females are a little longer than males. If unharmed, these animals can live till the age of 65.

            As they are at the top of the food chain, whales have an important role in the overall health of a marine ecosystem. But today, they have a very insecure existence due to human activities.

            The biggest threat faced by the sei whale population is commercial whaling. Besides, there is something called scientific whaling, carried out by countries like Iceland and Japan. It means killing whales for scientific research.

            There have also been events of mass deaths of sei whales in the past due to pollution, and the presence of toxic substances in water.

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Why the Grevy’s zebra is considered an endangered animal?

            The Grevy’s zebra is an important member of the horse family. Also known as the imperial zebra, they are the most endangered of the zebra species. Historically, they were seen in the semi-arid scrublands and plains of Somalia, Ethiopia, Eritrea, Djibouti, and Kenya in East Africa. But now, their range is confined to a few parts of Southern Ethiopia, and Northern Kenya.

            Compared to its relatives, Grevy’s zebras have larger ears and narrower stripes. They feed mostly on grass, roots, and tree bark, and also on hard seeds. It is believed that these zebras can live without water for about three days.

            During the 1970s, the population of Grevy’s zebras was thought to be 15,000. But at the start of the 21st century, this number came down to 3500.

            Today, there are estimated to be around 2500 in the wild. In captivity, there are around 600 individuals surviving. The main reason for the fall in population is poaching. The skin of these zebras is of great value in the global market.

Picture credit: google