Mosquito! Our Greatest Foe
Mosquito! Our Greatest Foe
Few animals on Earth evoke the hostility that mosquitoes do. Their irritating bites, itchy, and nearly ubiquitous presence can ruin a garden barbecue or a hike in the woods. They have an incredible ability to sense our cruel intentions, taking flight and disappearing milliseconds before a fatal swat. And in our rooms, the persistent, whiny hum of their buzzing wings can wake the soundest of sleepers.
When most people think of mosquitoes, they imagine their annoying sound and their bite. Believe it or not, there is much more to know about mosquitoes than you think and you’re about to learn all those mosquito facts! Some of them are:
- Mosquitoes were almost there in the Jurassic era
- Scientists accept that mosquitoes originated in South Africa and finally spread to the rest of the world
- Mosquitoes have emerged to the point where there are nearly 2,700 different species of mosquitoes
- Old mosquitoes were up to three times bigger than today’s mosquitoes
- Some cultures connect mosquitoes with rebirths of dead people
- Mosquitoes are nearly 16 millimetres long
- The normal weight of a mosquito is about 2.5 milligrams
Why do we celebrate World Mosquito Day?
World Mosquito Day was first organized in 1897 when the link between mosquitoes and malaria transmission was discovered by Sir Ronald Ross. Ross is responsible for the annual observance, having declared soon after his discovery that the day should be known as World Mosquito Day in the future and celebrated annually on August 20.
It endeavours to raise awareness about the causes of malaria and how it can be prevented, as well as fundraising for research into the cure of malaria. It is also a tribute to the groundbreaking work of Sir Ross and scientists who have supported him.
What is the history and evolution of Mosquito?
Even though your first sense when you see a mosquito is to kill it and make it history, you may be astonished to learn a bit about the real history of mosquitoes.
Mosquitoes are one of the deadliest species in the world. Their capacity to carry and spread infections to humans causes millions of deaths every year. Several distinctive mosquitoes can transmit many different diseases.
The oldest known mosquito with anatomy related to modern species was discovered in 79-million-year-old Canadian amber from the Cretaceous. An older sibling species with more primitive traits was found in amber that is 90 to 100 million years old.
Genetic studies indicate that the Culicidae and Anopheline clades may have separated about 150 million years ago. The Old and New World Anopheles species are thought to have subsequently diverged about 95 million years ago.
How long do Mosquitoes live?
The length of the mosquito life cycle and lifespan alters between species and is reliant upon environmental conditions such as temperature and moisture. The first three steps are aquatic and last 5–14 days, depending on the varieties and the ambient temperature, eggs hatch to grow larvae and pupae. The adult mosquito develops from the pupa as it floats at the water cover. Adults live for 4–8 weeks.
Mosquitoes have mouthparts that are adjusted for piercing the skin of plants and animals. While males typically feed on nectar and plant juices, the female wants to obtain nutrients from a “blood meal” before she can lay eggs.
What are the diseases transmitted by Mosquito?
Beyond the nuisance factor, mosquitoes are vectors, or carriers, for some of humanity’s most deadly diseases, and they are public enemy number one in the battle against global infectious disease. Mosquito-borne diseases create millions of deaths worldwide every year with an unbalanced effect on children and the aged in developing countries.
There are more than 3,500 species of mosquitoes, but the members of three bears are the main charge for the spread of human diseases.
Aedes (of which the voracious Asian tiger is a member), Anopheles (the only species known to transmit malaria), Culex mosquitoes serve as vectors (living organisms that can carry infectious diseases between humans or from animals to humans) for the following diseases:
Dengue fever, Chikungunya, Lymphatic filariasis, Yellow fever, Rift Valley fever, Zika, Malaria, Lymphatic filariasis (also called elephantiasis) and encephalitis in Africa, Japanese encephalitis, West Nile fever, Lymphatic filariasis.
Mosquitoes spread disease in a variety of ways. In the event of malaria, parasites attach themselves to the abdomen of a female mosquito and enter a crowd as she feeds. In other cases, such as yellow fever and dengue, a virus invades the mosquito as it feeds on an infected human and is transmitted through the mosquito’s saliva to the following victim.
Do you know, how does the Mosquito sucks the blood?
Mosquitoes utilize exhaled carbon dioxide, body odours and warmth, and movement to a house in on their victims. When biting with their proboscis, they hit two tubes into the skin: one to inject an enzyme that inhibits blood clotting, the other to suck blood into their bodies.
Do Mosquitoes have immune systems?
Mosquitoes have immune systems that combat virus infections. If the virus endures the initial defences in the mosquito gut, the virus must surpass several further barriers to infection before transmission via saliva can occur. The virus must infect and leave the mosquito’s gut cells to replicate in the mosquito’s body (called the hemocoel). Virus particles must also affect and escape salivary gland cells to be carried to another host during the next blood feeding.
Do Mosquitoes have viral infections?
You’ve probably seen a mosquito bite before. So you know that mosquito bites can cause red, itchy bumps. But is that all the mosquito bites can do?
Disease vectors:
Mosquitoes are known as disease vectors because they can transmit diseases from one animal to another. When a mosquito bites a person who has an infection, the mosquito gets the disease as well. The mosquito can then spread this virus to other people it bites. However, mosquitoes don’t encounter any symptoms from the diseases they carry.
In some cases, a mosquito that is affected by a virus experiences lower fitness (e.g., limited egg-laying, decreased survival). When the number of virus bits in a mosquito is powerful, the virus particles can also start damaging cells in the salivary glands, sometimes obstructing transmission. The degree of fitness charges varies between mosquito-virus systems.
Other factors affecting virus transmission are environmental conditions, such as temperature, may influence vector competence (the mosquito’s strength to become infected with and carry a pathogen).
In general, warmer temperatures improve the rate of virus replication, hence improving the chances that a skilled vector could transmit the virus to another host. However, warmer temperatures may also reduce mosquito survival rates.
The virus dose ingested by a mosquito during blood feeding can also affect the female vector ability. If a mosquito ingests a low virus dose during blood feeding, it takes a greater time for the virus to replicate to the level required for transmission in saliva. Conversely, if a more powerful virus dose is ingested, virus replication promotes the virus transmission rate.
Since there is variability in mosquitoes abilities to carry pathogens, it is essential to have surveillance-based mosquito control programs that automatically evaluate the excess of mosquito species of public health concern in their areas.
Targeted mosquito control utilizing a variety of procedures is necessary to eliminate the most vulnerable mosquitoes, and not all mosquitoes are a public health risk.
What are the impacts on the ecosystem?
The only silver lining to that cloud of mosquitoes in your garden is that they are a good source of food for thousands of animals, including bats, birds, dragonflies, and frogs. Besides, humans are not the primary choice for most mosquitoes looking for a feed. They normally prefer horses, cattle, and birds.
National Vector Borne Diseases Control Programme (NVBDCP):
The National Vector Borne Disease Control Programme (NVBDCP) is an umbrella programme for control and prevention of vector-borne diseases viz. Malaria, Dengue, Japanese Encephalitis (JE), Chikungunya, Lymphatic Filariasis and Kala-azar.
Out of these six disorders, two diseases specifically Kala-azar and Lymphatic Filariasis have been targeted for elimination by 2015. The States are liable for the implementation of the programme, whereas the Directorate of NVBDCP, Delhi presents technical support, policies and aid to the States in the form of cash & commodity, as per approved pattern.
Malaria, Japanese Encephalitis, Filaria, Dengue and Chikungunya are spread by mosquitoes whereas Kala-azar is carried by sand-flies. The communication of vector-borne diseases depends on the prevalence of infective vectors and human-vector connection, which is moreover influenced by several factors such as sleeping habits of human, climate, density and biting of vectors etc.
It is one of the technical departments of the Directorate General of Health Services under the Ministry of Health and Family Welfare, Government of India and is the nodal agency accountable for the prevention and control of all vector-borne diseases in India.
