KNOW MOSQUITO : YOUR NEIGHBOUR

KNOW MOSQUITO 

Since birth, we the Indians are familiar with mosquito. They are our neighbour, always surrounds us - in drains, in garden, corner  of balcony, kitchen, bedroom even inside mosquito net. We can`t prevent them from our contact. We try to avoid in many ways like mosquito coils, oils, cards and variety of spray. We want to avoid but they always follow us, because some of them live with our blood or need our blood like vampire.

Mosquito are most important insect from the standpoint of human health. They are found worldwide. Let`s know them in details in their life style and what disease they can cause directly or indirectly. They feed on our blood, spread disease and cause death.

Mosquito are of many variety. Like human some belongs to Aryan, some Mongoloid, some Negro in origin, mosquito may be of different species. Though there are thousands of species of mosquito all over worlds, few are related to our health hazards. They are

• Anopheles
• Cules
• Aedes
• Mansonia
• Coquillettidia
•  Culiseta
•  Psorophora
• Uranotaenia
•  Wyeomyia
• Toxorhynchites

Among them 4 species are important in relation to human disease in Indian subcontinent.

LIFE CYCLE

Human born with human figure, then then they grow, passes different phases of life and die but their looks and figure remains like human. In case of mosquito, they passes several stages of life and looks of each stage are different. Different type of mosquito have different characteristics in relation to stages of life cycle. but over all, all have 4 stages in life.  These are-

• 1.   Egg:
• 2.   Larva
• 3.   Pupa
• 4.   Adult

We are concerned and acquainted with adult form. So now let`s have a discuss on adult form of mosquito.

General description

The body of mosquito consists of 3 parts.

HEAD

semi global outline- having a pair of large compound eys, long needle like structure called “proboscis” by which they suck blood, a pair of palpi- on either side of proboscis, a pair of “Antena” – which differ in male and women.

THORAX

 large and rounded. Contain a pair of wings and 3 pairs of leg.

ABDOMEN

consists of 10 segments, last two are modified to genetalia.

Character of different adult type of mosquito:

Anopheles

Also known as Marsh mosquites, this genus has about 460 different species. 100 can transmit human Malaria, only 30–40 commonly transmit parasites of the genus Plasmodium which cause malaria in humans. Anopheles gambiae is important because it’s relation with most dreaded form of malaria- The Falciparum Malaria. 45 species of anopheles are found in India. They are vector for Malaria and Filaria (not in India). Malaria occurs in > 200 million people annually. Many of them die.

Aedes

This genus of mosquito were originally found in tropical areas, but literally found everywhere except Antarctica. These mosquito can easily be recognised because of it`s striped and banded character on their legs, so named “tiger mosquito.” Aedes albopictus is called the Asian tiger mosquito and Aedes aegypti is called the “yellow fever mosquito”

Important member of this group are Aedes aegypti, Aedes albopictus, Aedes vittatus. It is the first proved vector of a virus disease- Yellow fever.

They live in a corners of houseand female are feerless biter, as they need blood for the development of their egg.  The do not fly long distance, usually remains within 100 meters around house.

It lays egg in artificial accumulation of water in and around the dwelling-such as water accumulated in Brocken bottle, discarded tins, flower pots, coconut shells etc.

Culex

Also known as the House mosquito or the “nuisance mosquito” which are terrible pests of man. They are most active at dusk, but are known to be active daytime biters.

Culex fatigans are strong winged mosquito, can travel up to 11 km. it enter the house at dusk and reaches maximum density by midnight which is their peak biting time. Leg below the knee are their preferred site of biting. During day they rest indoor- in dark corners, under furniture.

They are found everywhere globally except the extreme North.

Mansonia

This genus is very aggressive and feeds primarily on larger mammals. It is most active at sunset. They fly great distances in search of blood meals.  These are big and black or brown mosquito with speckling on their wings and legs.

They breed in ponds and lake containing certain acquatic plants,. The eggs are laid as star shaped clusters on the under surface of leaves. The larva and pupa are attached to the rootlets of these plants by their siphon. Later, when about to become adult, the pupa come to the surface water and adult emerge and escape. The control of this mosquito is easy by removing these plant.

Culiseta

This species does not feed on humans; therefore, it cannot transmit the virus to humans. Most Culiseta species are cold-adapted. These species are found throughout the year in Southern California and feed on several vertebrate species encompassing birds, livestock, rodents, reptiles.

The larvae of most species are found in ground waters and rock pools. Little is known about the blood feeding- most species feeds on birds and mammals

Psorophora

This genus females are considered to be extremely aggressive. Most of the species are known to feed on larger mammals, including humans, during the day or night and are known to travel long distances in search of blood meals

Males and females are large and yellow-colored. The proboscis is yellow with black tip. The abdomen is pale with a paler tip. The thorax is dark brown with a thin, bright yellow stripe which goes down the middle with two dark stripes on each side. Like all mosquitoes, the males have bushy antennae and the females do not.

They lay eggs either as single eggs on moist soil Typically, females in the genus are capable of laying their eggs on dry or damp land to hatch months or years later, depending on the species.

Toxorhynchites

Known as “elephant mosquito”. They does not consume blood. Like male, female also feed on plant nectar- so, do not poses any human risk. Interstingly, their larva prey on larva of other mosquito.

Uranotaenia

They feed primarily on reptiles and amphibians, and are not known to bite humans. 

Wyeomyia

Adults are not known to travel far from the bromeliad habitats. They are not a common vector, nor are they an aggressive species Mostly found in Central and South America, this genus aren't known to carry diseases, so don't pose a risk to humans. There are 140 known species, and they generally inhabit flowers, bamboo, tree holes, and containers.

Coquillettidia

This species is extremely aggressive and feeds primarily on large mammals. This species also is suspected of being a bridge vector for Eastern Equine Encephalitis (transmitting the virus from the bird to a human or horse). This species will often fly great distances in search of blood meals.

Disease transmitted by different type of mosquito:

In Indian subcontinent, 4 types of mosquito transmit disease commonly.  They are

Anopheles : Malaria in India, Filaria in some other part of world.
Culex : They cause disease such as West neil fever, Bancroftian filariasis, Japanese encephalitis, Viral arthritis etc.
Aedes : Aedes mosquito is responsible for many dreaded disease in human like, Dengue, Chikungunya, yellow fever, Rift vally fever, and more recently Zika virus disease and nipah virus disease.
Mansonia : These mosquito causes Burgian (Malayan) filariasis and Chikungunya fever.
Culiseta : they cause disease in animals. This genus is the primary vector for Eastern Equine Encephalitis.
Psorophora : They are vector for iiheus virus and causes encephalitis.

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