Know Mosquitoes better

Hello hivers,
I really hope you enjoyed your day so far as I wish you enjoy the rest of it too.

So today, my class went on a visitation at the National Arbovirus and Vectors Research Centre located here in Enugu, Nigeria and I discovered a whole lot of things about an arthropod virus that we are very familiar with, MOSQUITO.

I will be sharing the knowledge with you all, just stick to the end and you will learn a lot👍.

We arrived at the venue at exactly 9am and were ushered in by a security personnel into the auditorium where we met the research scientists and did some introduction.

They went further to give us a general overview on what they do there before dividing us into four (4) groups to go and visit their various laboratory rooms and have a visual representation of what they already taught us.

I will be talking basically about two of the labs which are;

1. The in​sec​ta​ry
2. The Entomology/ Parasitology lab.

But before then, let's get to refresh ourselves on the basic knowledge about mosquitoes.

Mosquito is a member of the arthropod family. They are vectors that transmits deadly diseases to man and animals.

They are insects that have complete metamorphosis in their lifecycle, by this, I meant to say that they grow from egg to larva to pupa and then to Adult mosquito.

The lifecycle days vary depending on the particular specie In question.

We have over 500 various species of mosquito but the three most important of them includes;

1. Female Anopheles mosquito which transmits a parasite that causes Malaria

2. Culex mosquito which transmits a parasite that causes Elephantiasis.

3. Aedes aegypti mosquito which transmits a parasite that causes Yellow Fever and Dengue fever.

Classes of Mosquitoes:

The Wild Mosquitoes:

These are the mosquitoes surviving on their own. They are the ones that bite us at home and the ones that have freedom of flying all over the world in search of people to bite.

They feed on Plant Nectar during their formative stage.

The Strange Mosquitoes:

These are the mosquitoes that have been separated from the outside world and placed in various insectaries for the purpose of research. They feed on sugar solutions and various feeds such as cornflakes during their formative stage...Rich kids😂

Haven said all these, Let's now get down to business

THE INSECTARY

Basically, insectary is a place for rearing and keeping insects.

For the purpose of this post, this is a place for keeping and rearing mosquitoes
We first went to the Female Anopheles insectary lab.

FEMALE ANOPHELES MOSQUITO:

The bowl contains the egg, the larva and the pupa because all the three stages are in water

The eggs of this specie cannot survive dessication, hence, they are transported into a water containing container within 24hours else they will all die off.

The Larva of the female Anopheles Mosquito lies completely horizontal in the water, this is because it has its spiracles along the sides so that it can respire effectively but once it grows into an adult, it lies vertically.

The Adult Female Anopheles has a nocturnal lifestyle which means that they only bite at night.

Since these are the strange Mosquitoes and feed on cornflakes and other feeds, the feeds sometimes leads to fungal growth and harms the Mosquitoes, hence ,the water in which they are breed is changed every two days.

THE AEDES AEGYPTI MOSQUITOES:

The black dots you see are the eggs of the Aedes aegypti Mosquito

Unlike the Female Anopheles Mosquito, the eggs of the Aedes aegypti Mosquito can survive dessication. Their eggs are black in colour and are laid singly.

The Larva of the Aedes aegypti lies vertical on water because of its siphon which it breathes with unlike the Anopheles that has spiracles but the adult lies horizontally.

The Adult Aedes aegypti Mosquito are diurnal in nature which means that they bite all round the clock unlike the Female Anopheles Mosquito.

They appear black with spotted white when viewed through a microscope.

The Aedes aegypti is also called Tyre breeders or container breeders as they are the easiest place to get their eggs. They love anything coloured black.

The Aedes aegypti Mosquito has its greatest infectivity stage at F0 (future generation zero).
When sampled out and soaked multiple times, the infectivity stage reduces.

THE CULEX MOSQUITO:

This specie of Mosquito has a very close relation with the female anopheles Mosquito.

Their eggs also can survive dessication.

Their larva lies horizontal but slightly inclined at an angle of 45⁰ because of their siphon to be able to breathe properly while their adult still lies vertically but slightly inclined at an angle of 45⁰ also.

Just as the female anopheles Mosquito, the culex Mosquito is also nocturnal which means they bite only at night.

THE ENTOMOLOGY/ PARASITOLOGY LAB

This sector of the lab specializes in outbreaks (epidemics) of diseases caused by arthropod borne viruses.

The one we were taken to was exclusively for Aedes aegypti Mosquito, maybe, it was because of the not too long outbreak of yellow fever in Nigeria.

The lecturer made us understand that once there is an outbreak of such disease in a particular state, they are sent to those states to investigate the state by Sampling method.

Sampling method is the random collection of specimens which in this case, the Aedes aegypti Mosquito from various points of the state in question.

Sampling collection is representative in nature in the sense that you cannot take the whole aedes aegypti Mosquito in the state as it is not even possible but the goal is that you will get a sample that will represent the whole state and hence will be able to get a result that can be generalized.

The one he is holding is the dipper while the one on the table is the laddle

He went further to show us the laddle and the longer laddle-like structure called the dipper.

They are used for scooping Aedes larvae from rivers when you don't want to enter inside the rivers.

He also showed us the Prokopack aspirator for scooping adult aedes Mosquito too.

He also showed us the Ovitrap (that is the black cup you see on the table above in the picture) used for laying traps for Aedes aegypti mosquitoes to come and lay their eggs inside.

Because of their love for black colours, the Ovitrap is always black colored with cotton cloth inside it where the eggs are collected.

Then we were given the opportunity to view the Mosquitoes through the microscope, I was able to get some of the pictures... I hope you appreciate them.

The microscope containing the Aedes aegypti Mosquito we viewed

MORTALITY CALCULATION

When a new insecticide is discovered and it's mortality rate wants to be checked, they do it using the following processes;

The Adult Aedes aegypti Mosquitoes in the area are collected using the Prokopack aspirator and inserted inside the WHO tube bioassay which provides a result within 24hours.

Picture of the WHO bioassay tubes

The WHO tube bioassay is divided into two;

• The insecticide embedded tube
• The Holding tube

A total of 25 Mosquitoes are inserted into each of the Holding WHO bioassay tubes and monitored for an hour.

After one hour, some of the Mosquitoes will die and you will remove them and replace them with other ones.

The ones that died must have died because they were unhealthy or because of other cofactors that you may not know about but the aim of observing them and removing them once they die before you introduce the insecticide is so that you will be working with Mosquitoes that are fully healthy.

Once you check after an hour later and all 25 Mosquitoes you introduced inside the Holding WHO bioassay tubes are alive, you transfer them inside the Insecticide embedded WHO bioassay tube and leave them for the next hour.

When the hour elapses, most of the mosquitoes depending on how effective the insecticide is will die but trust nature that some will still be alive.

You transfer all of the Mosquitoes in the insecticide embedded WHO bioassay tubes out into the holding WHO bioassay tubes and provide them with feed to avoid them from dying of hunger and you will be thinking they died from the Insecticide, hence, removing hunger/malnutrition as another cofactor for death.

Then, the mortality rate is calculated by dividing the number of dead Mosquitoes over the total number of Mosquitoes you used for the experiment and multiply by 100.

1. If the value you got was from 98% to 100%, then the new insecticide is very effective.

2. If the value you got was from 91% to 97%, then the new insecticide is effective with a view of resistance in sight.

3. If the value you got is below 90%, then, you need to find a better insecticide as they are resistant to what you just produced.

FUN FACTS

1. You can remember the nocturnal nature of the female anopheles Mosquito and Culex Mosquito and also their lying position by linking them to vampires.
   Vampires bites at night and also make a weird vertical position as if they are trying to make themselves taller before they attack.... I hope it helps.

2. A lecturer told us that the reason why Mosquitoes bite us is because we expire Carbon dioxide(CO2) and they are attracted to it.
   So I am now giving you a hint to avoid Mosquito bites....stop breathing 😂😂.

How To Minimise Mosquito Bites And Hence The Diseases They Cause

• Do not leave waters open for long as they see them as suitable habitats to lay eggs

• Use WHO recommended insecticides to avoid using the one that will kill the Mosquitoes and also kill you.

• Avoid building residential homes near riverine areas

• Use oils on inevitable stagnant waters near you.

You deserve an award for reaching the end and I really hope you learnt a lot?
The pictures are all mine
Thanks for reading through👍