What you need to know about mosquitoes
How is it possible that such a small insect can be so dangerous?
Even if for you the mosquitoes represent maybe only a small nuisance with bites and itchings, these insects are still responsible for the death of nearly 800 000 people in the world because of the diseases they can transmit to humans.
Initially reserved for the tropics, these disease-carrying mosquitoes are invading more countries thanks to climate change and worry more and more.
Malaria, Zika, dengue … the list of serious illnesses is long and a reason to better know our flying enemies to better protect us.
There are so many questions to ask about mosquitoes, we will try to answer as much as possible, but if you still have questions, be free to ask us, we will be happy to answer you !
What is the life cycle of mosquitoes?
What are the different species of mosquitoes and the diseases they can transmit
How to recognize a mosquito bites and what to do if you have been bitten ?
How mosquitoes are attracted by humans ?
What is a mosquito ?
A mosquito is a small flying insect with a fine body, a fine dough and wings. They have a long mouth appendage to feed or sting.
It exists about 3,500 mosquito species in the world. The vast majority feed on fruits and flowers. Only 6% of these species bite (only female mosquito), they need proteins contained in the blood of animals for the maturation of their eggs. And only half of these blood-hungry species can carry parasites, bacteria or viruses that cause human and animal diseases
Here are some interesting facts about mosquitoes:
- These insects can fly at about 1 to 1.5 miles per hour (1.6 – 2.4 km/h).
- When they bite, they suck 0.001 to 0.01 milliliter of blood.
- Females, those that annoy you, can live 2-3 weeks.
- Most of the time, mosquitoes prefer to stay just above the ground around 25 feet, because it is where humans and animals live. Nevertheless, some mosquitoes have been found in 20 th floor apartments or 2000 feet underground in mines because mosquitoes can follow humans like hunters.
What is the life cycle of mosquitoes ?
It takes around 8 to 10 days from eggs to adults.
Here some facts about each stage:
Eggs:
- Mosquitoes generally lay 100 eggs at a time.
- Eggs can survive without water for up to 8 months.
Larva
- It’s rainwater or humans adding water to containers with eggs that will trigger the larvae to grow in a pupa.
Pupa
- The body of adult mosquitoes will emerge from the pupa.
Adult
- Mosquitoes can detect you with the smell of you sweat and the heat produce by your body.
Why do mosquitoes exist ?
Members of the ecosystem
Since mosquitoes have been present on Earth for 100 million years, they have had time to evolve with other species, which makes mosquitoes an important member of ecosystems even if the effects, if they completely disappear, are not well understood.
In the food chain, “Mosquitoes are delectable things to eat, and they’re easy to catch,” says aquatic entomologist Richard Merritt, at Michigan State University in East Lansing.
Hundreds of species of fish have for main meal the mosquito larvae, if they disappear, the fish would have trouble to feed properly, some species might even disappear as the mosquitofish (Gambusia affinis), expert at killing mosquitoes and used as biocontrol in Asia.
Furthermore, mosquitoes serve as food for many species of insect, spider, salamander, lizard and frog. Even specie of bird relies on mosquito to feed themselves, indeed according to Bruce Harrisson, entomologist at the North Carolina Department of Environment and Natural Resources the population of a migratory birds passing above the tundra could be reduced from 50% if mosquitoes stop to exist.
They clean up aquatic ecosystems
Scientists have shown that mosquito larvae act as a filter in aquatic ecosystems. In fact, the larvae develop in the water, to feed and grow, they filter this water. In doing so, they rid it of bacteria and wastes found there, helping to clean up our environment.
They can be pollinators
On the 3,500 species of mosquitoes, only 6 % of theses bite human and animal for their blood, the large majority feed only on sugar found in flowers and fruits. Therefore, they can carry pollen and take the role of pollinators for thousands of plant species. Beside, they are not crucial compare to bees and other pollinator, especially because they are not pollinator of crops cultivated by humans.
So Mosquitoes have a role in our ecosystem but as said entomologist Joe Conlon, of the American Mosquito Control Association, “They don’t occupy an unassailable niche in the environment, If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take over”.
What are the different species of mosquitoes and the diseases they can transmit ?
As said previously, it exists around 3,500 species of mosquito and the large majority don’t care about humans.
There are only 210 species for wich the female need to get blood and the proteins inside in order to mature their eggs. Moreover, only hundreds of these blood drinkers can carry parasites, bacteria and virus responsible of dangerous diseases.
Here are the one you should know. If you want to know more about the diseases mentioned, where they are localized, what are the symptoms and what are the treatment, we invite you to read our special article about it.
Aedes aegypti (Yellow fever mosquito)
What diseases they can carry ?
Dengue, yellow fever, chikungunya, Zika virus
How to recognize the yellow fever mosquito ?
This mosquito size from 4-7 mm when adult. It looks very similar to the Aedes albopictus, but the European centre for disease prevention says that you can recognize it.
- Llyre shaped white scales on the dorsal surface of the thorax .
- White basal bands that appear as stripes on each tarsal segment of the hind legs.
- Dark brown abdomens
- Females are larger than males larger and possessed minute palps with silver or white scales present on their tips.
Where are they ?
Native to Africa, they are now globally distributed in tropical, subtropical and mild temperate regions. Indeed, they spread to more temperate regions during the summer months. For the moment they are not localized in cold countries.
Where do they grow and when do they bite ?
Aedes aegypti larvae require standing water for the completion of their growth cycle. Therefore, you can find them in tree holes and plant axils but also in vases, water tanks and tyres.
They are active and can bite in the day and at crepuscule.
Only the female Aedes aegypti bites, they feed almost exclusively on humans under most circumstances when given the opportunity
Aedes albopictus (Asian Tiger Mosquito)
What diseases they can carry ?
Chikungunya, dengue, West Nile virus
How to recognize the Asian tiger mosquito ?
These mosquito sizes to 10 mm, larger than the previous one. Its name comes from the prominent white stripes over its black body.
They have :
- A single white stripe running from the middle of the eyes, over the dorsal side of the thorax
- Numerous white bands cover the palps and tarsi, which are the appendages found near the mouth.
- Bold, Black and shiny scales on its back
Where are they ?
This specie doesn’t come from Africa as Aedes aegypti but is native to Asia. Firstly only localized in subtropical regions around the world, but with the global trade, climate change and its adaptation capacity, this mosquito become the most invasive one and invaded Europe, Africa and North and South America.
Where do they grow and when do they bite ?
The larvae need water that is enclosed with dense vegetation and adequate shading. The vegetation is necessary for the breeding of male mosquitoes.
Thus, you can find it in flower pots, bird baths, abandoned containers and obstructed gutters, and more frequently in tyres because they are normally stored outside and collects rainwater, which it holds for a long period, allowing enough time for reproduction. These mosquitoes are weak fliers, :so if they lay their eggs near your house, be sure when they will become adult they will come for you and not your neighbors.
Aedes albopictus is active during the day, low temperatures can inhibit their feeding but higher humidity can promote it. Their population is quite seasonal, it increases in summer thanks to the higher temperature. Furthermore, the female tiger mosquito can annoy you for 30-40 days.
The tiger mosquito feeds on many different species of birds and mammals such as humans, deer, dogs, rabbits, turtles, rats, cats, without specific searching.
Culex quinquefasciatus (Southern mosquito or brown mosquito)
What diseases they can carry ?
Japanese encephalitis, Lymphatic filariasis, West Nile fever, Ross river virus, Alfuy, Dengue.
How to recognize the southern mosquito ?
Adult Culex quinquefasciatus vary from 3.96 to 4.25 mm in length.
The mosquito is brown with the proboscis, thorax,
wings, and tarsi darker than the rest of the body. The head is light brown with the lightest portion in the center.
Where are they ?
The brown mosquito is now world spread. Firstly only localized in hot countries between the south of USA to New Zealand, that’s explaining its name, it has invaded most of the other counties at the exception of really cold counties like Russia, Iceland, Canada, Finland ect…
Where do they grow and when do they bite ?
Like the majority of mosquitoes, the southern mosquito lays its eggs in waters ranging from waste water areas to bird baths, old tires, or any container that holds water enough time to complete its life cycle. Once born, they don’t fly over more than 1 kilometers (0,6 miles).
Culex quinquefasciatus are opportunistic feeders, they can bite mammals and birds throughout the night.
Anopheles (Around 68 known species can transmit diseases)
What diseases they can carry ?
Malaria ( Main Vector), lymphatic filariasis
How to recognize the Anopheles ?
Anopheles can size to 5-20mm. Their colors is usually dark brown to black and their corps has 3 sections which are the head, thorax and abdomen.
Where are they ?
Exept Antartic and Arctic, theses species are everywhere. Even if their presence don’t necessary impose Malaria epidemic, a risk of outbreak is still possible, especially because of travelers that can bring back the disease when they come back from a country where Malaria is present.
Where do they grow and when do they bite ?
Malaria vector mosquitoes can grow in fresh water or salt-water, vegetative or non-vegetative. You can find them in ground pools, small streams, irrigated lands, freshwater marshes, forest pools, and any other place with clean, slow-moving water.
Theses mosquitoes essentially feed on humans, other mammalians and birds. They are active at dusk, at dawn and along the night. They can bite you inside and outside your house.
Haemagogus
What diseases they can carry ?
Yellow fever
How to recognize the yellow fever mosquito ?
Their colors is dark brown and they don’t have strips.
Where are they ?
For the moment they are only localized in the rain forest of south america
Where do they grow and when do they bite ?
The female Haemagogus lays its eggs in between layers of tree bark or in cut bamboo. The eggs will grow to larvae with the rain.
The haemagogus is active the day but as they are located in rain forests, they are less likely to bite human, but they can bite monkeys.
This last is more likely to be in contact with human, especially because of poaching and can transmit the yellow fever to poachers and this last to other humans.
Do you know ? It exists a lot of other vector born diseases transmitted by other insects as ticks, flies and so on, if you want to know more about it we have a special article on it.
How mosquitoes are attracted by humans ?
Mosquitoes can find you by several ways. Indeed, the major one is your sweat. Mosquitoes can smell a large variety of compounds contain in sweat like octanol, lactic acid and ammonia. A lot of theses compounds are produced by your skin-microbia.
And you know what ? Foot Odours are the most attractive, that’s why biting preferentially occurs on feet or ankles.
Earlier studies shown CO2 as a potential attractant, but it has been recently proved otherwise in independent studies in Wageningen Agricultural University and Kenya.
Nevertheless, Female mosquitoes still seem to have olfactory organs sensitive to CO2 (up to 150 feet away) that enhance their capacity to detect the sweat compounds.
Another way is the light produce by your heat body that mosquitoes can detect and be attracted to.
Furthermore, if you are Type A blood, you ae less likely to be bitten compare to Type O blood according to a Japanese study.
Do you know ? 85 % of your genetic can also makes you are a mosquito magnet.
How to recognize a mosquito bites and what to do if you have been bitten ?
When the mosquito bites you, It leaves proteins in your blood vessel, which triggers an allergic reaction to your immune system.
The inflammatory reaction is characterized by a circular redness the size of a coin. The sting can also be manifested by a pimple slightly lighter than the skin, circular and the area around is red. Sometimes, when the bite come form the tiger mosquito the circle is larger than other mosquito bites.
It is hard, hot and painful. The bite causes itching more or less important and may last several days. Moreover, excessive scratching can aggravate the lesion.
In case of allergic reaction, very strong itching or other symptoms out of the ordinary, especially fever, it is necessary to consult a doctor as soon as possible.
You can find the symptoms of the diseases here.
And what to do if you have been stung ?
Accordind to Pr Stéphane Gayet, infectiologist at the University Hospital of Strasbourg, France, if you feel that you have been stung, it is advisable to apply disinfectant on the sting, or at least to wash it with soapy water, within 15 minutes.
Viruses, parasites or bacteria may not have been able to propagate in your blood vessels yet.
You can also relieve itching with anti histamines or other natural method, we have done an article on it.
How governments can control mosquitoes ?
Public authorities have several ways to fight the mosquito invasion.
They can set up indoor and outdoor spraying with insecticides.
Indoor spraying is the most widely used method to control mosquitoes in Africa. It is effective for 3–6 months, depending on the insecticide used and the type of surface on which it is sprayed. The insecticide DDT is the most often used and can be effective for 6–12 months.
Outdoor spraying outer surfaces of domestic animal shelters, outdoor latrines and other damp places can help control sandflies and mosquitoes, especially in case of an epidemic. Indeed, this method can reduce the level of virus transmission if used at the beginning of the epidemic.
Another way is to add insecticides in drinking water storage containers in order to reduce the population of mosquito larvae in place at risk for diseases such as dengue and chikungunya fever. WHO has guidelines about this method to avoid toxic dosage to humans.
More recently, other method are created to fight mosquitoes
Biological control
Some fish and small crustaceans are used as biocontrol against the larvae of mosquitoes. In many countries, small ornamental fish are introduced in water storage tanks to feed on the larvae.
Only native species should be used because exotic species may escape into natural habitats and threaten indigenous fauna.
Here some example of this method:
Vietnamese government used copepods in large water-storage tanks, combined with source reduction, successfully eliminated Ae. aegypti in many communes and has prevented dengue transmission for a number of years.
In Tanzania, Azolla, an aquatic plant that grows on the surface of water, making it difficult for larvae to reach the surface to breathe, has been successfully used to control malaria-carrying mosquitoes in rice fields.
Genetic control
The first example of this method is the genetical engineering of male mosquitoes, progenies of these last will be sterile, so large amount of modified male mosquito are released in the nature in order to reduce the population.
Wolbachia bacteria can also have the same purpose.
Furthermore, other studies have succeeded in modifying mosquitoes so that they can no longer transmit dengue parasites
How to protect yourself against mosquitoes ?
Nets and Screen
In addition to the previous method, you can protect yourself against mosquitoes. We have made a more detailed article about it here.
You can adapt your house in order to prevent mosquitoes to enter in by using window nets and door screen. We already made an article on how choose these products and already selected for you the best ones in your country.
Moreover, you can also install air conditioning and/or fans to keep mosquitoes away.
WHO recommendation is to use insecticide-treated bednets. They are one of the most efficient and cost-effective ways to protect against mosquito-borne diseases, particularly malaria.
You can find the best bed nets in your country here.
Repellents
Repellents are a very effective way to protect you from mosquito bites when you are not at home.
We explained in this article how they work and what you need to know about mosquito repellents.
Repellents use most of the time DEET, but you can find also natural ones. The protection time can vary from 10 min to 10h depending on the product’s quality. That’s why we have selected for you the best repellents available in your country or the one your are visiting.
Moreover, your clothes can be helpful if they are long sleeved, light-coloured shirts and trousers.
Clothing can be treated with products that contain permethrin, a chemical compunds that kills mosquitoes when they land on you. Pre-treated outdoor clothing are commercially available and can remain protective for up to 70 washes.
Mosquito Traps or Mosquito Killers
A mosquito trap, or also called mosquito killer, is a device that will attract mosquitoes and some other bugs and will suck it up with a fan or zap them. If the mosquitoes are suck in, they will die by dehydration or drowned in water. Big advantage : no chemicals used.
If you want to know how they work and why to buy one, we have a guide for you. And if you are interested to buy one, here is the best !
There is also natural way to fight back mosquitoes, as using specific plant in your garden or have your own bio control. We detail these methods in this article.
Conclusion
Now, you know everything you need about mosquitoes and how to protect yourself against them !
You know what ? The best way to fight mosquitoes is that everyone knows our flying enemy and how to protect themselves from it in order to limit its spread and the transmission of diseases !
Help the fight by liking our FB and sharing this article with everyone you know !
I appreciate the information you presented about the mosquitos, specifically the fact that they need standing water to lay eggs. This makes me think about my aunt’s garden as it has a lot of pond areas that are perfect for mosquito breeding places, making me concerned that her house might have to deal with them if she’s not careful. To be on the safe side, I’ll help her find a pest control service that can help her prevent mosquitos from multiplying in her garden.
Thailand is a country with a tropical climate, a high degree of humidity and high temperatures; circumstances in which mosquitoes thrive. If you’re going to Thailand, you can’t avoid having to deal with mosquitoes. But no need to panic, the health risks are low and protecting yourself against mosquito bites is pretty easy. This is everything you need to know about mosquitoes in Thailand!