Mosquitoes: Friends and Foes?

Published in Better Ways

Setting the record straight with a balanced view about mosquitoes and their place in the natural chain!

Mosqutio Mosqutio Photo: Sondre Dahle (reproduced with permission)

About mosquitoes

There are over 3,500 species of mosquito, with more being found in great numbers all the time round the world. Mosquitoes, like flies, belong to the order named Diptera, because they have two wings. They belong to the family Culicidae and are classified in two main mosquitoes as pollinatorsgroups, Culicines and Anophelines.

Mosquitoes develop from eggs into worm-like larvae, which transform into pupae with a hardened outer skin, emerging in the end as fully formed male and female mosquitoes. Not long after emerging, once they have developed enough strength to fly adequately, the mosquitoes mate, after which the males die. The females feed up before laying their eggs, either on blood or nectar or sap, depending on the species. The eggs are laid in fresh, brackish or salt water, whether clean or polluted. Any standing water can be home to mosquito eggs, whether a natural pool, water butt or water collected in old car tyres or ruts in ditches, to name just a few. Culex mosquitoes lay their eggs in compact clumps, while the Anopheles group lays its eggs singly. Eggs can take just a few days or up to several months to hatch. The larvae which develop from the eggs mostly breathe at the surface of the water; some feed near the surface, while others find food deeper down. The larva transforms into a pupa, still living in the water, but no longer feeding. The adult mosquito comes out of the pupa and into the air after two to seven days, depending on circumstances. The whole life cycle takes between two and four weeks.

What are mosquitoes good for?

Mosquitoes suffer from a bad press, but they are not all bad!

- mosquito larvae in freshwater habitats help to purify the water by eating detritus: they have tiny brushes in their mouths which beat to create currents bringing in food particles, which are then transferred into their bodies

- some mosquito larvae feed on other insects

- mosquito larvae are food for dragonfly and damselfly larvae (nymphs), which live in their watery habitats for between two and six years, during which time they can consume enormous amounts of mosquito larvae as well as other small insects

- mosquito larvae are a food source for freshwater fish such as trout, perch, mosquitofish (gambusia affinis and gambusia holbrooki) and guppies (poecilia reticulata)

- killifish are small fish which eat developing mosquitoes in the egg, larva and pupa stages: when their numbers are highest, mosquito populations are greatly reduced. There are different types of killifish, which can live in fresh, brackish and salt water.

- adult mosquitoes are food for other species, notably bats, dragonflies, damselflies and insectivorous birds such as bee-eaters, all of whom have a voracious appetite for mosquitoes

- mosquitoes have a role in pollination: they feed on nectar (not just blood) and so can transfer pollen from plant to plant, as has been described in Norwegian researches; the North American Blunt Leaved Bog Orchid (Platanthera obtusata) provides a specific example

- the diverse roles and activities of mosquitoes, including night-time pollination, are being extensively researched, especially at the Smithsonian Institute in North America

Mosquitoes as pests

Mosquitoes are generally disliked and even hated by humans, because they bite. Mosquito bites can cause reactions ranging from mild irritation to severe allergic discomfort and, in some cases, disease. It is estimated that only about 3% of mosquito species carry zoonotic diseases (i.e. diseases which are dangerous for humans), but because of these, mosquitoes as a whole are targeted for annihilation in many countries, including Croatia.

In the HZJZ Yearbook for 2020 (in Croatian), where the figures for infectious diseases are given in item 5 'Zarazne bolesti u Hrvatskoj', malaria cases are given as 5 (imported); dengue fever cases: 3 (imported); West Nile fever: 0; Zika virus: 0. So the incidence of mosquito-borne diseases in Croatia is negligible, despite the rise in mosquito numbers reported in the initial monitoring, and the presence of potential disease carriers noted over the years.

Mosquito species as potential disease carriers which have been identified in Croatia according to factsheets issued by the European Centre for Disease Prevention and Control.

Aedes albopictus (Asian tiger mosquito): can carry dengue fever, chikungunya virus, dirofiariasis. This mosquito has been monitored in Croatia since 2016 (link in Croatian).

Aedes japonicus (East Asian bush or rock pool mosquito): possibly could become a transmitter of diseases such as West Nile fever, but is not considered a definite vector for disease transmission. Monitoring in 2016 and 2017 revealed that it was spreading in Croatian territory.

Anopheles atroparvus: can transmit malaria; possibly associated with West Nile fever. This species has been identified in Croatia.

Anopheles labranchiae: can transmit malaria. This species has been identified in Croatia.

Anopheles plumbeus: can transmit malaria. This species has been identified in Croatia.

Anopheles sacharovi: can transmit malaria. This species has been identified in Croatia.

Culex pipiens: can transmit West Nile fever and Usulu virus; possibly could transmit various other viruses. This species has been identified in Croatia.

Self-protection against mosquitoes

Note: the suggestions given here are based on the wide variety of personal experiences, including our own, which people have shared over the years. Always make sure that you do not use any substances, whether natural or chemical, in any way which can cause incidental harm to yourself, others, animals or the natural environment. Bear in mind that some essential oils are toxic to pets. If in doubt, seek professional advice. We accept no responsibility for misuse of the information we are sharing.

Personal protection

- Many foods create smells in our bodies which mosquitoes apparently don’t like, including garlic, onions, vinegar, chili peppers, lentils, beans and tomatoes, so eating them may help to repel mosquitoes.

- Many people find that taking a vitamin B supplement reduces the effects of mosquito bites, and indeed may make one less prone to get bitten.

- Avoid or at least limit alcohol, as drinking alcohol causes our bodies to release more carbon dioxide than normal, which attracts mosquitoes.

- Mosquitoes are attracted to lactic acid, which is produced when you sweat, and even from eating salty food: bathe or shower frequently if you are prone to sweating.

- Wear light-coloured clothing: mosquitoes are apparently attracted to darker colours.

- Using a fan may help to keep mosquitoes away from you.

- Natural repellent sprays which may help to protect your skin can be made from various essential oils individually by adding a few drops of the chosen substance to water in a spray bottle. Some essential oils can be mixed together for more potency: you can find numerous examples of homemade sprays on the internet and in herbal books. Always heed precautionary advice. In particular test a small area of your skin for allergy before applying any new concoction more generally on your body. Do not apply sunscreen before or after spraying your skin with an essential oil solution.

- Suitable scents which mosquitoes hate include tea tree oil, peppermint oil, mint oil, lavender oil, neem oil, citronella oil, tulsi (holy basil, ocimum sanctum) oil, lemon eucalyptus oil, cedarwood oil, lemon grass oil, castor oil, and cinnamon oil among others.

Around the home

- Use mosquito screens over windows, also nets around beds if possible.

- Do not leave lights on inside your home in the evening with the windows and doors open.

- Cloves and lemon: slice some lemons in half, insert cloves into each half and spread them around your home.

- Essential oil sprays can be applied round your home as well as to your skin.

- A garlic spray made by crushing some garlic cloves and boiling them in water, when cooled, can be applied around the home.

- A mixture of apple cider vinegar and witch hazel in equal quantities can be an effective anti-mosquito spray round the home.

- Candles scented with essential oils such as citronella can deter mosquitoes.

Outdoors

- Many birds feed on mosquitoes and other insects, so attracting them into your garden or on to your balcony can help control mosquito numbers.

- Never leave standing water in any kind of container (eg pots, old tyres), as these are ideal breeding grounds for mosquitoes. Spreading coffee grounds in puddles or stagnant water kills the mosquito eggs.

- Some plants repel mosquitoes, including basil, mint, feverfew, rue (ruta graveolens and ruta chalepensis), citronella and catnip, so they are good to plant in the garden or in pots around the outside of your home. (Note: some of these plants are skin irritants and can cause allergic reactions: They can also be very harmful if ingested by people or animals, so take care to keep them out of reach of very young children or puppies!)

- If you use an outdoor barbecue in the summer, burning some sprigs of rosemary or sage on it will help repel the mosquitoes.

Killing mosquitoes

In Croatia, measures to control mosquitoes were introduced several years ago. The Insect Control Programme has descended into a system of mass extermination of insects of all kinds using poisons which are potentially dangerous not only to the insects but to animals and humans. The result has been disastrous collateral damage. Mosquitoes have flourished while their natural predators have been decimated.

Extermination programmes using chemical pesticides don't work!

Many people use chemical insecticides in the home, without realising the potential harmful effects they might have on human health and the environment. You can check on the possible ill-effects of the active ingredients in many chemical insecticide products using our reference list ‘Pesticides and their Adverse Effects’.

A 'mozzie-swiper racket'. Photo Vivian Grisogono, courtesy of Nada Kozulić

We do not recommend killing insects, especially not with poisons. However, if you feel you have to, natural alternatives to chemical insecticides include garlic, camphor, pyrethrum and apple cider vinegar. and electronic mosquito-zappers. A very effective, simple way to put a stop to mosquitoes buzzing irritatingly around you is to use a special 'mozzie-swiping racket' which kills on contact with its steel mesh construction - and does not require any special tennis skills to do its job!

The 'mozzie-swiper' metal mesh 'strings. Photo Vivian Grisogono, courtesy of Nada Kozulić

Information compiled by Nada Kozulić, Nicholas Haas and Vivian Grisogono, 2022.

NOTE: Many thanks to Sondre Dahle, senior engineer at the Norwegian Institute for Nature Research for permission to use his mosquito photograph. You can read about his researches in this interview.

You are here: Home Voluntary Organizations Better Ways Mosquitoes: Friends and Foes?

Eco Environment News feeds

  • Energy secretary says countries must work together during conference at which US delegate called net zero ‘dangerous’

    Britain will find “common ground” with the US on energy and the economy including on nuclear power, despite differences over climate policy, the UK energy secretary, Ed Miliband, has pledged.

    He was speaking at the close of a two-day, 60-country conference in London on energy security, hosted by the government and the International Energy Agency (IEA), at which the US delegate Tommy Joyce attacked net zero policies as “dangerous” and “damaging”, and said it was in the interests of “our adversaries”.

    Continue reading...

  • Trees are being cleared for rainforest mega-event – but state governor says a ‘new history’ is under way

    Fake metal trees have been set into the concrete ground of the Amazonian host city of this year’s climate summit, prompting scandalised contrasts with the once-living vegetation that has been cleared in preparation for Cop30 in Brazil.

    But in an unlikely convergence of views, both the centre-right state governor and leftwing social movements insist this is a storm in a plant pot compared with the darkening geopolitical threats to the world’s biggest diplomatic gathering, which will take place in November in Belém.

    Continue reading...

  • Transforming a former industrial area in Sweden will bring psychological benefits for future residents and reduce construction’s climate impact

    Although activity is high, it is surprisingly quiet inside the construction site of a high school extension in Sickla, a former industrial area in south Stockholm that is set to become part of the “largest mass timber project in the world” according to the Swedish urban property developer Atrium Ljungberg.

    Just a few months remain until students enter the premises, but there is no sound of drilling or pounding against concrete walls. The scent of wood is unmistakable, and signs of the material can be spotted everywhere – from glulam (glued laminated timber) columns and beams in the building’s frame to cross-laminated timber (CLT) slabs in the floors, ceilings and staircases. CLT, made by gluing together layers of planed wood into panels, offers strength and rigidity comparable to concrete but is significantly lighter and quicker to build with.

    Continue reading...

  • Employees of water firms who obstruct investigations into spills could face jail under new rules that come into force on Friday

    Water company bosses have entirely escaped punishment for covering up illegal sewage spills, government figures show, as ministers prepare to bring in a new law threatening them with up to two years in prison for doing so.

    Only three people have ever been prosecuted for obstructing the Environment Agency in its investigations into sewage spills, officials said, and none received even a fine.

    Continue reading...

  • Authorities warn of mudslides during intense rainfall, as Kenya is hit by deadly flash flooding

    After Storm Hans battered northern Italy in the runup to Easter, severe weather continued to lash much of the country this week. Since Tuesday, the conditions have triggered potent showers and thunderstorms, and yellow and orange weather warnings have been issued.

    With winds generally remaining light this week, the greatest concerns surround the risks from intense rainfall, as slow-moving heavy showers can deliver a prolonged downpour to a fairly localised area. The authorities have warned people to avoid high-risk areas such as roads with steep embankments amid a threat of flash flooding and mudslides.

    Continue reading...

  • UK prime minister tells energy summit his government is determined to transition energy system from fossil fuels to renewables

    Continue reading...

  • The Anohni and the Johnsons singer is collaborating with marine scientists for two special shows at Sydney’s Vivid festival that will show the reef’s plight

    Anohni Hegarty is about to go to the Great Barrier Reef for the first time. “I feel like I’m going to Auschwitz,” she says nervously. “On the one hand, I’m so excited to go because the landscape is so beautiful, and I know there’s going to be so much that’s gorgeous. And yet, I’m also scared.”

    In a week, the British-born, New York-based avant garde singer of Anohni and the Johnsons is flying to Lizard Island, a paradise of powdery sands on the reef, 1,600km north-west of Brisbane. Its luxury villas and bluest of blue waters are a stark contrast to the grim nature of Anohni’s assignment: documenting the current state of the world’s biggest coral reef.

    Continue reading...

  • Some households aren’t suited to solar – but do batteries make environmental or financial sense on their own?

    Many people want to reduce their carbon footprint but for various reasons can’t install solar panels. Some roofs face the wrong way, others are overshadowed or subject to heritage restrictions, and apartment blocks often lack space.

    Landlords are also often reluctant to install solar systems in rental properties since the benefits flow to the tenants rather than the property owner.

    Continue reading...

  • Hurricane Katrina: Mississippi Remembers captures the grief and resilience of survivors in the Magnolia state

    Twenty years ago this August, the United States Gulf coast was irrevocably changed when Hurricane Katrina, one of the deadliest and costliest storms to ever hit the country, made landfall. Making landfall as a strong category 3, the storm, which was so vast it stretched the length of the Mississippi Gulf coast all the way into Alabama, hit the Mississippi-Louisiana coastal border before continuing northward.

    Since then, superstorms fueled by the climate crisis have become relatively commonplace in the country, but the impact of Katrina endures to this day. Immediately following the storm, the country and world were enthralled by tragic stories out of New Orleans, where the levees failed to a catastrophic effect and the local, state and federal responses were disastrous. But Mississippi, which received the maximum impact from the storm surge, was largely left out of the national narrative around Katrina.

    Continue reading...

  • Americans have often moved between states for opportunities. Now they’re being forced to uproot themselves to escape hostile forces under Trump

    Continue reading...

Eco Health News feeds

Eco Nature News feeds