I hate mosquitos. I hate them because they seem to love me. The blame for this undoubtedly lies with the supurb quality of my blood. My blood is vital for my survival, it is prime steak for a female mosquito. We are locked into battle for it. The female mosquitos puncture my skin with four sharp stylets on their proboscis (piercing, sucking mouthpart), the other two stylets form a sucking tube for withdrawing the vital fluid. So far I have only lost a little of the red liquid, and I have plenty to share with the tiny insect. The problem is that to stop the blood from clotting and keep it flowing up her tubes, she dribbles a little of her own saliva down the line. The saliva causes my allergic reaction.
Male mosquitos I don’t mind so much, except for their role in producing more females. Only the females suck blood, males seek out sweet liquids such as nectar or rotting fruit. The females require protein from blood to produce and lay eggs.
This column regularly espouses the benefits of biodiversity. It encourages people to love all nature, including cockroaches, spiders, earwigs, centipedes and such. Hug your hymenoptera (bees and wasps) might be our catchcry. But when I consider the mosquito, I am reminded of that little ditty:
The Lord in his wisdom made the fly
And then forgot to tell us why
The mosquito is a member of the order Diptera. It is a type of fly. Its name comes from the Spanish for ‘little fly’. It is also responsible for a huge number of deaths, from malaria, yellow fever, dengue and many other diseases.
The larvae of mosquitos are aquatic, they are known as ‘wrigglers’ because of their swimming action. They breath air by swimming to the surface and sucking air through a siphon at end of their abdomen. They have tiny mouthparts which are like brushes that filter food from water. Mosquito pupae are called ‘tumblers’ and are also aquatic. In this stage they do not feed, but they must still move and ‘tumble’ or they would drown.
The adult males are destinquished by their bushy antennae. A little hard to see at night, I usually dispatch any mosquito in my room with equal enthusiasm, regardless of sex.
The horrible whining noise which can be as severe a torment as the sting is caused by vibration of the halteres (modified hind wings) when thee fly.
There are around two hundred and twenty species of mosquito in Australia. The Anopheles mosquito lives here and it transmits malaria. The common banded mosquito (Culex annulirostris) carries Murray Valley encephalitis and Ross River fever. Saltmarsh mosquitoes also carry Ross River fever. Adeles aegypti carries dengue fever. You may have heard that health authorities are worried about the effects of global warming on their distrtibution around the country, as the diseases they carry are a significant health risk. Some experts propose that heating of the atmosphere from burning of fossil fuels could even carry malaria to Brittain (from Africa), and to Victoria (from Asia).
Mosquitoes lay their eggs in any convenient patch of stagnant water. Even small areas such as puddles, or even a hoof print are suitable for some mosquitoes
Control for most people involves insect repellants containing DEET (Diethyl toluamide). I refuse to use these products.
Start your control program by eliminating breeding areas. This may mean small areas of water such as blocked gutters, old paint tins etc. Anything which can hold water can breed mozzies. You can try the oil or kerosine floating on water trick. It works for most mozzy larvae, by preventing their tiny air tubes from breaking the surface tension and getting to the air. Parrafin oil is the best. The problem is the each time a tank overflows, the surface oil is lost and must be replaced. Some mosquitos can outwit this trick by sticking a tube into the stem of an aquatic plant and stealing air! Best to ensure gutters are not holding water and empty all containers, such as pot plant saucers (try filling them with sand), old tyres, bottles etc, empty bird baths and pet drinking water at least once per week to prevent the wrigglers completing their cycle.
This technique is only partly effective if you have neigbours or live near a puddle. Salt marsh mosquitoes (Aedes camptorhynchus and vigilax) are known to travel 1 - 2 kms for a blood meal, in the right wind conditions they may travel 50 kms from their breeding site.
Mosquitoes feed mainly at night. You can try to reschedule outdoor activity and stay indooors around dusk to avoid their bite. Wear loose fitting clothing, covering as much as your body as possible, to stop them puncturing your skin through the weave of close-fitting clothes.
Fit 1mm insect screens on windows and doors to prevent their entry. Screen need mantenance to ensure they always fit and have no joles. You can also screen rainwater and septic tanks.
One of the best controls is to stock ornamental ponds and pools with fish. Fish such as guppies and many of the smaller native fish love wrigglers and tumblers.
For sleeping comfort, a good net is best. You can burn mosquito coils or insense, but most of them contain chemicals which I don’t care to breathe (some of them can dissolve your syntheitic clothing).
There are natural repelants. Try eating or burning or rubbing your skin with garlic, sage, rosemary or parsley. Commercially available pennyroyal oil or citronella are best. You can also try citronella oil candles which work well on a still or slightly breezy night. Repellants do work most of the time, but must be applied reqularly. If the mozzies are really hungry, they will put little pegs on their noses and bite you anyway.
Local government and other health authorities often apply pesticides to the environment to eliminate mozzies. Unfortunately the other values of swamps are counted for so little that the collateral damage from pesticides is ignored. Overseas there are biological controsl available, such as a strain of the common Bacillus thuringiensis (sold as Dipel). I am not aware that the anti-mozzy strain, Bacillus thuringiensis var isrealii is available in Australia. It is very effective, but lasts for only three days and must be reapplied regularly.
Apart from fish, bats make the best mosquito predators. Fit bat boxes or leave hollow limbs in trees to encourgae them. Dragonflies and Damselflies also do a very fine job, especially their aquatic larvae. Other predators include frogs, lizards, small spiders, ground beetles, praying mantis (small, imature phase) and small birds.
The best news of all is that a small dab of tea-tree oil ona bit will completely remove the itch. How many sleepless nights I had before I discovered this simple, cheap and instantaneous remedy.
Now why did God make this pesky little fly.