Over 3,500 species of mosquitoes have already been described from various parts of the world. Some mosquitoes that bite humans routinely act as vectors for a number of infectious diseases affecting millions of people per year. Others that do not routinely bite humans, but are the vectors for animal diseases, may become disastrous agents for zoonosis of new diseases when their habitats are disturbed, for instance by sudden deforestation. Many, if not all, blood-sucking species of mosquitoes are fairly selective feeders that specialize in particular host species, though they often relax their selectivity when they experience severe competition for food, defensive activity on the part of the hosts, or starvation.
In the sense of the entire family Culicidae, mosquitoes are cosmopolitan; in every land region except for Antarctica. Worldwide introduction of various mosquito species over large distances into regions where they are not indigenous has occurred through human agencies, primarily on sea routes, in which the eggs, larvae, and pupae inhabiting water-filled used tires and cut flowers are transported. However, apart from sea transport, mosquitoes have been effectively carried by personal vehicles, delivery trucks, trains, and aircraft. Man-made areas such as storm water retention basins, or storm drains also provide sprawling sanctuaries. Sufficient quarantine measures have proven difficult to implement. In addition, outdoor pool areas make a perfect place for them to grow.
To be able to reduce or prevent the risk of infestation, without a chemical treatment, their breeding source must be found and eliminated. Such breading zones can be found in areas of stagnant water (covered fountains, wells, ponds, stagnant water in various forms). Many measures have been tried for mosquito control, regarding the elimination of the breeding places, such as exclusion via window screens and mosquito nets, biological control with parasites such as fungi and nematodes, or predators such as fish, copepods, dragonfly nymphs and adults, and some species of lizard and gecko.
Preventing infestation relies heavily on reducing the potential sources of infestation (thus, of breeding places) and transforming the environment in such a way that is unsuitable to mosquitoes. It is recommended cleaning the area on a surface as large as possible, eliminating vegetation that keeps the shade and humidity or other objects that could encourage mosquito breeding.
Mosquitoes undergo four life stages: egg, larva, pupa, and adult. Disrupting a mosquitoes’ life cycle and habitat may reduce the number of mosquitoes around you and your environment. Below are some steps you can take to reduce mosquito populations before choosing to use a pesticide product.
Preventive measures against mosquitoes
– remove any sources of stagnant water, be that a pool, random containers such as tin cans, coconut shells, old pet bowls, old tires, empty flowerpots, clogged gutters, unfiltered fish ponds, or simply an indentation in the ground where rainwater gathers;
– otherwise, you can also accomplish the task of driving mosquitoes away by making the stagnant water an unsuitable breeding ground: change the salinity of the water or throw some Bacillus thuringiensis israelensis granules in the water; this is a species of bacteria that functions as a larvicide, while still being non-toxic to children and pets; the life cycle usually lasts up to a month, so be sure to replace it;
– if none of the above are an option, be sure to regularly and carefully maintain ponds and swimming pools, keeping the water fresh and, in the case of the latter, treating it with the proper chemicals so as to make it uninhabitable to mosquitoes; replace any other sources of water (such as pet bowls) frequently;
– empty and change the water in bird baths, fountains, wading pools, rain barrels, and potted plant trays at least once a week to destroy potential mosquito habitats;
– it is also recommended that you remove any aquatic plants that you may have in your garden;
– mow your grass and trim your shrubs regularly, paying special attention to the vegetation around the aforementioned sources of water; this will decrease moisture and increase sun and wind exposure;
– planting flowers and whose odour is not pleasing for mosquitoes, such as thyme, marigold, basil, lavender, mint, rosemary, geranium;
– installing a home for bats, which are known to be ferocious consumers of insects, especially mosquitoes; equally effective in fighting mosquitoes in the yard and garden are dragonflies;
– seal any cracks and crevices around the house, paying special attention to windows and doors, that mosquitoes – or any insects – may use as an entry;
– use window screens on both windows and doors; if you have open areas, such as porches, it is recommended that you close them in using screens and netting, too;
– use mosquito nets around beds; remember to also protect your pets in the same manner, especially at night;
– insecticide-impregnated mosquito nets are particularly useful; while they kill mosquitoes, along with other species of insects that may harm humans, they do so without affecting the general ecology of the area, so they can be safely used even on a camping trip;
– switch any outdoor lighting to LED lights, yellow bug lights, or sodium lamps, seeing as these do not attract mosquitoes;
– citronella-based products can be used to repel mosquitoes, both indoors and outdoors; burn a candle, use incense oils, or plant citronella plants in pots or directly in the soil around your house;
– other useful essential oils include lemon eucalyptus, lavender, or catnip, although a mixture of several types is usually more effective; if you use an oil burner, the heat, combined with the smell, will create a 2 – 3 m radius mosquito-free zone;
– working with the same principle, it is worth mentioning that some people have also found planting garlic to be effective in repelling mosquitoes; if you want to try this, simply plant it around the house, in pots that you can lay out on porches or in balconies, or sprinkle garlic powder in all the above-mentioned places;
– fans can also be useful in keeping mosquitoes away, seeing as they will not be able to advance towards you and, thus, will not have an opportunity to bite you;
– keep swimming pool water treated and circulating.
Eliminating such mosquito breeding areas can be an extremely effective and permanent way to reduce mosquito populations without resorting to insecticides. Biological control or “bio-control” is the use of natural enemies to manage mosquito populations.
Adult mosquitoes prefer to rest on weeds and other vegetation. Homeowners can reduce the number of areas where adult mosquitoes can find shelter by cutting down weeds adjacent to the house foundation and in their yards, and mowing the lawn regularly. To further reduce adult mosquitoes harbouring in vegetation, insecticides may be applied to the lower limbs of shade trees, shrubs and other vegetation.
Many of the mosquito problems that trouble homeowners and the general population cannot be eliminated through individual efforts, but instead, must be managed through an organized effort. Because of the great variety of species of mosquitoes and the differences in the biology of each one, it would be impossible to put together a set of measures or rules that would be effective in all circumstances. However, all of the above will go a long way towards, if not eliminating, at least controlling the mosquito population. And should you be already dealing with an infestation, and you are not only trying to prevent it, you can visit our article about “How to get rid of mosquitoes” for further details regarding biological and chemical elimination methods.